Does everyone have an autistic syndrome? - notes

Comments from Dr D MacIntyre

Professor Gillberg gave a fascinating review of the patterns and aetiology of autistic syndromes, a lot of it based on his own work in the field over a 30 year period. He described four main variants. Classical autistic syndrome is apparent before the age of three. Occasionally there is initial normal development in the infant and then regression but that is the exception. The dominant feature is a lack of reciprocal interaction with others in both social activity and communication. Any interaction with others is on the individual's own terms. This is associated with a restricted development of imagination.

The definition of Asperger's Syndrome seemed a little more difficult. The ICD10 classification requires normal development for the first three years which doesn’t always happen, and requires only three separate symptoms which could lead to a very broad inclusion within the diagnosis. Chris Gillberg following Asperger's original description suggested five of six separate features were required – social impairment e.g. lack of empathy or no friends; a narrow all absorbing specific interest; habits or behaviours which become an abnormal routine or ritual; a speech or language peculiarity e.g. delayed or pedantic speech or poor comprehension of normal conversation implying a lack of awareness of the mental prospective of others – "concrete conversation"; poor non verbal communication; motor clumsiness.

Two other groups – atypical autism or autistic like condition where individuals don’t fill the full criteria for diagnosis; and childhood disintegrative disorder – a condition which appears after three years of age and may be associated with provocative factors.

Recent publicity has suggested an increase in autistic syndromes however Professor Gillberg quoted his own survey from Gothenberg in 1977 which suggested prevalence figures similar to now at 0.7%. Some surveys using a less rigid diagnosis suggest higher prevalence but this may simply reflect a distribution of some features of autism as a continuum within society. This raised the question of whether autism is simply one end of a spectrum of behavioural characteristics – a disorder of empathy. Professor Gillberg preferred to see a variety of different syndromes which have autism as a cardinal feature. In many of these syndromes other developmental or psychiatric features are prominent – mental retardation, epilepsy and other aspects of visual hearing or sensory impairment. This co-morbidity is an important general issue – in the past autism was under diagnosed; now there can be a risk of missing other conditions in the presence of autism – attention deficit, depression, eating or sleep disorders for example. It is likely that the apparent increased prevalence of autism is due to increase awareness and diagnostic substitution.

There is a clear genetic link. Between 10 and 20% of siblings of a proband with classic autism exhibit features of the autistic spectrum – in identical twins this rises to between 60 and 90%. In general first degree relatives have an increase incidence of assorted social or functional disorders. There is some evidence pointing to specific genetic involvement in neurological development. Studies of histological changes in the brain have shown a number of different patterns of damage – varying from specific brain stem and cerebellar or frontal / temporal damage in classic autism to more widespread damage in patients with associated mental retardation. The general concept of aetiology is therefore of genetic predisposition possibly with an environmental insult during development leading to neurochemical damage which results in impaired social and neurocognitive functions leading in turn to the full blown syndrome.

The outcome in autistic syndromes is very variable depending on initial features but in at least 50% there remains major disability. Nonetheless more detailed and early diagnosis does allow interventions giving prospect of improvement. A high rate of secondary psychological problems is a major complicating factor. In future more detailed knowledge of specific subgroups might allow more effective management or treatment options. Greater awareness on the problem and better acceptance of people with autism might also improve their prospects.

In discussion Professor Gillberg was asked about the male preponderance (3:1). He wondered about the normal range of male and female behaviour, about the possibility of some testosterone effect, and about whether certain behaviours might be regarded more readily as abnormal in a boy. In further discussion of prognosis he suggested that very few with classic autism managed gainful employment. In Asperger’s Syndrome this figure might be around 50%. There is no currently useful specific drug treatment though treatment of identified complicating psychological factors is important.

In thanking Professor Gillberg for his address Dr Elaine Morrison, President of the Medical Chirurgical Society reflected the views of the audience that we had heard a fascinating and informative review of the subject from someone who is clearly a world expert speaking from a background of major clinical and research experience.