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Biomedical subjects

R G Perrin

Publications and source records attributed to R G Perrin.

30 records · Page 2Linked to original sources
PubMed1982

Analysis of facial displays and verbal report to assess subjective state in the non-invasive detection of limbic system activation by procaine hydrochloride.

The problem of scalp EEG as a measure of cortical or subcortical activity is particularly relevant to complex partial seizures as the abnormal discharging is frequently limbic in origin [14, 30]. Livingston [38] has suggested that administration of intravenous procaine as a limbic activator and cortical suppressor would be of utility in diagnosing limbic involvement in complex partial seizures. While there is considerable evidence derived from experimental animal models that procaine hydrochloride is a limbic system activator that acts preferentially on subcortical epileptic foci at lower doses than on less active epileptic foci or non-epileptic tissue [2, 4], it was necessary to demonstrate that procaine activates the human limbic system. The non-invasive approach taken in the present study was to compare the published effects of direct electrical stimulation of the human limbic system [31] to the behavioural and subjects effects of intravenous procaine administration. The areas in which we obtained the most robust procaine effects (hallucinations, emotions and alimentary sensations) were also Halgren et al.'s [31] most repeatable effects. The correspondence between electrical stimulation effects and procaine administration effects was striking - with verbal report by patients matching exactly in many instances. Furthermore, analysis of facial displays proved useful in providing access to subjects state fluctuations which would otherwise have gone undetected. The data provide strong evidence that procaine hydrochloride can be used as a human limbic system activator. Future research will investigate the clinical and diagnostic significance of differential response to procaine.

Diazepam↗
PubMed1982

Intradural extramedullary spinal metastasis. A report of 10 cases.

The management of 10 patients with symptomatic localized intradural extramedullary spinal metastasis is reviewed. The single most common primary source was carcinoma of the breast (four cases). The initial symptom in nine patients was pain, with five patients reporting a characteristically severe cramping discomfort with radicular distribution. All patients underwent laminectomy decompression. At the time of surgery, six of the patients were weak but ambulatory and four were bedridden. Following surgery, four patients enjoyed some measure of pain relief, seven patients became ambulatory, and three remained bedridden. Two patients achieved a "satisfactory" result, and were walking and continent 6 months after surgery. Secondary brain tumors were demonstrated or implicated in nine patients, supporting the concept that the spinal metastases represented tertiary deposits following dissemination via the cerebrospinal fluid. Symptomatic intradural extramedullary spinal metastasis causes a virulent clinical syndrome with poor prognosis and disappointing outcome after treatment. Given the high incidence of associated cerebral metastatic involvement, total neuraxis radiation and/or chemotherapy should be considered when symptomatic spinal metastasis is discovered to be intradural and extramedullary.

Adult↗
PubMed1978

The neurosurgical management of spinal metastases causing cord and cauda equina compression.

The authors report a series of 100 consecutive patients with spinal metastases causing cord or cauda equine compression, who were treated with surgical decompression. Of these, 30% (all women) had breast cancer. The most common primary neoplasm in man was prostatic carcinoma. Pain was the earliest and most prominant symptom, followed by weakness. Bladder dysfunction was recorded in 40 patients. The thoracic region was the most common site of cord compression (76 patients). Surgical treatment involved urgent and extensive laminectomy decompression. Concomitant spinal stabilization was required in 10 cases, involving posterior rib graft fusion in seven and Harrington rod instrumentation in three. At last follow-up review, 29 of these patients were living with an average postoperative survival of 2.3 years; 71 patients had died with an average survival of 8.8 months. Surgical decompression produced effective pain relief in 70% of the patients. Postoperatively, 58 patients could walk; of these, 40 were walking and continent of urine 6 months following surgery (including five patients who were totally paraplegic on admission). Positive approach and aggressive management in this problem can achieve results superior to those generally reflected in the literature.

Adult↗
PubMed1975

Electroencephalographic signs of ethanol tolerance and physical dependence in the cat.

Spontaneous electrical activity was recorded from three cortical and five subcortical sites, via permanently implanted electrodes, in five conscious, freely-moving adult cats. Initial observations were made during and after an intravenous infusion of ethanol, 1 g/kg. The animals then received ethanol by gastric intubation, in doses of 1.5 g/kg every 8, 12 or 24 h, for a period of 5 weeks. Electrical and behavioral observations were repeated on the day following the last gavage, before and during another intravenous infusion of ethanol 1 g/kg. All animals showed EEG changes which are interpreted as signs of tolerance to and dependence on alcohol. EEG changes appeared up to a day earlier than gross behavioral signs of alcohol withdrawal.

Action Potentials↗
PubMed1971

Electroencephalographic and behavioral alterations produced by delta-1-tetrahydrocannabinol.

The administration of small doses of Delta(l)-tetrahydrocannabinol to cats with indwelling electrodes produced a disruption of both the electroencephalogram and behavior. Some of these alterations, including the appearance of a high-voltage slow wave electroencephalogram in the awake and moving animal, have been observed in cats that had been administered other drugs known to cause hallucinogenic states in man.

Animals↗