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Biomedical subjects

R D Adams

Publications and source records attributed to R D Adams.

13 recordsLinked to original sources
PubMed1978

Split-interval illusion: size of effect with pulse-bounded durations.

The magnitude of the split-interval illusion was measured by method of constant stimuli, with variable intervals between 700 and 1300 msec. and a 1000-msec. standard. All intervals were bounded by 20-msec.-1-kHz pulses and contained a single 20-msec.-2-kHz pulse which either split the interval in a 25:75 ratio or a 75:25 ratio. Intervals split early were overestimated relative to equivalent intervals split late by an average of 8.4% of the 1000-msec. standard.

Acoustic Stimulation↗
PubMed1977

Intrauterine brain death. Neuraxial reticular core necrosis.

Report is given on the first example in which the clinical and electrographic criteria of brain death were obtained at birth. Global destruction of the central nervous system of a type seen only with anoxia and circulatory failure had occurred in utero without appreciable disturbance of maternal health. Neuropathologic reaction in fetal tissues was identical with that which has been observed in the child or adult in the brain death syndrome. Functional disturbance of cerebral spinal circulation of sufficient degree to destroy neuronal tissue had happened without change in maternal circulation and without demonstrable lesions in the placenta or the cardiovascular apparatus of the fetus.

Brain Death↗
PubMed1976

Hemangioblastoma of the spinal cord. Review and report of five cases.

Eighty-five cases of hemangioblastoma of the spinal cord are reviewed, including five new ones. While current views of the incidence, histology, and cytogenesis are presented, the main purpose of this article is to call attention to the identifying clinical and radiological characteristics of these spinal tumors. Median age at onset of symptoms was 30 years. The ratio of men to women was 1.1:1. Presenting symptoms were usually radicular pain or posterior column sensory loss or both. The lesions were most often single (79%), intramedullary (60%), and located in the cervical or thoracic spinal cord. There was associated syringomyelia in 67% of intramedullary cases and meningeal varicosities in 48% of all cases. Lindau disease and hemangioblastomas in other central nervous system locations were present in 33% of cases. The characteristic roentgenographic picture is a densely vascular tumor in association with a larger avascular syrinx and meningeal varicosities. Surgery is the only definitive treatment.

Adolescent↗
PubMed1975

Certain notable clinical attributes of the histiocytic sarcomas of the central nervous system.

By the term reticulum cell sarcoma we denote any tumor composed predominantly of undifferentiated cells, some of which have the qualities of histiocytes. The origin of such CNS tumors may be traced to circulating monocytes, perithelial ro meningeal histiocytes or microgliocytes. The ubiquity of cells of the monocyte-histiocyte series allows six possibilities of CNS involvement: a) primary in the brain: b) secondarily involve the brain or spinal cord by extending from a cranial bone or vertebra to the epidural space c) rarely to involve intraneuronal tissues (lymph nodes, bone, viscera) and then later to localize to the brain substance d) to spread from brain outside the nervous system e) to evoke any one or several of the paraneoplastic diseases (polymyositis, polyneuritis, cerebellar degeneration, f) to permit widespread infections of the nervous system such as multifocal leucoencephalitis. Clinical attributes to be emphasized are the relative rarity of hematogenous metastases (2 of 121 cases), the relatively high incidence of such tumors in immunologically suppressed individuals (12 of 5000 cases), the frequency of primary tumors of CNS (23 of 144 cases), the high incidence of epidural and dural involvement from osseous lesions (13 of 121 cases); the rapid evolution of clinical phenomena; the rarity of paraneoplastic syndromes; the occasional spontaneous and frequent therapeutic regression upon x-radiation. The common invasion of pia and ependyma by the tumor cells and their natural tendency to phagocytosis opens unrealized possibilities of clinical diagnosis by cytological examination and culture of CSF. Early diagnosis by these methods permits avoidance of surgery and the use of radiation and possibly chemotherapy, which may be rewarded by symptomatic regression and potential cure.

Bone Neoplasms↗
PubMed1975

The pathological anatomy of posthemiplegic athetosis.

Disorders of movement after hemiplegia have been described for more than a century, but their pathological anatomy and physiology have remained poorly understood because of ambiguous terminology and incomplete studies. We examined the brains of 5 patients which had been serially sectioned where there had been well documented pure motor hemiplegia acquired in childhood. In 4 patients handicapped by hemiathetosis the main lesion was partial destruction of the caudate nucleus and putamen. In the fifth case, where non-disabling involuntary movements only appeared in later life, there was gliosis of the caudate nucleus and thalamus. Striatal lesions produce involuntary movement disorders if the corticospinal and other major motor tracts are partly intact. We propose that degeneration of the thalamic nuclei receiving striatal efferents (ventralis anterior, ventralis lateralis and centrum medianum), wheter primary or secondary, appears to remove an essential modulating influence on the corticospinal system which can only become manifest if this system is relatively preserved.

Adult↗
PubMed1975

Pure pan-dysautonomia with recovery. Description and discussion of diagnostic criteria.

The patient described in this report appears to have had a unique, severe, pure pan-dysautonomia, and has been investigated in sufficient detail to specify precisely the disorders of functions subserved by the autonomic nervous system. Though we cannot rule out the possibility of an unknown autonomic toxin, we have no evidence for it and suggest that our patient's disorder be considered an acute polyneuritis, restricted to the autonomic system. Comment is made on tests of autonomic dysfunction and on the reliance which can be placed upon the results.

Blood Pressure↗
PubMed1975

Diverticulation of the cerebral ventricles: a cause of progressive focal encephalopathy.

Diverticulation of the lateral ventricles of the brain has received little attention in the literature on hydrocephalus. From clinical observations on one child and one adult with diverticulation, it is apparent that force of CSF within the diverticulum is greater than that against the normal parts of the ventricular wall. In both cases, regression of focal symptoms occurred after insertion of a shunt.

Brain Damage, Chronic↗
PubMed1975

Cerebrospinal fluid acid-base and lactate changes after seizures in unanesthetized man. I. Idiopathic seizures.

The natural course of acid-base changes in arterial blood and lumbar cerebrospinal fluid of patients admitted after major motor seizures was correlated with simultaneously determined lactate levels. In 10 patients with idopathic seizures studied less than 3 hours after the seizure, arterial lactate and cerebrospinal fluid lactate were elevated in association with a mild arterial metabolic acidosis. The elevated cerebrospinal fluid lactate persisted despite a return to normal of the arterial lactate in seven patients studied between 3 and 6 hours after the seizure. All values were normal in five patients studied more than 4 days after a major seizure.

Acid-Base Equilibrium↗
PubMed1975

Cerebrospinal fluid acid-base and lactate changes after seizures in unanesthetized man II. Alcohol withdrawal seizures.

Acid-base changes in arterial blood and lumbar cerebrospinal fluid were correlated with simultaneously determined lactate levels in patients admitted after alcohol withdrawal seizures. Arterial and cerebrospinal fluid lactate was elevated in association with a marked respiratory alkalosis in 13 patients studied 5 to 12 hours after the seizure. Similar elevations of arterial and cerebrospinal fluid lactate were found in five patients during delirium tremens without antecedent withdrawal seizure. The cerebrospinal fluid lactate determined on admission appeared to correlate best with the length and severity of the alcohol withdrawal syndrome that developed in patients after a withdrawal seizure.

Adult↗