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Biomedical subjects

H H Morris

Publications and source records attributed to H H Morris.

At least 91 records · Page 5Linked to original sources
PubMed1985

Ipsilateral trigeminal sensory responses to cortical stimulation by subdural electrodes.

Twelve patients with medically intractable epilepsy had plates of chronic subdural electrodes placed over the lateral and basal cortical hemispheres during evaluations for surgical therapy. During cortical stimulation, ipsilateral sensations involving any of the branches of the trigeminal nerve were noted in the eye, face, and mouth. Some responses could have been due to dural or direct trigeminal nerve trunk stimulation, but others were probably due to electrical stimulation of trigeminal fibers accompanying the pial-arachnoidal vessels. These fibers had been demonstrated in animals, but not in humans.

Adolescent↗
PubMed1985

Preservation of voluntary saccades after intracarotid injection of barbiturate.

We studied voluntary saccades in 44 patients undergoing Wada testing before surgery for intractable epilepsy. After intracarotid injection of barbiturate, and while they were hemiplegic, patients could still make voluntary saccades toward or away from the side of injection. Sustained ipsiversive deviation of gaze was not noted. Saccades made away from the side of injection were slower than ipsilateral saccades in only 3 of 10 tests. These data support the hypothesis of parallel, independent pathways from the frontal eye fields and from the superior colliculi to the brainstem reticular nuclei that generate saccades.

Amobarbital↗
PubMed1985

Electrodes.

The electrical potentials of the brain are quite small and their electrical field may be restricted. Detecting these potentials is difficult especially as the distance between the electrode and the generator increases. Noninvasive electrodes only 'sample' the electrical activity synchronized over a large area of the brain. The international 10/20 system of electrode placement, the T1,T2 electrodes and other more closely placed electrodes record activity generated mainly from the brain convexities. Nasopharyngeal, ethmoidal, and sphenoidal electrodes record activity generated primarily from basal structures. Invasive electrodes including epidural and subdural electrode arrays and depth electrodes permit detection and precise localization of electrical activity generated from deep or relatively small brain regions.

Action Potentials↗
PubMed1984

Cortical afterdischarge and functional response thresholds: results of extraoperative testing.

We have evaluated the afterdischarge thresholds and functional response thresholds in 21 patients with chronically implanted arrays of subdural electrodes. Afterdischarge thresholds varied from 2 to greater than 15 mA over the tested cortex, by as much as 12 mA in individual patients, and by as much as 12 mA between adjacent electrodes. Thresholds for functional alteration varied from 2 to 15 mA in tested cortex, by as much as 9.5 mA in individually tested patients, and by as much as 6.5 mA between adjacent electrodes. We conclude that the optimal localization of functional cortical areas requires different stimulation intensities at different points. The use of too high an intensity would produce afterdischarges at some positions. The use of too low an intensity would falsely make others appear functionally "silent."

Adolescent↗
PubMed1984

Transient neuropsychological abnormalities (including Gerstmann's syndrome) during cortical stimulation.

A patient with intractable partial seizures was intensively studied before surgical removal of the epileptogenic focus. A subdural electrode array was surgically placed over the left temporoparietal cortex to better localize the epileptogenic focus and localize cortical function. In addition to speech and sensory findings, acalculia, agraphia, right-left confusion, and finger agnosia were transiently produced by electrical stimulation in the perisylvian area. These findings and their relationship to the controversy surrounding Gerstmann's syndrome are discussed.

Adolescent↗
PubMed1983

Langerhans' cells in human cervical epithelium: an immunohistological study.

Langerhans' cells are intraepithelial dendritic cells believed to be important in the recognition and processing of exogenous antigens. They were demonstrated by immunohistological methods in cervical tissue obtained from 10 subjects ranging in age from 30 weeks gestational age to 62 years. Langerhans' cells were clearly delineated in all tissue sections and appear to form a relatively constant component of both the transformation zone and ectocervical epithelium. In addition to Langerhans' cells, a population of T lymphocytes characterized as predominantly T-cytotoxic/suppressor cells have also been demonstrated. The interaction between Langerhans' cells, T lymphocytes and stromal macrophages and their relation to antigen recognition is discussed.

Adult↗
PubMed1983

Langerhans' cells in human cervical epithelium: effects of wart virus infection and intraepithelial neoplasia.

The distribution of Langerhans' cells and T and B lymphocytes in cervical epithelium affected by wart virus infection (WVI) and intraepithelial neoplasia (CIN) has been studied by immunohistological techniques with a panel of monoclonal antibodies. In comparison with normal tissue epithelium infected by wart virus consistently showed a partial depletion or absence of both Langerhans' cells and T lymphocytes. The few Langerhans' cells which remained showed loss of their normal dendritic processes and were confined to the vicinity of the basement membrane. In contrast, epithelium from patients with CIN showed an increase in spindle-shaped Langerhans' cells associated with increased numbers of stromal and intraepithelial lymphoid cells. These findings suggest that there is a marked difference in host immune responses in these two conditions and may explain why WVI tends to persist in the epithelium while CIN is often associated with a lymphoid reaction.

Adult↗
PubMed1983

The constellation of adult acid maltase deficiency: clinical, electrophysiologic, and morphologic features.

This report outlines the clinical, electrophysiologic, and morphologic findings in seven patients with adult acid maltase deficiency. The diagnosis was confirmed biochemically in four of these individuals. Adult acid maltase deficiency must be considered whenever clinical diagnoses of polymyositis, especially the chronic form, and limb-girdle muscular dystrophy are being entertained.

Adult↗
PubMed1982

Prosopagnosia: a double dissociation between the recognition of familiar and unfamiliar faces.

Two cases of a dissociation between prosopagnosia and impaired capacity to match familiar faces were studied. Recognition of familiar faces recovered in the first patient, whereas prosopagnosia persisted in the second patient despite recovery of matching unfamiliar faces and other visuoperceptive skills. This double dissociation is discussed in relation to current views of prosopagnosia.

Adult↗
PubMed1981

Juvenile Niemann-Pick disease with vertical supranuclear ophthalmoplegia. Two cases reports and review of the literature.

Examination of two siblings who had histories of progressive decline in speech, intelligence, and coordination disclosed vertical supranuclear ophthalmoplegia, hepatosplenomegaly, and signs of diffuse CNS dysfunction. Niemann-Pick "foam cells" were found in the bone marrow of both patients. The features of these cases correlate in appearance and clinical findings with those of 21 other previously reported cases, which are reviewed in this article. Knowledge of the clinical manifestations of this particular variety of Niemann-Pick disease should aid in its earlier diagnosis.

Adult↗
PubMed1981

Quantitative indexes of computed tomography in dementia and normal aging.

Quantitative indexes of compute tomography were compared in 28 patients with Alzheimer dementia and in 30 elderly persons with no history of neurologic disease. Age-corrected ventricle-brain ratios were abnormal for half of the dementia patients, whereas only a single subject in the control group had ventricles outside the limits of normal variation. Measurement of the distance between the third ventricle and Sylvian fissure indicated that the dementia patients had significantly more atrophy in this area. Employment of quantitative indexes standardized for age may aid in differentiating cerebral atrophy associated with dementia from that associated with normal aging.

Aged↗
PubMed1981

Asterixis associated with sodium valproate.

Intoxication with most anticonvulsants can produce asterixis. Asterixis rarely occurs with therapeutic serum anticonvulsant levels. We report two patients with asterixis who were taking valproic acid and had serum levels within the therapeutic range. Neither patient had clinical or laboratory evidence of hepatotoxicity. Only one other patient has been reported with valproate-associated asterixis in the absence of toxic serum drug levels or hepatotoxicity. Asterixis seems to be due to a central effect of the drug unrelated to hepatotoxicity or sedation.

Adult↗