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Biomedical subjects

W S Risk

Publications and source records attributed to W S Risk.

9 recordsLinked to original sources
PubMed1993

Viewing speed and frequency resolution in digital EEG.

This study of viewing speed and frequency resolution of a digital electroencephalograph (EEG) system explains how, in spite of limited video monitor resolution, technological advances permit digital EEG presently to approach paper EEG performance, and in the foreseeable future to exceed it. Analyses of aspects of eye and brain physiology and elements of digital technology reveal how an image traditionally inscribed on paper can be displayed on a video monitor so that viewing and interpretation are as quick and accurate as on paper. Results are compared to standards set by capabilities of the eye and paper EEG.

Brain↗
PubMed1980

Isoprinosine treatment in 18 patients with subacute sclerosing panencephalitis: a controlled study.

Isoprinosine (inosiplex), a proposed antiviral agent, was given to 18 patients with subacute sclerosing panencephalitis (SSPE). No great improvement occurred in any patient soon after treatment, but 2 patients did improve substantially several months after discontinuing Isoprinosine. Spontaneous improvement also occurred in 4 out of 96 controls. Because of the variable natural history of SSPE, differences in clinical improvement between treated patients and controls were not significant. Changes in serial measles antibody titers did not correlate with therapy.

Antibodies, Viral↗
PubMed1980

Intracranial dermoid cyst in Goldenhar's syndrome. Case report.

A patient with Goldenhar's syndrome and an ipsilateral intracranial dermoid cyst is reported. It is suggested that the combination of both entities may not be coincidental but due to their related embryological origin. This report also reemphasizes the value of computerized tomography in the preoperative diagnosis of intracranial dermoid cysts.

Adult↗
PubMed1979

The variable natural history of subacute sclerosing panencephalitis: a study of 118 cases from the Middle East.

A variable natural history was found in a standardized follow-up study of 118 patients with subacute sclerosing panencephalitis (SSPE). Only 20% followed the sequence:behavior change, mental deterioration, periodic attacks, severe debility, and death within a year. Six stages were identified: 0, subtle psychointellectual symptoms; 1, obvious psychointellectual and neurological changes; 2, stereotyped attacks; 3, vegetative psychomotor condition; 4, improvement; 5, relapse. Illness began in stage 0 for 32%; 1, 36%; 2, 19%; 1 and 2 simultaneously, 13%. In early development, 77% were hyperactive, and 27% had psychointellectual difficulties one to five years prior to obvious illness. The average duration of each stage was as follows: stage 0, two years; 1, 2.5 months; 2, 7.5 months; 3, 5.5 months; 4, 3.5 years; 5, 1.5 years. Noteworthy improvements and plateaus occurred in more than half of the patients. In stage 4, improvement was long-term and substantial for 5% and modest for 18%. Survival followed an exponential curve with an average half-life of 1.8 years; 41% of the patients survived beyond two years. Half of the patients passed through neither stage 0 nor stage 4; their half-life was 0.7 years. The remainder had a half-life of 3.0 years.

Follow-Up Studies↗
PubMed1978

Substantial spontaneous long-term improvement in subacute sclerosing panencephalitis. Six cases from the Middle East and a review of the literature.

Of 118 cases of subacute sclerosing panencephalitis identified in an extensive follow-up study in the Middle East, six patients were found by personal interview to have experienced substantial spontaneous long-term improvement. To our knowledge, this rate of 5% for such improvement is presently the most accurate estimate available. Relative to the onset of clinical illness, the conditions of two patients are still improving four to five years later, two are stable four to six years later, one relapsed and died recently after eight years, and one is currently in relapse after 11 years. The condition of five patients had not progressed beyond stage 2 before improvement began. All patients had characteristic clinical and electroencephalographic features. Two patients had brain biopsy specimens showing panencephalitis without inclusions. Five patients had highly elevated levels of serum and CSF measles antibodies. In this article, the course of illness and extent of disability are described, published reports of improvement are reviewed, and the possibility of subclinical illness is discussed.

Activities of Daily Living↗
PubMedDate not supplied

Chronic tetanus: clinical report and histochemistry of muscle.

A patient who was partially immune to tetanus developed nonfulminant tetanus after a minor injury. Manifestations of the disease persisted for over 17 months. Electrophysiologic studies revealed an absent silent period in the masseter muscle, large-amplitude F-responses, and denervation. A muscle biopsy showed neurogenic atrophy with reinnervation. This observation supports the existence of chronic tetanus and provides morphologic evidence for a peripheral action of tetanus toxin in humans.

Adult↗