Table 1.

Demographic and clinical information of the study participants

	PML group, n = 43 Median (range)	Control group, n = 25 Median (range)
Gender (female/male), n (%)	30 (68.2)/14 (31.8)	18 (72)/7 (28)
Age (years)	43.5 (32–71)	44.6 (21–52)
Natalizumab treatment duration (doses)	35.0 (13–86)	35.9 (12.1–88.4)
Asymptomatic at diagnosis, n (%)	8 (18.2)	n/a
Symptomatic at diagnosis, n (%)	36 (81.8)	n/a
Solely supratentorial PML lesions	35 (79.5)	n/a
Both supra- and infratentorial PML lesions	8 (18.2)	n/a
Solely infratentorial PML lesions	1 (2.3)	n/a

PML progressive multifocal leukoencephalopathy, n/a not applicable