Ludwig M. Auer

Prognosis after acute subdural or epidural haemorrhage

SummaryIn a series of 171 patients suffering acute subdural haemorrhage (SDH) (111 patients) or epidural haemorrhage (EDH) (60 patients) after closed head injury accumulated during the years 1978–1985 at the University Hospital of Graz, the mortality rate and the grade of clinical recovery were evaluated. The overall mortality in acute SDH was 57%, in acute EDH 25%, the percentages of good recoveries—full recovery and minimal neurologic deficit—25 and 58%, respectively. Outcome was found to be predominantly influenced by the preoperative state of consciousness, associated brain lesions, and, in comatose patients, the duration of the time interval between onset of coma and surgical decompression. When this interval exceeded two hours, mortality from SDH rose from 47 to 80% (good outcomes 32 and 4%, respectively). In acute EDH an interval under two hours lead to 17% mortality and 67% of good recoveries compared to 65% mortality and 13% of good recoveries after an interval of more than two hours. Age and concomitant injuries of other body regions proved to be of secondary importance.

Acute Operation and Preventive Nimodipine Improve Outcome in Patients with Ruptured Cerebral Aneurysms

Sixty-five patients with ruptured aneurysms were operated upon within 48 to 72 hours after subarachnoid hemorrhage (SAH) and were treated with a regimen of intra- and postoperative nimodipine for the prevention of symptomatic vasospasm. The clinical grading (Hunt and Hess) was I to III in 49 patients and IV or V in 16. The SAH was mild in 15 patients, moderate in 27, and severe in 23; 12 patients harbored an intracerebral hematoma, and 6 had intraventricular bleeding. Acute hydrocephalus was observed on preoperative computed tomography (CT) in 19 patients. On CT 3 days postoperatively (i.e., Day 3-4 after SAH), 30 of 65 patients still had subarachnoid blood; however, severe symptomatic vasospasm as the deciding threatening event during the delayed postoperative period was not encountered in this series. Transient symptoms of ischemia were noted in 2 patients (3%) and were accompanied by angiographic spasm in 1. Irreversible neurological deficit occurred in 2 patients (3%); in 1 of these, it was a complication of postoperative control angiography. Of the patients preoperatively graded I or II, 96% had an excellent to fair outcome 6 months postoperatively, and 1 patient (4%) had died because of a surgical complication. Among patients preoperatively graded III or IV, 86% had an excellent to fair outcome, and the remaining 14% had a poor outcome. Shunt-dependent hydrocephalus developed in 7% of the patients. Acute surgical repair of ruptured cerebral aneurysms and preventive topical and intravenous administration of nimodipine reduce management complications and improve outcome; above all, ischemic lesions from symptomatic vasospasm are reduced to a minimum.

Virtual Endoscopy for Planning and Simulation of Minimally Invasive Neurosurgery

OBJECTIVE: This article demonstrates the usefulness and the problems of present-state software for virtual endoscopy as a tool for the planning and simulation of minimally invasive neurosurgical procedures. METHODS: The software Navigator (General Electric Medical Systems, Buc, France) was applied for virtual endoscopic visualization of three-dimensional magnetic resonance data sets of healthy volunteers and neurosurgical patients, using a clinical magnetic resonance scanner (1.5-T Signa Hispeed; General Electric Medical Systems). Classical approaches for minimally invasive procedures were simulated. RESULTS: Virtual endoscopy provided impressive three-dimensional views of intracranial and intracerebral cavities, with visualization of many anatomic details of the brains inner and outer surfaces. The method proved to be especially suited for the simulation and planning of operations of intraventricular lesions, for which the technical limitations of the present state of development of this method have fewer implications. However, the present state of technology, as described in this article, has two major shortcomings: 1) the blood vessels cannot be visualized together with the brain tissue and cranial nerves; and 2) different tissue compartments cannot be stained in their original coloring, which would facilitate their recognition and thus orientation in space by anatomic landmarks. Another important disadvantage at this stage is time consumption for many single working steps. CONCLUSION: Virtual endoscopy is a promising tool for teaching and training in intracranial neuroanatomy as well as for planning and simulation of minimally invasive (e.g., endoscopic), mainly intraventricular, operations. Direct clinical application is, at this stage of development, limited by several technical shortcomings of visualization and quantification of distances and modeling of surfaces.

Disturbed cerebrospinal fluid circulation after subarachnoid hemorrhage and acute aneurysm surgery.

In 138 patients with ruptured cerebral aneurysms operated on within 48 to 72 hours after subarachnoid hemorrhage, an external ventricular drainage catheter was inserted before craniotomy and was used intermittently during the first week after surgery. In 51 patients, intracranial pressure (ICP) was

Indications for Surgical Treatment of Cerebellar Haemorrhage and Infarction

SummaryThis report summarizes the outcome of 56 patients with cerebellar lesions of vascular origin, 40 patients with cerebellar infarction, and 16 with spontaneous cerebellar haemorrhage. All patients had computerized tomography: occlusive hydrocephalus was diagnosed in 75% of patients with cerebellar haemorrhage and in 23% with cerebellar infarction.Nine out of 10 patients survived after early surgical evacuation of the haematoma and 4 of them recovered completely. Two patients underwent only external ventricular drainage (EVD), one died after 2 days, and the other recovered with a moderate deficit. Three of 4 medically treated patients died within one week; all had developed occlusive hydrocephalus. The fourth medically treated patient recovered completely; consciousness had never deteriorated nor had occlusive hydrocephalus developed.Among 40 patients with cerebellar infarction, 13 developed progressive deterioration of consciousness; 7 of them underwent decompressive craniectomy of the posterior fossa and survived. One patient had only external ventricular drainage and died. Four out of the 5 medically treated patients died during the acute phase.From these observations and several reports in the literature, it is concluded that both cerebellar haemorrhage and infarction should be operated on as soon as progressive deterioration of consciousness develops. This occurs more frequently in patients with cerebellar haemorrhage than with cerebellar infarction. Individual decisionmaking in each case necessiates intensive neurosurgical observation.

Prevention of symptomatic vasospasm by topically applied Nimodipine

SummaryA 2.4×10−5M solution of the Calcium-antagonist Nimodipine was administered to the exposed cerebral vessels in 17 patients intraoperatively clipping of a ruptured aneurysm. The interval between subarachnoid haemorrhage and operation was 48 to 72 hours. The CT investigation had revealed blood accumulation in the basal cisterns in all cases. Vasodilatation was observed in all instances; the percentage being greater in small vessels as compared to large vessels. Postoperatively, a neurological deficit combined with angiographically verified vasospasm occurred in two patients, but was reversible in both. Fifteen patients remained free from symptomatic vasospasm and were discharged without neurological deficit. In 13 of these patients and 3 additional cases, a plastic cannula was placed intraoperatively so that postoperative topical administration of Nimodipine was possible. Postoperative control-angiograms after a mean interval of 7 days from SAH did not show severe spasm in any of the patients; localised moderate asymptomatic spasm was found in 8 cases and was reserved in 5. Moderate postoperative symptomatic spasm was observed in 2 patients, treated and reversed in one patient. In 5 of 7 cases without evidence of spasm in the angiogram postoperative topical administration of Nimodipine caused vasodilatation. It is concluded, that topical intracisternal administration of Nimodipine reverses intraoperative vascular spasm and decreases the probability of postoperative symptomatic vasospasm after early surgery.

The Cerebral Venous System

&NA; The authors discuss the gross and microscopic anatomy and the physiology of the cerebral venous system. Cerebral veins under pathological circumstances (hypercapnia, arterial hypertension, and increased intracranial pressure), pharmacological observations, the venous blood‐brain barrier, and traumatic involvement are reviewed. Neoplastic involvement and radiological aspects are included. Surgical reconstruction of venous sinuses (including the Donaghy technique), tumor removal, sinus thrombectomy, and extraanatomical bypass of the transverse sinus are discussed. (Neurosurgery 17:663‐678, 1985)

Intracranial pressure oscillations (B-waves) caused by oscillations in cerebrovascular volume.

SummaryIn experiments during stepwise increases in intracranial pressure, B-waves could be provoked synchronously with pial vascular diameter oscillations. The vascular oscillations are known to be a sign of myogenic cerebrovascular regulation. An increase in their amplitude indicates vessel wall relaxation and impending failure of myogenic autoregulation. Therefore, vascular oscillations provoked during intracranial hypertension can be ascribed to a fall in transmural pressure and vessel wall tension. The resulting oscillations in the cerebral blood volume are reflected by ICP oscillations and lead to synchronous variation in ICP, the so-called “B-waves” with a frequency of 0.5 to 2 per minute.

Experimental intracerebral hemorrhage: Description of a double injection model in rats

For experimental purposes, the most common technique of producing an intracerebral hematoma in rats is the injection of unclotted autologous blood. All modifications of this model share the problem that size and extension of the hematoma are not reproducible, because the injected blood either ruptures into the ventricular system or it extends to the subarachnoid or subdural space. Therefore a double injection model of experimental intracerebral hemorrhage in rats has been developed using 19 male Sprague-Dawley rats. After inducing anesthesia a cannula was stereotactically placed into the caudate nucleus and an intracerebral hematoma was produced with the double injection method in which first a small amount of fresh autologous blood is injected which is allowed to clot (preclotting) in order to block the way back along the needle track; the actual hematoma is produced in a second step of the injection. The clot volume was measured on stained serial sections. A total injection volume of 50 microliters of autologous blood produced intracerebral hematomas of 41.1 +/- 10.0 microliters and of similar shapes. The double injection method allows to generate reproducible hematomas in rats. This new model of intracerebral hemorrhage will allow further investigation of fibrinolytic and cytoprotective therapies.

Unfavorable outcome following early surgical repair of ruptured cerebral aneurysms-A critical review of 238 patients

Among 238 consecutive patients admitted early with ruptured cerebral aneurysms, surgical repair within 48-72 hours was feasible in 200 cases. Unfavorable outcomes among the latter 200 patients are analyzed and discussed in this paper. Preoperatively, 148 patients were in Hunt and Hess grades I-III, 33 were in grade IV, and 19 in grade V. After clipping of the aneurysm, all patients received a regimen of topical intracisternal and intravenous/peroral medication with the calcium antagonist nimodipine. The overall rate of unfavorable outcomes was 25%, ie, outcome with moderate or severe deficit or lethal outcome. The reasons for unfavorable outcomes among these 49 patients were the devastating effect of the bleed (severe subarachnoid hemorrhage or additional intracerebral hemorrhage) in 31 patients (15% of the 200 patients), a surgical complication in 11 (5.5%), preoperative rebleeding in three (1.5%), delayed ischemia from vasospasm in one (0.5%), and various others in three further patients (1.5%). Unfavorable outcome occurred in 11% of patients with preoperative grades I-III, in 52% of patients with grade IV, and in 16 of 19 patients with grade V. Among the 141 patients with subarachnoid hemorrhage but not intracerebral or intraventricular hematoma, 16 made an unfavorable outcome, ie, 11% versus 56% among patients with intracerebral hematoma/intraventricular hematoma on preoperative computed tomography scan. The present data seem to speak in favor of early surgery. Since half of the patients with intracerebral hematoma and poor outcome had suffered previous warning leaks, it appears to be a continuing challenge to diagnose warning leaks before a massive hemorrhage occurs.