Biomedical subjects
D B Hier
Publications and source records attributed to D B Hier.
Focal left temporal lobe lesions and delayed speech acquisition.
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Autism and unfavorable left-right asymmetries of the brain.
Utilizing computerized brain tomography, left-right morphologic asymmetries of the parietooccipital region were judged in 16 autistic patients, 44 mentally retarded patients, and 100 miscellaneous neurological patients. In 57% of the autistic patients the right parietooccipital region was wider than the left, while this pattern of cerebral asymmetry was found in only 23% of the mentally retarded patients and 25% of the neurological patients. It is suggested that unfavorable morphologic asymmetries of the brain near the posterior language zone may contribute to the difficulties autistic children experience in acquiring language.
Familial amentia, unusual ventricular calcifications, and increased cerebrospinal fluid protein.
A sibship originally reported by Friedman and Roy as showing severe mental retardation, strabismus, hyperactive tendon reflexes, lalling speech, and foot deformities was restudied. Three major additional findings were noted. The cerebrospinal fluid protein concentration was increased two to three times above normal in four siblings who were available for study. Radiographs of cranial structures in three siblings showed identical pathologic intracranial calcifications which correspond in distribution to the choroid plexus. The choroid plexus was not demonstrable in one patient when radiolabeled 99m-Tc-pertechnetate was injected without perchlorate. Neuropathologic findings in one sibling included small subcortical heterotopias and atrophy of the choroid plexus with encasement by glial fibrils. These findings denote a new heredofamilial neurologic syndrome associated with mental retardation and a disorder of choroid plexus.
A genetic explanation for no sex difference in spatial ability among Eskimos.
Superior spatial ability may be inherited as an X-linked recessive trait. Since the sex ratio for an X-linked recessive trait depends on the gene frequency of the recessive allele, the absence of a sex difference in Eskimo spatial ability may reflect an unusually high frequency of the recessive allele in the Eskimo population.
Developmental dyslexia. Evidence for a subgroup with a reversal of cerebral asymmetry.
The computerized brain tomograms of 24 patients with developmental dyslexia were analyzed for cerebral asymmetry. Ten patients showed a reversal of the pattern of asymmetry regularly observed in normal right-handed individuals so that the right parietooccipital region was wider than the left. The ten dyslexic patients with this reversal of cerebral asymmetry had a lower mean verbal IQ than the other 14 dyslexic patients in this study. The reversal of cerebral asymmetry that occurred in ten of the dyslexic patients may result in language lateralization to a cerebral hemisphere that is structurally less suited to support language function and thus act as a risk factor for the development of reading disability.
Hypertensive putaminal hemorrhage.
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Chronic hydrocephalus associated with short stature and growth hormone deficiency.
A 28-year-old man with chronic hydrocephalus due to aqueductal stenosis was found to have a subnormal response of growth hormone to arginine infusion. It is postulated that compression of the pituitary by the enlarged third ventricle produced a deficiency of growth hormone and short stature.
Incongruous oral and written naming. Evidence for a subdivision of the syndrome of Wernicke's aphasia.
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The diagnosis of hypertensive intracerebral hemorrhage: the contribution of computed tomography.
Sixty-eight cases of hypertensive intracerebral hemorrhage were reviewed and the CT scans studied. The CT scan was accurate in localizing and measuring intracerebral hemorrhage. There were three cases of pontine hemorrhage which did not appear on the CT scan. Hemorrhages at other sites were always seen on the CT scan. The size of putaminal and thalamic hemorrhage as calculated from CT scan allowed accurate prognosis to be made at the onset. CT scanning has become the diagnostic test or first choice when intracerebral hemorrhage is suspected.
Nerve growth factor: relationship to the cyclic AMP system of sensory ganglia.
Nerve growth factor and N(6),O(2)' dibutyryl adenosine 3',5'-monophosphate both stimulate neurite elongation by explanted ganglia. However, the addition of nerve growth factor does not lead to increased amounts of adenosine 3',5'-monophosphate in intact ganglia, nor does it stimulate adenylate cyclase activity in broken ganglia cells.
Studies on the mechanism of action of nerve growth factor.
In this study, explanted chick-embryo sensory ganglia were treated with nerve growth factor, and cellular concentrations of neurotubule protein were measured chemically by a colchicine-binding assay. Even after brief time periods, ganglia treated with growth factor were enriched in neurotubule protein, as compared with untreated (control) ganglia. Furthermore, studies with ganglia treated with both vincristine and growth factor demonstrated that neurotubule protein synthesis can occur even though neurite outgrowth is abolished. Several lines of evidence indicate that the growth factor stimulates de novo synthesis of neurotubule subunit protein, and that this effect precedes neurite extension. Like nerve growth factor, dibutyryl cyclic AMP also stimulates neurite outgrowth from embryonic sensory ganglia, yet it does not increase neurotubule protein levels. Available information suggests that the ability of growth factor to elicit rapid neurite outgrowth is closely related to its ability to increase cellular neurotubule levels. Cyclic AMP appears to stimulate neurite outgrowth by a different mechanism.
On a possible relationship of cyclic AMP to the mechanism of action of nerve growth factor.
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Reversibility of CT and MR findings in neuro-Behçet disease.
A woman with neuro-Behçet disease characterized by recurrent attacks of meningoencephalitis is reported. During an attack of brain stem dysfunction characterized by dysarthria, diplopia, and ataxia, the postcontrast CT showed an enhancing lesion of the upper brain stem. During a subsequent attack characterized by subcortical dementia and amnesia, magnetic resonance (MR) showed abnormal signal intensity in the hypothalamus and upper brain stem. Upon remission of her symptoms, follow-up contrast enhanced CT and MR were entirely normal. Magnetic resonance is especially useful in localizing acute inflammatory lesions in Behçet disease. This case suggests that abnormal MR and CT findings in neuro-Behçet disease are potentially reversible and that radiographic improvement parallels clinical improvement.
Converting laserdisc video to digital video: a demonstration project using brain animations.
Interactive laserdiscs are of limited value in large group learning situations due to the expense of establishing multiple workstations. The authors implemented an alternative to laserdisc video by using indexed digital video combined with an expert system. High-quality video was captured from a laserdisc player and combined with waveform audio into an audio-video-interleave (AVI) file format in the Microsoft Video-for-Windows environment (Microsoft Corp., Seattle, WA). With the use of an expert system, a knowledge-based computer program provided random access to these indexed AVI files. The program can be played on any multimedia computer without the need for laserdiscs. This system offers a high level of interactive video without the overhead and cost of a laserdisc player.
Current concepts of cerebrovascular disease--stroke: stroke and drug abuse.
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Cerebral embolism in the Michael Reese Stroke Registry.
Infarction secondary to cerebral embolism was diagnosed in 127 (23.5%) of 540 patients in the Michael Reese Stroke Registry. Coronary artery disease, atrial fibrillation, valvular heart disease, mitral annulus calcification, and cardiomyopathy were the commonest etiologies. Echocardiography documented a potential embolic source in 7 patients without previously known heart disease, and clarified the cardiac pathology in many of the patients with known heart disease. The left anterior circulation was affected in 48%, right anterior in 37%, and posterior circulation in 15% of patients. CT was abnormal in 71% of the patients, and was approximately equally helpful in all locations. Nineteen percent of emboli presented with a deficit that was other than maximal at onset. Concurrent systemic embolism was unusual (2.3%). Prognosis was somewhat worse than in thrombotic stroke. Grouping of patients according to embolic source (intra-arterial, cardiac, and uncertain source) showed no differences in activity at onset, early course, or in subsequent course of the illness.
Racial differences in the distribution of posterior circulation occlusive disease.
We compared clinical and arteriographic features in 27 white and 24 black patients with symptomatic posterior circulation occlusive disease. The degree of arterial stenosis was measured independently by two examiners at 12 sites within the vertebrobasilar territory. Racial comparisons were made based upon the distribution of extra- and intracranial occlusive lesions and symptomatic sites of the lesions. White patients had significantly more angina pectoris, more lesions of the origin of the left vertebral artery and more high grade lesions of the extracranial vertebral arteries. Black patients had significantly higher mean diastolic blood pressure, more diabetes mellitus, more lesions of the distal basilar artery, more high grade lesions of intracranial branch vessels and more symptomatic intracranial branch disease. Race was found to be the only factor increasing the risk of intracranial posterior circulation occlusive disease. Knowledge of the contribution of race to the distribution of posterior circulation lesions will help guide evaluation and treatment strategies for patients with vertebrobasilar occlusive disease.