Cochrane Database Review in 2007 identified 10 small randomized trials of amphetamines in patients with stroke. They concluded that there is not enough evidence to support the routine use of amphetamines to promote recovery after stroke. Further controlled trials are needed.
Clinical Rehabilitation published a small study in 2003 that failed to show any effect of D-amphetamine on stroke recovery compared with the control group.
In 2001, Cerebrovascualar Disease published a study that compared traditional rehab to rehab combined with administration of d-amphetamine. They found that ”all patients improved significantly over the intervention period. Amphetamine-treated patients did not show any increase in motor function or ADL as compared to the control group.”
Restorative Neurology and Neuroscience published a study in 2005 on the effects of d-amphetamine on arm recovery. They concluded that “d-Amphetamine failed to facilitate motor performance during training sessions, to promote skill acquisition with training tasks, and most importantly to enhance motor recovery among patients with mild arm paresis after stroke.”
Cerebrovascular Disease in 2003 published a study concluding that “an increased intensity of physiotherapy in combination with dexamphetamine during the first week after stroke onset did not affect short- or long-term outcome in this limited sample of patients with severe stroke.” This study lasted only 5 days, and involved subjects with severe weakness and impaired consciousness no greater than 5 days after a stroke.
Stroke published a study in 2006 which concluded that “in stroke patients with a severe motor deficit, 10 mg AMPH coupled with physiotherapy twice per week for 5 weeks in the early poststroke period provided no additional benefit in motor or functional recovery compared with physiotherapy alone.”
So why do studies on rats show that it works, while studies on humans generally don’t?
Here’s a really in-depth article on the potential reasons that the results of animal studies on d-amphetamines haven’t been found in human studies. Published in Neurorehabilitation in 2009.
International Journal of Neuropsychopharmacology in 2007 published a study which found that, “compared to placebo, Dex enhanced both the rate of learning and the retention of words 1 wk and 1 month later.” They concluded that d-amphetamine seemed to promote improved short-term memory related to speech.
Neuropsychopharmacology in 2004, published a study that attempted to determine if the beneficial effects that some studies have found in D-amphetamine’s use to improve language re-learning after stroke are related to the drug’s arousing action on the cardiovascular system (increased heart rate, blood pressure, etc), or due to other mechanism’s of true neuroplasticity enhancement. They concluded “that AMPH’s plasticity-enhancing effect in humans is not related to its cardiovascular arousal. This suggests that the beneficial effects in stroke patients could also be obtained by less cardiovascular active drugs. Most stroke patients are excluded from treatment with this drug because of a significant risk of cardiovascular dysregulation.”
Until more research is published, I’m going to side with the cochrane review of 10 high-quality studies. The evidence is mixed, and there doesn’t seem to be enough potential benefit to outweigh the possible cardiovascular risks associated with d-amphetamines (effects on blood pressure and heart rate). However, I encourage you to discuss this with your doctor, especially if recovery of speech is one of the goals you are working toward (because there is some research supporting it’s use for improving language re-learning after a stroke).
Amphetamines for improving recovery after stroke.
At present, too few patients have been studied to draw any definite conclusions about the effects of amphetamine treatment on recovery from stroke. The suggested benefits on motor function and the non-significant trend towards increased risk of death could be related to imbalances in prognostic variables or other bias in the studies. Further research is therefore justified.