| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2004: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2003: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2002: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Research Abstract |
We studied the effects of stereotactic pallidal and thalamic surgeries on chorea and dystonia and abnormality of the neuronal firing pattern of the internal globus pallidus (GPi). The surgery was performed using microelectrode and CT guiding in 11 parkinsonian patients (6 females and 5 males, 49-74 years old), a patient with dentate-pallidoluysian atrophy showing chorea (Case 1, female, 29 years old, bilateral pallidotomy), a patient with off-dystonia (Case 2, male, 54 years old, unilateral pallidotomy), a patient with primary generalized dystonia (Case 3, female, 55 years old, unilateral pallidal DBS), and a patient with generalized dystonia and intracranial calcification (Case 4, female, 27 years old, bilateral thalamic DBS). Patients were evaluated according to the UPDRS or AIMS. Elgiloy, glass-coated microelectrodes with an impedance of 0.4 MΩ at 1000Hz were used for single-cell recording. No sedation was used in surgery, and all medication was withheld overnight and during surgery. Ten-to 30-second samples of spontaneous single-cell activity from GPi were recorded during mapping and stored on DAT tape. Neuronal signals were digitized at 50kHz, action potentials were discriminated according to the peak amplitude and window aperture onscreen, and the firing rates, oscillation indexes and burst ratios of single-cell action potentials were calculated. Chorea in Case 1 and dystonia in Case 2 were disappeared after surgery. Dystonia in Case 3 and Case 4 was improved by 30-50%. Neuronal recording from GPi during dystonia in Case 2 and Case 3 revealed that the mean firing rates were low, highly bursty and less oscillatory, as compared with firing patterns in off-state parkinsonian patients without dystonia. These results suggest that chorea and dystonia results from the decreased activities of the basal ganglia output, but the altered firing pattern is a significant factor underlying pathophysiology of these movement disorders.
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