Quantitative Susceptibility Mapping in Adults with Persistent-Post Concussion Symptoms after Mild Traumatic Brain Injury: An Exploratory Study.

ABSTRACT

BACKGROUND AND PURPOSE: It is estimated that 18-30% of concussion sufferers experience symptoms lasting more than 1 month, known as persistent post-concussion symptoms (PPCS). Symptoms can be debilitating, and include headache, dizziness, nausea, problems with memory and concentration, sleep and mood disruption, and exercise intolerance. Previous studies have used quantitative susceptibility mapping (QSM) to show altered tissue susceptibility levels in adults acutely following concussion, however this finding has yet to be investigated in participants with PPCS. MATERIALS AND METHODS: In this exploratory case-controlled study, we measured tissue susceptibility using quantitative susceptibility mapping (QSM) in 24 participants with PPCS following mild traumatic brain injury (mTBI) and 23 healthy controls with no history of concussion. We compute tissue susceptibility for seven white matter tracts and three deep grey matter regions and compare tissue susceptibility between groups using ANCOVA models controlling for age and sex. We also assess the relationship between regional tissue susceptibility and symptoms. RESULTS: There were no significant differences between tissue susceptibility in participants with PPCS compared to control subjects in any of the evaluated regions. However, we show lower tissue susceptibility across four white matter tracts was generally associated with worse symptoms in the PPCS group. Specifically, we saw relationships between white matter susceptibility and headache (p=0.006), time since injury (p=0.03), depressive symptoms (p=0.021) and daytime fatigue (p=0.01) in participants with PPCS. CONCLUSIONS: These results provide evidence in support of persistent changes in the brain months-to-years following injury and highlight the need to further understand the pathophysiology of PPCS, to determine effective prevention and treatment options. ABBREVIATIONS ATR Anterior Thalamic Radiation; Caud Caudate; CCB Corpus Callosum Body; CCG Corpus Callosum Genus; CCS Corpus Callosum Splenium; CH Cingulum; DHI Dizziness Handicap Inventory; ESS Epworth Sleepiness Scale; FM Forceps Minor; FSS Fatigue Severity Scale; GAD Generalized Anxiety Disorder; HIT-6 Headache Impact Test 6; IFOF Inferior Fronto-Occipital Fasciculus; ILF Inferior Longitudinal Fasciculus; mTBI mild traumatic brain injury; Pal Pallidum; PPCS Persistent Post-Concussive Symptoms; PCSC Postconcussional Syndrone Checklist; PHQ Patient Health Questionnaire; Put Putamen; RPQ Rivermead Post Concussion Symptoms Questionnaire; SLF Superior Longitudinal Fasciculus; QSM Quantitative Susceptibility Mapping.