Cortico-Cortical Inhibition in Patients with a Focal Lesion in the Basal Ganglia
Kujirai et al.(1993) proposed a new technique to investigate ipsilateral cortico-cortical inhibitory connections within the human motor cortex using paired magnetic stimulation. In normal subjects, a subthreshold conditioning stimulus suppressed responses to the suprathreshold test stimulus when it preceded the test stimulus by 1–5 ms. This effect was thought to reflect the function of inhibitory interneurons in the motor cortex. Many inputs to the motor cortex from various areas should influence excitability of such interneurons or output cells of the motor cortex. One of those major inputs is that from basal ganglia through thalamocortical pathways. Such influences must be distorted in basal ganglia disorders. In the present communication, we studied the ipsilateral cortico-cortical inhibition in 3 patients with a focal lesion in the basal ganglia in order to investigate whether changes occur in the above cortico-cortical inhibition (Kujirai et al., 1993) when inputs from the basal ganglia to the motor cortex are damaged.
KeywordsBasal Ganglion Conditioning Stimulus Motor Cortex Test Stimulus Involuntary Movement
Unable to display preview. Download preview PDF.
- Ugawa Y., Genba-Shimizu K and Kanazawa I, Somatosensory potential recovery (SEP-R) in various neurological disorders. Electroenceph. clin. Neurophysiol.(in press).Google Scholar