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Biomedical subjects

M H Lavyne

Publications and source records attributed to M H Lavyne.

At least 19 recordsLinked to original sources
PubMed1992

Epidural steroids, postoperative morbidity, and recovery in patients undergoing microsurgical lumbar discectomy.

Intraoperative epidural corticosteroids have been used by some surgeons to decrease pain following surgery for a herniated lumbar disc. In this study, 84 consecutively treated, comparable patients with unilateral lumbar disc herniation were prospectively assigned randomly to receive either epidural corticosteroids (40 mg methylprednisolone acetate) or saline at the conclusion of the operative procedure. The postoperative morbidity of these two groups was evaluated by tabulating the following parameters: pain relief as measured by consumption of postoperative pain medications; the length of hospital stay; postoperative functional status; and the time interval from surgery until return to work. The mean postoperative analgesic medications consumed was 12.2 +/- 1.9 mg of morphine equivalents in the corticosteroid group versus 12.2 +/- 1.8 mg of morphine equivalents in the control group. The mean hospital stay was less than 2 days in each group, and the mean interval until return to work was 21.2 +/- 2.7 days in the corticosteroid group versus 25.4 +/- 3.1 days in the control group. Moreover, no statistically significant difference was measured between the steroid-treated and control groups when the data were stratified for sex, age, and site of disc herniation. The mean outcome scores, which are derived from a postoperative assessment of pain relief resulting from surgery, functional status, and interval until return to work, were identical in the corticosteroid and control groups. This study concludes that epidural corticosteroid administration after microsurgical lumbar discectomy for unilateral disc herniation does not lessen postoperative morbidity or improve functional recovery.

Adolescent↗
PubMed1990

Is magnetic resonance imaging useful in guiding the operative approach to large pituitary tumors?

Forty-two patients with large pituitary tumors were studied with magnetic resonance imaging scans. Based on the operative findings, the tumors were divided into two groups. Tumors in Group 1 (n = 35) were soft or partially necrotic and were easily removed by suction and curettage. Tumors in Group 2 (n = 7) were firm and required sharp dissection or use of the laser for removal. Tumors were divided into two groups based on the long TR signal: a) isointense in comparison with white matter, or b) hyperintense in comparison with white matter. All 7 firm tumors (Group 2) had an isointense signal on long TR sequences. Thirty-two of 35 soft tumors showed a hyperintense signal on long TR sequences, and 3 an isointense signal. Based on these results, we recommend a transsphenoidal approach for the initial operation in patients with large pituitary tumors. If the tumor is largely isointense on the magnetic resonance imaging scan, we discuss with the patient preoperatively the possibility (70% in this series) that the tumor may be too firm to remove in a single transsphenoidal procedure. In these circumstances, a second, transcranial, procedure may be required to decompress the suprasellar structures adequately.

Adenoma↗
PubMed1990

Retrospective analysis of microsurgical and standard lumbar discectomy.

This report retrospectively evaluates 112 cases of microsurgical lumbar discectomy (MICRO) and 35 cases of standard discectomy (STND) performed by one neurosurgeon using data derived from a questionnaire and from chart review. The total amount of postoperative pain medication consumed and postoperative temperature curves in each group were compared to determine how postsurgical morbidity was affected by the MICRO and STND procedures. At a mean follow-up interval of 12.3 and 41 months, 97% of the MICRO respondents reported a good or excellent outcome. Patients with preoperative symptoms exceeding 6 months returned to work in 9.9 +/- 1.7 weeks; this interval decreased to 5.58 +/- 0.75 weeks, and overall outcome score improved significantly at 41 months' follow-up if symptoms were less than or equal to 6 months in duration before surgery. At 44 months' mean follow-up, 88% of the STND respondents reported a good or excellent outcome with no decrease in the return-to-work interval in patients who described symptoms of 6 months or less. Mean postoperative pain medication consumed by MICRO patients was one tenth that of STND patients, and temperature curves showed significant temperature elevations in the STND group when compared with the MICRO group, in which patients remained afebrile throughout the postoperative period. Within the limitations of a retrospective study, these data support the conclusion that a microsurgical approach to the lumbar herniated disc provides a more frequent and rapid convalescence than the STND approach.

Adult↗
PubMed1987

Tuboovarian abscess presenting as sciatic pain: case report.

The authors report the successful conservative treatment of a tuboovarian abscess in a 25-year old woman who presented with low grade fever and severe right sciatic pain. Computed tomography and ultrasonography corroborated a clinical diagnosis of tuboovarian abscess after an initial diagnosis of epidural abscess had been made. This is the first report of a tuboovarian abscess presenting principally as sciatic pain. The diagnosis and treatment of this lesion are discussed.

Abscess↗
PubMed1986

Colonic perforation by ventriculoperitoneal shunts.

Two cases of colonic perforation by a ventriculoperitoneal shunt are presented. One was diagnosed by routine abdominal roentgenograms, the other by instilling metrizamide into the distal shunt tubing. A review of the 32 previously reported cases revealed a mortality of 15%. Bowel perforation from a ventriculoperitoneal shunt should be managed with intravenous antibiotics as well as removal of the shunt. If the patient has a benign abdominal examination and no prior history of abdominal complications from a ventriculoperitoneal shunt then the abdominal catheter can be removed percutaneously. However, in the presence of severe peritonitis, or a previous history of serious abdominal problems from the shunt catheter, such as an infected pseudocyst or other intraabdominal pathology, such as active regional enteritis or an abscess, we recommend laparotomy for removing the catheter with primary closure of the bowel perforation.

Adolescent↗
PubMed1986

Craniotomy versus transsphenoidal excision of large pituitary tumors: the usefulness of magnetic resonance imaging in guiding the operative approach.

Fifteen patients with large pituitary tumors were studied with computed tomography (CT) and magnetic resonance imaging (MRI). CT was performed using General Electric 8800 and 9800 scanners (General Electric Co., Medical Systems Division, Milwaukee, Wisconsin). MRI was performed utilizing a Technicare superconducting scanner (Technicare, Cleveland, Ohio) at 0.5 tesla. Based on the operative findings, the tumors were divided into two groups. Tumors in Group 1 (n = 12) were described by the surgeon as soft or partially necrotic and easily removed by suction and curettage. Tumors in Group 2 (n = 3) were firm and required sharp dissection or the laser for removal. The tumors were divided into four categories based on MRI signal: (a) isointense with surrounding brain on spin echo (SE) 30 and SE 90, (b) increased signal intensity on SE 30 and SE 90, (c) decreased signal intensity on SE 30 and increased signal intensity on SE 90, and (d) isointense signal on SE 30 and increased signal intensity on SE 90. All three of the firm tumors were isointense with brain on MRI appearance. The tumor consistency (firm vs. soft) was not differentiable on CT scan. The transsphenoidal approach is less satisfactory than craniotomy in cases of firm, fibrous pituitary tumors. Based on our preliminary data, if the MRI signal in the tumor is isointense, then the surgeon should be prepared to deal with a fibrous tumor and might elect a transcranial rather than a transsphenoidal approach.

Adult↗
PubMed1986

Medulla oblongata edema associated with neurogenic pulmonary edema. Case report.

Neurogenic pulmonary edema (NPE) occurs in association with central nervous system disease without underlying cardiopulmonary problems. It is characterized by profound pulmonary vascular congestion and a fulminant clinical course. Although several reports document a role for experimental brain-stem lesions in the production of NPE, there have been only two studies in man correlating specific brain-stem lesions with NPE. The authors report a case of NPE occurring in a patient with von Hippel-Lindau disease and a dorsal medullary syrinx with postoperative dorsal medullary edema. The anatomical location of this patient's lesion is reviewed in the context of alternative theories of the pathogenesis of NPE.

Adult↗
PubMed1986

Effect of naloxone on cerebral perfusion and cardiac performance during experimental cerebral ischemia.

Transient global cerebral ischemia (TGI) was induced in awake rats using the "four-vessel" occlusion model of Pulsinelli and Brierley. Blood pressure, arterial blood gases, cerebral blood flow, and cardiac output were measured during the acute (up to 2 hours) and chronic (2 to 72 hours) postischemic time periods. Coincident with the onset of TGI, cardiac output and caudate blood flow were depressed. The former returned to baseline within 30 minutes after the conclusion of TGI, and the latter progressed to hyperemia at 12 hours (81.8 +/- 4.9 vs 68.6 +/- 3.9 ml/min/100 gm tissue (mean +/- standard error of the mean] and oligemia at 72 hours (45.5 +/- 4.8 ml/min/100 gm tissue) post-TGI in the untreated control rats. Arterial blood gases and blood pressure were unchanged. Naloxone (1mg/kg) given at the time of TGI or as late as 60 minutes post-TGI and every 2 hours thereafter for 24 hours or bilateral cervical vagotomy prevented the depression in cardiac output and blocked the hyperemic-oligemic cerebral blood flow pattern that was predictive of stroke in this rat model. Changes in cardiac output after TGI in this model appear to be mediated by parasympathetic pathways to the heart from the brain stem. Opiate receptor blockade probably blocks endogenous opioid peptide stimulation of these brain-stem circulatory centers, which results in inhibition of parasympathetic activity and improvement in cardiac output. The usefulness of naloxone in the treatment of experimental stroke may be a function of its ability to improve cerebral perfusion in pressure-passive cerebrovascular territories. Variations in cardiac output during experimental stroke may explain the dissimilar responses to naloxone treatment reported by other investigators of experimental stroke.

Animals↗
PubMed1985

Intracranial space-occupying lesions in acquired immune deficiency syndrome patients.

The recent description of the acquired immune deficiency syndrome (AIDS) followed the observation of an increased incidence of unusual neoplasms and opportunistic infections in previously healthy homosexual men, intravenous drug abusers, Haitians, hemophiliacs, and certain infants. Active research efforts on this group of patients established a defect in cellular immunity. Six patients with AIDS who underwent neurosurgical procedures for intracranial space-occupying lesions are presented. Two of the patients had toxoplasmosis brain abscesses, one had primary central nervous system lymphoma, one had cytomegalovirus encephalitis, one had progressive multifocal leukoencephalopathy, and one patient remained undiagnosed despite pathological examination of the brain tissue specimen. We recommend brain biopsy in AIDS patients with space-occupying lesions because the regimen for the various conditions differs. Although the central nervous system diseases found in AIDS patients are associated with a high mortality rate, four of the six patients responded favorably to specific treatment.

Acquired Immunodeficiency Syndrome↗
PubMed1979

Clinical and radiologic remission in reticulum cell sarcoma of the brain.

Two patients with cerebral reticulum cell sarcoma (CRCS) are reported in whom neurologic abnormalities and radiologic (computerized tomographic [CT] scan) evidence of tumor remitted. In one patient, remission followed craniectomy and corticosteroid therapy and lasted for eight months. In the other patient, at least four remissions occurred over a span of seven years, each in conjunction with the administration of corticosteroids. Corticosteroids may favorably alter the biologic activity of tumor tissue in some cases of CRCS, predisposing to clinical remission and disappearance of tumor on CT scan.

Adult↗
PubMed1978

Localization of vertex lesions seen on CT scan.

A simple method is presented for localizing the anatomical site of vertex lesions seen on a computerized tomography (CT) brain scan, using the patient's plain lateral skull film.

Brain Neoplasms↗
PubMed1977

Decrease in neostriatal blood flow after D-amphetamine administration or electrical stimulation of the substantia nigra.

Local blood flow was measured in the caudate nuclei and, in some cases, other areas of rat and monkey brain by the hydrogen clearance technique. Resting values for caudate blood flow in the rat were similar to those reported elsewhere, i.e., 69 +/- 4 ml/min/100 g in the caudate. Administering D-amphetamine sulfate (0.5 mg/kg, i.p.) to rats reduced caudate flow by a maximum of about 33% after 30 min; this effect could be blocked by pretreatment with haloperidol (5.0 mg/kg, i.p.), a drug that blocks dopamine receptors. D-Amphetamine sulfate (1.5 mg/kg) also reduced caudate but not cortical blood flow in unanesthetized monkeys. Electrical stimulation of the pars compacta of the substantia nigra reduced ipsilateral caudate flow by about 25% without affecting flow in the contralateral caudate. This effect varied with the frequency and intensity of stimulation. These studies suggest that the intraparenchymal release of brain dopamine may modify intraparenchymal (local) blood flow.

Animals↗
PubMed1976

Reversal of experimental cerebral vasospasm by intravenous nitroprusside therapy.

Cerebral vasospasm was induced in dogs by intracisternal injection of blood. After angiographic demonstration of spasm, sodium nitroprusside was infused intravenously and its effect on the diameter of the basilar artery was studied angiographically. Ten experiments were performed within 90 minutes of the induction of spasm and nine experiments were performed 24 or 48 hours later. Significant dilatation of the basilar artery was achieved in all cases and it persisted for as long as the infusion of nitroprusside continued. The drug produced a modest degree of systemic hypotension. In six experiments it was possible to avoid hypotension by a simultaneous infusion of dopamine.

Animals↗