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Biomedical subjects

H S Singer

Publications and source records attributed to H S Singer.

118 records · Page 7Linked to original sources
PubMedDate not supplied

Neurobiological issues in Tourette syndrome.

The Tourette syndrome (TS) represents an intriguing disorder that overlaps the clinical fields of neurology and psychiatry. Composed of a spectrum of familial, involuntary motor and vocal tics and co-morbid neuropsychological problems, this disorder has become a model for investigators interested in neurobehavioral research. Although the subject of numerous reports since Tourette's original description in 1885, over the past decade there has been a rapid expansion of knowledge pertaining to the phenomenology of tic syndromes and their associated problems, the role of genetic and environmental factors, and the underlying pathophysiology. The role of frontal-subcortical circuits, dopaminergic neurotransmission, and second messenger systems are highlighted. This report provides a framework for understanding current neurobiological issues in TS.

Humans↗
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Development of behavioral and emotional problems in Tourette syndrome.

Tourette syndrome is a movement disorder with multiple neuropsychiatric features. Using the parent form of the Child Behavior Checklist by Achenbach and Edelbrock, we identified behavioral and emotional difficulties in 78 males, 6-16 years of age, with Tourette syndrome. Symptoms most often identified included obsessive-compulsive behavior, aggressiveness, hyperactivity, immaturity, withdrawal, and somatic complaints. Abnormal checklist scores were most prevalent in adolescents with Tourette syndrome. Tic severity was not a statistically significant predictor of behavioral disturbance, although a suggestive relationship between tic severity and behavioral disturbance was observed in the 12- to 16-year-old group. Dividing Tourette syndrome patients into those with or without hyperactivity failed to identify whether hyperactivity had a major impact on abnormal behaviors. Our results illustrate the relative frequency of psychopathology in Tourette syndrome and emphasize the need for a comprehensive approach to this syndrome.

Adolescent↗
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Destructive encephalopathy in incontinentia pigmenti: a primary disorder?

A 3-day-old infant with incontinentia pigmenti presented with acute encephalopathy associated with neuroradiographic findings of hemorrhagic necrosis and brain edema. No specific infectious, inflammatory, vascular, or metabolic abnormality was identified. We speculate that there is a variably expressed mutant protein in incontinentia pigmenti that could cause either developmental brain malformations or a destructive process.

Brain Diseases↗
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Sleep disorders in Tourette syndrome: a primary or unrelated problem?

Sleep disturbances are a common complaint in children with either Tourette syndrome (TS) or attention-deficit hyperactivity disorder (ADHD). Because a significant number of individuals with TS also have ADHD, we attempted to determine whether sleep difficulties reported in TS are a primary problem or are related to the co-occurrence of ADHD. Using a parent-completed sleep questionnaire, data were collected on boys, ages 7-14 years. Three groups, TS-only (N = 57), ADHD-only (N = 21), and TS+ADHD (N = 89), were compared to an age-matched control population (N = 146). The complaint of "poor sleep" occurred in 26% with TS-only, 48% with ADHD-only, and 41% with TS+ADHD; all were significantly different from 10% found in controls. Of 19 sleep questionnaire items, the incidence of problems occurred statistically more frequently in 5 of 19 for the TS-only group, in 6 of 19 for the ADHD-only group, and in 17 of 19 for the TS+ADHD group. Boys with TS+ADHD had many sleep problems which appeared to be related to an arousal disorder. Although the use of medications, especially stimulants and anti-depressants, were different between the TS-only and TS+ADHD groups, this factor did not account for the large discrepancies in sleep disturbance. In boys with TS, sleep problems usually occurred with the co-morbid feature ADHD.

Adolescent↗
PubMedDate not supplied

Effects of anticonvulsants on cell growth and enzymatic and receptor binding activity in a neuroblastoma x glioma hybrid cell culture.

The effects of anticonvulsants on markers of growth, intracellular enzymes, and synaptic functions were evaluated using a rapidly dividing cholinergic neuroblastoma x glioma hybrid cell-line (NG108-15). Cell cultures were exposed for 4 days to phenobarbital, phenytoin, carbamazepine, or valproic acid. Anticonvulsant concentrations added to the media were selected to produce free levels in the cell media that were equivalent to free levels in humans ranging from therapeutic to very toxic. Free levels of anticonvulsants in the toxic range affected cell number, protein content, and neurochemical markers. However, only valproic acid and phenytoin reduced cell growth at therapeutic free drug concentrations. Valproic acid was the only medication to act as a differentiating agent, significantly increasing the activity of choline acetyltransferase, beta-galactosidase, and muscarinic cholinergic receptor binding. These results emphasize the importance of performing drug studies at appropriate free drug concentrations and suggest that valproic acid differs from other commonly prescribed anticonvulsants by having both a growth-suppressing and a differentiating effect.

Animals↗
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Haloperidol, fluphenazine and clonidine in Tourette syndrome: controversies in treatment.

The value of haloperidol, fluphenazine and clonidine as therapeutic agents for Tourette's syndrome was retrospectively reviewed. Haloperidol improved tic symptoms in 50/60 patients, but side effects often nullified these benefits. Fluphenazine was an effective drug for tic suppression in 24/31 patients. Direct comparison of these drugs in 23 patients confirmed the efficacy of fluphenazine and showed it to produce fewer adverse effects than haloperidol. Clonidine was helpful in 47% and caused few side effects. These results support the use of clonidine for the treatment of tics and suggest that fluphenazine can be considered an alternative to other neuroleptic drugs.

Child↗
PubMedDate not supplied

Moyamoya-like disease in Down's syndrome.

We present a case of a 6-year-old girl with Down's syndrome who developed recurrent hemipareses. Cerebral angiography showed bilateral supraclinoid stenosis of internal carotid arteries and complexes of dilated collateral vessels, consistent with moyamoya disease.

Basilar Artery↗