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Biomedical subjects

R D Adams

Publications and source records attributed to R D Adams.

At least 55 records · Page 3Linked to original sources
PubMed1986

MR and CT of occult vascular malformations of the brain.

The need for improved specificity in the diagnosis of "occult" vascular malformations led to the use of MR in suspected cases in order to determine MR's potential for improved diagnostic accuracy. Six patients with six lesions histologically diagnosed as vascular malformation after partial (1) or complete (5) microsurgical excision were studied by CT, MR, and selective magnification subtraction angiography. In all cases, the cerebral lesions were apparently solitary and were visible as focal lesions on both CT and MR. Since angiography failed to reveal the pathologic blood vessels of the lesions, and no arteriovenous shunting was evident, these lesions were termed vascular malformations occult to angiography (VMOTA). Angiography revealed a mass effect in only two cases. MR did not reveal additional vascular malformations missed by CT. In each case, MR, which was performed in an attempt to support the diagnosis suggested by CT, did in fact do so by revealing signal abnormalities indicative of nonacute hemorrhage within the lesion on T1- and T2-weighted pulse sequences. Although, as on CT, MR features of these lesions were found to be nonspecific, the MR criteria reinforced the probable diagnosis of VMOTA in an additional 30 cases that had shown similar nonspecific CT features. In this second group, excluded from this study, in which histologic verification was not obtained because of perceived hazards of surgery, the increased assurance regarding the diagnosis led to proton-beam therapy without histologic verification in 18 cases. It is concluded that MR can provide significant improvement in the accuracy of diagnosing VMOTA beyond that obtainable just by plain and contrast-enhanced CT.

Adult↗
PubMed1983

Bragg-peak proton-beam therapy for arteriovenous malformations of the brain.

Patients with arteriovenous malformations of the brain, who are subject to disabling or fatal recurrent hemorrhage, seizures, severe headache, and progressive neurologic deficits, may be considered unsuitable for conventional therapies (craniotomy with excision or embolization), usually because of the location, size, or operative risk of the lesion. We have treated such patients with stereotactic Bragg-peak proton-beam therapy and report the follow-up of 74 of the first 75, 2 to 16 years after treatment. Proton-beam therapy is intended to induce subendothelial deposition of collagen and hyaline substance, which narrows the lumens of small vessels and thickens the walls of the malformation during the first 12 to 24 months after the procedure. Two deaths from hemorrhage occurred in the first 12 months after treatment, but no lethal or disabling hemorrhages occurred after this interval. Seizures, headaches, and progressive neurologic deficits were in most cases arrested or improved. Bragg-peak proton-beam therapy appears to be a useful technique for treatment of intracranial arteriovenous malformations, especially those that are unsuitable for treatment by other methods.

Adolescent↗
PubMed1983

The coughing child. A primary care perspective.

Cough in children, even in infants under 1 year of age, is a frequent problem in clinical practice. Many causes are possible and should be considered, but only a few are likely. In primary care, appropriate evaluation is based on skillful history taking. In an ostensibly healthy child or infant with recurrent episodes of nighttime cough preceded by an upper respiratory infection, asthma should be strongly considered. This is especially important when there is a positive family history of asthma.

Age Factors↗
PubMed1982

Fabry disease: impaired autonomic function.

Previous reports of extensive lipid accumulation within neurons of the autonomic nervous system in Fabry disease suggest an anatomicopathologic basis for the peculiar pain, diminished sweating, and gastrointestinal symptoms experienced in this disorder. To further assess autonomic function in Fabry disease, noninvasive clinical tests were performed on 10 patients. Diminished sweating was found in each; the loss was approximately uniform proximally and distally, suggesting sweat gland dysfunction rather than autonomic neuropathy. Impaired pupillary constriction with pilocarpine, and reduced saliva and tear formation were found in half the patients. Disordered intestinal mobility was demonstrated in the oldest patients. In all cases, the cutaneous flare response to scratch and intradermal histamine was diminished, and pruritus was not experienced. Signs of autonomic dysfunction are present in Fabry disease and correlate with the known lipid deposition in autonomic neurons.

Adolescent↗
PubMed1980

H. Houston Merritt.

Explore the source record for details and available documents.

History, 20th Century↗
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↗