P369 Oscillatory activity in the human internal globus pallidus in different pathologies

Abstract

Objectives Study the differences in the oscillatory activity of the internal globus pallidus (GPi) in Parkisnon’s disease, dystonia, chorea and Tourette’s sindrome Methods 13 patients with Deep Brain Stimulation (DBS) of the GPi were studied by means of local field potential (LFP) recordings through the stimulation electrode. Seven patients had dystonia, and two patients had Parkinson’s disease, chorea and Tourette’s syndrome, respectively. Long segments (>5 min) of GPi-LFP recordings at rest were selected from each patient (in PD patients, “on” and “off” medication). Results The two PD patients had low-beta, high-beta and HFO peaks in the “off” power spectrum. In the “on” state, the low-beta peak attenuated and the HFO peaks changed in frequency and power, as expected. The patients with dystonia showed theta and high-beta peaks. However, either no HFO peak or a much smaller one (in only two patients) was observed. The two patients with chorea had high-beta and HFO peaks only. The patients with Tourette’s sindrome had no evident beta peaks, but HFO activity was very evident. Conclusions The activity observed in PD patients in the GPi is similar to that observed in the STN, including the presence of HFOs. HFOs are also observed in patients with chorea or Tourette’s syndrome, but might be absent or smaller in patients with dystonia. Beta peaks were absent in the two patients with Tourette’s syndrome. Significance The GPi and STN show similar oscillatory activity in PD, including HFOs. Different neurologic diseases are associtated with different oscillatory activities in the GPi.