Table 4.

Numbers of neurons with grouped discharge and low firing rates in GPi and STN in patients with LID and without LID.

Type of cell	PD with LID (GPi: n = 6)	PD without LID (GPi: n = 6)	PD with LID (STN: n = 15)	PD without LID (STN: n = 15)
Grouped discharge	7 (16.3%)	0** (0%)	17 (16.0%)	2** (1.8%)
Low frequency firing	10 (23.3%)	2** (5.4%)	16 (15.1%)	2** (1.8%)
Total	43	37	106	109

**Indicates significance, (chi-square test P < 0.05) compared with patients without LID. GPi, globus pallidus internus; STN, subthalamic nucleus; ISI, interspike interval; CV, coefficient of variation; PD, Parkinson’s disease; LID, levodopa-induced dyskinesia.