Traumatic lesions of the brain stem: electroencephalographic and computer-tomographic follow-up study in the acute phase.

Combined EEG and CT examinations were carried out in a prospective study of 20 patients with acute midbrain syndromes. After head injury EEG and CT examinations were repeated at intervals no longer than 3 days. In 13 younger patients alpha waves and spindles occurred during the first few days after injury even in a patient with a thalamo-cortical tract lesion as visualized in CT scan. CT revealed ponto-mesencephalic haemorrhage in 2 patients and ponto-mesencephalic oedema in two others. Increase and decrease of oedema correlate well with the EEG changes: at the time of the most pronounced brain oedema (days 3-12) the most serious EEG changes are found. A midbrain syndrome following head injury implies a poor prognosis.