P169. Impaired gesture performance as potential endophenotype of schizophrenia

Abstract

Introduction Disturbed social functioning including nonverbal communication is a core characteristic of schizophrenia. One crucial factor of nonverbal communication is gesturing. Gesturing is impaired in patients with schizophrenia. We aimed to test whether impairments in gesture performance would be present in unaffected first degree relatives of schizophrenia patients and could therefore be a potential marker of the disorder. Method We investigated 29 unaffected first degree relatives of schizophrenia patients and 29 control subjects matched for age, gender, education level, nonverbal intelligence and income. Participants performed a comprehensive test for gesture performance the Test of Upper Limb Apraxia (TULIA) ( Vanbellingen et al., 2010 ). In brief, the TULIA assesses the performance of gestures in two principal domains, i.e. imitation (production after demonstration) and pantomime (production following verbal instruction). For both domains three semantic subgroups were tested: meaningless, transitive (tool related) and intransitive (symbolic non-tool related) gestures. In addition motor behavior, working memory and frontal lobe function was assessed. Furthermore psychic experience was assessed in first degree relatives. Results First degree relatives of schizophrenia patients showed relatively severe difficulties during gesture performance. In fact, 24% of the relatives scored below the cut-off scores. In addition motor behavior was impaired in relatives. Relatives showed abnormal involuntary movements (AIMS), neurological soft signs (NSS) and abnormalities in movement (Modified Rogers Scale, MRS) as more prevalent. Moreover gesturing was predicted by impaired motor behavior in relatives. Conclusions Gesture performance impairment has been shown in unaffected first degree relatives of schizophrenia patients. Furthermore poor gesturing was associated with impaired motor behavior in first degree relatives. Our results indicate that deficits of gesturing could be linked to motor functioning. Moreover gesturing could present a potential maker of vulnerability for schizophrenia ( Table 1 ).