The enigmas of autism
We no longer speak of autism, but more widely of “pervasive development disorders”. Also, the behaviour and suffering they cause is no longer attributed to mental problems – new pathways to our understanding of the disorder are opening up in the field of genetic diseases, neurobiology, the cognitive sciences and brain observation using imaging techniques. Still, research continues to struggle in the face of this complex and multiform condition. At present, the only hope lies in early detection and the quality of the support environment – ideally one tailored to an individual’s specific needs – offered to those who live with this terrible handicap.
“At first there is an extreme solitude that causes the child to put up a defence in the form of disdain, ignorance and the exclusion of everything that comes from the exterior”. It was Leo Kanner, an Austrian physician who emigrated to the United States, who was the first to describe the condition in such terms. That was in 1943, a time when child psychology was in its infancy.
Studying 11 children at the Johns Hopkins Hospital in Baltimore who had the same symptoms, Kanner spoke of autism and refused to classify these patients in other categories of mental illness. He wanted to understand the mysterious mechanism by which these children were denied contact with the outside world and the true nature of this behavioural disorder that appears at around the age of three and is characterised by a desire for isolation, a refusal to communicate, the search for stereotyped activities, self-mutilation and the need to scream.
In fact, Kanner was not the first to use the term autistic. Hans Asperger of the Vienna University Hospital had already used the expression “autistic psychopaths” back in 1938 at a conference on child psychology. He lent his name to Asperger’s syndrome. This and different forms of autism are today included in the vast family of pervasive development disorders, the signs and seriousness of which can vary greatly.
The psychology years
Before this complex category was created, autism long remained within the exclusive domain of psychiatrists and psychoanalysts as other avenues of research seemed blocked. One of the most famous and controversial of these psychiatrists is Bruno Bettelheim who, in The Empty Fortress (1967), gives an account of the work he conducted on three children, Laurie, Marcia and Joey, who were locked in a state of mutism. It was on the basis of these observations that he formulated the hypothesis of a very early disturbance of the relationship between mother and child. In the late 1970s, the overemphasis on a purely psychoanalytical explanation of autism sparked a countermovement marked by closer cooperation between psychiatrists, the parents of autistic children and autistic adults who had acquired the ability to integrate. The parents were tired of being stigmatised as “refrigerator mothers” and society’s perception of autism was beginning to change. The medical sciences were seeking new ways forward in the fields of biology, neurocerebral research and genetics. So what kind of illness were they facing, now that it was no longer labelled a mental illness? What was its nature and how should it be defined?
The multifarious PDDs
Until 1975, the World Health Organization (WHO) regarded autism as a sub-group of psychoses specific to childhood. New classifications were drawn up during this time and an approach adopted – today widely accepted – that combines a range of disorders under the name pervasive development disorders (PDDs). These have the common characteristic of impairing social interaction and communication. PDDs cover autism strictly speaking, atypical autism, Asperger’s syndrome, and non-specified PDDs together with all their different degrees of severity. Children suffering from these disorders show a variety of clinical symptoms. Often unable to acquire language, or only to a very limited degree, they do not respond to stimuli, smile and look around them very little, can be aggressive towards themselves (self-mutilation) or others (with a penchant for biting), adopt repetitive behaviour (often playing in a stereotyped manner by lining up objects the one behind the other), refuse change (such as moving an item of furniture), follow rituals (by eating or dressing in the same order), display neurotic-type behaviour (such as swaying from side to side) and can have sleeping problems.
Progress in genetics in the 1980s shed light on the existence of an important genetic factor (present in between 20% and 30% of cases, depending on the researchers). The rate of recurrence within the same family is considerable and the risk of appearance within the families of autistic persons is 45 times greater than for the general population. The difficulty at present is posed by the many genes involved that vary from case to case, not all of which have been discovered. The more research progresses, the more clear it becomes that numerous genes could result in a predisposition to autism. Beginning in 1992, French and Swedish researchers working on the PARIS project studied hundreds of families with one or two handicapped children to identify the regions and the genes that could be responsible. In 2003, an article published in Nature Genetics revealed two genetic mutations, NLGN3 and NLGN4, prevent the formation of neuroligins – cell adhesion proteins located on the synapses. These genes were found on the X chromosome short arm and the mutation appears both among patients suffering from autism and from Asperger’s syndrome. The NLGN4 gene also seems to be involved in other forms of mental retardation. Since then, several other genes required for synapses structure have been identified (neurexins, connectins, SHANK3, etc.). Studies are also being carried out on related syndromes such as neurofibromatosis, tuberous sclerosis and Fragile X syndrome (the most common form of hereditary mental retardation and autism) that are associated with autism in between 10% and 50% of cases.
Snapshots of the brain
Other researchers working on brain imaging have also increased our knowledge of the mechanisms involved. PET (Positron Emission Tomography) and fMRI (Functional Magnetic Resonance Imaging) have shown – by comparing handicapped and normal subjects – an activity deficit in several zones located in the two temporal lobes. In 2000, Monica Zilbovicius, a Brazilian researcher, recorded a fall in blood pressure at rest in the temporal lobe and a decreased grey matter concentration at the same location. These functional and anatomic anomalies in regions that play a key role in processing auditory information and integrating various sensorial modalities could therefore explain certain clinical traits of autism. A number of research projects are ongoing, showing that autistic persons present an anomaly in the cortical processing of auditory information. On the other hand, these cortical regions are also involved in “social perception”, i.e. the processing of information such as a particular look or facial expression and also posture that are necessary for analysing the mood and intentions of others. These results suggest functional and anatomical anomalies located within the “social brain” in autistic subjects. Various environmental factors have also been studied, producing apparently less convincing results. The MMR vaccine (Measles--Mumps-Rubella) was called into question by the London gastroenterologist, Andrew Wakefield, who claimed to have found a viral infection introduced by the measles vaccine in the bowel of children, an infection that could have caused neuronal lesions and blocked development in young subjects (15-24 months). Further research was unable to reproduce these observations. The result was nevertheless reduced vaccine coverage in certain countries (the United Kingdom, Ireland and the Netherlands in particular), leading to a resurgence of epidemics and death in some cases. Another equally controversial hypothesis concerns mercury, or ethyl mercury to be precise, a stabiliser found in non-live vaccines. No sound correlation has been proven on this subject.
In about 75% of cases autism is associated with mental retardation (only between 5% and 15% of autistic adults become autonomous) while certain subjects possess surprising IQs and can be very gifted in certain fields. Daniel Tammet of London, for example, has been obsessed by mental arithmetic since an epileptic fit at the age of four and it was to benefit research into this illness that, at the Museum of the History of Science in Oxford, he publicly recalled pi to 22 514 decimal points. With an exceptional eidetic memory (1), which he uses in his particular way, he knows a dozen languages and learned Icelandic in just four days. But these gifted autistic subjects are very much the exception, with no more than around 50 cases recorded worldwide. Most often it is a serious handicap; painful to live with for the subjects and those close to them, and in the face of which many questions remain unanswered by medicine despite promising research. At present, the only treatment is care that is adapted to the way they experience the world.
- The eidetic memory, also known as photographic memory or absolute memory, is the ability to remember a large number of images, sounds or objects down to the smallest details. The American Kim Peek, who has Asperger’s syndrome, and who served as the model for Barry Morrow’s film Rain Man, can recall the content of 12 000 books and reads at the rate of one page every 10 seconds.