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.

Brain H-3-catecholamine metabolism in experimental cerebral ischemia.

Unilateral ligation of a common carotid artery in gerbils causes a major depletion of brain dopamine, which is most marked in brain regions known to receive dopaminergic projections. To determine whether this depletion reflects release of stored dopamine, a radioactive label (H-3-dopamine) was introduced into brain dopamine pools 4 hours prior to ligation. Twenty-four hours later, brain H-3-catecholamines were profoundly depressed ipsilateral to the lesion among animals exhibiting clinical signs of stroke. Within brain regions known to receive dopaminergic projections, common carotid ligation also was associated with a selective decrease in the concentration of H-3-deaminated metabolites. These data suggest that cerebral ischemia is associated with release of catecholamines, as well as with impaired oxidative metabolism of catecholamines.

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.

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.

A variable-angled suction nerve root retractor for lumbar spine surgery.

A simple, variable-angled suction nerve root retractor is described for use primarily in lumbar disc surgery.

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.

Thoracic complications of ventriculoperitoneal shunts: case report and review of the literature.

Thoracic complications of ventriculoperitoneal shunts are rare, but potentially serious. The authors report a case of a drainage of cerebrospinal fluid into the tracheobronchial tree through a peritoneal shunt catheter that migrated into the chest. After injection of contrast material into the shunt, a plain radiograph of the chest revealed a bronchogram. The symptoms resolved after a revision of the shunt. Published case reports of this and other thoracic complications of ventriculoperitoneal shunts are comprehensively reviewed. A classification of such complications into three types is proposed as follows: intrathoracic trauma during placement of a shunt, migration of the peritoneal catheter into the chest (by either a supradiaphragmatic or a transdiaphragmatic route), and pleural effusion accompanying cerebrospinal fluid ascites. The possible mechanisms and contributing factors are discussed.

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.

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.

Retractor for lumbar microdiscectomy: technical note.

The authors describe a modification of an existing lumbar spine retractor for use in lumbar microdiscectomy.

Symptomatic spinal epidural lipomatosis after local epidural corticosteroid injections: case report.

OBJECTIVE AND IMPORTANCE: Spinal epidural lipomatosis, which causes symptomatic compression of neural elements, is a well known but uncommon complication of Cushing's syndrome. Spinal epidural lipomatosis has been reported frequently in association with chronic systemic corticosteroid therapy, but thus far only one case has been attributed to local epidural corticosteroid injections. CLINICAL PRESENTATION: We report another case of symptomatic spinal epidural lipomatosis after epidural corticosteroid injections. This is the first such case documented by magnetic resonance imaging and confirmed with surgical exploration. INTERVENTION: The patient's symptoms of neurogenic claudication resolved after lumbar laminectomy in the region of previous corticosteroid injections and the removal of epidural fat, which was compressing the thecal sac. CONCLUSION: This case should alert clinicians that epidural lipomatosis, which causes symptomatic thecal sac compression, is a possible complication, not only of systemic glucocorticoid therapy, but also of local epidural corticosteroid injections.

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.

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.

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.

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.

Effect of intravenous sodium nitroprusside on cerebral blood flow and intracranial pressure.

Local cerebral blood flow was measured with the hydrogen clearance technique during intravenous infusion of nitroprusside in monkeys. Concentrations of the drug required to reduce the mean arterial blood pressure by less than 40% resulted in no significant change or only a slight increase in regional cerebral blood flow. Larger doses, however, produced a loss of cerebral autoregulation, thereby inducing a drop in cerebral blood flow. Intracranial pressure rose proportionately to the nitroprusside dose during the infusion.

Giant intracranial aneurysms of the anterior circulation: clinical characteristics and diagnosis by computed tomography.

The computed tomography (CT) characteristics and clinical features of giant (globoid) aneurysms of the anterior circulation are reviewed. These lesions appear on the CT scan as smoothly encapsulated ovoid masses, within which a partially patent lumen is seen after the infusion of iodinated contrast material. With careful analysis of the CT scan it may be possible to differentiate giant internal carotid artery, anterior cerebral artery, and middle cerebral artery aneurysms from other parasellar and hemispheric lesions.

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.

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.

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.