Reversible post-traumatic bilateral extensive restricted diffusion of the brain. A case study and review of the literature

Primary objective: To increase the knowledge about diffuse traumatic brain injury (TBI) by reporting the magnetic resonance imaging (MRI) findings observed in a patient with reversible extensive restricted diffusion of the brain at diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) maps. Case study: An 18-year-old patient was admitted after high-energy closed TBI. Glasgow Coma Scale score was 4. Head computed tomography showed small left frontal and temporal haemorrhagic contusions and a small haemorrhage in the left thalamus. Ten days later, brain MRI showed diffuse high-signal intensity on T2-weighted images and DWI and restricted diffusion in the subcortical white matter of both centri semiovali, genu and splenium of corpus callosum and parietal cortex bilaterally (mean ADC value = 0.434-0.811 10-3 mm2 s-1). Eleven days later, follow-up brain MRI showed gliotic changes in the left splenium of corpus callosum, a clearcut decrease of T2-weighted high-signal intensity and resolution of abnormalities at DWI and ADC maps in all other involved sites. This was confirmed 36 days later. Three months later, the patient did not show neurological, cognitive or neuropsychiatric deficits. Conclusions: In the patient reported herein, closed TBI most likely induced diffuse excitotoxic injury of the brain which resulted in mainly reversible cytotoxic or intramyelinic oedema.