[Post-traumatic amnesia in the evaluation of minor cranial injuries]

Quantitative assessment of brain damage is a primary condition for studies in neurotraumatology. Scored clinical evaluation, neurophysiological and neuroimaging techniques are usefully applied in highly disabled or comatose patients. In minor head injury (MHI), where focal neurological signs are excluded by definition, quantification of brain dysfunction is still uncertain. We compared the incidence of post-traumatic amnesia (PTA), skull fractures and altered Auditory Brainstem Responses (ABR) in 165 patients examined within 48 hours from a MHI. Skull fractures were found in 25%. They are, however, an indirect evidence of potential cerebral damage. ABR alterations, which show brainstem dysfunction, were present in 10% only. PTA exceeding 30 min occurred in 60% of MHI patients. This clinical method seems a sensitive method for assessing brain dysfunction even in MHI patients.