Chronic Central Pain Among Community-Dwelling Survivors of Moderate-to-Severe Traumatic Brain Injury: A Quantitative Sensory Testing Study.

Background: Central pain associated with changes in sensory thresholds is one of the most enduring consequences of major trauma. Yet it remains sparsely studied among community-dwelling survivors of moderate-to-severe traumatic brain injury (TBI). Purpose: To describe and compare thermal and mechanical sensory thresholds in home-based patients with and without central pain after moderate-to-severe TBI with a cohort of healthy controls. Design: Cross-sectional. Method: Thresholds for cold/heat detection, thermal pain, touch, and distorted sensation were gathered using quantitative sensory testing (QST). QST was performed on the painful and contralateral pain-free body regions in TBI participants with pain (TBI-P) and on both forearms in TBI participants without pain (TBI-NP) and healthy controls (HC). Central pain was characterized using the Brief Pain Inventory-Short Form. Results: We tested 16 TBI-P patients, 17 TBI-NP patients, and 16 HC. Mean time since injury for TBI patients was 24 +/- 15 months. TBI-P and TBI-NP patients showed significant loss in innocuous mechanical sensitivity compared to HC (F = 18.929; Bonferroni-adjusted p <= .001). Right-left differences in cold pain sensations were significantly larger in TBI-P than in TBI-NP and HC participants (F = 14.352; Bonferroni-adjusted p <= .001). Elevated heat sensitivity thresholds were also observed in TBI-P participants but remained within normal range. Conclusion: Damage to cutaneous mechanoreceptors is a necessary, but not sufficient, condition for the development of chronic central pain following TBI. Damage or incomplete recovery of cutaneous thermoreceptors may be a contributing factor to chronic pain after TBI.