PubMed Health⌕ Search

Biomedical subjects

R J Ignelzi

Publications and source records attributed to R J Ignelzi.

16 recordsLinked to original sources
PubMed1979

Excitability changes in peripheral nerve fibers after repetitive electrical stimulation. Implications in pain modulation.

The Melzack-Wall gate control theory has been invoked to explain the peripheral analgesia resulting from repetitive electrical stimulation of peripheral nerve. This model emphasizes presynaptic inhibitory interactions among afferent fiber terminals in the spinal cord. An alternative explanation, that of velocity change in peripheral nerve fiber conduction, has been suggested by compound action potential studies from our laboratory. The present study was designed to extend this work, and to investigate the single fiber changes subsequent to brief (5- to 20-minute) periods of repetitive, high frequency (180 to 200/sec) electrical stimulation through an implantable peripheral nerve cuff device of the type used clinically for pain relief. Most fibers, regardless of their diameter (estimated from conduction velocity), show one or more of the following characteristics: a transient slowing of conduction velocity, an increase in electrical threshold and/or a decrease in response probability following a period of repetitive electrical stimulation. This supports the hypothesis that there are changes in direct peripheral nerve fiber excitability occurring under conditions simulating clinical electroanalgesia.

Animals↗
PubMed1977

Post-irradiation pituitary sarcoma.

A fibrosarcoma developed in the pituitary fossa of a patient who had been irradiated 13 years previously for treatment of pituitary adenoma. The tumor was a large aggressively growing spindle cell neoplasm which eroded adjacent structures, causing increased intracranial pressure, and eventual cerebellar tonsillar herniation. In common with previously described post-irradiation sarcoma of the pituitary, this lesion developed in the path of irradiation after a long latent period, did not metastasize, and contained histologically recognizable benign appearing pituitary adenoma interspersed among the spindle cell tumor. The dose of radiation (5000 rads) also lay within the range associated with sarcomatous transformation.

Aged↗
PubMed1977

Ascending lumbar venography in lumbar-disc disease.

For fifty-five patients with acute low-back pain or radicular pain, ascending lumbar venography was as accurate as myelography (86 per cent) in localized herniation of a lumbar disc in surgically proved cases. Myelography and lumbar venography are complementary diagnostic studies which should be used together in doubtful cases. Lumbar venography is easily performed is well-tolerated, and is relatively painless. It is not associated with arachnoiditis and has a negligible complication rate.

Humans↗
PubMed1976

Recovery from anterograde and retrograde amnesia after percutaneous drainage of a cystic craniopharyngioma.

A case is reported of a cystic craniopharyngioma involving the floor and walls of the third ventricle. Pronounced anterograde and retrograde amnesia were documented preoperatively by formal testing. Rapid improvement in both new learning capacity and remote memory occurred after percutaneous twist drill drainage of the cystic portion of the tumour. The relevance of these observations to the amnesic syndrome and its neuropathological basis is discussed.

Amnesia↗
PubMed1976

Spinal subdural hematoma.

The authors report a case of subacute spinal subdural hematoma in a patient with ankylosing spondylitis. Only 18 such cases have been reported in the nonradiological literature. Early diagnosis is imperative in order to minimize neurological sequelae.

Hematoma, Subdural↗
PubMed1976

Direct effect of electrical stimulation on peripheral nerve evoked activity: implications in pain relief.

Experiments were performed with a peripheral neurostimulator, used clinically for pain relief, on isolated cat cutaneous peripheral nerve to determine the effect of electrical stimulation on components of the compound action potential. The results show that neurostimulation alters the conduction velocity and the amplitude of both the A-alpha and beta and the A-delta waves with the more slowly-conducting A-delta component showing the greatest changes. This direct alteration of peripheral nerve activity distal to the first synapse in the spinal cord might contribute to the mechanism of pain relief.

Action Potentials↗
PubMed1975

Cerebral mucormycosis following open head trauma. Case report.

The authors describe a case of human cerebral mucormycosis following open head trauma and craniotomy, and discuss possible roles of steroids and antibiotic therapy in its pathogenesis. They suggest that the common usage of prolonged broad-spectrum chemoprophylaxis in head trauma may require critical review.

Amphotericin B↗
PubMed1975

Analysis of the treatment of basilar skull fractures with and without antibiotics.

The efficacy of chemoprophylaxis in the treatment of basilar skull fractures was studied in 129 patients over a 2-year period; antibiotics were found ineffective in preventing central nervous system infections, and in some cases may have proved harmful. It is suggested that a more rational approach to the treatment of basilar skull fractures includes close observation of the patient for early signs of meningitis, and if these should develop, treatment with antibiotics appropriate to the organism involved.

Ampicillin↗