Influence of long term administration of fluoxetine on cerebral threshold and muscle activation patterns in chronic stroke.

Stroke is one of the major causes of disability in developed countries. After stroke most patients suffer from hemiparesis, and especially the distal parts of the body are affected. Even after intensive training many patients still suffer from motor impairment. Previous studies have been done examining the possibility of improving motor recovery by studying the effects of neuropharmaca.
One neuropharmaca of which the effects are studied before are selective serotonin reuptake inhibitors (SSRIs). However, inconsistent results were found, as some studies found an improved motor function, while other studies did not found any effect at all. Most of these studies only measured motor function.
Several, more sensitive, variables are correlated with motor function. This study examines the effects of fluoxetine (an SSRI) on these variables. As changes in these parameters will possibly explain why fluoxetine could improve motor function.
Primary objective of the study is to measure the effects of long term fluoxetine administration on brain excitability and muscle activity.
Hypotheses are: (1) long-term use of fluoxetine causes the excitability of the primary motor area of the brain to change; and (2) Long-term administration of fluoxetine causes the muscle activation patterns to increase. Also some secondary hypotheses will be measured: (3) Long-term use of fluoxetine modulates activation of areas in the brain during voluntary movement; (4) Long-term administration of fluoxetine increase the communication between areas in the brain; (5) Long-term administration of fluoxetine causes the motor function to change.
The primary study parameters are: motor threshold, and stimulus response curve (SRC) to measure excitability of the brain, and the root mean square (RMS) of the electromyogram (EMG) during movement of the lower part of the arm, to measure muscle activation.
Secondary study parameters are: activation of frequencybands in the brain, phase-synchronization in the brain to measure communication between different areas, and the Fugl-Meyer score, and grip strength to measure motor function.
The study design is a doubleblind placebo controlled study.
Twenty-eight chronic stroke patients will be included. They have to be over the age of 18. Fourteen patients will receive one tablet containing 20 mg of fluoxetine every day, during 12 weeks. The other 14 patients will receive a placebo for 12 weeks.
The patients are asked to come to the research centre for four times (start of the trial, and after 6, 12 and 20 weeks). Every time all parameters will be measured. Also a depression questionnaire has to be answered to control the group for signs of depression. In the 6th week a blood sample will be taken.

1: Long term use of fluoxetine causes the excitability of the primary motor area of the brain to change

2: Long term administration of fluoxetine causes the muscle activation patterns to change

20 mg of fluoxetine during 12 weeks