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ObjectiveThe evaluation of memory complaints in mild traumatic brain injury (mTBI) remains an important clinical consideration, especially in the context of comorbid psychiatric symptoms such as posttraumatic stress disorder (PTSD). We compared subjective memory complaints in veterans with and without a history of mTBI, examined ratings between those with single versus multiple mTBIs, and investigated associations between memory complaints and PTSD symptom severity.Methods117 outpatient veterans (mTBI: n = 79 [single mTBI: n = 22, multiple mTBI: n = 57], military controls [MCs]: n = 38) completed a TBI history assessment, the Prospective-Retrospective Memory Questionnaire (PRMQ), and the PTSD Checklist-Military Version (PCL-M).ResultsHierarchical multiple regression showed that greater PCL-M scores significantly predicted elevated PRMQ-Total scores, accounting for 38% of the variance explained (P < .001). mTBI status predicted an additional 5% of variance in memory complaints (P < .01). The multiple-mTBI group endorsed more memory complaints than either MCs (P < .01) or the single-mTBI group (P < .05), who did not differ from MCs (P > .50).ConclusionsComorbid PTSD symptoms are an important factor when considering memory complaints in veterans with a reported history of mTBI. However, independent of comorbid PTSD symptoms, mTBI status-particularly in the context of repetitive neurotrauma-uniquely contributes to memory complaints. Findings suggest that veterans with a history of multiple mTBIs may be a particularly vulnerable group in need of specialized interventions and/or psychoeducation.

OBJECTIVE:Fatigue is a complex, multidimensional phenomenon that commonly occurs following traumatic brain injury (TBI). The thalamus-a structure vulnerable to both primary and secondary injuries in TBI-is thought to play a pivotal role in the manifestation of fatigue. We explored how neuroimaging markers of local and global thalamic morphometry relate to the subjective experience of fatigue post-TBI. METHODS:Sixty-three Veterans with a history of mild TBI underwent structural magnetic resonance imaging and completed questionnaires related to fatigue and psychiatric symptoms. FMRIB's Software (FSL) was utilized to obtain whole brain and thalamic volume estimates, as well as to perform regional thalamic morphometry analyses. RESULTS:Independent of age, sex, intracranial volume, posttraumatic stress disorder, and depressive symptoms, greater levels of self-reported fatigue were significantly associated with decreased right (P = .026) and left (P = .046) thalamic volumes. Regional morphometry analyses revealed that fatigue was significantly associated with reductions in the anterior and dorsomedial aspects of the right thalamic body (P < .05). Similar trends were observed for the left thalamic body (P < .10). CONCLUSIONS:Both global and regional thalamic morphometric changes are associated with the subjective experience of fatigue in Veterans with a history of mild TBI. These findings support a theory in which disruption of thalamocorticostriatal circuitry may result in the manifestation of fatigue in individuals with a history of neurotrauma.