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Biomedical subjects

I S Cooper

Publications and source records attributed to I S Cooper.

At least 37 records · Page 2Linked to original sources
PubMed1976

Some neurophysiological effects of cerebellar stimulation in man.

This paper presents the results of neurophysiological studies of the effects of cerebellar stimulation on H reflexes, late reflexes, blink reflexes, evoked potentials and EEG patterns in 18 human subjects (Male 13, Female 5, Age 25.8+/-10.0, Epileptic 9, Cerebral Palsy 9). In addition to the effects of cerebellar stimulation on the H reflex studies on soleus we assessed V1 and V2, "late" responses (Upton et al., 1971), cortical somatosensory evoked potentials (SSEP) after median nerve stimulation, and visual evoked responses (VER) after flash stimulation. Experiments were extended to assess recovery curves of all the potentials and we examined the effects of changes on the rate or voltage of cerebellar stimulation. Cerebellar stimulation was inhibitory to all the responses except the visual evoked potentials. Serial studies in five patients produced consistent results. Preoperative and postoperative results were compared in two patients with no significant difference in the results in the absence of cerebellar stimulation. Ipsilateral cerebellar stimulation (CS) had the greatest inhibitory effects on H, V1 and V2 responses in the arm and leg whereas contralateral CS produced the greatest effects on cortical SSEPs. There was a greater bilateral effect on SSEPs and reflex responses after right CS than left CS and this may be the first indication of "dominance" in the cerebellar hemispheres. Cerebellar stimulation in patients on diphenylhydantoin produced minimal effects on SSEP's and this observation has led to further studies in patients taking diphenylhydantoin. Recovery of amplitude of the reflex and cortical responses took eight to 30 minutes after one minute of cerebellar stimulation. Serial CS of one minute on and one minute off produced increasing inhibition of SSEP's and reflexes for up to five stimulations. Recovery after cessation of cerebellar stimultion was associated with rebound excitation in six patients, the rebound being noted in the amplitude of H reflexes and SSEP's as well as in the frequency of paroxysmal spike and wave discharges in the EEG. The correlation of the results of such quantitative neurophysiological tests with clinical improvement may allow prediction of clinical improvement may allow prediction of clinical results after cerebellar stimulation. These techniques have already been used to measure the threshold of stimulation and may allow optimal stimulation characteristics to be assessed. The prolonged neurophysiological effects of stimulation may allow the use of maximum effective intervals between optimal epochs of stimulation so that any cerebellar damage can be minimized.

Adolescent↗
PubMed1976

Psychological effects of short term cerebellar stimulation in epilepsy.

The effects of short term cerebellar stimulation on integrative functions as measured by standardized psychological tests were studied. The patient group consisted of 12 epilepsy patients undergoing chronic cerebellar stimulation as treatment for intractable seizures. Three comparison groups included nonstimulated epilepsy patients, stimulated cerebral palsy patients, and stimulated stroke patients. Cerebellar stimulation resulted in some alterations in test performance. Improvements occurred from first to second test administration for both stimulated and nonstimulated subjects, as a probable practice effect. Short term stimulation of the cerebellar cortex does not result in apparent deficits. However, significant improvement in verbal output and in visual-motor performance occurred for the stimulated epilepsy group along with a small decrement in sustained concentration in a numerical task. Preliminary hypotheses were offered to explain the results.

Adult↗
PubMed1976

Impedance and spontaneous electrical activity as a localizing method in percutaneous spinal surgery.

Simultaneous recording of impedance and spontaneous electrical activity of the spinal cord was accomplished by use of a roving electrode. The method for this double monitoring in cats and in human surgery is described. The impedance method revealed a significant and well-delineated difference between the gray and white matter of the spinal cord which can be seen clearly on the recording. Well-localized high electrical activity was observed in the anterior horn.

Action Potentials↗
PubMed1976

Chronic cerebellar stimulation in cerebral palsy.

Data are presented for the first 50 patients with cerebral palsy who underwent chronic cerebellar stimulation for symptom alleviation. We observed significant shorter and longer term improvement in spasticity as well as athetosis, speech, and functional status. Continuing increments in improvement were noted as a function of time on stimulation. In many instances, psychometric test scores and behavior also were improved. There was one death in this series. There were no neurologic complications due to cerebellar stimulation. The results of this study warrant the judicious use of cerebellar stimulation for symptomatic and functional relief in cerebral palsy.

Activities of Daily Living↗
PubMed1976

A psychometric study of chronic cerebellar stimulation in man.

Groups of patients with intractable epilepsy or spasticity of varying etiologies underwent psychological testing before and during chronic cerebellar cortex stimulation, a neurosurgical technique designed for the relief of these symptoms. The battery of psychological tests permitted a standardized assessment of intellectual, memory, and perceptual functions. Other behavioral dimensions were assessed through structured interviews. No apparent declines in higher integrative functions followed shorter or longer term cerebellar stimulation. In contrast, stimulated patients tended to show increments in tests of recent memory and verbal output beyond that of unoperated comparison groups. Subjective reports of increased "alertness" and reduced depression and anxiety were also frequently given. Psychological and neural factors may both contribute to the observed behavioral alterations. It was concluded that the cerebellum participates in behavioral functions by modifying cortical and subcortical mechanisms relevant to integrative behavior and emotions. Specific hypotheses were presented.

Adolescent↗
PubMed1976

The natural history of dystonia.

We have analyzed 226 patients with a diagnosis of dystonia musculorum deformans seen in our clinica between 1955 and 1974. These were evenly divided between male and female, but of the 226 patients, 225 were white and only one was black. Forty-two percent were Jewish, as contrasted with 3% Jewish population in the United States. It is interesting to note that a family history was obtained in 28% of both the Jewish and the non-Jewish groups. Thirty of the patients reported a significant viral infection within 3 months preceding the onset of symptoms. Only six patientss had a history of one or more remissions during the course of their illness. The mean duration of symptoms before examination in this series was 8.6 years with a duration of 1 to 42 years. Fifty-six of the patients had been diagnosed as having conversion hysteria at some time during the course of their illness. The majority of the patients had the onset of symptoms between the ages of 5 and 10, although the age span was from 2 to 45 years of age. Seventy-six of the patients had an IQ statistically significant above average (3). Each symptom, rate of progress of the disease, and various other factors in the history were corrolated with age, sex, ethnic group, mode of onset, and 20 other variables. The most pertinent subgroupings affecting the natural history were the age on onset and the ethnic group and family history. Trunkal involvement was most common in the non-Jewish group with a positive family history. This particular sub-group of patients showed predominately midline symptomatology. In the groups below the age of 13, the onset was almost invariably in one of the four limbs. However, in the group 14 years of age and older, 30% had their initial dystonic symptoms in the neck and a total of 40% of the patients whose onset was at age 14 or later, had marked nuchal symptoms. This clear-cut predominance of limb involvement in the youngest groups is also indicated by the observation that 38% in the youngest group had become confined to a wheelchair because of gait abnormalities, whereas none of those whose age of onset was 14 or older were disabled to this degree by gait abnormality. The most rapidly progressive and incapacitating symptomatology was seen in those patients with onset of symptoms below the age of 8 so that in general the younger the age at onset, the more rapid the progress of the symptoms.

Activities of Daily Living↗
PubMed1976

Psychological studies in dystonia musculorum deformans.

Sixty-eight patients with DMD underwent psychometric assessment before or after thalamic surgery. Statistical comparisonss between categories of patients were undertaken as a function of religion, family history, and age at onset of symptoms as independent variables. It was found that Jewish patients, with negative family history, and age at onset of symptoms from 9 to 13 years, scored significantly higher on IQ tests than did all other groups. Other psychological test data revealed no specific personality patterns in the DMD patients, particularly no pattern of conversion hysteria or hysteria. Pre- and postoperative psychological testing in a small group of patients revealed no evidence of any changes in intellectual, cognitive, or personality functions as a consequence of thalamic surgery, involving up to 10 lesions in some instances.

Adolescent↗