Differences in Callosal and Forniceal Diffusion between Patients with and without Postconcussive Migraine

BACKGROUND AND PURPOSE: Posttraumatic migraines are common after mild traumatic brain injury. The purpose of this study was to determine if a specific axonal injury pattern underlies posttraumatic migraines after mild traumatic brain injury utilizing Tract-Based Spatial Statistics analysis of diffusion tensor imaging. MATERIALS AND METHODS: DTI was performed in 58 patients with mild traumatic brain injury with posttraumatic migraines. Controls consisted of 17 patients with mild traumatic brain injury without posttraumatic migraines. Fractional anisotropy and diffusivity maps were generated to measure white matter integrity and were evaluated by using Tract-Based Spatial Statistics regression analysis with a general linear model. DTI findings were correlated with symptom severity, neurocognitive test scores, and time to recovery with the Pearson correlation coefficient. RESULTS: Patients with mild traumatic brain injury with posttraumatic migraines '' were not significantly different from controls in terms of age, sex, type of injury, or neurocognitive test performance. Patients with posttraumatic migraines had higher initial symptom severity (P =.01) than controls. Compared with controls, patients with mild traumatic brain injury with posttraumatic migraines had decreased fractional anisotropy in the corpus callosum (P =.03) and fornix/septohippocampal circuit (P =.045). Injury to the fornix/septohippocampal circuit correlated with decreased visual memory (r = 0.325, P =.01). Injury to corpus callosum trended toward inverse correlation with recovery (r = -0.260, P =.05). CONCLUSIONS: Injuries to the corpus callosum and fornix/septohippocampal circuit were seen in patients with mild traumatic brain injury with posttraumatic migraines, with injuries in the fornix/septohippocampal circuit correlating with decreased performance on neurocognitive testing.