Table of Contents
ISRN Psychiatry
Volume 2013, Article ID 876171, 9 pages
Clinical Study

Disrupted Central Inhibition after Transcranial Magnetic Stimulation of Motor Cortex in Schizophrenia with Long-Term Antipsychotic Treatment

1National Institute for Health and Welfare, Forensic Psychiatry, P.O. Box 30, 00271 Helsinki, Finland
2Psychiatric Hospital for Prisoners, P.O. Box 49, 20251 Turku, Finland
3BioMag Laboratory, Helsinki University Hospital HUCH, P.O. Box 340, 00029 Helsinki, Finland
4Department of Clinical Neurophysiology, Helsinki University Hospital, P.O. Box 1020, 10601 Ekenäs, Finland
5Institute of Biomedical Engineering, Tampere University of Technology, P.O. Box 553, 33101 Tampere, Finland

Received 9 January 2013; Accepted 4 February 2013

Academic Editors: C. M. Beasley and P. Gourzis

Copyright © 2013 Aulikki Ahlgrén-Rimpiläinen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Aims. Schizophrenia is a neuropsychiatric disorder associated with mental and motor disturbances. We aimed to investigate motor control, especially central silent period (CSP) in subjects with schizophrenia ( ) on long-term antipsychotic treatment compared to healthy controls ( ). Methods. Latency and duration of motor evoked potentials (MEPs) and CSPs were measured with the help of single pulse transcranial magnetic stimulation (TMS) and intramuscular electrodes. After stimulation of the dominant and nondominant motor cortex of abductor digiti minimi (ADM) and tibialis anterior (TA) muscle areas, respective responses were measured on the contralateral side. Results. MEPs did not differ significantly between the groups. Multiple CSPs were found predominantly in subjects with schizophrenia, which showed a higher number of CSPs in the dominant ADM and the longest summarized duration of CSPs in the nondominant ADM ( ) compared to controls. Conclusions. There were multiple CSPs predominantly in the upper extremities and in the dominant body side in subjects with schizophrenia. Behind multiple CSPs may lie an impaired regulation of excitatory or inhibitory neurotransmitter systems in central motor pathways. Further research is needed to clarify the role of the intramuscular recording methods and the effect of antipsychotics on the results.