Chester W. Beyer

Cerebrospinal fluid dynamics in patients with pseudotumor cerebri

CSF dynamics were determined as a function of intracranial pressure in patients with pseudotumor cerebri. Servocontrolled variable rate lumbar infusions were used to determine net CSF-absorptive capacities and resting pressures in 10 patients; serial studies were done in 5 of the patients. Nearly all of the patients had abnormally low CSF-absorptive capacities. On the other hand, marked elevations in resting pressure were not a constant feature of the disease. Concurrent changes in the cerebrovascular bed could introduce errors into this manometric determination of CSF dynamics; the significance of this potential artifact is examined. The results of this study suggest that the CSF compartment may be of etiological importance in the pathophysiology of pseudotumor cerebri.

Intravascular use of isobutyl 2-cyanoacrylate: Part 1 Treatment of intracranial arteriovenous malformations.

The intravascular use of the rapidly polymerizing acrylic compound, isobutyl 2-cyanoacrylate (IBC), in 10 patients with intracranial arteriovenous malformations (AVMs) is described. The monomer was introduced into each malformation at craniotomy using angiographic control and microvascular dissection technique to identify, isolate, and inject the major components of each vascular lesion while attempting to preserve normal arterial circulation. Postoperative angiography was used routinely to evaluate the results of IBC embolization. Four patients underwent the injection and immediate surgical excision of an intracranial AVM, and 6 underwent injection alone; 3 of the latter had residual malformation demonstrated on postoperative angiography, and 1 of these patients had the remnants of her malformation occluded by a second embolic procedure. There was no operative mortality nor permanent neurological morbidity. Three patients suffered transient neurological dysfunction in the immediate postoperative period.

Failure of extracranial-intracranial arterial bypass in acute middle cerebral artery occlusion: case report.

Extracranial-intracranial arterial bypass procedures provide important augmentation of collateral circulation to cortical areas rendered potentially ischemic by therapeutic occlusion of major branches of the circle of Willis. Although the case studies reported to date in general reflect positively on this use of the bypass procedure, this report of a patient who failed to tolerate acute middle cerebral artery occlusion despite the presence of a patent superficial temporal-middle cerebral artery branch anastomosis points up several of the practical and theoretical limitations of this therapeutic approach. Certain modifications of the timing of the bypass procedure, the selection of donor and recipient arteries, and the mechanics of intracranial arterial occlusion may allow a wider application of extracranial-intracranial arterial bypass in this therapeutic setting.

Servo-controlled lumbar infusions: a clinical tool for the determination of CSF dynamics as a function of pressure.

The variable rate lumbar subarachnoid infusion technique allows rapid quantitative study of the cerebrospinal fluid (CSF) compartment. Numerous pressure plateaus are studied in a brief time period with a servo-controlled system. The test determines the difference between rates of CSF absorption and formation as a function of pressure. On-line computer data analysis increases experimental efficiency to guarantee statistical significance. Animal and patient data are presented in the report.

Traumatic middle cerebral artery aneurysm: case report.

A case of traumatic middle cerebral artery aneurysm is presented. The case demonstrates some of the difficulties encountered when dealing with this type of aneurysm. The unusual surgical approach required for obliteration is described.

Furosemide in the intraoperative reduction of intracranial pressure in the patient with subarachnoid hemorrhage.

The effect of furosemide in the intraoperative reduction of intracranial pressure was measured in 25 patients undergoing the operative repair of a ruptured intracranial aneurysm. Seven patients with similar intracranial lesions served as controls. A single bolus of 80 mg of furosemide was administered intravenously after the induction of anesthesia, and sequential measurements were made of intracranial pressure, mean arterial pressure, and arterial blood gases. A mean decrease of intracranial pressure of 56% was measured in the furosemide-treated patients, whereas the control patients demonstrated a mean decline of subarachnoid pressures of 18%. These changes are significant at the P less than 0.005 confidence level, whereas changes in mean arterial pressure, mean arterial pCO2, and base line arterial pCO2 were statistically insignificant. This study suggests that intravenous furosemide is a quick, dependable, and effective mechanism for the intraoperative reduction of intracranial pressure in the postsubarachnoid hemorrhage aneurysm patient.

Serum and CSF Brain-Specific Isoenzyme Profiles in Experimental Cerebral Ischemia and Infarction

The goal of our investigative efforts has been to develop an objective means by which ischemic infarction of brain tissue can be promptly and reliably detected and the volume of infarcted tissue can be usefully estimated. The precedent for our investigations stems from the significant role that isoenzyme determination has had in the evaluation of myocardial ischemia and infarction and arises directly from the work of two investigators at our institution6 who developed the radioimmunoassay technique for the delineation of the brain-specific isoenzyme creatine phosphokinase BB (CK-BB). Utilizing these two investigators’ radioimmunoassay technique with their assistance and encouragement, we have attempted to apply this method of quantification to a canine experimental stroke model.