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Biomedical subjects

R F Spetzler

Publications and source records attributed to R F Spetzler.

At least 199 records · Page 11Linked to original sources
PubMed1989

The efficacy of intravenous nimodipine in the treatment of focal cerebral ischemia in a primate model.

The clinical and pathological effects of nimodipine on cerebral infarction were investigated in 12 male baboons. In randomized/blind trials, six animals given intravenous nimodipine (2 micrograms/kg/min load, 1 microgram/kg/min maintenance) for 96 hours starting 50 minutes before 6-hour double-clip occlusion of the middle cerebral artery were compared to 6 control animals. Standardized neurological examinations were performed by examiners blinded to the animals' therapy on Day 7 and Day 14 after stroke. On Day 14 the animals were killed. The brains were studied pathologically, and the relative areas of infarction were quantified. Intracranial pressure was lower in nimodipine-treated animals; however, the range of intracranial pressure values in each group was broad. Two control animals with high intracranial pressure died. There were no deaths among the nimodipine-treated animals. The neurological scores on Days 7 (P less than or equal to 0.01) and 14 (P less than or equal to 0.05) were significantly different between the two groups. The nimodipine-treated animals had less clinical evidence of infarction compared to controls. Nimodipine-treated animals tended to have smaller areas of infarction; however, the difference between the two groups was not statistically significant. The infusion of nimodipine in the treatment of focal cerebral ischemia is safe and does not appear to aggravate the extent of infarction or to exacerbate intracranial hypertension. The clinical neurological evaluations indicate that nimodipine may improve or preserve neurological outcome after stroke.

Animals↗
PubMed1989

Synovial chondromatosis of the temporomandibular joint with intracranial extension. Case report.

The authors report the unusual presentation of an intracranial extension of synovial chondromatosis of the temporomandibular joint. The patient presented with a peripheral facial nerve paralysis and anacusis. Computerized tomography revealed the lesion, but fine-needle biopsy was inconclusive. Craniotomy with removal of the tumor was performed, and pathological studies confirmed the diagnosis. The facial nerve dysfunction was thought to be secondary to direct neural compression.

Chondroma↗
PubMed1989

Management of juvenile spinal AVM's by embolization and operative excision. Case report.

A small group of spinal arteriovenous malformations (AVM's) most commonly present in children or young adults, are characterized by a large size, high flow, the presence of multiple feeders, and frequent extension to paraspinous structures. Cardiac output requirements may be significantly increased by these so-called "juvenile" malformations, and a bruit is commonly noted. This report describes the obliteration of a juvenile spinal AVM. Staging of embolization and operative procedures was used to obliterate the AVM successfully without morbidity.

Adult↗
PubMed1989

The transoral approach to the superior cervical spine. A review of 53 cases of extradural cervicomedullary compression.

The transoral-transclival surgical approach is the most direct operative approach to pathology ventral to the brain stem and superior spinal cord. In selected patients, this approach is efficacious in the treatment of extradural compressive lesions from the cervicomedullary junction to the C-4 vertebra. The authors have used the transoral surgical approach in treating 53 patients with lesions compressing the ventral extradural brain stem or the cervical cord. The evaluation, management, and long-term outcome of these patients are described (median follow-up time 24 months). The operative morbidity rate in this series was 6%, and the operative mortality rate was zero. The authors review specific features of the transoral procedure, including methods of retraction, microsurgical techniques, and adjunctive measures to avoid cerebrospinal fluid fistulae, that contributed to these good results.

Adolescent↗
PubMed1989

Protection against cerebral ischemia: the role of barbiturates.

Cerebral ischemia is a complex injury process that occurs when the nutrient blood supply to cerebral structures is reduced below critical levels. The causes of cerebral ischemia are protean, but the underlying pathophysiologic mechanism that leads to injury is a mismatch between the supply of nutrients to a given cell (or population of cells) and the demand of the cell(s) for those essential nutrients. Extensive research is ongoing in our attempt to find a treatment strategy and/or pharmacologic agent that might protect cerebral structures when exposed to ischemia. To date, few strategies or agents have proven themselves truly "protective." In this communication, the complexities of the cerebral ischemia injury process will be reviewed, the principles of cerebral protection (both practical and theoretical) will be outlined, and the merits of barbiturate anesthesia with regard to planned temporary cerebral ischemia will be discussed.

Barbiturates↗
PubMed1988

Cerebral cavernous malformations. Incidence and familial occurrence.

We studied 24 patients with histologically verified cerebral cavernous malformations, reviewing the familial occurrence and presenting signs, symptoms, and radiographic features of the disorder. Eleven patients had no evidence of a heritable trait and had negative family histories. Thirteen patients were members of six unrelated Mexican-American families. Sixty-four first-degree and second-degree relatives were examined, and family pedigrees were established. Most relatives (83 percent) were asymptomatic; 11 percent had seizures. Magnetic resonance imaging was performed in 16 relatives (5 of whom were asymptomatic). Fourteen of the 16 studies revealed cavernous malformations; 11 studies identified multiple lesions. As compared with computerized tomography and angiography, magnetic resonance imaging was far more accurate in detecting cavernous malformations. We conclude that cavernous malformations are more prevalent than previously reported, and that a familial form of the disorder exists that is more common than expected, with a high incidence of multiple lesions and an increased frequency of occurrence among Mexican-American families. Magnetic resonance imaging is the radiographic technique of choice for the identification and follow-up of these lesions.

Cerebral Angiography↗
PubMed1988

Surgical management of large AVMs.

The surgical management of large AVMs (those greater than 6 cm in maximal diameter) should be based on a thorough understanding of the chronic hemodynamic changes produced by lesions and the acute stress placed on the cerebral vasculature by their removal. In addition to haemorrhage, seizure, and headache, these larger lesions often present with symptoms of cerebral vascular insufficiency. Angiography frequently demonstrates a high-flow arteriovenous shunt with evidence of vascular steal from the surrounding brain. In many cases there is a virtual absence of normal hemispheric filling. When the steal is sufficient to produce an area of chronic ischaemia in the brain surrounding the AVM, there is an increased risk of swelling and haemorrhage associated with complete excision. We have developed a strategy for the surgical management of these large lesions that involves a stepwise reduction of flow through the AVM using pre- and intraoperative embolization, followed by complete excision. The details of this management strategy are described, and results in 24 patients with exceptionally large AVMs are presented.

Adult↗
PubMed1988

The transoral approach to the anterior superior cervical spine. A review of 29 cases.

The transoral surgical approach is the most direct operative approach to pathology ventral to the brain stem and superior spinal cord. This approach is useful in the treatment of extradural compressive cervicomedullary lesions in selected patients. Twenty-nine patients with ventral extradural brain stem or cervical cord compressive lesions who were treated via the transoral surgical approach are presented. Their evaluation, treatment, and long-term outcome will be reviewed (median follow-up, 24 months). Specific features of the transoral procedure, including intraoperative monitoring, methods of retraction, and microsurgical techniques that contributed to minimal operative morbidity (3%) and zero operative mortality, will be discussed.

Humans↗
PubMed1988

The association of venous and cavernous malformations. Report of four cases and discussion of the pathophysiological, diagnostic, and therapeutic implications.

Four cases of venous malformation associated with a cavernous malformation are reported. Because cavernous malformations are often angiographically occult and do not have a characteristic appearance on computed tomography (CT), they are seldom recognized preoperatively and may be missed if the surgical specimen is not carefully reviewed. This association, however, may not be rare and may explain the presence of symptomatic venous malformations. Magnetic resonance (MR) imaging is particularly sensitive in detecting cavernous malformations and is highly specific. It is recommended that every symptomatic venous malformation be worked-up with a high field strength MR Unit.

Adult↗
PubMed1988

Comparative transoral dural closure techniques: a canine model.

A watertight dural closure is difficult to achieve after transoral-transclival operation for ventral intradural lesions at the craniocervical junction. These procedures have a high morbidity and mortality from cerebrospinal fluid (CSF) fistula, meningitis, and abscess. We used a canine model to test three different techniques of dural closure after transoral intradural operation: primary suture closure, laser patch weld, and fibrin glue patch closures. The primary suture closure technique was inadequate. All eight leaked CSF at the time of operation, and five had radiographic leaks and were incompetent at autopsy. All seven of the laser closures leaked CSF at operation, yet only one was incompetent at autopsy. The fibrin glue technique was superior and provided a solid seal at operation, even with repeated Valsalva maneuvers to 40 mm Hg. The immediate and persistent seal at operation is clinically significant because it may prevent CSF leak, meningitis, and abscess formation in human patients after transoral surgery. Fibrin glue is excellent for repairing complex dural defects and merits evaluation in clinical trials.

Animals↗
PubMed1988

Aneurysms of the basilar artery treated with circulatory arrest, hypothermia, and barbiturate cerebral protection.

Complete circulatory arrest, deep hypothermia, and barbiturate cerebral protection are efficacious adjuncts in the surgical treatment of selected giant intracranial aneurysms. These techniques were utilized in seven patients, one with a large and six with giant basilar artery aneurysms; four had excellent results, one had a good result, one had a fair outcome, and one died. The rationale for the use of complete cardiac arrest with extracorporeal circulation, hypothermia, and barbiturate cerebral protection is outlined. The surgical and anesthetic considerations are reviewed. The perioperative morbidity and long-term results support the use of these techniques in selected patients with complex intracranial vascular lesions.

Aged↗
PubMed1988

Reconstruction of the MCA bifurcation after excision of a giant aneurysm. Technical note.

A patient with a giant aneurysm of the left middle cerebral artery (MCA) presented with a history of subarachnoid hemorrhage and ischemic symptoms. When the aneurysm was explored, its base was found to be very firm and atherosclerotic. Temporary clips were applied to the MCA, the aneurysm was excised, and the MCA bifurcation was reconstructed using microsurgical techniques. Good flow in the reconstructed MCA trunk was demonstrated by intracranial Doppler ultrasonography. A description of the operative procedure is presented.

Cerebral Angiography↗
PubMed1988

Appearance of venous malformations on magnetic resonance imaging.

The magnetic resonance (MR) imaging appearance of venous malformations, all angiographically verified, was evaluated in 11 patients. A venous malformation is characteristically depicted as a tubular area of decreased signal intensity in the white matter of the brain. In one patient, a histologically verified cavernous malformation was also present with a characteristic mixed signal-intensity core on the T2-weighted MR images. Care should be used when evaluating venous angiomas to exclude the presence of a lesion with associated prominent venous drainage, such as a glioma.

Brain Neoplasms↗
PubMed1988

Recurrent Lhermitte-Duclos disease in a child. Case report.

A case of recurrent Lhermitte-Duclos disease (dysplastic gangliocytoma of the cerebellum) in a child is described with a summary of the clinical presentation and associated malformations, and a review of other cases reported in the literature. The histological examination and electron microscopic findings, with special reference to the cytological changes found during evaluation of the recurrence, are presented. Theories regarding the pathogenesis of Lhermitte-Duclos disease are reviewed.

Adolescent↗