BACKGROUND AND PURPOSE: This study aimed to assess the indices of corticomotor excitability (CE) in drug-naive Parkinson disease (PD) patients and to investigate its relationship with asymmetry and severity of clinical symptoms. MATERIAL AND METHODS: Eleven (4 men) drug-naive PD patients (mean age: 53.1 ± 9.8 years) and 13 (7 men) healthy controls (mean age: 51.7 ± 4.2 years) were included. All PD patients were rated on the motor section of the Unified Parkinson's Disease Rating Scale (UPDRS) with measurement of the side-specific score separately for arms and legs. Resting motor threshold (RMT), central silent period (CSP), amplitude of motor evoked potential (MEP) and central motor conduction time (CMCT) evoked by a single pulse of the transcranial magnetic stimulation were recorded in all subjects from the left and right abductor digiti minimi (ADM) and extensor digitorum brevis (EDB). RESULTS: Parkinson disease patients showed higher MEP (1.8 ± 0.9 vs. 1.1 ± 0.8 mV, p < 0.05) and shorter CMCT (6.1 ± 0.9 vs. 7.4 ± 1.0 ms, p < 0.05) recorded from the ADM on the more affected side. CSP recorded from the more affected ADM was under the normal range in five and from the less affected ADM in four PD patients. For CSP recorded from the EDB, respective values are four for the more affected side and three for the less affected side. The rigidity from the more affected arm and leg correlated negatively with the respective CSP recorded from the ADM (r = -0.74, p < 0.01) and EDB (r = -0.68, p < 0.04). CONCLUSIONS: In the early stage of untreated PD the CE parameters are altered only on the more affected side. The shortening of CSP reflects the severity of rigidity on the more affected side.
BACKGROUND AND PURPOSE: This study aimed to assess the indices of corticomotor excitability (CE) in drug-naive Parkinson disease (PD) patients and to investigate its relationship with asymmetry and severity of clinical symptoms. MATERIAL AND METHODS: Eleven (4 men) drug-naive PDpatients (mean age: 53.1 ± 9.8 years) and 13 (7 men) healthy controls (mean age: 51.7 ± 4.2 years) were included. All PDpatients were rated on the motor section of the Unified Parkinson's Disease Rating Scale (UPDRS) with measurement of the side-specific score separately for arms and legs. Resting motor threshold (RMT), central silent period (CSP), amplitude of motor evoked potential (MEP) and central motor conduction time (CMCT) evoked by a single pulse of the transcranial magnetic stimulation were recorded in all subjects from the left and right abductor digiti minimi (ADM) and extensor digitorum brevis (EDB). RESULTS:Parkinson diseasepatients showed higher MEP (1.8 ± 0.9 vs. 1.1 ± 0.8 mV, p < 0.05) and shorter CMCT (6.1 ± 0.9 vs. 7.4 ± 1.0 ms, p < 0.05) recorded from the ADM on the more affected side. CSP recorded from the more affected ADM was under the normal range in five and from the less affected ADM in four PDpatients. For CSP recorded from the EDB, respective values are four for the more affected side and three for the less affected side. The rigidity from the more affected arm and leg correlated negatively with the respective CSP recorded from the ADM (r = -0.74, p < 0.01) and EDB (r = -0.68, p < 0.04). CONCLUSIONS: In the early stage of untreated PD the CE parameters are altered only on the more affected side. The shortening of CSP reflects the severity of rigidity on the more affected side.
Authors: Robert Chen; Alfredo Berardelli; Amitabh Bhattacharya; Matteo Bologna; Kai-Hsiang Stanley Chen; Alfonso Fasano; Rick C Helmich; William D Hutchison; Nitish Kamble; Andrea A Kühn; Antonella Macerollo; Wolf-Julian Neumann; Pramod Kumar Pal; Giulia Paparella; Antonio Suppa; Kaviraja Udupa Journal: Clin Neurophysiol Pract Date: 2022-06-30