[Inconsistent motor dominance in schizophrenic patients. Evidence in favor of neurodevelopmental changes].

INTRODUCTION

Motor left lateralization preference and lateralization inconsistencies have often been reported in schizophrenia and interpreted as an expression of a neurodevelopmental deficit in this disorder. However, the reported findings are contradictory and plagued by methodological errors.

METHOD

The aim of this work is to examine functional motor lateralization preferences and lateralization inconsistencies in a sample on 78 schizophrenic patients by using a reliable method and comparing them with a nonclinical sample as a control group. We also study the potential associations between lateralization and several clinical, neuropsychological and neuroimage variables.

RESULTS

No significant differences are found between schizophrenics and the control group in functional motor preferences. Other relevant finding are: absence of correlation between crural, ocular and hand preference; an association between the severity of negative symptoms and lateralization inconsistency; and an earlier clinical onset and a smaller brain volume in right-handed schizophrenics with ocular crossed lateralization as compared with right-handed schizophrenics with consistent ocular lateralization.

CONCLUSION

These findings back up the hypothesis of a neurodevelopmental deficit in schizophrenia.