Severity of parkinsonism associated with environmental manganese exposure

Table 3 UPDRS3 motor outcomes, overall and by community, Gauteng province, South Africa, 2016–2020

	All participants N = 716	Mn smelter community (Meyerton) N = 621	Reference community (Ethembalethu) N = 95
	n (%)	n (%)	n (%)
Total UPDRS3 score ≥ 15^a	123 (17.2 %)	120 (19.3 %)	3 (3.2 %)
	Mean (SD)	Mean (SD)	Mean (SD)
UPDRS3^a
Total score	8.5 (7.1)	9.3 (7.2)	3.7 (4.1)
Minimum	0	0	0
Median	7	8	2
Maximum	52	52	20
Upper limb bradykinesia^b	3.7 (3.2)	4.0 (3.2)	1.5 (2.1)
Minimum	0	0	0
Median	3.5	4	1
Maximum	17	17	8
Upper limb rigidity^c	1.0 (1.3)	1.1 (1.3)	0.4 (0.7)
Minimum	0	0	0
Median	0	0	0
Maximum	5	5	3
Lower limb bradykinesia^c	0.7 (1.1)	0.8 (1.2)	0.3 (0.6)
Minimum	0	0	0
Median	0	0	0
Maximum	6	6	2
Lower limb rigidity^c	1.0 (1.4)	1.1 (1.4)	0.3 (0.7)
Minimum	0	0	0
Median	0	0	0
Maximum	6	6.0	2.5
Rest tremor^d	0.04 (0.3)	0.1 (0.3)	0.0 (0.0)
Minimum	0	0	0
Median	0	0	0
Maximum	3	3	0
Action tremor^c	0.1 (0.5)	0.2 (0.5)	0.04 (0.2)
Minimum	0	0	0
Median	0	0	0
Maximum	4	4	2
Axial signs^e	1.9 (2.4)	2.0 (2.4)	1.2 (1.9)
Minimum	0	0	0
Median	1	2	1
Maximum	24	24	13

Abbreviations: Mn manganese; UPDRS3 Unified Parkinson Disease Rating Scale motor subsection part 3
^a Poorer motor performance is indicated by greater UPDRS3 scores.
^b Sum of six UPDRS3 subscores: Finger-tapping, hand rotations, and rapid arm movements for each limb.
^c Sum of the two UPDRS3 subscores (one for each limb).
^d Sum of five UPDDRS3 subscores: Upper limbs, lower limbs, and face.
^e Sum of eight UPDRS3 subscores: Speech, facial expression, neck rigidity, difficulty arising from a chair, posture, gait, postural instability, and global bradykinesia.

ISSN: 1476-069X