7. Cortical plasticity in patients with l-dopa induced dyskinesias

Abstract

Objective: Effects of PAS 25 protocol in PD patients with l -dopa induced dyskinesias (LID). Subjects and methods: We analyzed 10 patients with PD who had dyskinesias as a side effect of l -dopa therapy and 10 healthy subjects in control group (CG). Plasticity and excitability of the hand primary motor cortex of the more affected side were evaluated using transcranial magnetic stimulation (TMS) techniques. Recording was done before (Tb), immediately (T0) and 30 min after procedure (T30). Patients were tested in “off” and “on” states. Results: There was no difference for MEP between groups. Patients with l -dopa induced dyskinesias with medication immediately after PAS, showed decrease of slope at higher levels of stimulation (150% rMT, p = 0.058) compared with CG. All subjects show a decrease of SP ( p p = 0.034) compared with CG, without significance for ICF ( p = 0.578), regardless of the applied procedures. Conclusion: Patients with LID have a higher inhibition, probably due to involuntary movements. It is possible that their brain is “working” at smaller scale. PAS 25 protocols had no significant effect on cortical plasticity in patients with PD who have LID.