Table 1.

Number and firing frequency of cells by subgroup

	Primary		Secondary static		Secondary NBIA
Participants, (n)	14		22		8
Median age in years (range)	13.4 (4.5–18.1)		10.5 (3.3–17.8)		10.1 (4.3–17.2)
	GPi cells	GPe cells	GPi cells	GPe cells	GPi cells	GPe cells
Cells, (n)	123	31	109	39	31	17
Median firing frequency (Hz)	13.5	13.5	9.6	7	25	15.9
Minimum–maximum frequency (Hz)	1–112	2–115	1–66	1–75	6–82	4–72
IQR	8.0–29.5	5.1–24.3	3.2–23.5	6.0–24.4	12.9–38.3	3.3–19.4

GPe, globus pallidus externa; GPi, globus pallidus interna; NBIA, neuronal brain iron accumulation.