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Biomedical subjects

J J Stockard

Publications and source records attributed to J J Stockard.

28 records · Page 2Linked to original sources
PubMed1975

Effects of acute and chronic paleocerebellar stimulation on experimental models of epilepsy in the cat: studies with enflurane, pentylenetetrazol, penicillin, and chloralose.

Effects of acute and chronic paleocerebellar stimulation were evaluated in four experimental models of epilepsy in 24 adult cats chronically implanted with bilaterally symmetric parasagittal electrocorticographic electrodes and anterior lobe cerebellar stimulation electrodes. Pentylenetetrazol was given intraveneously in 50-mg increments or 4% enflurane was inspired until grand mal seizures occurred spontaneously or were triggered by photic or auditory stimuli. Alpha-chloralose, 50 mg/kg, was injected intraperitoneally to produce a model of stimulus-sensitive myoclonus and sodium penicillin G, 350,000 units/kg, was injected intramuscularly to produce a model of petit mal epilepsy. One- to 250-Hz electrical stimulation of paleocerebellar cortical surfaces was performed with constant-voltage or constant-current stimulators at threshold and suprathreshold intensities with average intensities of 8 V and 2.5 mA, respectively. Acute or chronic, threshold or suprathreshold paleocerebellar stimulation did not predictably alter the electrographic or clinical manifestations in any of these four models.

Acoustic Stimulation↗
PubMedDate not supplied

Monitoring of cerebral perfusion during anesthesia by time-compressed Fourier analysis of the electroencephalogram.

Time-compressed Fourier analysis of the electroencephalogram has proven to be a useful analytical procedure during anesthesia and surgery which simplifies data interpretation by presenting the EEG in a time-compressed frequency domain rather than the conventional time domain. This method of data analysis graphically accentuates the electroencephalographic correlates of ischemia-induced cerebral dysfunction and other cerebral oxygen consumption abnormalities. The ability to accentuate trends in frequency and power is derived from sequential plotting of spectra to produce a graph with three dimensional axes of frequency, time, and power. In carotid endarterectomies the system has proven more useful than the conventional EEG in assessing the need for a vascular shunt to maintain internal carotid flow during endarterectomy. In open-heart surgery time-compressed EEG spectral analysis has allowed early recognition of cerebral ischemia resulting from arterial hypotension and venous hypertension. Five cases are presented which demonstrate the ability of our system to reflect developing cerebral ischemia.

Aged↗
PubMedDate not supplied

Electroencephalographic abnormalities following halothane anesthesia.

In 7 subjects, serial EEGs, serum bromide determinations, and psychological tests were done prior to and following 13.83 +/- 0.74 (SEM) MAC-hours of halothane anesthesia. Significant psychological impairment demonstrated 2 days following anesthesia in these subjects was absent 2 weeks following exposure to halothane. Nonspecific postanesthetic slowing of the EEG was found, qualitatively similar to but more marked than that following exposure to enflurane. Generalized EEG slowing, with a tendency toward posterior delta activity and significant reduction of frequency and amplitude of the alpha rhythm, persisted for 6 to 8 days following anesthesia. Rare sharp-wave activity developed in 3 subjects in the 1st week after halothane. A potentially psychoactive postanesthetic serum bromide level of 2.97 +/- 0.17 mEq/L (SEM) was found 5 days following anesthesia. Electroencephalographic changes characteristic of mild bromide intoxication were absent, suggesting that the psychological impairment noted after halothane anesthesia is probably not due to this metabolite; these psychological changes are probably due instead to persistence in the circulation of unchanged halothane.

Adult↗
PubMedDate not supplied

Ectopic internal carotid artery seen initially as middle ear tumor.

An ectopic carotid artery is rare. Its first symptoms may be neurological and could bring the patient to the neurologist during the initial evaluation. However, more often, the neurologist examines a patient in whom serious neurological deficit has occurred after transtympanic exploration of an undiagnosed vascular mass. Because diagnosis can be definitively established by angiography and the consequences of injury to an aberrant carotid artery are serious, operative exploration of vascular middle ear masses probably should be deferred until an ectopic carotid artery has been excluded by angiography.

Adult↗