Monday, July 23, 2007

Knowledge and myth, hard science and caring art - the confusions of autism

The Neurology of Autism edited by Mary Coleman, Emeritus Clinical Professor of Pediatric Neurology at Georgetown University, is a collection of chapters on the latest information in such topics as the difference between syndromic and non-syndromic autism, chromosomes which might be implicated, brain regions affected, whether autism can be reversible, therapies - both traditional and alternative, and the epidemiology of autism. Each of the chapters is written by an expert in that area and provides a comprehensive review of the work. They are explicit about the limits chosen for that review, and give a broad view - not just concentrating on the most mainstream material. While the book jacket advertises the book as suitable for everyone - clinicians, students, researchers, and parents - I would say that is only true for some parts. The chapters focusing on chromosomal disorders and neurotransmitters are complicated and the writing is dry. Discussions of the many disorders that can feature autistic symptoms and on the brain regions affected by it are byzantine and pretty technical - if words like dentatothalamocortical and vermian freak you out, these chapters would be difficult for you. However, the discussions on therapies and the chapter on epidemiology are particularly thorough and accessibly written.

I'll summarize some key points from the book that might be of general interest:

More than 90% of children with autism appear to have a genetic component to their disease.

It seems to be agreed that the autistic syndromes begin impairing the brain before birth, even though the the markers clinicians routinely used to make a diagnosis tend not to be apparent until the child is between 18 and 24 months old.

There is likely not one single anatomical location in the brain whose abnormality underlies autism in all patients.

Autism likely involves the development of abnormal connections between regions of the brain - some models involve too many connections, others involve too few, yet others involve the rewiring of connections for purposes other than those which they are usually used as a compensatory strategy.

The two major diagnostic handbooks used by the mental health professions define the chief criteria for autism as possessing a certain number of abnormalities of social interaction, impairments in verbal and non-verbal communication, and a restricted repertoire of interests and activities present from early childhood.

There is a range of autistic disorders which spans intelligence and language abilities from high functioning to severely impaired.

The diagnostic criteria for Asperger syndrome specifies that there has been no delay in language and cognitive development - although there are some language peculiarities and motor issues often seen in Asperger, so there is some disagreement on what should constitute an Asperger's diagnosis or whether either a diagnosis of high-functioning autism on the one hand or merely describing the child as socially unusual on the other is more appropriate.

Family background, genetic factors, developmental milestones, motor coordination, and the savant skills (outstanding skill in a specific area, such as mathematics or music that are seen in around 10% of the autistic population) are all taken into account, but they are not defining criteria for diagnosis because there is not enough agreement given the current research.

Autistic symptoms are seen in connection with a wide variety of underlying diseases, each of which is probably due to a somewhat different neurological cause - Rett Syndrome, tuberous sclerosis complex, de Lange syndrom and Neurofibromatosis are a few of the diseases that fall under a larger umbrella term MCA/MR syndrom (multiple congenital anomalies and mental retardation). Furthermore, it is not know whether these syndromes can be said to manifest autistic symptoms or whether it would be more accurate to say that the individual has both the syndrome and autism.

It is likely that what is referred to as autism is actually different disease entities which will each be found to have their own pathology and resulting subset of symptoms

We see frequent mention in the popular press about whether the increased number of diagnosed cases of autism constitute an increase in the incidents of disease itself or just the awareness of it. The chapter on epidemiology by Christopher Gillberg reviews studies published in English from the 1960s through 2003 - examining them decade by decade. This intelligent analysis concludes that the prevalence of autistic spectrum disorders (autism, Asperger syndrome, and atypical autism or pervasive development disorder) are somewhere between .6% and 1.1%. That is 20 - 100 times high than the rates recorded 40 years earlier however, the definition of autism has changed in that time and now comprises a much broader group of conditions, which is what accounts for much of that difference. Clinician Lorna Wing rediagnosed her own cases from a study she conducted in the 1970s using updated criteria - it trebled that rate of diagnosis. Gillberg lists other influencing factors as well, but he is careful to point out that, given current diagnostic criteria, girls are currently probably underdiagnosed.

Another chapter on alternative therapies by Lorenzo Pavone and Martino Ruggieri reviews the literature on everything from vitamins, low-phenylalanine diets, gluten and casein free diets, and ketogenic diets to detoxification of heavy metals, auditory integration therapy, holding therapy, and dolphin assisted therapy. The reviews are balanced and respectful - never dismissive - but they are appropriately frank about whether evidence is anedoctally or research based, what type of study was conducted (i.e. whether it was controlled or double-blind), their efficacy, and the potential risks of the therapy, if any.

The final chapter by Michele Zappella is a thoughtful review of how professionals providing diagnoses, interventions, or other services can (and should) consider their patient in the context of their entire family. Everything from how to provide information given the incomplete state of our knowledge to dealing with the depression and anxiety of a parent is considered. There are useful case examples as well.

Medical professionals should be aware that their power in these moments [diagnosis] is great; they can foster hope or despair, can favor union and solidarity within the family or its opposite. Different results can occur based on how we physicians behave and speak, and from what we do... It has been said that psychic pain can be an occasion to become more flexible and sensible.

All in all, this is not a layperson's volume, but the three chapters I focused on would be accessible to any reader. As a student in the field and a potential researcher and/or clinician dealing with this disease and the people affected by it, I found its earlier chapters provided such an unconnected list of information it only made me despair that the pieces will ever come together, but the later chapters were both informative, and useful. It is more and more apparent to me that part of delivering good care is not just mastering an overwhelming body of knowledge but also learning the limits of our understanding. It's a hard lesson to swallow.

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