Cerebral correlates of declarative memory dysfunctions in early traumatic brain injury

We investigated residual brain damage in subjects who suffered severe traumatic brain injury (TBI) in childhood, and its relationship with declarative memory impairment. Magnetic resonance imaging (MRI) volumetric data and memory performance were compared between 16 adolescents with antecedents of severe TBI and 16 matched normal controls. Volumes of grey matter, white matter, cerebrospinal fluid (CSF), hippocampus, and caudate nuclei were measured. Verbal memory was assessed by the Rey's Auditory Verbal Learning test and visual memory by the Rey's Complex Figure. TBI patients performed significantly worse than controls in both verbal and visual memory. Patients presented decreased white matter volume and increased CSF. The hippocampus was reduced, but not the caudate nuclei. Memory performance correlated with CSF. Plasticity is incomplete for structural and functional deficits in children with TBI. Hippocampal atrophy, white matter loss, and memory impairment remain until adolescence. Memory sequelae are related more to diffuse brain injury, as reflected by MRI findings of increased CSF, than to hippocampal injury.