TABLE 3.

Review of studies on movement-related beta ERD and ERS in dystonia, multiple sclerosis, and cerebral palsy.

Authors	Rec.	Task	Subjects	Main Findings
A. Dystonia
Crowell et al., 2012	ECoG	Movements of 5 different body parts	10 subjects with primary cervical or cranio-cervical dystonia, disease duration: 2–33 years; 11 PD subjects; PD duration: 6–20 years; 10 essential tremor subjects; disease duration: 15–42 years	Reduced ERD amplitude compared to PD and essential tremor patients.
Toro et al., 2000	EEG	Finger abduction	16 subjects with writer’s cramp	Reduced ERD amplitude in the 20–30 Hz frequency band.
van Wijk et al., 2017	MEG	Button Press	9 subjects with dystonia; disease duration: from 3 to 23 years. No controls.	Reduced ERD amplitude in lower beta frequency range.
Hess et al., 2020	EEG	Head turning task; Ballistic arm movement task; Pinch grip task	15 subjects with cervical dystonia (mean disease duration: 7.3 years); 23 subjects with dystonic tremor (6.4 years); 17 healthy age-matched controls	Reduced ERD amplitude in both cervical dystonia and dystonic tremor groups for both dystonic and non-dystonic muscles.
B. Multiple sclerosis (MS)
Leocani et al., 2001a	EEG	Thumb extension	32 subjects with relapsing-remitting MS, no motor disturbances	Reduced ERS and ERD amplitude correlated with greater fatigue scores in MS.
Waldman et al., 2020	MEG	Button press	14 subjects with pediatric onset MS	ERS amplitude reduced in MS patients.
Arpin et al., 2017	MEG	Knee extension	15 subjects with relapsing-remitting or relapsing MS.	Reduced ERS amplitude correlated with task performance deterioration.
Barratt et al., 2017	MEG	Clicking task	18 subjects with relapsing-remitting MS and 3 with progressive MS	Increased ERS timing.
C. Cerebral palsy (CP)
Kurz et al., 2020	MEG	Self-paced on/off switch	20 subjects with spastic diplegic presentation (mean age ± SD: 15.5 ± 3 years)	Increased ERD amplitude in CP; correlation with slower walking.
Kurz et al., 2017	MEG	Target force matching isometric knee extension	13 subjects with spastic diplegic presentation (mean age ± SD: 15.5 ± 3 years)	Increased ERD amplitude in CP in primary motor cortices, premotor area, inferior parietal lobe and inferior frontal gyrus. Reduced ERD in visual areas.
Kurz et al., 2014	MEG	Target force matching isometric knee extension	13 subjects with either spastic diplegia or hemiplegia (mean age: 14.25 years)	Increased ERD amplitude in CP.

(A) ERD amplitude is reduced in patients with dystonia. (B) Most studies found reduced ERS in MS, mostly in relation to fatigue. (C) In CP studies there is consensus about increased ERD amplitude.