Cognitive outcome and early indices of severity of head injury.

Neuropsychological outcome of 100 patients with severe head injuries is correlated with their clinical condition on admission. The aim of this paper is to estimate the reliability of several early indices of brain damage severity in formulating a prognosis. Both the Glasgow Coma Scale and the neurological syndrome involved appeared to be highly reliable in this respect. The duration of coma and of posttraumatic amnesia was not as significant. Since these two parameters were assessed when reviewing the cases, they have to be considered only as retrospective judgments. The findings emphasized the importance of reflex ocular motility and the value of recording electroencephalographic (EEG) activity, particularly EEG sleep patterns. The relationship between rapid eye movement sleep impairment and cognitive defects was highly significant. Analysis of surgical observations demonstrated that purely compressive expanding lesions were not as harmful as parenchymal damage. Of paramount importance was the time lapse between injury and surgery, since secondary lesions may develop and affect cerebral areas that are involved both in sleep organization and in memory functions.