Objective: In order to assess the functional integrity of motor pathways th
rough the corpus callosum (CC) in patients with schizophrenia transcallosal
ly mediated inhibition (TI) of voluntary tonic EMG activity, of first dorsa
l interosseus muscle following ipsilateral focal transcranial magnetic stim
ulation (fTMS) was investigated. In addition thickness and length of CC wer
Method: Twelve patients suffering from schizophrenia and 12 healthy control
s were investigated. CC morphology was measured in midsagittal MRI-slices.
Latency and duration of TI were calculated.
Results: In schizophrenics the duration of TI was significantly prolonged,
whereas latencies were not. In addition, a lack of TI was found unilaterall
y in three patients. Measurements of CC revealed a significantly reduction
of the length and thickness in the anterior part of CC in patients.
Conclusion: These findings indicate that measurement of TI could be used to
detect clinical silent affection of transcallosal motor pathways in schizo
phrenics. The effect of neuroleptic drugs has to be explored.