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Biomedical subjects

J Maroon

Publications and source records attributed to J Maroon.

17 recordsLinked to original sources
PubMed1992

Choristoma of the optic nerve and chiasm.

A 21-year-old patient with a biopsy-proved choristomatous malformation of the optic nerve and chiasm is presented. The patient experienced progressive unilateral vision loss and optic atrophy. A gadolinium-enhanced magnetic resonance image demonstrated chiasmal involvement that was not evident on computed tomographic scan or visual field testing. We believe this is the third reported case of a choristomatous malformation of the optic nerve and chiasm and the first report of magnetic resonance imaging findings.

Adult↗
PubMed1990

A randomized, controlled trial of methylprednisolone or naloxone in the treatment of acute spinal-cord injury. Results of the Second National Acute Spinal Cord Injury Study.

Studies in animals indicate that methylprednisolone and naloxone are both potentially beneficial in acute spinal-cord injury, but whether any treatment is clinically effective remains uncertain. We evaluated the efficacy and safety of methylprednisolone and naloxone in a multicenter randomized, double-blind, placebo-controlled trial in patients with acute spinal-cord injury, 95 percent of whom were treated within 14 hours of injury. Methylprednisolone was given to 162 patients as a bolus of 30 mg per kilogram of body weight, followed by infusion at 5.4 mg per kilogram per hour for 23 hours. Naloxone was given to 154 patients as a bolus of 5.4 mg per kilogram, followed by infusion at 4.0 mg per kilogram per hour for 23 hours. Placebos were given to 171 patients by bolus and infusion. Motor and sensory functions were assessed by systematic neurological examination on admission and six weeks and six months after injury. After six months the patients who were treated with methylprednisolone within eight hours of their injury had significant improvement as compared with those given placebo in motor function (neurologic change scores of 16.0 and 11.2, respectively; P = 0.03) and sensation to pinprick (change scores of 11.4 and 6.6; P = 0.02) and touch (change scores, 8.9 and 4.3; P = 0.03). Benefit from methylprednisolone was seen in patients whose injuries were initially evaluated as neurologically complete, as well as in those believed to have incomplete lesions. The patients treated with naloxone, or with methylprednisolone more than eight hours after their injury, did not differ in their neurologic outcomes from those given placebo. Mortality and major morbidity were similar in all three groups. We conclude that in patients with acute spinal-cord injury, treatment with methylprednisolone in the dose used in this study improves neurologic recovery when the medication is given in the first eight hours. We also conclude that treatment with naloxone in the dose used in this study does not improve neurologic recovery after acute spinal-cord injury.

Acute Disease↗
PubMed1990

Percutaneous automated biopsy in the diagnosis of primary infectious spondylitis.

Three cases of primary infectious spondylitis, two caused by Staphylococcus aureus and one by tuberculosis, were diagnosed using the method previously described for automated percutaneous discectomy. All three patients, in whom biopsy using fine needle techniques previously was unsuccessful, had positive cultures from specimens obtained using the automated method. The method combines the advantages of local anesthesia and minimal morbidity with the obtaining of adequate material for culture and pathological examination.

Adult↗
PubMed1989

Automated percutaneous discectomy at the L5-S1 level. Use of a curved cannula.

Previously, a major limitation to percutaneous disc decompression to relieve symptoms of sciatica was the inability to approach the L5-S1 level. Obstruction by the iliac crest prevented the instrumentation from entering the L5-S1 disc space. In this paper, the authors describe a curved cannula which can be placed down to the L5-S1 disc space over a straight trocar that has been anchored at the annulus. The cannula bends the flexible aspiration probe back into the plane of the disc so that it is no longer obstructed by the sacral end plate. Using this system, the L5-S1 disc space was successfully removed in 90% of 30 cases.

Catheterization↗
PubMed1988

Automated percutaneous discectomy: preliminary experience.

In 1985, Onik, described a new automated lumbar disc aspiration technique that utilizes a probe with the guillotine cutting technology used in vitrectomy and arthroscopic instrumentation. The probe's small size (2 mm in diameter) minimizes the risk of nerve injury, while its automated action permits rapid, safe removal of disc material. The technique and our preliminary results in patients treated with this method are described.

Dermatologic Surgical Procedures↗
PubMed1987

Automated percutaneous diskectomy: initial patient experience. Work in progress.

A new method has been developed for percutaneously decompressing herniated lumbar disks. The method entails gaining access to the disk space through the use of an introduction system and a cannula. A 2-mm aspiration probe called a Nucleotome is then placed through the cannula into the disk space, and the nucleus pulposus is aspirated. Thirty-six patients have undergone the procedure, with a successful result in 31. There were no significant complications encountered, and the procedure is now being done on an outpatient basis. These preliminary results indicate that automated percutaneous diskectomy has the potential to replace laminectomy in the treatment of uncomplicated herniated disks.

Humans↗
PubMed1979

Diagnostic approaches to pituitary adenomas.

The utility of diagnostic tests for pituitary adenoma was compared in 12 patients. Endocrine and radiologic studies were always abnormal, even when neuro-ophthalmologic tests were normal. In most cases, both tomography of the sella turcica and CT scan revealed a mass in the region of the sella turcica. For more precise definition of suprasellar extension of the mass, metrizamide CT cisternography or tomographic pneumoencephalography with metrizamide provided similar details, although CT cisternography was much more easily done. Angiography provides a means to exclude an aneurysm or vascular malformation, a vascular tumor, or an aberrant course of the internal carotid artery.

Adenoma↗
PubMed1976

Experimental middle cerebral artery microsurgical embolectomy.

The canine middle cerebral has been embolized using the method of Molinari. Microsurgical embolectomies were done at two hours and six hours post-embolism. Animals done at two hours remained virtually intact neurologically, and hence fared better than control dogs whose embolus remained in place. Animals done six hours post embolism had increased neurologic morbidity and mortality as compared to the controls. Pathologic study revealed hemorrhagic infarctions in 50% of the animals done six hours post embolism.

Animals↗
PubMed1976

Epidermoid of the fourth ventricle: discovery by computerized tomography.

A case of fourth ventricular epidermoid is presented. The initial diagnosis was considered to be multiple sclerosis. Computerized axial tomography demonstrated the lesion without enhancement. Since fourth ventricular epidermoids may present in a variety of ways, the value of computerized tomography is emphasized.

Adult↗
PubMedDate not supplied

Air embolism during trans-sphenoidal pituitary operations.

Doppler ultrasonic cardiac monitoring of patients undergoing trans-sphenoidal pituitary operations in the semisitting position has revealed the occurrence of venous air embolism in 3 of 31 consecutive cases. One such case is presented. Air may be drawn into the venous system whenever a gradient exists between the site of operation and the right heart. During trans-sphenoidal operations the most likely portals of venous air entry include the intercavernous connections within the sella, venous channels through nonpneumatized bone, inadequately sealed subnasal vessels, and vascularized metastatic tissue in the pituitary. Because the potential for morbidity and mortality from air embolism is so great, rapid diagnosis with the Doppler unit and prompt treatment, including aspiration of air from the right atrial catheter, administration of 100% oxygen, performance of the Valsalva maneuver, saline irrigation of the wound, and hemostasis of open vessels, are essential. Technetium-macroaggregated albumin (TEMAA) lung scans are helpful in postoperative verification of venous air embolism.

Adenoma↗
PubMedDate not supplied

Far-lateral disk herniation: treatment by automated percutaneous diskectomy.

Automated percutaneous diskectomy has certain advantages over other surgical approaches to the treatment of far-lateral disk herniation; primarily, the procedure can be performed under local anesthesia without soft-tissue disruption. We describe four patients with far-lateral herniations who were successfully treated with the procedure.

Adult↗