Table 2.
Studies showing normal or enhanced SAI in PD patients.
| Reference | Participants (mean age ± SD, y) | ON/OFF medication (UPDRS III) | Disease duration (years) or (months)° | L-dopa equivalent dose (mg) | Cognitive decline | SAI | Main findings | Interpretation |
|---|---|---|---|---|---|---|---|---|
| ISI | ||||||||
| Nelson et al. (2018) | 10 PD (61 ± 8) 11 HC (52.3 ± 10.4) | ON (12.2 ± 9.8) OFF (19.8 ± 7.9) | 5.9 ± 3.42 | 614.2 ± 179 | NA | N20+3 | Normal SAI in ON and OFF in both side | PD demonstrates reduced activation of S1 (fMRI) and long sensorimotor integration (LAI) |
| Dubbioso et al. (2017a) | 11 PD (62.3 ± 2.2) 8 LRRK2-PD (61.96 ± 3.9) 10 HC (59.4 ± 1.6) | PD-ON (23.4 ± 4.7) LRRK2-PD-ON (19.8 ± 7.9) | PD-ON (8.6 ± 1.2) LRRK2-PD-ON (8.4 ± 2.1) | PD-ON (838.1 ± 117.1) LRRK2-PD-ON (1015.9 ± 231.2) | NA | N20+2 to +8 ms (2 ms Δ) | Normal SAI | LRRK2-PD exhibits normal fast sensorimotor integration, but reduced motor cortex plasticity |
| Ponzo et al. (2017) | 10 PD (65.7 ± 9,8) 8 LRRK2-PD (64.2 ± 8.3) 10 HC (63.5 ± 4.0) | PD-ON (9.5 ± 2.7) PD-OFF (24.2 ± 2.9) LRRK2-PD-ON (11.5 ± 4.2) LRRK2-PD-OFF (26.0 ± 9.3) | PD (7.4 ± 4.2) LRRK2-PD (8.5 ± 5) | PD (620 ± 87.1) LRRK2-PD (557.8 ± 53.4) | NA | N20-4 to +8 ms (4 ms Δ) | Normal SAI | LRRK2-PD exhibits normal fast sensorimotor integration, but increased motor cortex plasticity and disinhibition. |
| Picillo et al. (2015) | 14 PD with FOG (63 ± 12) 10 PD without FOG (65 ± 10) 11 HC (62.4 ± 6.2) | PD-ON with FOG (17 ± 12) PD-ON without FOG (13.5 ± 8) | PD-ON with FOG (6.5 ± 4) PD-ON without FOG (5 ± 2) | PD-ON with FOG (1022.5 ± 771.2) PD-ON without FOG (560 ± 255) | MCI Level I in PD with FOG (71.4%) and without FOG (10%)* | N20+2 to +8 ms (2 ms Δ) | Normal SAI | Normal SAI in PD patients with FOG |
| Zamir et al. (2012) | 12 PD (64.7 ± 10.3) 10 HC (63.1 ± 8.8) | PD-ON (13.6 ± 5.1) PD-OFF (23.1 ± 9.1) | 7.3 ± 3.2 | 767.9 ± 484.3 | Normal | N20+3 | SAI is not modulated by iTBS | iTBS produces similar effects on cortical excitability for PD and controls |
| Degardin et al. (2012) | 11 PD ON (61.5 ± 8.5) 8 PD OFF (61.3 ± 9.6) 10 PD de novo (60.6 ± 11.8) 11 PD ON-sham (61.5 ± 9.9) | PD-ON (17.4 ± 8.1) PD-OFF (29.3 ± 8.6) PD de novo (13.6 ± 4.5) PD-ON sham (19.5 ± 11.6) | PD-ON (6.8 ± 2.7) PD-OFF (6.2 ± 2.5) PD de novo (1.8 ± 1) PD-ON sham (8.2 ± 5.2) | PD-ON (785 ± 418) PD-OFF (646 ± 282) PD de novo (0) PD-ON sham (754 ± 485) | NA | N20 | SAI is not modulated by iTBS | iTBS might improve both akinesia and sensory processing in patients with PD taking levodopa |
| Nardone et al. (2005) | 8 PSP (68.2 ± 10.5) 10 PD (66.5 ± 11.8) 15 HC (NA) | PSP-OFF (36.4 ± 24.8) PD-OFF (39.7 ± 17.2) | 8 PSP (22.4 ± 10.5)° 10 PD (19.1 ± 9.2)° 15 HC (NA) | 8 PSP (68.2 ± 10.5) 10 PD (66.5 ± 11.8) 15 HC (NA) | Dementia in 60% of PD and in 50% of PSP (DSM-III criteria) | N20+2 to +8 ms (1 ms Δ) | ↑ SAI in PD Normal SAI in PSP and HC | Different cholinergic dysfunction between PSP and PD |
| Di Lazzaro et al. (2004) | 3 PD de novo (67.3 ± 9.1) 12 HC (73.1 ± 5.4) | PD-OFF affected side (8.7 ± 4.6) | NA | NA | NA | N20+2 to +8 ms (1 ms Δ) | ↑ SAI more affected side compared to the less affected side and HC | SAI is enhanced in the more affected side in PD-OFF medication |
iTBS, intermittent theta-burst-stimulation; NA, not applicable; PD, Parkinson’s Disease; HC, healthy control; FOG, freezing of gait; PSP, progressive supranuclear palsy; MMSE, mini mental state examination; MoCA, Montreal Cognitive Assessment; MCI, mild cognitive impairment; *MCI criteria according to the Level I of the MDS (Movement Disorder Society) commissioned Task Force (Litvan et al., 2012).