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Biomedical subjects

O J Andy

Publications and source records attributed to O J Andy.

At least 37 records · Page 2Linked to original sources
PubMed1983

Thalamic stimulation for control of movement disorders.

Chronic recurrent thalamic stimulation has been effective in alleviating a variety of movement disorders. In contrast to thalamic lesions, it is preferred for the treatment of intractable motor disorders in low-risk elderly patients and patients with diffuse brain lesions secondary to trauma. Abnormal diencephalic electrical discharges have been observed and thought to be associated, in some way, with either generating or sustaining the movement abnormalities. The beneficial effects are ascribed to an electrophysiologic functional ablation of the discharging systems. This interpretation is based on the observation that the diencephalic discharges are attenuated by the applied stimulation and that the beneficial effects are reversible even after several months of applied therapeutic stimulation.

Adult↗
PubMed1983

Thalamic stimulation for chronic pain.

Electrical stimulation of the thalamus was found to be effective for the treatment of chronic intractable pain of various etiologies. Diencephalic recordings revealed spontaneous focal electrical discharge patterns with relatively low activation thresholds. Localization of the optimum thalamic discharge site is used as a guide for the electrode implant to be used for chronic stimulation. The thalamic sites which most frequently displayed the low threshold spontaneous focal discharge activity were the CM-Pf complex and related intralaminar nuclear structures. Generation of diencephalic pain-reverberating circuits was discussed in relation to explaining the pain syndromes herein described. The applied electrical stimulation is thought to electrophysiologically 'jam' the low threshold discharging systems and thereby alleviate pain.

Adult↗
PubMed1983

Diencephalic seizures. Case report.

Intractable complex partial and diencephalic seizures in 1 patient are being treated effectively by intermittent daily electrical stimulation in the right thalamus in conjunction with phenytoin, 200 mg/day. Electrical stimulation in the right thalamus was found to suppress spike and sharp wave discharge activity temporarily in the right thalamus and in the left parietal and right scalp leads. It was postulated that beneficial effects from electrical stimulation were due to electrically 'jamming a low-threshold discharge system'.

Electric Stimulation Therapy↗
PubMed1980

Parafascicular-center median nuclei stimulation for intractable pain and dyskinesia (painful-dyskinesia).

Medial thalamus stimulation was used to treat chronic intractable pain associated with dyskinesia. Relief from both the pain and the motor disorder occurred concomitantly. However, maximum pain reduction was attained at a relatively faster rate than maximum reduction from the motor disability. It is postulated that pathologic changes in the center median nucleus secondary to lenticulo-striate-internal capsular lesions account, in part, for both the pain and the dyskinesia. Electrical stimulation of the center median(n) parafascicular nuclear complex presumably simultaneously activates both the neurohumeral and tertiary sensory pain inhibitory system for pain control, and the suprasegmental gamma system for motor control.

Adult↗
PubMed1979

The human amygdala. I. Electrophysiological responses to odorants.

Nine patients had an amygdalotomy for attempted relief of intractable seizures and, as an aid for localization, recordings were made from the amygdala and later computer analyzed. The background activity is 3-18 c/sec; in response to odorants sinusoidal bursts are seen, synchronous with inspiration at 12-24 c/sec, but mainly 40-70 c/sec. Each odorant is associated with a given group of frequency components. However, for many different odorants the number of these components is restricted and the hypothesis is presented that odor discrimination in man's amygdala is not determined by which components are present, but the patterning of the components according to their amplitude. Odorants within the same odor class produced similar patterns of response. Epileptiform activity was recorded in two different forms, one in response to odors, similar in frequency to the slower bursts, except for sharper configurations, at times progressing to clinical seizures and the second as an insertion discharge from an advancing electrode, similar in frequency to the faster bursts. These latter data suggest that the repertoire of a given neural system or structure may be limited to specific frequencies but the configuration or patterning of these frequencies define the different states of the structure.

Amygdala↗
PubMed1978

The K-complex in thalamic depth recordings.

K-complexes were recorded from the thalamus in a patient having stereotaxic surgery for intractable stump pain. Two insertions were performed, one in the lateral and the other in the medial thalamus. It was found that, (1) very prominent K-complex activity was present at the depth electrode with relatively meager representation of these forms at the scalp; (2) the trailing spindle component of the K-complex was well displayed on the scalp, but the sharp and slow components were not readily visible in the scalp recordings, suggesting a multiple system response; (3) insertion into the lateral thalamus revealed much K-complex activity in contrast to the relatively little amount found with the insertion into the medial thalamus. These findings support earlier hypotheses of a subcortical origin, and specifically thalamic participation, in the K-complex formations.

Adult↗
PubMed1977

Verbal learning dysfunction with combined centre median and amygdala lesions.

Stereotaxic lesions in either or both amygdala did not impair verbal learning ability (presented by ear as a paired-associates test). Centre median lesions alone did not impair this form of learning; however, when combined with a left amygdala lesion a significant decrease in scores occurred which persisted for up to two years after operation. The data support a hypothesis that medial thalamic structures have alerting functions in learning mechanisms.

Amygdala↗
PubMed1977

Quantitative comparison of the amygdala in insectivores and primates.

Comparative architectonic studies have resulted in a classification of the amygdaloid complex which differs somewhat from the commonly used classification (first proposed by Humphrey, 1936) by separating the cortical amygdaloid nucleus from the centromedial group and assigning it to the basolateral group, which then forms a cortico-basolateral group. The size changes of these groups and of the nucleus of the lateral olfactory tract (belonging to the centromedial group) and the large-celled part of the basal nucleus (belonging to the corticobasolateral group) have been investigated in representatives of an ascending primate scale. In all structural complexes investigated so far, the small-celled part of the cortico-basolateral group is the most progressive. In descending order of progression there follow: the corticobasolateral group as a whole, the amygdala as a whole, and the large-celled basal nucleus. No clear changes were found in the centromedial group as a whole, whereas the size of the nucleus of the lateral olfactory tract, which represents a small component of this latter group, shows a strong reduction. These differences in the developmental trends point to increasing or decreasing capacities of the functional (limbic and olfactory) systems, to which these structures are related.

Amygdala↗
PubMed1976

Psychomotor-psychic seizures treated with bilateral amygdalotomy and orbitotomy.

A 26-year-old woman developed seizures and psychiatric disorders after having been in coma with encephalitis for a protracted period at age 11. Seizures were psychomotor, minor motor, and major motor with auras of fear, panic, and olfaction. The patient hallucinated, had paranoid ideas, was depressed, and attempted suicide. Medical and psychiatric treatment with anticonvulsants and tranquilizers was ineffective. Depth and surface EEG recordings revealed bilateral discharge abnormality in temporal, frontal, and thalamic areas. Lesions were placed in the temporal and orbitofrontal area bilaterally for the psycho-motor-psychic seizures and in the left thalamus for the minor motor seizure. The seizures were relieved without the incapacitating complications that occur with standard lobotomy and temporal lobe resection. Improvement of the psychic component of the seizures is believed due to interrupting seizure discharging circuitry in the temporal and frontal areas. The term temporofrontal seizures is proposed for the anatomic designation of psychomotor-psychic seizures.

Adult↗
PubMed1975

Thalamotomy for psychopathic behavior.

Six patients characterized by psychopathic behavior were treated with lesions placed in the center median nucleus of the thalamus. There was marked improvement of the psychopathic behavior in five patients. One patient with unilateral thalamotomy was parqially improved. Four of the six patients have been productive and earn a living. The other two have been partially productive. There were no long-lasting postoperative complications after thalamotomy for psychopathic behavior. The various and hyperirritability, and previously have been collectively identified as the "hyperresponsive syndrome". The psychopathic behavior in these condition of the diencephalon.

Adolescent↗
PubMed1975

Amygdalotomy for bilateral temporal lobe seizures.

A 37-year-old woman had bilateral anygdalotomy for psychomotor and minor motor seizures and long periods of very pronounced mental depression. The patient has been seizure-free for four years postoperatively. A preoperative left temporal spike focus disappeared after extensive left anygdalotomy. Of particular interest in this case is the recovery of olfactory and memory functions which were partially impaired by the bilateral lesions. Bilateral anygdalotomy is effective in relieving temporal lobe seizures without the complications and deficits that usually occur with resections of the bilateral temporal lobe.

Accidents, Traffic↗
PubMed1975

Post-lesion yawning and thalamotomy site.

Yawning during hyperventilation occurred in certain patients post-thalamotomy. It was found that all of the lesions which elicited yawning (during the routine recording of electroencephalograms) were localized to the medial portion of the center-median nucleus. Yawning was noted to persist up to 3(1/2) years post surgery. Another group of patients who yawned when hyperventilated were patients with a history of a recent head injury who showed post-traumatic behavioral changes. Patients in both groups were young. There was no direct relationship between yawning and EEG abnormality. It was suggested that yawning during hyperventilation may serve as a sign of brain damage, especially at the brain stem level, in young patients.

Adolescent↗