中枢性脳卒中後疼痛の病変部位の検討

抄録

Objective: We previously reported that the specific lesions in the thalamus, putamen, or brain stem could develop central poststroke pain (CPSP) in the retrospective MRI study. However, these findings can reflect only frequent locations of stroke. Therefore, in this study, we prospectively investigated detailed key structures to develop CPSP using voxel–based lesion map and odds ratio (OR) map comparing to patients without pain or with mild pain.

Methods: Subjects were chronic stroke patients with sensory disturbance, and underwent a brain MRI scan of three–dimensional T1 weighted images with a same protocol. The stroke lesion causing sensory disturbance was extracted as volume of interest, and spatially normalized to the standard brain space. OR of each voxel was calculat­ed in the following two conditions (condition 1: CPSP patients vs. patients without pain; condition 2: patients with severe or moderate pain vs. mild pain or no pain). We localized regions related to CPSP or CPSP with moderate pain or more using electrical brain atlases.

Results: 71 patients (CPSP, n=53; patients without pain, n=18; patients with severe or moderate pain, n=38; mild or no pain, n=33) were recruited and their brain MRI were analyzed. The voxel–based OR map of the condition 1 showed that the lesion of the ventro–caudalis posterior externus (V.c.p.e) nucleus of the thalamus (OR, 8.7) had a high risk of CPSP. The OR map of the condition 2 showed that lesions of the pulvinar mediale (Pu.m; OR, 8.5), ventro–caudalis portae (V.c.por; OR, 5.5), and V.c.p.e (OR, 3.3) had a high risk of severe or moderate pain.

Conclusion: This study suggested that the border of the ventral posterior nucleus and pulvinar could be one of the key structures to develop clinically significant CPSP.