Online ISSN : 1687-8329


Quick Search 

April2013 Vol.50 Issue:        2        Table of Contents
Full Text

Effect of Verbal Auditory Cues on Cortical Motor Excitability in Parkinson’s disease: Evidence from Motor Evoked Potential

Noha A. Sawy1, Enas M. Shahine1, Ghada A. Achmawi 2

Departments of Physical Medicine, Rheumatology and Rehabilitation1;

Neurology and Psychiatry2; Alexandria University; Egypt


Background: Parkinson's disease (PD) patients rely on external cues to guide movements. Objective: To study the effect of verbal auditory cues on cortical motor excitability of PD patients. Methods: The study included 17 PD patients and 15 controls. Motor evoked potentials (MEP) were recorded from abductor pollicis brevis muscle at baseline, following repetitive rhythmic thumb abduction-adduction at preferred speed and with verbal cues. Number of Repetitive movement cycles (RMC), resting motor threshold (RMT), central motor conduction time (CMCT), MEP amplitude ratio and cortical silent period (CSP) duration were measured. Results: At baseline, PD patients had significantly higher MEP amplitude ratio and shorter CSP mean duration than controls. At their preferred speed, PD patients had significantly lower RMC compared to controls (p =0.005) and compared to baseline, they had significantly lower RMT, prolonged CMCT and increased CSP mean duration. With verbal cues, both PD patients and controls could increase significantly RMC (p =0.000, 0.028 respectively). Following verbal cues, none of MEP parameters has changed significantly among patients compared to controls and compared to performance without cues. Conclusion: PD patients have significant cortical hyperexcitability than normal subjects. Performing a repetitive motor task with or without verbal auditory cues may normalize cortical excitability level in PD patients. [Egypt J Neurol Psychiat Neurosurg.  2013; 50(2): 199-204]

 Key Words: Parkinson’s disease, verbal auditory cues, cortical motor excitability, motor evoked potential.

Correspondence to Ghada A. Achmawi, Department of Neurology, Faculty of Medicine, Alexandria University; Egypt.Tel.: +201005786379   e-mail:

2008 � Copyright The Egyptian Journal of Neurology,
Psychiatry and Neurosurgery. All rights reserved.

Powered By DOT IT