The drug Lamotrigine can reduce the pain that affects some stroke patients, according to a study published in the journal Neurology. Central post-stroke pain occurs in eight per cent of stroke patients and is difficult to treat. The only current treatment, amitriptyline, doesn't work for many patients, and has many side effects.
The pain is felt in areas of the body that have sensory loss from the stroke. Researchers think the pain occurs when the stroke damages the fibres in the brain or in the spinal cord that lead to the thalamus area of the brain. The loss of sensory information to the brain creates a hyperexcitability, or excessive response to stimuli, in that area of the brain.
"Lamotrigine, which has mainly been used for epilepsy patients, reduces hyperexcitability in brain cells, so we wanted to see if it would help people with central post-stroke pain," said study author and neurologist Troels Staehelin Jensen, of Aarhus University Hospital in Aarhus, Denmark.
For the study, 30 people with central post-stroke pain were given lamotrigine in a randomized, double-blind study. The participants took lamotrigine for eight weeks, waited two weeks with no medication and then took a placebo for eight weeks, or vice versa.
Taking lamotrigine reduced the pain patients felt by an average of 30 per cent with twelve patients' responses categorised as 'clinically significant improvements'.
While taking lamotrigine, patients had few side effects, including mild rashes and headaches.
"The current treatment for this type of pain - the antidepressant amitriptyline - can cause side effects including sedation, low blood pressure and cardiac arrhythmia, so this new treatment is a good option for people who cannot tolerate amitriptyline or don't respond to it," Jensen said.