Autism in tuberous sclerosis: evoked potential evidence for a deficit in auditory sensory processing.
OBJECTIVE
Autism is a frequent manifestation of tuberous sclerosis complex (TSC) being reported in up to 60% of the patients. Its presence is in association with cortical and subcortical lesions involving the temporal lobes. This study was designed to shed light on the functional mechanisms linking anatomical lesions of TSC and behavioural phenotype by investigating scalp recorded event related potentials to auditory stimuli.


METHODS
Fourteen children with TSC, seven of which fulfilled the DSM IV criteria for autistic disorder were selected for this study. All of the subjects underwent high resolution MRI, EEG, brainstem auditory evoked potentials, cognitive and behavioural evaluation. Electrical evoked responses to two different pitches, presented with different probability (80% 1000 Hz, 20% 1500 Hz) were recorded from 21 scalp electrodes in the autistic and non-autistic subgroups, to assess central auditory processing and automatic memory.


RESULTS
The first component of the long latency auditory response (N1) had a significantly prolonged latency with lower amplitude in all of the patients with autistic behaviour who, contrary to non-autistics had MRI lesions involving one or both temporal lobes. A mismatch negativity was detected in all subjects and had a longer latency in subjects with autistic behaviour.


CONCLUSIONS
To our knowledge this is the first electrophysiological evidence of a deficit in auditory information processing and automatic memory in TSC patients with autistic behaviour.
Seri
S
S
Department of Clinical Neurophysiology, The Birmingham Children's Hospital NHS Trust, and The University of Birmingham, UK. stefano.seri@bhamchildrens.wmids.nhs.uk
Cerquiglini
A
A
Pisani
F
F
Curatolo
P
P
D001307:Auditory Perception / Q000502:physiology*; D001321:Autistic Disorder / Q000209:etiology / Q000503:physiopathology*; D002648:Child; D005072:Evoked Potentials, Auditory; D006801:Humans; D011446:Prospective Studies; D011930:Reaction Time / Q000502:physiology; D013702:Temporal Lobe / Q000503:physiopathology; D014402:Tuberous Sclerosis / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*