Central poststroke pain: a review of pathophysiology and treatment.

BACKGROUND Central poststroke pain (CPSP) is a disabling morbidity occurring in 8%-14% of patients with stroke. It is infrequently recognized and difficult to manage. OBJECTIVE We systematically reviewed the pathophysiology and treatment of CPSP. METHODS We conducted a Medline search using the key words "central post-stroke pain," "post-stroke pain," "CPSP and basic studies," "CPSP and clinical features," "CPSP and pharmacological treatment," "CPSP and nonpharmacological treatment" and "CPSP and treatment guideline." The articles related to CPSP were categorized into clinical features, pathophysiology and treatment, and then systematically reviewed. RESULTS Stroke along the spinothalamocortical pathway may result in CPSP after a variable period, usually after 1-2 mo. CPSP may be spontaneous or evoked, variable in intensity and quality. It tends to improve with time. CPSP is associated with mild motor symptoms with relative sparing of joint position and vibration sensations. The pathophysiology of CPSP is not well understood, but central disinhibition, imbalance of stimuli and central sensitization have been suggested. There are few class I and class II studies regarding its management. Amitriptyline and lamotrigine (class IIB) are recommended as first-line and mexiletine, fluvoxamine and gabapentin as second-line drugs. In pharmacoresistant patients, repetitive transcranial magnetic stimulation and deep brain stimulation have been beneficial. CONCLUSIONS CPSP patients present with diverse sensory symptoms and its pathophysiology is still poorly understood. Amitriptyline and lamotrigine are effective treatments. Further studies are needed to understand the pathophysiology and investigate newer therapeutic modalities.