Long-term changes in short-interval intracortical facilitation modulate motor cortex plasticity and L-dopa-induced dyskinesia in Parkinson's disease

Autor: Andrea Guerra, Francesco Asci, Alessandro Zampogna, Valentina D'Onofrio, Antonio Suppa, Giovanni Fabbrini, Alfredo Berardelli
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Brain Stimulation, Vol 15, Iss 1, Pp 99-108 (2022)
Druh dokumentu: article
ISSN: 1935-861X
DOI: 10.1016/j.brs.2021.11.016
Popis: Background: Abnormal glutamatergic neurotransmission in the primary motor cortex (M1) contributes to Parkinson's disease (PD) pathophysiology and is related to l-dopa-induced dyskinesia (LID). We previously showed that short-term treatment with safinamide, a monoamine oxidase type-B inhibitor with anti-glutamatergic properties, improves abnormally enhanced short-interval intracortical facilitation (SICF) in PD patients. Objective: To examine whether a long-term SICF modulation has beneficial effects on clinical measures, including LID severity, and whether these changes parallel improvement in cortical plasticity mechanisms in PD. Methods: We tested SICF in patients with and without LID before (S0) and after short- (14 days - S1) and long-term (12 months - S2) treatment with safinamide 100 mg/day. Possible changes in M1 plasticity were assessed using intermittent theta-burst stimulation (iTBS). Finally, we correlated safinamide-related neurophysiological changes with modifications in clinical scores. Results: SICF was enhanced at S0, and prominently in patients with LID. Safinamide normalized SICF at S1, and this effect persisted at S2. Impaired iTBS-induced plasticity was present at S0 and safinamide restored this alteration at S2. There was a significant correlation between the degree of SICF and the amount of iTBS-induced plasticity at S0 and S2. In patients with LID, the degree of SICF at S0 and S2 correlated with long-term changes in LID severity. Conclusions: Altered SICF contributes to M1 plasticity impairment in PD. Both SICF and M1 plasticity improve after long-term treatment with safinamide. The abnormality in SICF-related glutamatergic circuits plays a role in LID pathophysiology, and its long-term modulation may prevent LID worsening over time.
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