Relationship of Cerebral Blood Flow to Cognitive Function and Recovery in Early Chronic Traumatic Brain Injury

• Published in: Journal of neurotrauma Vol. 37; no. 20; pp. 2180 - 2187
• Main Authors: Ware, Jeffrey B, Dolui, Sudipto, Duda, Jeffrey, Gaggi, Naomi, Choi, Robin, Detre, John, Whyte, John, Diaz-Arrastia, Ramon, Kim, Junghoon J
• Format: Journal Article
• Language: English
• Published: United States Mary Ann Liebert, Inc 15.10.2020; Mary Ann Liebert, Inc., publishers
• Subjects: Atrophy; Biomarkers; Blood flow; Cerebral blood flow; Cognitive ability; Consciousness; Executive function; Magnetic resonance imaging; Measuring techniques; Microvasculature; Morbidity; Neuroimaging; Original; Psychology; Recovery (Medical); Rehabilitation; Spin labeling; Substantia grisea; Time series; Traumatic brain injury; cognitive function; vascular injury; MRI; CBF; adult brain injury; ASL; TBI; blood flow
• ISSN: 0897-7151; 1557-9042
• DOI: 10.1089/neu.2020.7031

Traumatic brain injury (TBI) is a leading cause of morbidity worldwide, for which biomarkers are needed to better understand the underlying pathophysiology. Microvascular injury represents a subset of pathological mechanisms contributing to cognitive dysfunction after TBI, which may also impair subsequent neural repair thereby inhibiting cognitive recovery. Magnetic resonance imaging (MRI)-based measurement of cerebral blood flow (CBF) by arterial spin labeling (ASL) provides an appealing means of assessing microvascular disruption in TBI; however, the relationship between CBF alterations in the early chronic post-TBI setting and cognitive dysfunction as well as subsequent cognitive recovery remain poorly understood. Structural MRI and ASL were performed in 42 TBI subjects 3 months post-injury and 35 matched healthy controls. Neuropsychological testing was performed in each subject, as well as in a subset of TBI patients (  = 33) at 6 and/or 12 months post-injury. TBI and control subject CBF data were compared between groups in a voxel-wise fashion while controlling for the effects of structural atrophy. A region-of-interest approach was then used to compare CBF to clinical and neuropsychological measures within the TBI group in a cross-sectional fashion, as well as to the degree of subsequent cognitive recovery among subjects with follow-up testing. At 3 months post-injury, the TBI group demonstrated lower performance in each cognitive domain (  < 0.05), as well as widespread reductions in gray matter CBF independent of structural atrophy (  < 0.05). Within the TBI group, CBF was moderately correlated with injury severity (  = -0.43;  = 0.009) and executive function (  = 0.43;  = 0.01). In the longitudinal analysis, there was a positive correlation between initial CBF and processing speed recovery (  = 0.43;  = 0.015) independent of age, education level, and initial test score. Early chronic TBI is associated with widespread gray matter CBF deficits, which are correlated with injury severity and cognitive dysfunction. CBF may predict subsequent recovery in some cognitive domains.