[Neuropsychological sequelae of head injury]

Traumatic brain injury (TBI) neuropsychological sequelae are consequence of the combination of focal and diffuse cerebral lesions. Foci of concussion usually involves frontal lobes. Fronto-basal lesions produces important changes in mood, personality and behavior, and dorsolateral lesions impairment of executive functions (lack of planning, flexibility and use of strategies). Left temporal concussion can produce aphasia. Hippocampal and parahippocampal atrophy are essentially responsible of memory dysfunctions. Diffuse axonal damage is related to impairment of attention, speed of mental processing and frontal lobe functions. The development of neuroimaging techniques, especially tridimensional magnetic resonance acquisition and analysis, allows accurate anatomo-functional correlates. Genetic variables can explain in part individual differences in the degree of memory impairment and the relationship of TBI with Alzheimer's disease.

The TBI percussion model performed in rat and mouse allows the study of the interrelationship among structural damage, memory changes, genetic factors, and the effects of pharmacological treatment.