10 Jan Post-Stroke Pain
Stroke is a critical medical event that can have long-term debilitating sequelae. Post-stroke pain is such a chronic sequela of stroke that has a huge toll on the patient’s well-being, lifestyle, and productivity. The prevalence of chronic post-stroke pain is up to 40% four to six months after a stroke. Shoulder pain is the most common type affecting about 70% of post-stroke patients. If
Central post-stroke pain occurs when the stroke damages the spino-thalamocortical pathway resulting in persistent pain. It occurs in about 8% incidence in the first year after stroke. This is an intense type of pain localized in the affected limbs but can affect the entire side of the body with an aching and burning quality. It may be associated with other sensory disturbances, such as abnormal temperature sensation, dysesthesia and hypersensitivity to touch. But the response to light touch and vibration are often spared. The pain seems to get better with relaxation and worsens with emotional and physical stress. It can be challenging to properly diagnose post-stroke pain and too in a timely fashion. In some cases, post-stroke pain appears after having stopped their active care for these patients. This results in frequent misdiagnoses and/or significant delays before treatment begins. Diagnosis is further complicated by the fact that these patients may also have cognitive and speech deficits as other sequelae of the stroke. There may be concurrent depression, anxiety, and sleep disturbances as well.
Interestingly, oral medications found to provide relief from post-stroke pain include antidepressants and anticonvulsants, while opioids are not so effective. Amitriptyline, which is a tricyclic antidepressant is effective in improving the pain, but the dose needs to be titrated individually. It dies have anticholinergic side effects and careful monitoring is necessary.
Anticonvulsants are effective for treating neuropathic pain. Gabapentin is the most commonly used type for treating a variety of neuropathic pain conditions including post-stroke pain. It is a structural analog of the neurotransmitter gamma-aminobutyric acid (GABA), and it is relatively safe, with typical side effects of dizziness and sedation.
Lamotrigine is an anti-epileptic medication. It is reasonably effective against post-stroke pain and is relatively well-tolerated, except for a rare chance of severe adverse reactions, such as Stevens-Johnson syndrome and toxic epidermal necrolysis.
In cases where pharmacologic therapy fails, brain stimulation approaches have been tried. Motor cortex stimulation can modulate the pain pathways and may provide satisfactory long-lasting pain relief in some cases. These approaches include deep brain stimulation is a surgical procedure that requires the insertion of electrodes in specific areas of the brain. Another method is repetitive transcranial magnetic stimulation (rTMS), which is a non-invasive procedure that creates a brief high-intensity magnetic field and may lead to a small but long-lasting pain relief. Transcutaneous electrical nerve stimulation (TENS) may also be effective but their efficacy has not been well-documented. It is a crucial diagnosis that can be missed and may be difficult to treat, warranting careful attention of experienced clinicians while caring for post-stroke patients.