Central post-stroke pain: predictors and relationship with magnetic resonance imaging and somatosensory evoked potentials

BACKGROUND: Central post-stroke pain (CPSP) is an under-recognized complication of stroke although it can lead to deterioration in quality of life and impairment in activities of daily living. Its estimated prevalence varies between 18.6 and 49%. OBJECTIVE: To investigate the prevalence and predictors of CPSP in ischemic stroke patients and to find its relationship with somatosensory evoked potentials (SSEPs) and magnetic resonance imaging. PATIENTS AND METHODS: Sixty five consecutive patients with recent first attack of ischemic stroke who were admitted to the Neurology Department, Suez Canal University Hospitals were recruited. Patients were subjected to clinical assessment, Hamilton depression rating scale, brain MRI, short-form McGill Pain Questionnaire (SF-MPQ), daily pain rating scale (DPRS), stimulus evoked pain, and SSEPs. RESULTS: The total prevalence rate of CPSP was 35.4% (n = 23). The mean age of the patients developed CPSP was significantly lower than those without CPSP (p = 0.004). Deep sensory dysfunction was statistically significantly higher among CPSP group than non-CPSP group (p = 0.001). CPSP group showed statistically significant higher prevalence of thalamic stroke (p = 0.007), as well as significant abnormalities in inter-peak interval (IPL) of median and tibial nerves SSEPs (p < 0.05). Thalamic group showed higher abnormalities in IPL of median and tibial nerves compared to extra-thalamic group, but without statistically differences. CONCLUSION: The prevalence of CPSP was found to be 35.4%. Predictors of CPSP include; deep sensory dysfunction, prolongation of tibial N21–P40 IPL, smoking history, age < 50 years, presence of thalamic stroke and prolongation of median N9–N20 IPL.