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Biomedical subjects

M H Lavyne

Publications and source records attributed to M H Lavyne.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1983

Subchoroidal trans-velum interpositum approach to mid-third ventricular tumors.

Our experience with the subchoroidal, trans-velum interpositum approach to mid-3rd ventricular tumors is reviewed, and our operative technique is described. Excellent exposure of the mid-3rd ventricle is gained by opening the foramen of Monro posteriorly after dividing the septal vein and/or the thalamostriate vein from the ipsilateral internal cerebral vein. There has been no morbidity or mortality in eight successive cases. The principal advantage of this technique is that the fornix is preserved and memory function is not at risk.

Adolescent↗
PubMed1983

Intraoperative localization of subcortical brain tumors: further experience with B-mode real-time sector scanning.

Intraoperative ultrasonography is a potentially useful tool for the neurosurgeon faced with the task of finding and removing small subcortical brain tumors. With the B-mode real-time sector scan equipment now available, satisfactory images of the intracranial contents can be obtained. Others have reported obtaining images by applying the transducer directly to the dura mater or cortex. This carries the risk of pressure damage to the brain. Furthermore, the presence of acoustical noise in the region close to the transducer results in poor image resolution in the superficial region of the cortex. To circumvent these two problems, we have used a saline-filled cylinder placed over the craniotomy site to achieve acoustical coupling. This technique also increases the area of cortex visualized by the pie-shaped beam of the sector scan by separating the transducer from the brain surface.

Adenocarcinoma, Papillary↗
PubMed1983

Effect of low dose gamma-butyrolactone therapy on forebrain neuronal ischemia in the unrestrained, awake rat.

Low dose gamma-butyrolactone (GBL) therapy alters the natural history of experimental forebrain ischemia in the awake rat. After 30 minutes of four-vessel ischemia, repeated hydrogen cerebral blood flow determinations in awake rats over 72 hours revealed that low dose GBL therapy prevented the development of regional cerebral hyperemia and later the prolonged cerebral hypoperfusion that was experienced by the nontreated controls. Moreover, the low dose GBL-treated group had significantly less neuronal tissue loss than that in comparable brain regions of the nontreated controls. Before the stroke studies, GBL dose-response experiments performed on normal rats indicated that high dose GBL therapy produced seizures, systemic hypertension, metabolic acidosis, hyperthermia, and death.

4-Butyrolactone↗
PubMed1982

Simple decompression and occasional microsurgical epineurolysis under local anesthesia as treatment for ulnar neuropathy at the elbow.

Decompression of the ulnar nerve in the cubital tunnel will reverse ulnar neuropathy at the elbow in most patients. We believe that operating under local anesthesia has allowed us to identify those few patients who will not respond to simple decompressive surgery. Among the 20 cases of ulnar neuropathy managed in this fashion, intraoperative motor-sensory improvement occurred after simple decompressive surgery in 16. Four patients who failed to improve after cubital tunnel decompression underwent microsurgical epineurolysis immediately thereafter, under the same local anesthetic, with prompt improvement. Local anesthesia and microsurgical epineurolysis seem to be useful adjuncts to simple decompressive surgery for ulnar neuropathy.

Female↗
PubMed1981

Ventriculoatrial shunting for hydrocephalus complicating tuberculous meningitis.

Relatively little attention has been focused on the management of increased intracranial pressure which develops in patients with tuberculous meningitis. In the acute phase of infection, cerebral edema is the most common cause; whereas in the subacute or chronic phases, hydrocephalus is most often implicated. Patients with tuberculous meningitis may fail to show neurologic improvement or deteriorate despite appropriate medical therapy, no matter what the pathogenesis of increased intracranial pressure. The patient we describe illustrates the usefulness of ventricular shunting in patients with hydrocephalus who fail to respond to the administration of antituberculous and pressure-reducing agents.

Aged↗
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↗