Objective: To demonstrate subacute progression of brain atrophy (from 4.5-29mo postinjury) in moderate to severe traumatic brain injury (TBI) using structural magnetic resonance imaging (MRI).
Design: Within-subjects, repeated-measures design.
Setting: Inpatient neurorehabilitation program and teaching hospital (MRI department).
Participants: Adults (N=14) with moderate to severe TBI.
Interventions: Not applicable.
Main outcome measures: Neuroradiologist readings and volumetric measurements (total brain cerebrospinal fluid and hippocampus) at 4.5 months and 2.5 years postinjury.
Results: Ten of 14 patients showed visible atrophy progression. Significant increase in cerebrospinal fluid (CSF) volume (t(13)=-4.073, P<.001) and decrease in right and left hippocampal volumes (t(13)=4.221, P<.001 and t(13)=3.078, P<.005, respectively) were observed from 4.5 months to 2.5 years. Compared with published normative data, patients with TBI showed significantly more pathologic percent annual volume change for the hippocampi (t(26)=-3.864, P<.001, right; and t(26)=-2.737, P<.01, left), and a trend for CSF (t(26)=1.655, P=.059).
Conclusions: This study provides strong MRI evidence for subacute progression of atrophy, as distinct from early, acute neurologic changes observed.