Abstract
INTRODUCTION:
Patients with Scans-Without-Evidence-of-Dopaminergic-Deficit (SWEDD) often present asymmetric rest tremor not responsive to levodopa. Although a dystonic origin of this tremor has been proposed, the underlying pathophysiology of such condition is still unclear. An abnormal activity in the Cerebello-Thalamo-Cortical circuit is involved in the pathogenesis of tremor and other movement disorders. Here we used different paradigms of cerebellar transcranial magnetic stimulation to evaluate the Cerebello-Thalamo-Cortical functioning in patients with normal scans.
METHODS:
Cerebello-Thalamo-Cortical circuit was investigated in 12 patients with normal scans, 8 patients with Parkinson's Disease (PD), 8 patients with adult-onset isolated dystonia and 9 healthy controls. We studied the effects of a single cerebellar magnetic pulse over the excitability of the contralateral primary motor cortex tested with Motor-Evoked-Potentials (Cerebellar-Inhibition) both at rest and during arm extension. Furthermore, we also tested the effects of cerebellar continuous-Theta-Burst-Stimulation on Motor-Evoked-Potentials amplitude.
RESULTS:patients with normal scans compared to controls show a deficient Cerebellar-Inhibition at rest but not in arm extension; in both conditions they differ from PD but not from dystonic patients. Cerebellar Continuous-Theta-Burst-Stimulation induced the expected long-lasting cortical inhibition of Motor-Evoked-Potentials amplitude in patients with normal scans differently from PD and dystonic patients.
CONCLUSIONS:
patients with normal scans show a mild impairment in Cerebello-Thalamo-Cortical circuit that emerges only at rest. Such neurophysiological phenotype differs from the one observed in PD and dystonic patients, suggesting a distinct involvement of this pathway in the pathophysiology of these disorders.
Lingua originale | English |
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pagine (da-a) | 23-28 |
Numero di pagine | 6 |
Rivista | PARKINSONISM & RELATED DISORDERS |
Volume | 28 |
DOI | |
Stato di pubblicazione | Pubblicato - 2016 |
Keywords
- Cerebello thalamo cortical
- Dystonia
- Parkinson's disease
- SWEDD
- Tremor