TABLE 2.
Review of studies on movement-related beta ERD and ERS over cortical and subcortical structures in Parkinson’s disease with EEG, MEG, cortical (ECoG) and subcortical (STN DBS) recordings.
| Authors | Rec. | Task | Subjects | Main Findings |
| Pfurtscheller et al., 1998 | EEG | Self-paced movements | 17 subjects with PD tested on-drug; mean age ± SD: 61.6 ± 6.1 years; PD duration: 3.8 ± 3.0 | Reduced ERS in PD compared to controls. |
| Magnani et al., 1998 | EEG | Self-paced movements | 10 subjects with PD tested off-drug; PD duration: 2–9.2 years; age range: 44–77 | Delayed ERD peak latency in PD compared to controls. |
| Brown and Marsden, 1999 | EEG | Wrist movements | 12 subjects with PD tested on- and off-drug; age range: 45–70 | Drug treatment restores ERD to normal control group level; ERD improvement correlates with motor performance improvement. |
| Heinrichs-Graham et al., 2014b | MEG | Right index tapping | 19 subjects with PD tested off-drug; disease duration: 1–9 years; age range: 52–77 | Significantly diminished ERD in PD compared to controls. |
| Stegemöller et al., 2016 | EEG | Index movements paced by 1–3 Hz tones | 9 subjects with PD tested on- and off-drug; age range: from 53–77 years | Lower amplitude of ERD-ERS peak to peak amplitude in PD both off/on medications compared to controls. |
| Moisello et al., 2015 | EEG | Arm reaching task | 15 subjects with PD tested on-drug; mean PD duration ± SD: 6.7 ± 4.1 years; age: 60.7 ± 6.7 | ERD-ERS peak to peak amplitude (beta modulation) reduced in PD. Attenuated ERS in PD. Lower practice-related beta modulation increase in PD compared to controls. |
| Nelson et al., 2017 | EEG | Arm reaching task | 11 subjects with PD tested on-drug; mean PD duration ± SD: 5.0 ± 2.1 years; age 59.1 ± 5.8 | Decreased retention of motor skills and lower practice-related beta modulation increase in PD compared to controls; 24-h retention correlates with beta modulation increase. |
| Wu et al., 2019 | MEG | Go/No Go task | 12 subjects with PD tested off-drug; PD duration: 1–20 years; age range: 53–77 | Reduced ERD in NoGo; reduced ERS during both Go and NoGo in PD. Delayed ERD and ERS during Go in PD compared to controls. |
| Vinding et al., 2019 | MEG | Proprioceptive stimulation passive index movements | 12 subjects with PD tested on- and off-drug; PD duration: 1–11 years; age range: 45–75 | Reduced ERS in PD compared to controls. No change with medication |
| Labyt et al., 2005 | EEG | Relaxation and contraction | 16 subjects with PD; PD duration: 0.5–3 years; age range: 40–77 | Delayed ERD peak and ERS disappearance during voluntary relaxation with the more affected limb. |
| Magnani et al., 2002 | EEG | self-paced finger movement | 14 subjects with PD tested on- and off-drug; PD duration: 2–6 years; age range: 54–78 | Delayed ERD in akinetic PD patients compared to controls and improves after chronic drug treatment. |
| Praamstra and Pope, 2007 | EEG | Choice response task | 10 subjects with PD tested off-drug; PD duration: 6–9 years; age range: 56–68 | Reduced ERD and ERS in PD compared to controls |
| Weersink et al., 2020 | EEG | Instructed arm swing | 17 subjects with PD | Reduced ERD during gait preparation and movement onset compared to controls. |
| McLinden et al., 2021 | EEG | Self-paced finger tapping | 8 subjects with PD tested on-drug; PD duration: 1–15 years; age range: 56–80 | Reduced ERD in PD compared to controls. |
| Tamás et al., 2006 | EEG | Self-paced on/off switch | 10 subjects with PD on-drug, PD duration: 0.5–11 years, age: 41–80; 10 subjects with essential tremor, 0.5–20 years, 48–81; 10 normal subjects | No group differences. In PD, reduced ERS amplitude for the tremulus hand compared to the other hand. In essential tremor, delayed ERS for the most affect hand compared to the other one. |
| Johari and Behroozmand, 2021 | EEG | Button press and speech tasks, predictable and unpredictable time | 15 subjects with PD on-drug; Hoehn and Yahr: 1–3, median 1.5; age range: 60–75 years | PD were always slower than controls. Pre-movement beta ERD had similar time courses, but with between-task differences |
| Smith et al., 2012 | EEG | Postural responses to backward surface translations | 12 subjects with PD on-drug; mean PD duration: 77 years; mean age: 67.5 | Greater ERD in PD compared to controls. Increased beta ERD in PD was associated with decreased adaptability of postural responses. |
| Labyt et al., 2003 | EEG | Index extension and targeting motor task | 12 subjects with PD tested off-drug; PD duration: 0.2–3 years; age range: 44–80 | Reduced ERS in the more akinetic limb. |
| Devos et al., 2003a | EEG | Self-paced wrist flexions | 10 subjects with PD tested on- and off-drug; median PD duration: 15 years; median age: 60 | ERS amplitude decreases in advanced PD, but increases with Levodopa. |
| Devos et al., 2003b | EEG | Self-paced wrist flexions | 10 subjects with PD tested on- off-drug and on- off-STN; PD duration: 7–23 years; age: 44–73 | Both STN stimulation and medication increase ERD amplitude. |
| Rowland et al., 2015 | ECog, STN-DBS | Reaching task | 10 subjects with PD tested off-drug, PD duration: 4–15 years, age: 47–72; 8 subjects with essential tremor; disease duration: 6–50 years; age: 59–78. | Stronger ERD in PD compared to essential tremor in cortex. |
| Kondylis et al., 2016 | EcoG | Visually cued hand grip task | 11 subjects with PD off-drug, age range: 47–71 years; 6 subjects with epilepsy, 19–50 years; 9 subjects with essential tremor, 55–78 years | Greater ERD in PD compared to both control groups. |
| Canessa et al., 2016 | EEG, STN-DBS | Arm reaching movements | 7 subjects with PD tested off-drug; disease duration: 10–19 years; age range: 51–67 | Stronger beta ERD and ERS in STN of the hemisphere with less striatal dopaminergic innervation during reaching. |
| Kühn et al., 2004 | STN-DBS | Go/No Go task | 8 subjects with PD tested on- and off-drug; PD duration: 10–22 years; age range: 50–71 | ERD and ERS in the STN had pattern similar to that of cortical activity. |
| Kühn et al., 2006 | STN-DBS | Wrist extension (ME), motor imagery and non-motor visual imagery tasks | 8 subjects with PD tested off-drug; PD duration: 5–17 years; age range: 43–67 | Movement and motor imagery produce in the STN similar ERDs that are larger than ERD elicited by visual imagery. ERS is larger during movement than during either motor or visual imagery. |
| Oswal et al., 2013 | STN-DBS | Reward-complexity task: limb movements | 9 subjects with PD tested on- and off-drug; PD duration: 8–19 years; age range: 26–62 | Drug treatment increases ERD in the STN. |
| Doyle et al., 2005 | STN-DBS | Joystick movements | 14 subjects with PD tested on- and off-drug; PD duration: 8–18 years; age range: 43–73 | Drug treatment increases ERD duration and magnitude. ERD latency and magnitude inversely correlate with degree of motor impairment. |
| Joundi et al., 2013 | STN-DBS | Synchronized finger tapping | 11 subjects with PD tested on-drug; PD duration: 2–17 years; age range: 42–70 | ERD and ERS changes with the rate of finger tapping in the STN. |
Most studies found reduced ERD and ERS amplitude compared to healthy controls. Studies with ECog and STN-DBS either had no control groups or comparison was made with patients with a different disease state.