Bertram Feinstein

Stereotactic Localization (with Computerized Tomographic Scanning), Biopsy, and Radiofrequency Treatment of Deep Brain Lesions

In eight patients stereotactic biopsy of deep brain lesions was performed. Adequate tissue was obtained, and the information helped considerably in planning further therapy. No significant complications occurred in these patients. In three of the cases, the stereotactic coordinates were determined from the computerized tomographic (CT) scan. In one patient, after biopsy, stereotactic radiofrequency (RF) lesions in the tumor resulted in temporary improvement.

Suppression of an Epileptiform Type of Electrocortical Activity in the Rat by Stimulation in the Vicinity of Locus Coeruleus

Stimulation in the locus coeruleus, or in the vicinity of this nucleus or of its ascending tracts, could markedly suppress the appearance of epileptiform‐like ECoG bursts. The latter were i induced in rats by a subconvulsive dose of pentylenetetrazol. Electrode sites were identified histologically. A unilateral stimulus suppressed bursts bilaterally. An individual burst already in progress could be aborted, stopping within less than 0.5‐1 sec after onset of a stimulus train. The antiepileptiform actions occurred with no evidence of any desynchronizing effect of the stimulus on the resting ECoG; they appear to be different in sites of origin and nature from those reported for stimulation of the reticular activating system. It is proposed that stimulation of the ascending noradrenergic system in the brain stem may limit the development and spread of hyperexcitatory, epileptiform states.

Stimulation of Locus Coeruleus in Man

Stimulating electrodes were chronically implanted unilaterally (in 1975–1977) in the vicinity of the locus coeruleus (LC) in three patients, one with cerebral palsy-spastic quadriplegia, two with epil

Threshold stimulation of the lateral thalamus and globus pallidus in the waking human.

Abstract Threshold stimulation of four subcortical targets in unanesthetized Parkinson patients is described. The targets are in the globus pallidus and the lateral nuclear mass of the thalamus; coordinates are specified. Responses include tremor, coordinated movements, sensation, and miscellaneous responses involving emotion, etc., tremor being the most frequent response in all targets. Statistical investigation shows significant difference between pallidal and thalamic targets with respect to the frequency of the various responses. It is suggested that parkinsonian symptoms may appear because of unbalanced activity between interacting portions of the central nervous system which results from a combination of the pathological lesion and normal brain cell loss with age.

Electrical stimulation of therapeutic targests in waking dyskinetic patients

Abstract Threshold responses (of 282 patients with Parkinsons disease and 69 patients with other dykinesias) to electrical stimulation of therapeutic targets have been tabulated. The most frequently elicited responses were initiation or augmentation of the patients own symptoms: tremor and rigidity in Parkinsons disease and the patients own involuntary movement in other dyskinesias. Distribution of various response as a function of stimulus current is characteristic of a given target.

Cortical and thalamic activation in conscious sensory experience

Our work has been aimed directly at the question of the nature of the spatio-temporal configurations of cerebral neural activities which elicit, or are at least uniquely correlated with, the conscious awareness of a somatosensory experience in the awake and alert individual. We have focused the study on the differences between cerebral functions associated with stimuli that are at or just above threshold level for eliciting a conscious sensory experience, as opposed to those with stimuli that are below such a threshold. The implication is that there are some unique differences between physiological cerebral states above and below this threshold level. The term threshold is used by us in tF.e broad sense of the just adequate levels for all significant parameters of a stimulus (electrical in our studies) not merely that for intensity (Libet et al., 1964; Libet, 1972). (To avoid confusion with threshold levels for various,other types of responses to stimuli, particularly for evoked potentials (EP’s), the thresholdlevels for eliciting a conscious sensory response will be referred to as „threshold-c.’)

An Integrated System for Brain Stimulation and Lesion Production in Human Stereotaxic Surgery

An electronic system for stimulation and lesion production in stereotaxic surgery is described. This system allows accurately monitored noninjurious prelesion stimulation and the production of radiofr