Indexed on: 18 Apr '16Published on: 18 Apr '16Published in: Archives of Physical Medicine and Rehabilitation
To examine: (1) differences in patient-reported outcomes, neuropsychological tests, and thalamic functional connectivity (FC) between patients with mild traumatic brain injury (mTBI) and healthy controls; (2) the longitudinal association between changes in these measures.Prospective observational case-control study.Academic medical center.Thirteen patients with mTBI (mean age = 39.3 years, 4 female) and 11 healthy, age and sex-matched control subjects (mean age = 37.6, 4 female) were enrolled.Not applicable.Resting-state FC (3T MRI scanner) was examined between the thalamus and the Default Mode Network (THAL-DMN), Dorsal Attention Network (THAL-DAN), and Frontoparietal Control Network (THAL-FPC). Patient-reported outcomes included pain (Brief Pain Inventory), depressive symptoms (Patient Health Questionnaire-9), post-traumatic stress disorder (PTSD Checklist), and post-concussive (Rivermead Post-Concussion Questionnaire) symptoms. Neuropsychological tests included the D-KEFS Tower test, Trails B, and Hotel task. Assessments occurred at 6 weeks and 4 months after hospitalization for patients with mTBI and at a single visit for controls.Student's t-tests found increased pain and depressive, PTSD, and post-concussive symptoms, decreased performance on Trails B, increased THAL-DMN FC, and decreased THAL-DAN and THAL-FPC FC in patients with mTBI compared to healthy controls. Spearman correlation coefficient indicated that increased THAL-DAN FC from baseline to 4 months was associated with decreased pain and post-concussive symptoms (corrected p < 0.05).Findings suggest that alterations in thalamic FC occur after mTBI and improvements in pain and post-concussive symptoms are correlated with normalization of thalamic FC over time.