Showing posts with label antiepileptic. Show all posts
Showing posts with label antiepileptic. Show all posts

Saturday, 9 February 2019

Psychiatric and seizure medicines for autism: what 'works' best

The paper by Devon Coleman and colleagues [1] represents pretty good scientific value for money by my reckoning. Describing the results of a 'survey' called the "National Survey on Treatment Effectiveness for Autism" created by the researchers, the aim was to provide "separated... scales for overall benefits and overall AEs [adverse effects]" for a wide range of interventions used in the context of autism.

The focus this time around was on "Psychiatric and Seizure medications data" but it looks like there may be quite a bit more to see from this group in future with regards to data on "supplements, diets, therapies, and educational interventions" also collected during this initiative. Before continuing on with this paper I have to hat-tip the authors for mentioning a great and much under-valued resource in autism circles: "the Parent Ratings of Behavioral Effects of Biomedical Interventions Survey,... conducted by the Autism Research Institute (ARI) and published in 2008." Indeed, in other posts talking about the medicines cabinet and autism (see here) I've expressed my positive views of the ARI resource albeit with caveats.

Anyhow: "we report ratings of 26 psychiatric and seizure medications by 505 participants." Researchers actually noted that nearly 900 people completed their survey; most of whom were described as the "Primary caregiver of an individual with autism." Some people might um-and-ah about the lack of 'authentic autistic representation' in this study, but one needs to bear in mind that most participants - about three-quarters - were under 18 years of age, most diagnosed with autism and not autism spectrum disorder (described as "less severe than a diagnosis of autism") and most were currently described as having mild, moderate or severe autism. I know this won't be enough for some people, but there you have it.

Then to the medicines that were 'graded', which fell into "five general categories: stimulants (four medications), SSRIs [selective serotonin reuptake inhibitors] (five medications), antipsychotics (four medications), seizure (nine medications), and other (four medications)." There's a lot of data included in the Coleman paper which really is too much for a blog post. I'll direct you to Figure 8 of the Coleman paper which provides a handy 'net benefit score' taking into account an 'overall benefit score' and an 'overall adverse score' for each medicine. When it came to SSRI medicines - typically indicated for treating depression - sertraline came top. When it came to antiepileptic medicines - primarily used to manage epilepsy and/or seizures - lamotrigine came top. When it came to antipsychotic medicines, aripiprazole came top. I was also interested to see that buspirone, a medicine typically indicated for anxiety, also did pretty well according to the Coleman results, which kinda ties in with some continuing research interest in this medicine with autism in mind (see here). Researchers also provide a handy 'medications for symptoms' overview as a consequence of their results (see Table 7) covering various symptoms from aggression/agitation to tics/abnormal movements. I can see this being particularly useful when it comes to physicians having to make big medication decisions (which should never be entered into lightly).

There's a couple of other details that are also mentioned in the Coleman paper outside of those 'how was medicine rated?' sentiments. Some details are not likely to make many friends in some quarters. So, around 2% of participants were described as follows: "No current diagnosis, but he/she was on the autism spectrum previously." Yes folks, such data once again harks back to the idea that for some people at least, autism is not a lifelong diagnosis (see here and see here). And also: "Thirty-four percent of participants had early onset of symptoms, but 56% had normal development followed by a plateau or regression." Regression accompanying autism is not the 'dirty' concept that it used to be (see here). Indeed, in the few years that I've been blogging about autism research, I've seen it become a lot more commonplace to talk about regression and autism (see here) even to the point that some now talk about it being 'the rule rather than the exception' (see here). Interesting.

And then there's something even more controversial in the Coleman paper: "The perceptions of possible causes of the regression are listed in Table 2." So we have things like high fever, illness, seizure and then... vaccination. I know this takes us into some uncomfortable territory, but the authors report that 51% of respondents to their survey who cited regression as part of the clinical picture mentioned vaccination as the 'perceived cause' whether singly or in conjunction with other factors. Of course I'm going to provide a link to what the population-based science says on this matter (see here) with the caveat that such 'perceived cause' data perhaps needs objective and dispassionate follow-up (see here and see here).

The Coleman results are not without their limitations as per author comments such as: "The survey is retrospective and based on respondent memory which reduces the accuracy" and "The results are subject to “placebo effect” since it represents clinical data without a placebo control, so the real benefit is likely less than the perceived benefit." But let's not take too much away from the findings and how they may, as well as informing clinical practice, also hopefully lead to further inquiry to make medicines safer and more reliable for those on the autism spectrum who access them.

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[1] Coleman DM. et al. Rating of the Effectiveness of 26 Psychiatric and Seizure Medications for Autism Spectrum Disorder: Results of a National Survey. J Child Adolesc Psychopharmacol. 2019 Feb 6.

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Friday, 7 September 2018

In-utero exposure to antiepileptic drugs and offspring learning disability

There was something quite familiar about the findings reported by Laura Fuglslang Bech and colleagues [1] investigating any "association between in utero exposure to antiepileptic drugs and learning disabilities in the first year of compulsory education among offspring." Familiar because this class of medicines - antiepileptics - used to primarily treat/manage epilepsy and seizure disorders have been put under the spotlight in recent years as a result of various *associations* with offspring childhood developmental disorders/conditions when used during pregnancy (see here and see here).

Obviously one has to be quite careful when it comes to talking about this class of medicines. Antiepileptics, as I have mentioned before, are not typically dispensed willy-nilly, and on many occasions have proved to be not just a life-enhancer but also a lifesaver to those living with epilepsy. The balancing act comes when they are prescribed to women of child-bearing age and ability, and the possibility of them producing 'adverse' effects' on the developing child.

Bech et al focused on learning disability as a possible offspring outcome following pregnancy exposure to a range of antiepileptic medicines. One of those marvellous Scandinavian population registries provided the research starting point (based in Denmark) and lead to the participation of some 630 cases ("offspring exposed to antiepileptic drugs in utero") and 430+ controls ("unexposed offspring of mothers previously redeeming antiepileptic drug prescriptions").

Results: "Learning disabilities were identified among 7.1% cases compared with 3.7% for controls." Although not at first glance showing a huge difference between the groups, a little statistical analysis revealed that: "During any trimester, the adjusted OR [odds ratio] of the association between in utero exposure to antiepileptic drugs and learning disabilities was 2.20 (95% CI 1.16 to 4.17)." When taking into account different types of antiepileptic medicines and their possible risk profile, yet again one particular medicine stuck out: valproate. As the authors mention: "valproate carried a higher risk (OR 4.67, 95% CI 1.73 to 12.59)" compared with other antiepileptic medicines. This accords with other findings.

As with any observational study of this type, one has to be a little careful with the old 'correlation is not necessarily causation' thing. But set against a tide of research observing similar trends - particularly with respect to the use of valproate - and indeed, a rodent model of autism called the valproate rodent model of autism - it's getting ever harder to say that pregnancy valproate use in particular, is not associated with a variety of adverse offspring outcomes...

If in doubt, please speak to your prescribing physician. Please don't tinker yourself with things that you shouldn't tinker with...

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[1] Bech L. et al. In utero exposure to antiepileptic drugs is associated with learning disabilities among offspring. J Neurol Neurosurg Psychiatry. 2018 Aug 3. pii: jnnp-2018-318386.

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Monday, 7 May 2018

"evidence that in utero exposure to certain AEDs can cause developmental problems in children"

AEDs mentioned in the title of this post refer to antiepileptic drugs, a class of medicines that provide life-enhancing and sometimes life-saving relief from symptoms of various conditions headed under the term epilepsy. As I've mentioned previously on this blog, the management of epilepsy is not something to be taken lightly given what the condition(s) can mean in terms of (life-threatening) risks. AEDs provide both an important management and preventative tool. Don't ever forget that.

The results published by Arron Lacey and colleagues [1] add to a bank of peer-reviewed research observing that whilst various AEDs provide an important service with regards to the management of epilepsy, they are not however without potential risks of their own. Indeed, the risks following consumption of such medicines - or at least certain AEDs - during pregnancy when it comes to offspring outcomes are seemingly becoming more and more evident as ever more [peer-reviewed] science appears...

I should at this point mention that no medical or clinical advice is given or intended on this blog. This is even more pertinent when it comes to this topic and what epilepsy means to many, many people. If you want further information about the topic discussed today, please, speak to your prescribing physician and don't make any medication changes without their input and say-so.

OK, Lacey et al started out with the aim of investigating "the effect of AED exposure in utero on the educational attainment of children born to mothers with epilepsy using anonymised, routinely collected healthcare records and the results of a standard national educational assessment." That anonymised database was something called the Secure Anonymous Information Linkage (SAIL) databank, a resource funded by Health and Care Research Wales, thus providing a clue as to the population on which this research was carried out with.

Researchers identified women diagnosed with epilepsy - "a diagnosis of epilepsy if their GP [general practitionerrecord contained an epilepsy diagnosis code as well as a record of repeat AED prescriptions" - who had children, and looked also at their child's education attainment at 7 years of age. In case you might not be familiar with measuring educational attainment here in the UK (yes, Wales is a country part of the UK), the particular assessments taken at 7 years of age are called the Key Stage 1 (KS1) SATs. Maths and English made up the core topics alongside science at the study time in question. Educational data of offspring were included in the statistical mix and results reported as a function of maternal epilepsy and corresponding prescription of AEDs.

Results: "We demonstrate through the analysis of linked data in the SAIL databank that mothers being prescribed multiple AEDs and those being prescribed sodium valproate have children with significantly poorer attainment in national tests at the age of 7." The authors once again (see here) specifically zoomed in on a role for valproate when it came to educational outcomes of offspring; where: "there was no difference seen in children exposed to carbamazepine, lamotrigine or mothers who did not take drugs during pregnancy." Importantly also, authors noted that: "We did not find a significant decrease in attainment in children born to mothers with epilepsy who were not prescribed an AED during pregnancy" indicating that maternal epilepsy was probably not a 'cause' of the results obtained. Finally, when cases of smoking during pregnancy - something that also seems to be able to affect offspring developmental and/or cognitive outcomes - were removed from the statistical mix, authors reported that the results did not notably change.

There are some important strengths associated with the study results by Lacey and colleagues. A large cohort, clinical information on the diagnosis of epilepsy and associated prescribed AEDs, and the reliance on "a standardised national assessment as a measure of performance" with "results [that] would closer reflect the learning experience of children at this age compared with an IQ test" all add up to something pretty impressive. The authors note that they did not / were not able to control for other potentially important variables such as parental characteristics that may have impacted on the study results but no investigation is perfect. That analysis based on epilepsy medicated vs. not medicated during pregnancy kinda helps matters but does not mean every potentially important variable was controlled for.

So yet again, valproate use crops up and yet again it seems to be earning its 'black triangle' status. I've lost track of the number of health-related agencies that have provided guidance on valproate use during pregnancy - one of the latest seems to be the European Medicines Agency that recently recommended "new measures to avoid exposure of babies to valproate medicines in the womb." Also going as far as noting that: "Babies exposed are at risk of malformations and developmental problems." There's even a call for it to be "compulsory to enrol all women who take valproate into a national registry" [2].

How much more evidence is required? Indeed, how much more evidence [3]...

Then the question remains: how does gestational exposure to valproate affect something like academic achievement and developmental course? Well, we have some clues (see here) but further investigations are of course implied.

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[1] Lacey AS. et al. Educational attainment of children born to mothers with epilepsy. J Neurol Neurosurg Psychiatry. 2018. March 27.

[2] Thomas RH. Valproate: life-saving, life-changing. Clin Med (Lond). 2018 Apr 1;18(Suppl 2):s1-s8.

[3] Paton C. et al. A UK clinical audit addressing the quality of prescribing of sodium valproate for bipolar disorder in women of childbearing age. BMJ Open. 2018 Apr 12;8(4):e020450.

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Monday, 4 September 2017

Valproate use during pregnancy and/or breastfeeding and "greatest odds of adverse development"

As per other blogging occasions when I've talked about the antiepileptic drug (AED) valproate and its use specifically during pregnancy, I caution that no medical or clinical advice is given or intended on this blog. Anyone in any doubt or seeking an opinion on this other or any other AED should consult their prescribing physician. Don't mess with epilepsy. I repeat: don't mess with epilepsy.

The findings however reported by Areti Angeliki Veroniki and colleagues [1] (open-access) synthesising the available peer-reviewed evidence to compare "the safety of antiepileptic drugs (AEDs) on neurodevelopment of infants/children exposed in utero or during breast feeding" provides an all too familiar picture specifically in relation to valproate use during pregnancy. Namely: "Valproate alone or combined with another AED is associated with the greatest odds of adverse neurodevelopmental outcomes compared with control."

Utilising something called a Bayesian random-effects network meta-analysis (NMA), researchers set about synthesising and ranking various AEDs previously studied in terms of their safety when it comes to *association* with various childhood developmental diagnoses including autism and things like cognitive developmental delay. Based on the results from 29 studies reporting on AED use and 'neurological outcomes' including some 5000 patients, authors made some important observations.

Not to be alarmist but: "results suggest that AEDs generally pose a risk for infants and children exposed in utero or during breast feeding." The authors caution that their results whilst methodologically strong are not without limitations; not least that the studies in this area are observational only and therefore have "inherent biases because of confounding and shortcomings of these studies." That being said, the tide of such observational research cannot be readily ignored. If there is one or more confounding variables that is/are somehow being hidden behind something like valproate use during pregnancy and its potential risks of offspring developmental outcomes, they seem to be very well hidden indeed.

"Valproate was significantly associated with more children experiencing autism/dyspraxia, language, cognitive and psychomotor developmental delays versus children who were not exposed to AEDs." Valproate came 'top of the pops' when it came to those neurological outcomes. Other AEDs also showed associations with specific outcomes - "oxcarbazepine and lamotrigine were associated with increased occurrence of autism" - but the data pointed to valproate as potentially showing greatest risk to offspring. I should point out that there is a mouse model of autism that relies on offspring valproate exposure which, whilst subject to shortcomings (see here), kinda suggested that there may be an important association. Said animal research also reveals some potentially important avenues for perhaps mitigating any deleterious effects of valproate use on offspring too (see here) with the requirement for more experimental study.

"Future studies should assess the genetic contribution from the biological father, maternal seizures during pregnancy, exposure through breast feeding only, types of epilepsy and maternal family history." Of course the authors are right to talk about other factors that are probably important to various childhood developmental outcomes. But unlike a related area talking about medicines taken during pregnancy potentially affecting risk of something like autism and how one might tease apart medicine use from underlying health issue(s) (see here for example), I don't think it too likely that there is going to be a large bank of pregnant mums out there who present with epilepsy or other seizure disorder that is not going to be already managed via AEDs. Indeed, it would be rather unethical as well as unwise to leave epilepsy untreated under any conditions.

To close, where we're up to when it comes to government (UK) advice on AEDS such as valproate and pregnancy use. Again, if it doubt, talk to your prescribing physician.

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[1] Vernoniki AA. et al. Comparative safety of antiepileptic drugs for neurological development in children exposed during pregnancy and breast feeding: a systematic review and network meta-analysis. BMJ Open. 2017; 7: e017248.

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Friday, 20 May 2016

On the question of valproate use and pregnancy

I very much want to stress the point that 'no medical or clinical advice is given or intended' on this blog before proceeding further with discussions based on the commentary paper by Richard Balon & Michelle Riba titled: 'Should Women of Childbearing Potential Be Prescribed Valproate?' [1].

Valproate, as in preparations like sodium valproate, has been a particular talking point in recent years as a consequence of something of an emerging body of peer-reviewed science suggesting that its use during pregnancy may place offspring at some elevated risk for various neurodevelopmental outcomes (see here). The Medicines and Healthcare Products Regulatory Agency (MHRA) here in Blighty issued some revised guidance last year (2015) 'strengthening' warnings about the use of valproate under certain circumstances. This follows some research history on how for example, a valproic acid mouse model of autism has been used as "environmentally induced ASD [autism spectrum disorder] models in rodents" [2] for quite a few years.

Balon & Riba cover various points in the debate about valproate use during pregnancy specifically focused on the known "teratogenic outcome[s]" that have been reported down the years bearing in mind that valproate serves an important (sometimes life-saving) use. I was particularly struck by the 'interference' with folic acid metabolism discussed in their commentary on the basis of some science in this area [3]. With that pinch of salt at the ready, some readers might already know that folate metabolism has some research history in autism circles (albeit not necessarily settled science) and indeed, continues to make scientific waves. Accepting that valproate might have more than one action when potential offspring outcomes are concerned (see here), I do wonder if further research focus could be directed on the folate aspect of the drug when it comes to risk of various neurodevelopmental diagnoses for example?

The question of valproate use outside of the management of epilepsy is a focus of the Balon/Riba article; specifically "used in acute mania or in prophylaxis of bipolar disorder." Bearing in mind that various other medicines are available to manage these conditions and that "unplanned pregnancies are common in this population" [4] I don't think it's out of place for the authors to "recommend that the FDA and valproate manufacturers declare valproate contraindicated in women of childbearing age and issue guidelines for counseling women of childbearing potential with bipolar disorder." Indeed, NICE here in England, seem to have taken a lead on this...

If in doubt, please consult with your medical physician.

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[1] Balon R. & Riba M. Should Women of Childbearing Potential Be Prescribed Valproate? J Clin Psychiatry. 2016; 77: 525–526.

[2] Ergaz Z. et al. Genetic and non-genetic animal models for Autism Spectrum Disorders (ASD). Reprod Toxicol. 2016 Apr 30. pii: S0890-6238(16)30077-6.

[3] Fathe K. et al. Brief report novel mechanism for valproate-induced teratogenicity. Birth Defects Res A Clin Mol Teratol. 2014 Aug;100(8):592-7.

[4] Marengo E. et al. Unplanned pregnancies and reproductive health among women with bipolar disorder. J Affect Disord. 2015 Jun 1;178:201-5.

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ResearchBlogging.org Balon R, & Riba M (2016). Should women of childbearing potential be prescribed valproate? a call to action. The Journal of clinical psychiatry, 77 (4), 525-6 PMID: 27137420

Tuesday, 19 April 2016

Bumetanide for schizophrenia? A case report

Bumetanide - a medicine known as a diuretic - has appeared before on this blog (see here for example) in relation to some preliminary suggestions that at least some types of autism might be sensitive to intervention using this particular compound [1]. The names Lemonnier (Eric) & Ben-Ari (Yehezkel) are a big part of the research group interested in bumetanide and its use outside of more traditional indications; particularly, the focus on its action on NKCC1 onwards to an effect on GABA.

Whilst there is still interest in the use of bumetanide for 'some' autism [2], today I'd like to briefly bring your attention to an interesting report on the use of this pharmaceutic in an adolescent diagnosed with schizophrenia [3]. The case report by Lemonnier et al details how following the use of bumetanide, there was a corresponding effect on some of the positive symptoms of schizophrenia; in particular: "Long-term treatment reduced hallucinations significantly." The authors conclude that "Further clinical trials and experimental studies are warranted."

Although still early days, I find this to be interesting research if not the first time that NKCC1 has been mentioned with schizophrenia in mind. When one looks at the range of 'effects' potentially linked to the NKCC1 inhibitors such as bumetanide [4] one gets a flavour for what might be potentially linked. As Jaggi et al suggest: "The inhibitors of NKCC1 are shown to produce anxiolytic effects; attenuate cerebral ischemia-induced neuronal injury; produce antiepileptic effects and attenuate neuropathic pain." I'm particularly drawn to the 'antiepileptic effects' bit in particular, as a function of the quite long-standing association between schizophrenia and epilepsy (see here). I'm not putting my eggs in one scientific basket by saying that, but given what is known about NKCC1 and some 'refractory' epilepsy [5] for example, it sounds as good a place to continue investigations as any...

Music: Me First & The Gimme Gimmes with a classic... Top of the World.

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[1] Lemonnier E. et al. A randomised controlled trial of bumetanide in the treatment of autism in children. Transl Psychiatry. 2012 Dec 11;2:e202.

[2] Grandgeorge M. et al. The effect of bumetanide treatment on the sensory behaviours of a young girl with Asperger syndrome. BMJ Case Rep. 2014 Jan 31;2014. pii: bcr2013202092.

[3] Lemonnier E. et al. Treating Schizophrenia With the Diuretic Bumetanide: A Case Report. Clin Neuropharmacol. 2016 Mar-Apr;39(2):115-117.

[4] Jaggi AS. et al. Expanding Spectrum of Sodium Potassium Chloride Co-transporters in the Pathophysiology of Diseases. Curr Neuropharmacol. 2015;13(3):369-88.

[5] Sen A. et al. Increased NKCC1 expression in refractory human epilepsy. Epilepsy Research. 2007; 74: 220-227.

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ResearchBlogging.org Lemonnier E, Lazartigues A, & Ben-Ari Y (2016). Treating Schizophrenia With the Diuretic Bumetanide: A Case Report. Clinical neuropharmacology, 39 (2), 115-117 PMID: 26966887

Friday, 15 May 2015

Autism's environmental exposome (part 2)

Back in June 2012, I posted an entry on this blog titled: 'Autism's environmental exposome: fish and pharmaceuticals' covering some work by Michael Thomas & Rebecca Klaper [1] (open-access). In it, authors suggested that unmetabolized psychoactive pharmaceuticals (UPPs) - residues from certain medicines - present in drinking (or in the case of this work, swimming) water may "induce autism-like gene expression patterns in fish."

The UPPs in question were "FLX [fluoxetine], VNX [venlafaxine], and CBZ [carbamazepine] in a 3-component mixture" and the lucky fish volunteers were fathead minnows who got to swim with those UPPs. The data were interesting insofar as the potential "ability to induce ASD-like gene expression patterns in developing brains" as a function of exposure to those UPPs, albeit with concentrations used in the Thomas/Klaper study "higher than observed environmental concentrations". The idea being that drug residues are present in the environment around us and some, either alone or in combination, may potentially host some important biological effects.

Enter then further work from this group in the form of the paper by Gaurav Kaushik and colleagues [2] (open-access) who undertook some rather interesting network analysis among other things and concluded that: "protein products from gene sets with enriched expression in fish brains and human neuronal cells, due to an exposure of psychoactive pharmaceuticals, were comparatively more inter-connected to other neighboring proteins than protein products of non-enriched gene sets." Further: "these genes are more likely to experience altered expression upon exposure to PPCPs [pharmaceuticals and personal care products], causing further dysregulation of the whole interactome due to a ripple effect."

I'll be honest with you and say that I'm not altogether au fait with all the goings-on reported by Kaushik et al and their bioinformatics approach adopted so you'll have to take my interpretation with a pinch of salt.  What they appear to be suggesting is that the effects of UPP exposure may not be just centred on the gene expression patterns they previously reported but rather having something of a wider knock-on effect on how gene products are expressed and how this might map onto something like autism. Interestingly, this time around researchers also introduced valproate (VPA) into their investigations given the growing evidence base that "VPA is known to induce ASD [autism spectrum disorder]-like phenotypes in mice" (see here for more information) as it might in people [3]. They reported some potentially important connections - "enrichment effects of clinical doses of VPA are similar to those for environmental concentrations of pharmaceutical mixtures."

Accepting how the word 'chemical' has been very wrongly demonised over the years, the idea that environmental 'exposures' either singularly or as combinations, might have important effects on development and behaviour is something that requires quite a bit more investigation when it comes to something like autism. The idea that gene expression for example, can be modified by said exposures adds an extra layer of complexity to the rather too simplistic idea of 'genes vs. environment' when it comes to autism risk. One might also be minded to take into account gender/sex (see here) too particularly in light of some of the findings reported by Werling & Geschwind [4] recently...

Oh, and UPPs might not be the only pharmaceuticals requiring further research attention with wastewater and minnows in mind...

Music: Dinosaur Jr. - Freak Scene.

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[1] Thomas MA. & Klaper RD. Psychoactive pharmaceuticals induce fish gene expression profiles associated with human idiopathic autism. PLoS One. 2012;7(6):e32917.

[2] Kaushik G. et al. Psychoactive pharmaceuticals as environmental contaminants may disrupt highly inter-connected nodes in an Autism-associated protein-protein interaction network. BMC Bioinformatics 2015, 16(Suppl 7): S3.

[3] Wood AG. et al. Prospective assessment of autism traits in children exposed to antiepileptic drugs during pregnancy. Epilepsia. 2015. 11 May.

[4] Werling DM. & Geschwind DH. Recurrence rates provide evidence for sex-differential, familial genetic liability for autism spectrum disorders in multiplex families and twins. Molecular Autism 2015, 6:27.

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ResearchBlogging.org Gaurav Kaushik, Michael A Thomas, & Ken A Aho (2015). Psychoactive pharmaceuticals as environmental contaminants may disrupt highly inter-connected nodes in an Autism-associated protein-protein interaction network BMC Bioinformatics

Saturday, 3 January 2015

Anti-epileptic meds and pediatric serum vitamin D levels

No, I am not becoming obsessed with the sunshine vitamin/hormone despite us being only a few days into 2015 and this being my second post on vitamin D. It's just the way that the research posts fall; although regular readers will probably have noticed I do enjoy reading the various research on all-things vitamin D.
There has been an awakening...

The research fodder for today's post is the paper by Yun-Jin Lee and colleagues [1] who measured 25-hydroxy vitamin D levels (in serum) for quite a large participant group (N=143) of children "with epilepsy taking antiepileptic drugs" to ascertain what (if anything) happened to vitamin D levels as a consequence of said pharmacotherapy. Importantly, participants were medication-naïve at baseline (start of the trial) and followed up "at 6- to 12-month intervals".

Their results were interesting. "At the start of antiepileptic drugs and the last follow-up, vitamin D deficiency or insufficiency was recognized in 56.6% (81 of 143) and 79.0% (113 of 143), respectively." Deficiency and insufficiency by the way, were defined as <20 ng/mL (less than 20 ng/mL) and "between 21 and 29 ng/mL" respectively. When looking at the group as a whole, the authors reported that the average value of baseline serum vitamin D was 31.1 ± 14.7 ng/mL. This dropped to 20.2 ± 14.9 ng/mL at follow-up after the introduction of antiepileptic medication. Various factors might have influenced such a decrease including the use of more than one medication, a longer duration of medication use and being heavier in terms of weight. Age and type of antiepileptic did not however seem to play any significant role in the obtained results.

I should, at this point, draw attention to my primary caveat on this blog about not giving anything that looks, sounds or smells like medical or clinical advice. As per my other discussions on epilepsy and/or seizure-type disorders and their medication(s), please do not go altering medication patterns designed to control conditions which can be life-threatening without your healthcare professional being involved. Don't mess with epilepsy.

Onwards. This is not the first time that epilepsy and antiepileptic medication have been discussed in the peer-reviewed literature with vitamin D in mind. The paper by Mintzer and colleagues [2] (open-access) for example, discussed how consumers of carbamazepine or oxcarbazepine presented with significantly lower serum 25-hydroxyvitamin D (25-OHD) levels than asymptomatic controls. They concluded by suggesting that it may be "prudent" for such a patient group to receive vitamin D supplements alongside their medication. Indeed, if the paper by Holló and colleagues [3] is anything to go by, such supplementation might also be monitored for some potentially important positive effects too, although I hasten to add that I'm not suggesting that vitamin D is a cure-all for epilepsy.

Just before I go, I'd like to bring in some autism discussion into this post and what the Lee and other findings might mean for cases of autism and epilepsy combined. Acknowledging that epilepsy and/or seizure-type disorders are not an uncommon phenomena when a diagnosis of autism is received (see here), one might entertain the thought that issues with vitamin D present in cases of medication treated epilepsy might similarly overlay with autism + epilepsy in mind too. I've talked about vitamin D and autism a few times on this blog (see here and see here) and how, although not universally so [4], research into vitamin D deficiency and autism is in the ascendancy. Given the numbers of people with autism potentially in receipt of antiepileptic medication - suggested to be around 10% according to the paper by Aman and colleagues [5] in 2003 - one might be inclined to take such medication history into account when looking at issues with vitamin D in the context of [some] autism. Bone health as another potentially related factor [6] may be something else to consider in light of similar issues also potentially being present in cases of autism...

Music then: Los Lobos - Flor de Huevo.

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[1] Lee YJ. et al. Longitudinal Change of Vitamin D Status in Children With Epilepsy on Antiepileptic Drugs: Prevalence and Risk Factors. Pediatr Neurol. 2014 Oct 16. pii: S0887-8994(14)00606-7.

[2] Mintzer S. et al. Vitamin D levels and bone turnover in epilepsy patients taking carbamazepine or oxcarbazepine. Epilepsia. 2006 Mar;47(3):510-5.

[3] Holló A. et al. Correction of vitamin D deficiency improves seizure control in epilepsy: a pilot study. Epilepsy Behav. 2012 May;24(1):131-3.

[4] Uğur Ç. & Gürkan C. Serum vitamin D and folate levels in children with autism spectrum disorders. Research in Autism Spectrum Disorders. 2014; 8: 1641-1647.

[5] Aman MG. et al. Prevalence and patterns of use of psychoactive medicines among individuals with autism in the Autism Society of Ohio. J Autism Dev Disord. 2003 Oct;33(5):527-34.

[6] Nettekoven S. et al. Effects of antiepileptic drug therapy on vitamin D status and biochemical markers of bone turnover in children with epilepsy. Eur J Pediatr. 2008 Dec;167(12):1369-77.

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ResearchBlogging.org Lee YJ, Park KM, Kim YM, Yeon GM, & Nam SO (2014). Longitudinal Change of Vitamin D Status in Children With Epilepsy on Antiepileptic Drugs: Prevalence and Risk Factors. Pediatric neurology PMID: 25492388

Monday, 16 September 2013

Pregnancy antiepileptic use and offspring autistic traits

I'm a little bit slow in arriving at the paper by Gyri Veiby and colleagues* reporting a connection between maternal antiepileptic use and issues with offspring development (see here also for some news content). It's not that I don't find this particular topic to be absolutely fascinating - I most certainly do - but rather that other commitments, deadlines and interests keep getting in the way. Don't you sometimes wish you could be Multiple Man?
My first photo... @ Wikipedia 

Anyhow, for those of you who that haven't read my previous discussions on the growing body of research suggesting that we should perhaps be particularly mindful about the use of certain antiepileptic medicines during pregnancy (see here and here), the crux of the 'association' being made is that there may be some elevated risk of offspring autism under certain circumstances.

An automatic response to hearing about this possible link (aside from asserting that 'correlation does not equal causation') might be to say something along the lines of 'ban them' during pregnancy, as per another medicine (see here) with a very unfortunate history. But here's the thing: anti-epileptics aren't just some routine medicine used as pain relief or to help with other grumbling health-related issues that can be readily substituted. They can be, and often are, lifesavers: be in no doubt that untreated epilepsy can kill. And whilst it sounds easy to say that we should be prohibiting their use during pregnancy, the question then arises about what alternative you might suggest to control maternal epilepsy? Even though I'm enthused about things like ketogenic diets (see here) for example, and their growing use in treating some types of epilepsy, such measures are not always a good alternative to medication nor potentially great news for the developing child either (see here**). So we have a quandary.

Going back to the Veiby paper, it followed a slightly different vein to the previous work which looked at 'diagnosed' childhood outcomes such as autism following maternal use of anti-epileptics. Instead inquiring about specific facets of behaviour and development of offspring at 18 months and 36 months of age based on maternal report.

Using data derived from the Norwegian Mother and Child Cohort Study (MoBa) which covered a considerable sized cohort of pregnant women (more details are reported in this paper by Per Magnus and colleagues*** open-access), several thousand children were followed and included for the current study. MoBa, by the way, was also the source of data for one of the big folic acid studies with autism in mind (see here) and other interesting work (see here).

Anyhow, based on the analysis of records, some 333 children were reported to be exposed to antiepileptics in-utero as a result of maternal epilepsy. These children, when compared with non-exposed children, showed an increased frequency of issues with things like motor skills at 18 months alongside greater scores based on maternal reports of autistic-like behaviours.

At 36 months of age, these issues were still present in the exposed group. The frequency percentages for autistic traits in exposed and non-exposed children at the two time points were interesting (3.5% vs. 0.9% at 18 months, and 6% vs. 1.5% at 36 months). Just in case you're thinking that there might have been an effect from mum's epilepsy on child development and not the medication, the authors also reported no similar increased risk of developmental issues in those children born to mothers with epilepsy but who were unmedicated during pregnancy. Likewise when dads were diagnosed with epilepsy.

It's hard not to say that the evidence is stacking up for some effect of such medication when it comes to autism as a diagnosis and as a collection of symptoms/traits bearing in mind that risk is risk not fact. The announcement that the US FDA has now issued a warning about using the antiepileptics in question during pregnancy (which includes valproate) for treating things like migraine is testament to how seriously this issues is being taken. For many people, this is probably going to be worrying news.

With my cold, objective science hat on I'd also reiterate the suggestions from my previous posts on this topic that we have an interesting model developing potentially illustrative of how autism, at least some autism, might come about. Yes, autism research already uses a valproate mouse model of autism (see here for example) illustrative of the potential teratogenicity of the drug. But further than that are the reports that valproate for example, might have some interesting epigenetic effects on the genome, as per it being "a powerful HDAC inhibitor"*** (HDAC = histone deacetylases); indeed what effects it might have on certain comorbidity too****. One has to wonder whether this might have some effect also.

To close, I will reiterate the sentiments of this blog about not providing medical or clinical advice. Anyone requiring further information about this association, is directed to their supervising medical practitioner for further advice. Don't mess with epilepsy.

Something musical to close.... The Smiths and Sheila Take A Bow and the news that Morrissey has pulled his autobiography (which I assume would have been quite an interesting read).

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* Veiby G. et al. Exposure to antiepileptic drugs in utero and child development—A prospective population-based study. Epilepsia. 2013. doi: 10.1111/epi.12226

** Sussman D. et al. Effects of a ketogenic diet during pregnancy on embryonic growth in the mouse. BMC Pregnancy and Childbirth 2013, 13:109 doi:10.1186/1471-2393-13-109.

*** Haberland M. et al. The many roles of histone deacetylases in development and physiology: implications for disease and therapy. Nat Rev Genet. 2009 January; 10(1): 32–42.

**** Turgeon N. et al. HDAC1 and HDAC2 Restrain the Intestinal Inflammatory Response by Regulating Intestinal Epithelial Cell Differentiation. PLoS ONE. 2013. 8(9): e73785. doi:10.1371/journal.pone.0073785

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ResearchBlogging.org Veiby G, Daltveit AK, Schjølberg S, Stoltenberg C, Oyen AS, Vollset SE, Engelsen BA, & Gilhus NE (2013). Exposure to antiepileptic drugs in utero and child development: A prospective population-based study. Epilepsia, 54 (8), 1462-72 PMID: 23865818

Sunday, 12 May 2013

An interesting case report on autism and diet

Nodding syndrome.

Ever heard of it? Well, up until a few days ago I hadn't. That is before coming across articles on the topic by Richard Idro and colleagues* (open-access) and Angelina Kakooza-Mwesige and colleagues** (open-access). Whilst not specifically my line of expertise or interest, I was intrigued to read about how nodding and other symptoms of the epileptic variety, at least in some cases, seemed to be precipitated by food and showed a potential nutritional angle.
Curving spacetime @ Wikipedia  

Granted, the hows and whys of nodding syndrome are still a mystery, but the first thought that went through my mind was whether any specific types of food(s) might be implicated. Y'know in a similar vein to Marios Hadjivassiliou and the notion of gluten ataxia*** for example? Just speculating...

With all that talk of food and behaviour in mind there are a few things that piqued my attention towards the paper by Herbert & Buckley**** seemingly part of a string of articles looking at the topic of dietary intervention published in the Journal of Child Neurology. The first thing was the title of the paper: "Autism and Dietary Therapy" simply because I have some research interest in this area. Perhaps I might have mentioned it before...

Next was the authorship list, focused on at least one of the authors, Dr Martha Herbert (no disrespect intended to Dr Buckley). Alongside an already distinguished career in autism research, Dr Herbert is also making some waves with her new book: 'The Autism Revolution' co-authored with Karen Weintraub who wrote that very interesting Nature article on autism prevalence a few years back.

Finally, a sentence from the paper abstract: "Over the course of several years following her initial diagnosis, the child’s Childhood Autism Rating Scale score decreased from 49 to 17, representing a change from severe autism to nonautistic, and her intelligence quotient increased 70 points".

Such a dramatic description of change in presentation might once have been received with a very, very sceptical eye. Indeed I assume that still might be the case in some quarters. The publication of the Deborah Fein study (see here and here) on optimal outcome in relation to autism in conjunction with the rising tide of research looking at the potential benefits of early intervention for cases of autism, have perhaps made such observations slightly more 'acceptable', at least to some elements of the autism research community. Indeed I was also very taken by the recent BBC interview of Kristine and Jacob Barnet which discussed similar changes to symptom presentation in a young man now tipped for some absolutely amazing things. The fact that said changes detailed in the Herbert & Buckley paper seemed to occur at the same time that a "gluten-free casein-free ketogenic diet" was being followed is... interesting.

Now round about this time, some people might be thinking what does this study actually show? A case study of a girl / young woman with autism where comorbid epilepsy was controlled both by anti-seizure medication and a ketogenic diet (yes, such a diet has been linked to the control of cases of epilepsy). Said dietary intervention originating in the gluten- and casein-free (GFCF) dietary domain. As time went on, seizures dissipated and over time her clinical scores on the CARS reduced indicative of quite a change in her autism presentation.

One of course might say, a single case study, it means very little in the grand methodological scheme of things. That is unless you think back to the mantra 'if you've met one person with autism, you've met one person with autism' highlighting the power of the N=1 where autism is concerned (see here). That and the interesting viewpoint expressed by people like Gary Mesibov on the issue of evidence-based medicine when applied to a extremely heterogeneous condition like autism, sorry the autisms.

I am interested in the coincidental factors reported in this paper. I have questions: did the (almost) resolution of the epileptic symptoms carry any influence on the presentation of autism? In particular, I'm thinking back to that very interesting piece of research which suggested one particular type of autism (and epilepsy) might be related to a metabolic issue with the branched-chain amino acids (see here). Is this a potential model for that epilepsy-autism relationship for some people on the spectrum? What about the "resolution of morbid obesity" also reported; could this similarly have had any effect on symptom presentation?

I have questions about the role of the diet adopted in this case. A ketogenic diet, as well as finding some value in cases of epilepsy or seizure disorders, has also been looked at with autistic behaviours in mind. Yep, at least one trial***** albeit preliminary, suggested that this might be an option for some people on the spectrum bearing in mind I'm not making any recommendations. Down the years I've also heard anecdotal reports about how the GFCF diet might have aided in the reduction/amelioration of certain signs and symptoms linked to autism. The paper by Stephen Genuis (see this post) is one example. Just before you say something along the lines of 'there is no methodologically sound experimental evidence for dietary effect'; well, yes and no (see here) accepting the need for much more rigorous experimental study and that the evidence is not all one-way (see here).

If anyone has alternative explanations for the change in symptoms outside of just healthier eating, any placebo effect or just the research attention paid to the participant in question, please feel free to post them in the comments section. That being said, no mumbo-jumbo please like I've being reading today which has been roundly answered by psychiatry. Going back to the Fein study and the promise of more details to come, I'll be interested to see whether they report any of their optimal outcomers were following such a dietary intervention alongside other interventions.

And finally... one of the main points I take from the Herbert & Buckley paper is how it underscores the need for (a) a greater, more controlled look at the potential efficacy of dietary intervention - in whatever form - in relation to cases of autism, including the important categorisation of 'best' and 'non' responders, and (b) mechanisms... how on earth could removal of specific foodstuffs affect the presentation of autism? Leaky gut? Changes to the various populations of our bacterial masters? Allergy or intolerance similar to that noticed in cases of schizophrenia for example? I've talked about some of these potential options in a previous paper (see here******) if you're at all interested. (Sorry about the blatant self-promotion).

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* Idro R. et al. Nodding syndrome in Ugandan children—clinical features, brain imaging and complications: a case series. BMJ Open 2013; 3: e002540.

** Kakooza-Mwesige A. et al. Nodding Syndrome in Ugandan Children and Adolescents: Menage A Trios of Epilepsy, Autism, and Pediatric Catatonia. Autism 2012; 2: e112.

*** Hadjivassiliou M. & Grünewald R. The neurology of gluten sensitivity: science vs. conviction. Practical Neurology. 2004; 4: 124–126.

**** Herbert MR. & Buckley JA. Autism and dietary therapy. J Child Neurol. May 2013.

***** Evangeliou A. et al. Application of a ketogenic diet in children with autistic behavior: pilot study. J Child Neurol. 2003; 18: 113-118.

****** Whiteley P. et al. How could a gluten- and casein-free diet ameliorate symptoms associated with autism spectrum conditions? Autism Insights 2010; 2: 39-53.

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ResearchBlogging.org Herbert, M., & Buckley, J. (2013). Autism and Dietary Therapy: Case Report and Review of the Literature Journal of Child Neurology DOI: 10.1177/0883073813488668

Thursday, 25 April 2013

Prenatal valproate exposure and autism: reloaded

When does the the term 'correlation does not equal causation' become a moot point? It's a question I've often pondered, having discussed the issue quite a few times on this blog for all manner of correlations and associations linked to autism (sorry, the autisms).

The weight of the heart @ Wikipedia  
Is there, for example, a recognised tipping point where the weight of evidence correlating A with B might actually lead to the consensus that A causes B either wholly or partially?

Yes, I know that science deals with probabilities not absolutes (something which we are all guilty of forgetting from time to time) and that science is generally quite reserved about its findings. But surely as per the example of smoking and lung cancer, there must be a time when the likelihood that A causes B creeps over the 'chance' explanation to something a little more concrete and directional?

The reason for the question(s) follows the publication of a study by Jakob Christensen and colleagues* (open-access) which suggested that in large and pretty well-defined Danish cohort "maternal use of valproate during pregnancy was associated with a significantly increased risk of autism spectrum disorder and childhood autism in the offspring". Regular readers might remember that quite recently there was some similar chatter on this antiepileptic medication based on the Bromley paper (see here) but on an altogether smaller scale compared with the current dataset.

There has been some media attention paid to the recent trial (see here and here) which is perhaps not surprising given the suggestion that approximately 1 in 20 mothers who were using valproate during pregnancy to control epilepsy or seizure disorders subsequently had a child with autism or an autism spectrum disorder (ASD). The actual risk (absolute risk) was quoted as 2.5% and 4.4% respectively based on the 508 children exposed to valproate in-utero. Even the latest 'survey' figures of 1 in 50 children presenting with an ASD in the US are seemingly dwarfed by the Christensen findings.

There are obviously caveats to all this talk about risk, and how risk is risk, not certainty. That also valproate is actually quite effective in controlling cases of epilepsy** is a point which should not get lost in any discussions on risk. Indeed when one reads such studies linking drug A to condition B, it's all too easy to forget that drug A is being taken for a reason; often a very important reason. Physicians generally do not enter lightly into such clinical decisions, particularly in light of past scandals of medication and pregnancy (see here). Not forgetting too that epilepsy can, in extreme cases kill***.

Outside of the autism-valproate link (if I can call it that) the Christensen data also includes some other potentially interesting factoids, as per the suggestion that among children of mums with epilepsy who were not exposed to valproate during pregnancy (n=6152), the absolute risk of a diagnosis of autism and ASD were 1.02% and 2.44% respectively. I hasten to add that I'm not an expert on risk, absolute risk, but 2.44%, by my reckoning, equates as roundabout 1 in 40 with an ASD born to mums with epilepsy. I'm cautious not to read too much into this just in case I've got it completely wrong but if it is correctly interpreted, might imply some greater connection between offspring autism and a maternal history of epilepsy as per previous findings****.

I'm not going to go through all the possible weaknesses in the Christensen paper because the manuscript does that quite well enough itself including some discussion on that folate-autism link. Likewise my previous post on valproate and offspring autism talked about some of the possible mechanisms to account for any effect, so again no need to cover all that ground. There is one tidbit to pick up on: "Valproate is a fatty acid derivative" so the authors report. I've often wondered about this point and the suggested mechanism of seizure control in some cases by use of the ketogenic diet impacting on fatty acids (see the paper by Chang and colleagues*****). Assuming the Chang findings are accurate, does this place more emphasis on the HDAC inhibition side of things when it comes to valproate and offspring autism risk?

The question still remains about the 'correlation does not equal causation' mantra with prenatal valproate exposure and offspring autism in mind. The Christensen paper at the very least, makes a really strong case for a lot more detailed inspection of this potential association as once again the use of pharmacotherapy during pregnancy comes under the spotlight.

Oh, and just in case you thought I was singling out valproate for special attention in relation to autism, have a look at the recent paper by Dheeraj Raj and colleagues****** (open-access) on prenatal antidepressant exposure and offspring autism risk again adding to the previous literature. Indeed it makes me wonder if that environmental exposome fish experiment carried out a while back might well be a model, albeit with revisions, we need to revisit.

A song to close methinks. Something vintage and snazzy today.... Elvis and Viva Las Vegas.

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* Christensen J. et al. Prenatal valproate exposure and risk of autism spectrum disorders and childhood autism. JAMA. 2013; 309: 1696-1703.

** Marson AG. et al. The SANAD study of effectiveness of valproate, lamotrigine, or topiramate for generalised and unclassifiable epilepsy: an unblinded randomised controlled trial. Lancet. 2007; 369: 1016–1026.

*** Berg A. Mortality in epilepsy. Epilepsy Curr. 2001; 1: 28.

**** Leonard H. et al. Maternal health in pregnancy and intellectual disability in the offspring: a population-based study. Ann Epidemiol. 2006; 16: 448-454.

***** Chang P. et al. Seizure control by ketogenic diet-associated medium chain fatty acids. Neuropharmacology. 2013; 69: 105-114.

****** Raj D. et al. Parental depression, maternal antidepressant use during pregnancy, and risk of autism spectrum disorders: population based case-control study. BMJ. 2013; 346: f2059

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ResearchBlogging.org Jakob Christensen, Therese Koops Grønborg, Merete Juul Sørensen, Diana Schendel, Erik Thorlund Parner, Lars Henning Pedersen, & Mogens Vestergaard (2013). Prenatal Valproate Exposure and Risk of Autism Spectrum Disorders and Childhood Autism JAMA

Sunday, 3 February 2013

Antiepileptic exposure and offspring autism risk

The great autism research spotlight continues to focus its gazerbeam on the very earliest days of being for any clues governing why some children might go on to develop autism. I've kinda lost count of how many times I've talked about maternal exposure for this or that having been linked to an elevated risk of offspring autism; ranging from maternal inflammation to parental occupational exposure to the possibility that maternal medication history during pregnancy might singularly or cumulatively exert some potential effect on risk.

Baby @ Wikipedia  
Indeed this last factor on medication during pregnancy has once again been the source of some speculation following the publication of a paper by Bromley and colleagues* suggesting an increased risk of offspring autism in cases of exposure to various antiepileptic drugs in-utero.

A quick search of PubMed reveals that Dr Bromley has some history in looking at foetal antiepileptic exposure on developmental outcomes as per papers like this one and this one (open-access). There were a few clues in these papers that autism and other developmental disorders might well have been next on the list for investigation for this research group.

Press attention for the current study? Er, yes, it goes without saying particularly in light of headlines like: Epilepsy drug linked to tenfold increase in autism (complete with picture of pregnant mums holding their tummy) and Epilepsy drug link to brain damage in 17,500 babies. Aside from thinking that there is probably lots of money to be made in stock photos of pregnant women and their bumps, if I were a pregnant mum with epilepsy taking such meds, I would probably be straight on the phone to my doctor/midwife to ask about these findings.

So what did Bromley et al actually find and report:

  • Based on an analysis of children born to 528 pregnant mums based here in Blighty, physical and cognitive abilities were assessed at various point during early infancy and childhood.
  • Of the total cohort, data across various testing points were available for 415 children; of which 19 had been diagnosed with a "neurodevelopmental disorder" by the age of 6 years.
  • Some of these neurodevelopmental disorders included autism (n=12); others had diagnoses of conditions like ADHD and dyspraxia (developmental coordination disorder, DCD).
  • Looking through the kind of meds being taken by mum's during pregnancy, the authors reported a connection between greater offspring neurodevelopmental issues in those mothers who were taking anti-epileptic medication compared to those who weren't (7.4% vs. 1.8% respectively) as per the rate of epilepsy in mums-to-be (243/528; 46%).
  • Sodium valproate was in particular singled out as part of the study as per the text: "children exposed to valproate alone in the womb were six times more likely to be diagnosed with a neurodevelopmental disorder". Indeed an even greater risk if a cocktail of other meds were also used during pregnancy.

As one would expect, the authors have cautioned that pregnant women with epilepsy taking these medications does not automatically translate into offspring autism and on no account should pregnant women just stop taking the drug without appropriate medical advice. Risk, as I have discussed before, is risk not certainty and epilepsy can be a life-threatening condition.

Valproate has already some history with regards to its possible effects on the developing infant as per the description of foetal valproate syndrome** (open-access) highlighting its potential teratogenicity. With autism in mind, this is also not the first time that valproate has appeared in the research texts. I note for example papers like this one from Bristot Silvestrin and colleagues*** which talked about an "animal model of autism induced by prenatal exposure to valproate", also bringing in words like 'glutamate' which has also seen its fair share of scientific inquiry in recent times (see this post). There are several other papers I could cite with a valproate-autism connection but I don't want to bore you.

Valproate is also a compound I've become quite interested in recently as a result of being part of some very brief forays into the science writing domain and in particular on the topic of epigenetics (see here but now for PJ members only). Since doing a little bit of research in that area I've for example, read quite a bit on how valproate is now considered to be quite a potent HDAC inhibitor**** (open-access) with some potentially useful effects in cancer therapy. This HDAC inhibition quality - leading on to histone hyperacetylation - has also been questioned as a possible route towards some of the autism-like findings. To quote from the paper by Kataoka and colleagues***** "findings suggest that VPA-induced histone hyperacetylation plays a key role in cortical pathology and abnormal autism-like behaviours in mice". Bearing in mind mice are mice and not humans.

The Bromley paper is an interesting paper and certainly invites a lot more study into how prenatal valproate exposure *might* show some connection to offspring risk of autism and other developmental conditions. Not trying to be anti-medication or anything, the study also highlights how little we actually know about the medicines we take and in particular their potential for things like trans-generational effects...

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* Bromley RL. et al. The prevalence of neurodevelopmental disorders in children prenatally exposed to antiepileptic drugs. J Neurol Neurosurg Psychiatry. January 2013.

** Kini U. Fetal valproate syndrome: a review. Pediatric & Perinatal Drug Therapy. 2006; 7: 123-130.

*** Bristot Silvestrin R. et al. Animal model of autism induced by prenatal exposure to valproate: Altered glutamate metabolism in the hippocampus. Brain Res. 2013; 1495: 52-60.

**** Göttlicher M. et al. Valproic acid defines a novel class of HDAC inhibitors inducing differentiation of transformed cells. EMBO J. 2001;20:6969–6978.

***** Kataoka S. et al. Autism-like behaviours with transient histone hyperacetylation in mice treated prenatally with valproic acid. Int J Neuropsychopharmacol. 2013; 16: 91-103.

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ResearchBlogging.org Bromley, R., Mawer, G., Briggs, M., Cheyne, C., Clayton-Smith, J., Garcia-Finana, M., Kneen, R., Lucas, S., Shallcross, R., Baker, G., & , . (2013). The prevalence of neurodevelopmental disorders in children prenatally exposed to antiepileptic drugs Journal of Neurology, Neurosurgery & Psychiatry DOI: 10.1136/jnnp-2012-304270