Ross Bullock

Intracerebral hemorrhage in a primate model: Effect on regional cerebral blood flow ☆

The dynamic changes in regional cerebral blood flow (rCBF), induced by a developing intracerebral hematoma, were studied in eight anesthetized monkeys. Hematomas were generated by allowing femoral arterial blood to enter the caudate nucleus via a stereotactically implanted needle. Intracranial pressure peaked at 51 +/- 8 mmHg at 3 minutes after the ictus, and remained high throughout the 3-hour procedure. Cerebral blood flow was significantly reduced in all brain regions for 1 hour after the ictus. The lowest rCBF values were recorded in the immediate clot penumbra and were below threshold levels for ischemic neuronal damage for 90 minutes after the hemorrhage.

Chronic extradural hematoma

Thirty-five patients with late extradural hematomas are described in whom the interval between injury and operation was at least seven days. Interpersonal violence was responsible for the initial injury in about two-thirds of the cases. There was a uniformly favorable outcome in all the cases The mode of presentation, features of the computed tomographic (CT) scans, and the possible mechanism of formation of chronic extradural hematomas are discussed.

Acute carotid-cavernous fistula with retained knife blade after transorbital stab wound

A patient who sustained an acute carotid-cavernous fistula due to a stab wound is presented. The management problems related to acute intracranial-penetrating injuries are discussed, with particular reference to vascular injury.

Rupture of bacterial intracranial aneurysms following replacement of cardiac valves

Abstract Two patients with rheumatic valvular heart disease are discussed in whom a bacterial intracranial aneurysm ruptured in relation to cardiac surgery. Cardiac surgery may predispose such aneurysms to rupture. Cerebral angiography for detecting unruptured aneurysms and surgical excision prior to valve replacement may be indicated in certain patients.

Importance of screening logs in clinical trials for severe traumatic brain injury: Commentary

OBJECTIVEThe primary intent for obtaining screening logs in a randomized clinical trial is to assess selection bias in patient recruitment. This is particularly relevant to focused trials in heterogeneous populations such as traumatic brain injury (TBI) patients. We aimed to investigate the benefits of collecting screening logs in two randomized clinical trials conducted in TBI. METHODSScreening logs were collected as part of the conduct of two multicenter trials of neuroprotective agents in TBI: the Salzburg Atherosclerosis Prevention Program in Subjects at High Individual Risk study (n = 924) and the dexanabinol study (n = 861). Centers were requested to submit monthly information on all patients with TBI admitted to the intensive care unit, including demographics, time of injury and admission, injury severity, and, if not recruited, the reason(s) for exclusion. RESULTSIn the Salzburg Atherosclerosis Prevention Program in Subjects at High Individual Risk study, 52 centers submitted admission data on 4166 patients. In the dexanabinol trial, 96 centers submitted data on 7052 patients. On average, only 20% of patients screened for the Salzburg Atherosclerosis Prevention Program in Subjects at High Individual Risk study and 10% for the dexanabinol trial were enrolled. The main reasons for exclusion were neurological status (29 and 26%, respectively), age (24 and 30%, respectively), and admission outside of the time window (17 and 21%, respectively). Differences in patient characteristics between screened and enrolled patients, with substantial country-specific variation, were observed. CONCLUSIONThe collection of screening logs is necessary to report trial results according to the Consolidated Standards of Reporting Trials guidelines and to assess the generalizability of findings. Our experience shows the feasibility of collecting screening logs and illustrates how the potential for selection bias may creep into well-designed randomized clinical trials as a result of factors outside the control of investigators. Consistency and accuracy in screening log completion may further serve as an early indicator of center performance in a trial.