Search Results

You are looking at 1 - 10 of 30 items for

  • Author or Editor: Albert N. Martins x
Clear All Modify Search
Restricted access

Albert N. Martins

✓Fifty-one patients with symptomatic cervical disc disease refractory to conservative management were allocated at random to one of two treatment groups. The standard anterior approach devised by Cloward was used for 25 patients, and radical discectomy and foraminotomy for the other 26. All patients were followed for 6 months or longer with interview, physical examination, and radiographic evaluation. There was no difference in the success rate between the two groups. The large majority (92%) of patients in both groups were pleased with results of their operation. Because of technical factors related to operative exposure of the spinal canal and nerve roots, we prefer the Cloward procedure for patients symptomatic from advanced spondylosis and reserve discectomy without bone graft insertion for those with minimal spondylosis or soft disc herniations.

Restricted access

Side effects of spasmolytic agents in the monkey

Intracisternal phenoxybenzamine and phentolamine

Albert N. Martins and John K. Wiley

✓ The authors report a study of the physiological and morphological responses of the rhesus monkey brain to intracisternal injections of two potentially useful spasmolytic agents, phenoxybenzamine and phentolamine. Central nervous system function remained unaffected by intracisternal injections of either drug in doses that were small but nevertheless sufficient to attain pharmacologically effective concentrations in the cerebrospinal fluid. Larger doses of phenoxybenzamine caused a chemical basilar meningitis. Phentolamine caused arterial hypotension without meningitis. It is concluded that intracisternal spasmolytic therapy deserves further experimental evaluation.

Restricted access

Albert N. Martins and Thomas F. Doyle

✓ The exposed left superior frontal gyrus of the anesthetized macaque brain was focally traumatized by a jet of compressed air. Focal blood flow in tissue around the lesion and total cerebral blood flow was determined before and during the 4 hours after trauma by the hydrogen clearance technique. Blood flow fell in tissue adjacent to the injured brain but the reduction was not statistically significant. Total cerebral blood flow, blood flow in the right superior-frontal gyrus, and oxygen consumption of the brain was unaffected by the trauma. The authors conclude that neither spreading ischemia within uninjured tissue surrounding focally traumatized brain nor post-traumatic diaschisis is readily provoked in the anesthetized brain of the monkey.

Restricted access

John O. Susac, Albert N. Martins and Robert A. Whaley

✓ A middle-aged woman presented with the typical symptoms and signs of a compressive optic nerve lesion. Plain skull films, tomography of the optic canals, and selective angiography with magnification and subtraction were normal. Computerized transaxial tomography clearly showed the tumor, which was a meningioma of the optic nerve sheath. At surgery the tumor was found within the optic canal with intracranial and orbital extensions. It was strictly intradural and did not involve the surrounding bone at any point. This case documents the fact that an intracanalicular meningioma may be associated with normal tomograms of the optic canal.

Restricted access

Arthur I. Kobrine, Thomas F. Doyle and Albert N. Martins

✓ Focal blood flow was measured in the lateral funiculus and center of the spinal cord in the rhesus monkey both before and after a 600 gm-cm injury at T-10. Measurements made by the hydrogen clearance technique showed that blood flow in the lateral funiculus more than doubled within 4 hours after injury, returned to normal by 8 hours, and remained in the normal range for 24 hours. At no time was a hypoperfusion in the lateral funiculus present. Blood flow in the center of the spinal cord, at the level of the lesion, began to fall within 1 hour following injury and continued to fall for 4 hours. These data challenge the notion that spreading ischemia of the white matter is an important factor in the pathophysiology of experimental spinal cord injury.

Restricted access
Restricted access

Experimental delayed radiation necrosis of the brain

Part 1: Effect of early dexamethasone treatment

Albert N. Martins, Ralph E. Severance, James M. Henry and Thomas F. Doyle

✓ The authors have designed an experiment to detect a hitherto unrecognized interaction between high doses of the glucocorticoid, dexamethasone, and brain irradiation. Eighteen juvenile male rhesus monkeys received 1800 rads to the whole brain in 8.5 minutes. For 1½ days before and 10½ days after the irradiation, nine animals received approximately 2.9 mg/kg/day of dexamethasone intramuscularly in addition to irradiation, while the remaining nine animals served as the control group and received saline. All animals eventually developed a progressive neurological syndrome, and died of delayed radiation necrosis of the brain. The two groups were compared with regard to latency to onset of clinical signs, survival time, and number, distribution, and location of lesions of radionecrosis. Large doses of dexamethasone did not alter the susceptibility of the primate brain to delayed radiation necrosis. Detailed morphological study of the radionecrotic lesions supports the hypothesis that most, if not all, of the lesions develop as the consequence of injury to blood vessels.

Restricted access

Albert N. Martins, George J. Hayes and Ludwig G. Kempe