Radiological and clinical biomarkers in patients with central post stroke pain

Background. Central post-stroke pain (CPSP) occurs following cerebrovascular accidents and is a neuropathic pain syndrome that is characterized by stimulation-independent pain; shooting, burning, or electric shock-like sensation and paresthesia. Multiple pathogenetic theories have been proposed for the CPSP including disinhibition, central sensitization, thalamic changes, and altered function of spinothalamic tract (STT). Investigations such as MRI DTI can help to understand the pathogenesis of CPSP. Objective. To determine the radiological and clinical biomarkers in cases with CPSP. Methods. This case-control study was retrospectively conducted upon 60 persons divided into 20 CPSP cases (group 1), 20 cases with no CPSP (group 2) and 20 healthy controls (group 3). All subjects had Routine MRI and complete neurological examination including “Sensory testing but stroke patients were evaluated by quantitative assessment of neuropathic pain, the National Institutes of Health Stroke Scale (NIHSS), Ashworth scale, Modified Rankin Scale (MRS) and Hamilton depression rating scale (HAM-D scale). Results. Significant differences existed among studied groups as regard motor examination, sensory examination, NIHSS score and Hamilton depression score. A non-significant difference was detected among the groups regarding MRS findings. A significant difference existed between groups 1 and 2, between groups 1 and 3 while no significant difference was detected between groups 2 and 3 for all FA readings and all ADC readings in ipsilateral affected side assessed at internal capsule, midbrain, and pons. No significant difference existed between groups 1 and 2, between groups 1 and 3 and between groups 2 and 3 as regard FA readings and ADC readings in contralateral side assessed at internal capsule, midbrain, and pons. Conclusion. Our study highlighted the significance of white matter tracts (WMT) other than the conventional pain pathways in CPSP and can thus serve as a predictive marker for CPSP onset or a prognostic marker after any drug therapy or neuromodulatory treatment.