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Biomedical subjects

E Feldmann

Publications and source records attributed to E Feldmann.

At least 37 records · Page 2Linked to original sources
PubMed1995

Healing of rickets during vitamin D therapy despite defective vitamin D receptors in two siblings with vitamin D-dependent rickets type II.

We report the healing of severe rickets despite hypocalcemia in two siblings with absent vitamin D receptors; long periods of treatment with excessive doses of vitamin D led to relative hypoparathyroidism and a return to normal of calcium metabolism during calcitriol treatment. This finding suggests that some other regulating factor may substitute for the defective vitamin D receptor.

Dose-Response Relationship, Drug↗
PubMed1995

Treating intracerebral hemorrhage effectively in the ICU. The key steps: provide supportive care and determine the cause.

Consider intensive care for any patient with an intracerebral hemorrhage (ICH) and coma, cardiac ischemia, rhythm disturbances, severe respiratory distress, labile hypertension, or progressive neurologic deficits. Begin treatment with diuretics and prophylaxis of deep venous thrombosis; some patients may also require fluid restriction, hyperventilation, antiepileptic drugs, intracerebral drainage, or surgical evacuation. Common causes of ICH include hypertension; vascular malformations; hemorrhagic infarction; and administration of sympathomimetics, anticoagulants, or fibrinolytics. To predict outcome, consider both the clinical features and radiologic findings at presentation.

Cerebral Hemorrhage↗
PubMed1994

An absent ophthalmic artery or carotid siphon signal on transcranial Doppler confirms the presence of severe ipsilateral internal carotid artery disease.

Transcranial Doppler ultrasound provides a useful adjunct to extracranial ultrasound in the diagnosis of carotid bifurcation disease. Previous studies have shown that collateral flow patterns and diminished flow velocities in the ipsilateral middle cerebral artery correlate with hemodynamically significant carotid disease. In a series of 7,054 carotid duplex and transcranial Doppler examinations, 12.5% (95% confidence interval [CI]: 8.7, 16.4) of 287 ophthalmic arteries ipsilateral to an apparent carotid occlusion had no detectable flow signal, compared with 0.5% (95% CI: 0.3, 0.7) of 6,767 ophthalmic arteries ipsilateral to a non-occluded carotid artery (p < 0.001). Carotid siphon signals were not detectable in 24.4% (95% CI: 19.4, 29.4) of arteries ipsilateral to the carotid occlusion, versus 1.0% (95% CI: 0.8, 1.3) ipsilateral to nonoccluded carotid arteries (p < 0.001). A significant number of absent ophthalmic artery and carotid siphon signals (5.7 and 8.7%, respectively) were also found in patients with 80 to 99% extracranial carotid stenosis. A subset of 216 studies with angiographic correlation confirmed the high association of these transcranial Doppler findings with severe stenosis or occlusion of the internal carotid artery. Primary ophthalmological disease or siphon occlusion did not explain these findings. An absent ophthalmic artery or carotid siphon signal on transcranial Doppler examination is believed to represent a failure to detect slow flow distal to severe carotid bifurcation lesions. As a sign of ipsilateral carotid occlusion, the sensitivities of absent ophthalmic artery and carotid siphon signals are quite low (12.5 and 24.4%, respectively). The high specificities of 99.5 and 99.0%, however, make these findings useful in confirming the diagnosis of presumptive carotid occlusion by carotid duplex ultrasound.

Blood Flow Velocity↗
PubMed1994

Cerebral hemorrhage.

Explore the source record for details and available documents.

Cardiovascular Physiological Phenomena↗
PubMed1993

Premonitory symptoms in epilepsy.

We studied premonitory symptoms in 128 patients with partial and 20 patients with primary generalized epilepsy. Sixty symptoms were reported by 43 (29%) patients, all of whom had partial seizure disorders (P < .01). Symptoms began at least 30 minutes before seizure onset, lasted 10 minutes to 3 days, and were continuous. Irritability, depression, headache, 'funny feeling', and confusion were the most common symptoms. Premonitory symptoms are a warning system in some patients and may permit therapeutic interventions.

Adolescent↗
PubMed1993

The clinical utility of transcranial Doppler ultrasound in suspected vertebrobasilar ischemia.

The impact of transcranial Doppler ultrasound (TCD) on the management of 107 consecutively referred patients with suspected vertebrobasilar ischemia was studied. Physicians who referred patients for TCD of the posterior circulation were interviewed before and after being given the results of the TCD examination. Management plans devised prior to knowledge of the TCD results were compared to those devised after TCD results were given. Management changed in 42% of the patients after TCD results were given, and there was a 58% reduction in the use of angiography (p = 0.04) and a 128% increase in the use of aspirin (p = 0.005). Changes in the use of anticoagulants and other diagnostic or therapeutic approaches were not significant. TCD appears to have a significant impact on the management of patients with suspected vertebrobasilar ischemia.

Humans↗
PubMed1993

The transcranial Doppler standardization project. Phase 1 results. The TCD Study Group, American Society of Neuroimaging.

A project to pursue standardization of the performance and interpretation of transcranial Doppler studies was designed. Phase I consisted of a national survey of the current practice of transcranial Doppler in the United States. From 200 ultrasound laboratories surveyed about the use of transcranial Doppler, 60 completed questionnaires were returned. The results show that further standardization of transcranial Doppler performance and interpretation is necessary, and provide the foundation for phases II and III of the project.

Brain Diseases↗
PubMed1993

Transcranial Doppler validation pilot study.

The use of transcranial Doppler sonography (TCD) for the evaluation of patients with ischemic cerebrovascular disease remains controversial. This study was organized to gather preliminary data regarding the sensitivity and specificity of TCD when compared to cerebral angiography in detecting stenosing lesions and collateral flow patterns of the anterior cerebral circulation. Forty-two patients from six medical centers were prospectively enrolled. Each received cerebral angiography and TCD testing within 24 hours of each other. Based on TCD criteria established a priori, the results were first analyzed by a blinded investigator and then by computer. Computerized analyses were then repeated with modified criteria. Collateral flow through the anterior communicating and ophthalmic arteries was detected with sensitivities of 62% and 100%, and specificities of 98% and 92%, respectively. Internal carotid artery proximal and distal severe ( greater than 70%) stenoses were detected with sensitivities of 79% and 100% and specificities of 88% and 97%. Middle and anterior cerebral artery stenoses and middle cerebral artery occlusion were detected with specificities exceeding 98%; however, the data were insufficient to determine sensitivity. Computerized analyses did not permit improvement of sensitivity and specificity of the baseline criteria. The selected TCD criteria are highly specific in detecting intracranial stenoses and collateral flow patterns of the anterior circulation. The criteria have limited but acceptable sensitivity and specificity in detecting internal carotid artery origin severe stenoses, and are highly sensitive in detecting ophthalmic artery retrograde flow. A study with a larger sample is necessary to provide definitive guidelines for diagnosis.

Adult↗
PubMed1993

Factors associated with early presentation of acute stroke.

BACKGROUND AND PURPOSE: Patients with stroke symptoms commonly delay many hours before seeking medical attention. We sought to explore the factors associated with early presentation of stroke patients to physicians. METHODS: We prospectively studied 100 consecutive acute stroke patients presenting to three large, urban medical centers. Using a standardized, structured interview and chart review, we assessed patient education about stroke, risk factors, clinical features of the stroke, source of stroke recognition, and timing of presentation. We did not study the distance from the site of stroke onset to the site of physician contact. RESULTS: Stroke onset time was known in 96 of the patients. Mean patient age was 71.3 years, 79% had at least one stroke risk factor, 26% had prior transient ischemic attack, 19% had prior stroke, 74% had some high school education, and 86% had regular physicians. Only 8% had been previously educated about stroke symptoms. Eighty one percent of strokes were ischemic. The mean time to physician contact was 13.4 +/- 2.3 hours (median, 4.0 hours) and to neurologist contact was 21.2 +/- 2.9 hours. A skewed distribution of presentation times accounts for the mean-median differences. A small number of patients presenting very late could have an effect on the correlations between presentation time and the variables studied. Early presentation time was associated with increased age, the sudden onset of a stable deficit, and recognition that the symptoms signified stroke. Only the sudden onset of a stable deficit correlated independently with early presentation time (P = .0048). There was no correlation between presentation time and prior transient ischemic attack or stroke, headache, vomiting, loss of consciousness or seizures at onset, or stroke subtype, but a type II error could not be excluded. CONCLUSIONS: Despite their education level, regular health care, and risk factors, especially prior stroke and transient ischemic attack, these patients were not knowledgeable about stroke and delayed many hours before contacting physicians. The course of symptoms and recognition that they signified stroke were associated with earlier presentation. Patient education focused on groups at risk may hasten the presentation and treatment of acute stroke.

Acute Disease↗
PubMed1991

Diagnosis and treatment of cerebral amyloid angiopathy.

CAA is the infiltration of leptomeningeal and penetrating cortical vessels with amyloid, sparing the subcortical regions and the systemic vasculature. It occurs with increasing frequency after the sixth decade. The major clinical manifestation of CAA is lobar intracerebral hemorrhage, which can be sporadic or hereditary. CAA has also been associated with normal aging, Alzheimer's disease, cerebral infarction, and periventricular demyelination. Biochemical studies have shown that the amyloid deposits in the brains of patients with normal aging, sporadic CAA-associated hemorrhage, hereditary cerebral hemorrhage, and Alzheimer's disease are identical. The exact mechanism by which CAA produces lobar hemorrhages and the role of CAA in the development of dementia are unclear. Biopsy of the involved cerebral cortex and leptomeninges is the only definitive way to diagnose CAA. Acute management of CAA-associated lobar hemorrhage consists of aggressive control of associated hypertension and supportive care. Surgical removal of the hemorrhage has not been shown to improve survival. Antiplatelet and anticoagulant therapy should be avoided in elderly patients with known CAA.

Aged↗
PubMed1990

Caudate infarcts.

Eighteen patients had caudate nucleus infarcts (10 left-sided; 8 right-sided). Infarcts extended into the anterior limb of the internal capsule in 9 patients, and also the anterior putamen in 5 patients. Thirteen patients had motor signs, most often a slight transient hemiparesis. Dysarthria was common (11 patients). Cognitive and behavioral abnormalities were frequent, and included abulia (10 patients), agitation and hyperactivity (7 patients), contralateral neglect (3 patients, all right caudate), and language abnormalities (2 patients, both left caudate). The majority of patients had risk factors for penetrating artery disease. Branch occlusion of Heubner's artery, or perforators from the proximal anterior or middle cerebral arteries were the posited mechanism of infarction.

Adult↗
PubMed1990

Transient ischemic attacks presenting with a loss of pitch perception.

It has been suggested that the non-dominant hemisphere is specialized for receptive and expressive music and prosody. The present report describes a patient who experienced a series of non-dominant hemisphere transient ischemic attacks (TIA's) which included an inability to perceive intonation during one episode, and a failure to perceive melody during another. The perceptual losses during these TIA's are consistent with experimental results which suggest that the non-dominant hemisphere is specialized for complex-pitch processing. In some instances, amusia, dysprosody, and aprosodia reflect a common functional deficit.

Cerebrovascular Disorders↗
PubMed1990

Chinese-white differences in the distribution of occlusive cerebrovascular disease.

The distribution of cerebrovascular lesions is affected by race. Blacks and Japanese have more intracranial occlusive cerebrovascular disease, while whites have more extracranial disease. Despite a high incidence of stroke in China, there are few formal studies of the distribution of vascular occlusive disease in Chinese populations. We compared clinical and angiographic features of 24 white and 24 Chinese patients with symptomatic occlusive cerebrovascular disease. In symptomatic vascular territories, whites had more severe (greater than or equal to 50% stenosis) extracranial lesions, while Chinese had more severe intracranial lesions. When we counted mild and severe lesions in a symptomatic territory, whites had more extracranial lesions while Chinese had more intracranial lesions. When we combined symptomatic and asymptomatic territories, whites had more extracranial lesions, while Chinese had more intracranial lesions. White patients reported more transient ischemic attacks. The distribution of lesions, however, was not explained by differences in incidence of transient ischemia, hypertension, diabetes, hypercholesterolemia, or ischemic heart disease between the groups. The preponderance of intracranial vascular lesions in Chinese patients is similar to that seen in blacks and Japanese. Racial differences in the occurrence of extracranial and intracranial lesions raise the possibility of a different underlying pathophysiology for the 2 locations.

Aged↗
PubMed1989

Autoscopic phenomena with seizures.

We report the cases of 10 patients with seizures and autoscopic phenomena, which include seeing one's double and out-of-body experiences, and review 33 additional cases of autoscopic seizures from the literature. Autoscopic phenomena may be symptoms of simple partial, complex partial, or generalized tonoclonic seizures. Autoscopic seizures may be more common than is recognized; we found a 6.3% incidence in the patients we interviewed. The temporal lobe was involved in 18 (86%) of the 21 patients in whom the seizure focus could be identified. There was no clear lateralization of lesions in patients with ictal autoscopy. The response of autoscopic episodes to treatment usually paralleled that of the underlying seizure disorder. Autoscopic phenomena are likely to be discovered only on specific questioning of patients with epilepsy and may be an important, distressing feature of a chronic seizure disorder.

Adult↗
PubMed1988

MRI demonstrates descending transtentorial herniation.

Descending cerebral transtentorial herniation (DTH) is a serious and often fatal complication of intracranial mass lesions. The condition can be inferred from clinical neurologic signs, but has not been visualized during life. Using midsagittal magnetic resonance images (MRIs), we compared vertical brainstem position on 50 images from normals and 21 images from 15 clinically stable patients with large supratentorial tumors. The length of Twining's line (T), the perpendicular distance from T to the pontomesencephalic junction (T-PMJ), and from T to the apex of the midbrain aqueduct (T-A) were measured. We also measured lateral shifts of the diencephalon and midbrain on axial images. T-PMJ decreased from 2.04 +/- 0.06 mm in normals to 0.94 +/- 0.2 mm in patients with large cerebral tumors (p less than 0.0001). Similarly, T-A decreased from 6.35 +/- 0.13 mm in normals to 4.83 +/- 0.35 mm in patients (p = 0.001). Lateral diencephalic-midbrain shifts often accompanied DTH but to an unpredictable degree. Either lateral or downward brainstem shift could occur alone and did not necessarily produce specific neurologic signs or an altered state of consciousness. Anatomic DTH occurs in life, it can be quantified with MRI, and in slowly developing cerebral mass lesions the process can precede the appearance of neurologic signs and symptoms that indicate lower-diencephalic or midbrain dysfunction.

Brain Diseases↗
PubMed1987

Delayed hippocampal damage in humans following cardiorespiratory arrest.

Transient ischemia in animals produces delayed cell death in vulnerable hippocampal neurons. To see if this occurs in humans, we reexamined brain slides from all patients with anoxic-ischemic encephalopathy and a well-documented cardiorespiratory arrest. Eight patients dying 18 hours or less after cardiac arrest had minimal damage in hippocampus and moderate damage in cerebral cortex and putamen. Six patients living 24 hours or more had severe damage in all four regions. The increase in damage with time postarrest was significant only in the hippocampus. Delayed hippocampal injury now documented in humans provides a target for possible therapy that can be initiated after cardiopulmonary resuscitation.

Adult↗