Table 2.
Selected motor task-based and resting-state encephalographic studies in ALS.
| Authors | Year | n | EEG/MEG (channels) | Protocol | Main measure | Phenotype correlations |
|---|---|---|---|---|---|---|
| Westphal et al. (104) | 1998 | 16 ALS 16 HC |
EEG (11c) |
Self-paced R fist closure | Reduced BP | Spasticity correlation |
| Thorns et al. (105) | 2010 | 13 ALS 13 HC |
EEG (19c) |
Cued R or L index finger button press | Reduced BP | N/A |
| Inuggi et al. (107) | 2011 | 32 ALS 12 HC |
EEG (29c) |
Self-paced R thumb extension | Reduced MRCPs (only in UMN+ ALS) | Ipsilateral MRCP correlation with movement speed |
| Riva et al. (119) | 2012 | 16 ALS 15 HC |
EEG (29c) |
Self-paced R thumb extension | Reduced beta ERS; Unaltered beta ERD |
ERS correlation with CST damage via MRI and TMS |
| Gu et al. (108) | 2013 | 4 ALS 7 HC |
EEG (15c) |
Imaginary R wrist extension | Slower MRCP rebound | N/A |
| Bizovičar et al. (120) | 2014 | 21 ALS 19 HC |
EEG (30c) |
Self-paced R index finger flexion | Reduced beta ERD; Lateralised ERS |
None |
| Proudfoot et al. (122) | 2017 | 11 ALS 9 PLS 12 Presymp 10 HC |
MEG (306c) | Cued R or L index finger extension | Excess beta ERD; Delayed ERS |
Altered ERS lateralisation in PLS |
| Proudfoot et al. (126) | 2018 | 17 ALS 11 HC 5 Presymp |
MEG (306c) | Cued R and L hand grips | Reduced beta CMC; Reduced inter-hemispheric beta FC |
CMC unaltered in Presymp |
| Mai et al. (143) | 1998 | 18 ALS 14 HC |
EEG (18c) |
Resting | Reduced central alpha power | Alpha correlation with MRC and Norris scales |
| Santhosh et al. (144) | 2005 | 12 ALS 12 ALS |
EEG (8c) |
Resting | Reduced alpha power | N/A |
| Jayaram et al. (145) | 2015 | 6 ALS 32 HC |
EEG (124c) | Resting | Reduced central theta power; Widespread increased high gamma power | Gamma reduced only in patient with ALSFRS = 0 |
| Iyer et al. (147) | 2015 | 18 ALS 17 HC |
EEG (128c) | Resting | Increased FC especially within salience and default-mode networks | N/A |
| Nasseroleslami et al. (148) | 2017 | 100 ALS 34 HC |
EEG (128c) | Resting | Increased FC especially interhemispheric theta and fronto-parietal gamma | FC correlation with structural MRI degeneration |
| Fraschini et al. (150) | 2018 | 21 ALS 16 HC |
EEG (61c) |
Resting | Widespread reduced alpha FC | N/A |
| Proudfoot et al. (151) | 2018 | 24 ALS 24 HC 15 Presymp 9 PLS |
MEG (306c) | Resting | Widespread increased broadband FC | Similar changes in PLS. More subtle changes in Presymp. |
| Sorrentino et al. (154) | 2018 | 50 ALS 25 HC |
MEG (163c) | Resting | Broadband increased FC with disorganized topology | Advanced ALS associated with a more centralized, “vulnerable” network |
HC healthy control, FC functional connectivity, Presymp asymptomatic ALS-causing gene carriers, BP Bereitschaftspotential, MRCP movement related cortical potential, ERD event related desynchronization, ERS event related synchronization PLS primary lateral sclerosis, CMC cortico-muscular coherence UMN+ above average quantity of upper motor neuron signs, CST cortico-spinal tract, ALSFRS ALS functional rating scale (disability metric).