Coma Without Mass Lesions on CT Scan after Head Injury

ABSTRACT

We present a retrospective study on the patients with coma without mass lesion on CT scan after non-missile head injury. We reviewed various clinical and radiological features of these 53 cases and compared the outcome at one month with several variables which may affect the prognosis. The patients were selected by the following criteria;the patients had lost consciousness at least for 6 hours, the Glasgow coma scores were below B, and the CT scan did not demonstrate a mass lesion but might have small contusion, subarachnoid hemorrhage and pneumocephalus that caused no mass effect. Characteristic CT findings for the diffuse axonal injury-small intracerebral hemorrhage on corpus callosum, white mater, basal ganglia or around the third ventricle-were observed in only 21 of 53 cases(39.6%). Thus diffuse axonal injury can be diagnosed by clinical features not by the CT findings at present and the CT scan was required for ruling out any mass lesions. The mortality rate was 32.1%. However, 37.7% was remained in the vegetative state or severe disability. Only 30.2% could obtain functional recovery. The changes of pupil, duration of coma, Glasgow coma score, skull fracture and collapsed lateral ventricle on CT scan were identified as important features in determining the outcome(p<0.05). Age, systolic BP, PaO2 and obliteration of basal cistern and third ventricle on CT scan had no statistical significance.