Neuropediatrics 2010; 41 - P1325
DOI: 10.1055/s-0030-1265571

Impaired long term potentiation (LTP)-like plasticity in patients with high functiong autism and Asperger syndrome (HFA/AS)

N Jung 1, M Biscaldi-Schäfer 2, A Münchau 3, F Mainberger 1, T Bäumer 3, R Rauh 2, V Mall 1
  • 1Department of Paediatrics and Adolescent Medicine, University Medical Center Freiburg, Germany
  • 2Department of Child and Adolescent Psychiatry, University Medical Center Freiburg, Germany
  • 3Clinic and polyclinic of Neurology, University Medical Center Hamburg-Eppendorf

Introduction: Autism Spektrum Disorders are severe neurodevelopmental disorders accompanied by motor impairment. An impaired induction of LTP has been demonstrated in an animal model of autism. The aim of the present study was to investigate the induction of LTP-like plasticity by Paired Associative Stimulation (PAS) in patients with high-functioning autism and Asperger syndrome (HFA/AS).

Methods: PAS25 was performed in patients with HFA/AS (n=9; n=1 female; mean age: 18±4.3 years) and healthy probands (n=9; n=4 female; age: 22±5.2 years). The motor evoked potential (MEP amplitude) was measured before (Pre) PAS25, directly after (Post1), after 30 minutes (Post2) and after 60 minutes (Post3). Short intracortical inhibition was measured via paired pulse stimulation (inter-stimulus interval 2 and 3ms) in patients with HFA/AS.

Results: Patients with HFA/AS did not show a significant increase in MEPs (MEP Pre: 0.94±0.03; MEP Post1: 1.07±0.08; MEP Post2: 0.99±0.14; MEP Post3: 0.97±0.11) after PAS25 in opposite to healthy controls (MEP Pre: 1.00±0.04; MEP Post1: 1.26±0.14; MEP Post2: 1.64±0.29; MEP Post3: 1.71±0.19; post hoc t-Test Pre-Post3: p=0.01). Paired pulse stimulation did not show a significant dysinhibition in both inter-stimulus intervals.

Conclusion: Our results show – for the first time – a significant impairment in the induction of LTP-like plasticity in patients with HFA/AS. Genetic causes and a reduced excitatory synaptic connectivity as it has been demonstrated in animal models and deficits in sensory-motor integration have to be discussed as possible reasons.