No effect of a levodopa single dose on motor performance and motor
excitability in chronic stroke. A double-blind placebo-controlled cross-over
pilot study
Affiliations: Department of Neurology, University Medical Center
Eppendorf, Hamburg, Germany | Department of Neurology, University Hospital, Freiburg, Germany | Kliniken Schmieder, Allensbach, Germany
Note: [] Corresponding author: Dr. C. Restemeyer, Department of
Neurology, University Medical Center Eppendorf, Martinistr. 52 D-20246
Hamburg, Germany. Tel.: +49 40 42803 4761; Fax: +49 40 42803 6973; E-mail:
restemey@uke.uni-hamburg.de
Abstract: Purpose: Drugs that modulate neuronal transmission can influence
motor recovery after stroke. Here, we tested if a single dose of levodopa could
improve motor functions and change motor excitability in a group of chronic
stroke patients. Methods: Ten patients > 6 months after
their stroke participated in a placebo-controlled double-blind trial. On two
different occasions, they received either 100 mg levodopa or placebo in a
randomized order. After drug intake, they participated in one hour of
physiotherapy aimed at an improvement of dexterity. Motor functions were tested
by application of the Nine-Hole-Peg Test, a dynamometer measuring grip strength
and the Action Research Arm Test. In addition, transcranial magnetic
stimulation (TMS) was applied to study intracortical excitability, stimulus
response curves and silent periods. TMS studies and motor function measurements
were performed before drug intake, 45 minutes after drug ingestion and after
the physiotherapy. Results: Compared to placebo, levodopa neither improved
motor functions nor changed motor excitability as tested by TMS. Conclusion:
These findings suggests that a single levodopa dose is not sufficient to
improve motor function in chronic stroke. However, it cannot be excluded that
the lack of a beneficial effect is related to the small study sample.
Keywords: Stroke, rehabilitation, levodopa, motor function, transcranial magnetic stimulation
