Apport des approches inspirées de la neuropsychologie au diagnostic d’autisme chez l’adulte : une étude de cas

Abstract

Given that autism spectrum disorders are highly heterogeneous in their clinical presentation, diagnostic assessment in adults, whose symptoms may be complicated by the presence of various comorbidities and developmental trajectories, is not easily practiced in a clinical psychiatric setting. The present study aims at describing diagnostic assessments inspired by current research on cognition in autism. Core cognitive traits, such as theory of mind, executive function and weak central coherence, thought to be endophenotypic traits, are analyzed. Moreover, the utility of screening scales, constructed on the basis of these cognitive traits, is discussed. We describe the case of a 29-year-old French man, referred by his occupational physician, due to the onset of anxiety attacks in his workplace. During the first outpatient psychiatric assessment, he seemed inhibited, and revealed that social situations fueled his anxiety attacks. He was therefore diagnosed with personality avoidance disorder, depression and social anxiety. Although depression and anxiety decreased after Buspirone and Milnacipran were prescribed, some clinical symptoms, such as lack of interest in social situations, ritualized behavior, narrow specific interests (i.e., astronomy, history), and a very good memory for factual information, remained. According to the patient, these symptoms appeared during his infancy. These symptoms, consistent with Asperger Syndrome diagnosis, led to the administration of two screening scales: the Autism Quotient (AQ) and the Empathy Quotient (EQ). The results obtained in these scales were consistent with Asperger Syndrome diagnosis. They indicated the presence of qualitative difficulties in social interactions, a lack of spontaneous empathy and attention switching, among other behaviors. À comprehensive diagnostic assessment was then proposed. The Diagnostic Interview for Social and Communication disorders (DISCO), a semi-structured interview with parents, was used in order to gather developmental and behavioral information. A neuropsychological assessment was conducted with the patient. Both assessments revealed developmental and neurocognitive particularities consistent with Asperger Syndrome diagnosis. Among these cognitive traits, (i) episodic memory peculiarities, such as idiosyncratic encoding and retrieval strategies and impaired encoding of complex visual stimuli (ii) absence of significant difference between the verbal and the performance scales of the WAIS III, but significant differences among subtests, (iii) executive dysfunction found in flexibility and generativity tasks, (iv) perceptive focalization on details, and most importantly (v) significant impairment on theory of mind tasks are worth noting In conclusion, numerous adults with Asperger Syndrome were not diagnosed during childhood. This is probably due to the relatively recent changes in nosography, and their cognitive development, which is not characterized by language delay, in opposition to high functioning autism. Therefore, screening for autism spectrum disorders in a clinical psychiatric setting is important. Screening can lead to a more comprehensive assessment pinpointing developmental history, cognitive profile, and comorbidities, given that these three factors are indispensable for an effective therapeutic follow-up.