Single dose of fluoxetine increases muscle activation in chronic stroke patients.

Objectives: This pilot study explores the influence of a single dose of fluoxetine (20 mg) on the muscle activation patterns and functional ability of the muscles in the lower part of the arm in chronic stroke patients. Methods: A crossover, placebo-controlled clinical trial was conducted in 10 patients. After administration of either a single dose of fluoxetine (20 mg) or a placebo, muscle activation of the lower arm was measured during maximum (isometric) force of the musculus flexor carpi radialis and musculus extensor carpi radialis. Delay times, grip strength, and Motricity Index were measured to assess functional ability. Results: After fluoxetine intake, a significant increase in activation was found in both agonist and antagonist muscles of the paretic arm (P < 0.05). This increase did not influence the motor function. Conclusions: In this pilot study, it was found that fluoxetine influences motor output in chronic stroke patients. Therefore, fluoxetine may influence motor recovery after stroke. Additional studies have to be conducted to explore the effects of fluoxetine on motor recovery after stroke