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In this retrospective study of 67 aneurysmal patients, the predictive role of central conduction time (CCT) on vasospasm occurrence evaluated by means of transcranial Doppler sonography (TCD) and the correlation of CCT to blood flow velocity measured simultaneously in postoperative course were studied. Data about the clinical state of patients at the time of admission (Hunt Hess scale), severity of subarachnoidal hemorrhage on initial CT scan (Fisher grade), timing of surgery (acute or delayed), outcome (Glasgow Outcome Scale), severity of vasospasm graded by highest mean blood flow velocity (BFV) during the entire clinical course and CCT values measured at admission (preoperatively), then postoperatively (one day after surgery) and simultaneously with later TCD investigations were collected from the files. Interhemispheric difference of CCT was also calculated. The results showed that CCT at admission was not predictive for vasospasm. CCT measured either at admission or on the first postoperative day did not differ significantly in the different grades of vasospasm. Similar results were obtained in the acute and in the late operated group of patients. The results also suggest that increased CCT and interhemispheric difference at the time of admission indicate a worse prognosis, but this can be related to higher surgical risk rather than to a higher incidence of late ischemic deterioration. Simultaneous CCT and TCD examinations demonstrated that coincident and statistically significant (p0.01) increase of actual CCT (6.7 msec) was found only in the severe grade of vasospasm (BFV 200 cm/s). The authors discuss the role of CCT and TCD monitoring in the management of aneurysmal subarachnoid hemorrhage.

Two-hundred and fifty-two computerized tomography (CT) scans of 107 patients with head injuries were analyzed. The most frequent consequence of trauma was a diffuse swelling of the brain in 91% of the cases. The severity of brain swelling and its course can be estimated by the compression of (or absence of) the intracranial cerebrospinal fluid space. These observations may be of prognostic value as well. By measurement of the Hounsfield units (HU) in 52 cases the blood or water content in the brain tissues was assessed. An increase in blood content of the tissues (hyperaemia) can account for an increase in Hounsfield values. A decrease in HU suggests brain edema. The density measurements showed that in the first hours and days following head injury, the diffuse brain swelling was caused by severe cerebrovascular congestion in the majority (53%) of the cases. Immediate brain edema without a preceding hyperaemic phase occurs less frequently (32%). Between the 1st and 4th day after injury, edema started to prevail, and between the 5th and 8th day the edematous type of brain swelling was present almost exclusively.