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Biomedical subjects

J A Brunberg

Publications and source records attributed to J A Brunberg.

At least 73 records · Page 4Linked to original sources
PubMed1994

Gadopentetate dimeglumine-enhanced MR of the brain: clinical utility and safety in patients younger than two years of age.

PURPOSE: To evaluate the clinical utility and safety of gadopentetate dimeglumine as a contrast agent for MR of the brain in patients younger than 2 years of age. METHODS: In 125 consecutive patients younger than 2 years of age, MR images obtained before and after gadopentetate dimeglumine administration (0.1 mmol/kg) were independently and prospectively evaluated. After interpreting the unenhanced T1- and T2-weighted images, we rated the utility of contrast administration in each patient as not helpful, helpful, or essential for formulation of the radiologic diagnosis. Ratings were categorized both on the basis of the referring clinical diagnoses and on the basis of a radiologic diagnosis that was established from the clinical history and from the findings on the precontrast and postcontrast T1- and T2-weighted images. Patients' vital signs were recorded, and general medical status was observed for 120 minutes after gadopentetate dimeglumine administration. RESULTS: In no case did gadopentetate dimeglumine permit detection of lesions when precontrast T1- and T2-weighted images were normal. In only 4 of 125 patients were postcontrast images considered essential for establishing the radiologic diagnosis. Abnormal contrast enhancement was radiologically helpful in 20 of 125 patients. Lack of enhancement was considered helpful in 22 of 125 patients. No adverse clinical events or clinically important trends in vital signs were observed after contrast administration. CONCLUSION: The indiscriminate use of contrast agents in the MR imaging of patients younger than 2 years of age is not warranted. Appropriate decisions regarding the use of gadopentetate dimeglumine can be based on the findings in unenhanced T1- and T2-weighted images and on the referring clinical diagnosis.

Brain Diseases↗
PubMed1993

Depression in stroke rehabilitation.

Despite recent advances in understanding the pathophysiology of poststroke depression, major questions remain. They include the relative importance of lesion location and size and the confounding effects of time since stroke, age, prior history of depression, and cerebral atrophy. To evaluate these issues, we systematically assessed depressive features, functional status, and brain structure with computer tomography scans in 91 men undergoing stroke rehabilitation. Forty percent met DSM-III criteria for major depressive disorder. Mood disturbance was more severe for patients with right than with left hemisphere lesions, correlated with functional disability and lesion size, and was associated with previous history of depression. Age, time since stroke, and atrophy did not correlate with mood. Depression is common in delayed stroke recovery, regardless of lesion location. Because there are no demographic or anatomic features that predict the absence of depression, depression screening should be part of the assessment of all patients undergoing stroke rehabilitation.

Activities of Daily Living↗
PubMed1993

Autosomal dominant transmission of the Pallister-Hall syndrome.

We describe a 9-year-old boy and his 34-year-old father with the Pallister-Hall syndrome. The proband had precocious puberty, imperforate anus, postaxial polydactyly, hypospadias, a hypothalamic mass, and a displaced pituitary gland. The father had polydactyly, a hypothalamic mass, and a flattened pituitary gland. We conclude that the most likely cause of the Pallister-Hall syndrome is a mutation in a gene inherited in an autosomal dominant manner.

Abnormalities, Multiple↗
PubMed1993

Neuropsychological deficits are correlated with frontal hypometabolism in positron emission tomography studies of older alcoholic patients.

In an extension of previous work, we studied the behavioral correlates of medial frontal lobe glucose hypometabolism in chronically alcohol-dependent patients. Thirty-one male patients who were detoxified, medically stable, and free of other central nervous system risk factors for neuropsychological impairment were examined with (1) anatomic imaging (CT or MR), (2) functional imaging with [18F] fluorodeoxyglucose (18F-FDG) and positron emission tomography (PET), and (3) a battery of neuropsychological tests, including two measures of abstraction known to be generally sensitive to frontal lobe disease or dysfunction [the Wisconsin Card Sorting Test (WCST) and the Halstead Category Test (HCT)]. 18F-FDG PET data from 18 age- and sex-matched normal control subjects were used for comparison. All patients met criteria for severe alcohol dependence and for at least a mild degree of alcoholic-induced cognitive impairment. Although the mean IQ level of the alcoholic patients was in the average range, the concepts attained and the error scores on the WCST and HCT were significantly impaired in comparison with established norms. Local cerebral metabolic rate for glucose (LCMRglc) was significantly decreased in a sagittal strip of the medial frontal cortex in the alcoholic patients as compared with the normal controls. Comparison of data from PET scans and anatomic images indicated that the reduced LCMRglc could not be attributed to reduced amounts of tissue alone. A statistically significant relationship was found between LCMRglc in the medial frontal region of the cerebral cortex and performance on the WCST, but not the HCT. These findings suggest that chronic alcohol intake results in impaired function of cerebral tissue in the medial frontal region.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

In vivo cerebral metabolism and central benzodiazepine-receptor binding in temporal lobe epilepsy.

Positron emission tomography measured interictal cerebral glucose metabolism with [18F]fluorodeoxyglucose and central benzodiazepine-receptor binding with [11C]flumazenil in 10 mesial temporal lobe epilepsy (TLE) patients and in normal subjects. Eight TLE patients had mesial temporal, lateral temporal, and thalamic hypometabolism ipsilateral to EEG ictal onsets, with additional extratemporal hypometabolism in four. One had unilateral anterior mesial temporal hypometabolism only, and one had normal metabolism. Each patient had decreased benzodiazepine-receptor binding in the ipsilateral anterior mesial temporal region, without neocortical changes. Thus, interictal metabolic dysfunction is variable and usually extensive in TLE, whereas decreased central benzodiazepine-receptor density is more restricted to mesial temporal areas. Metabolic patterns in TLE may reflect diaschisis, while benzodiazepine-receptor changes may reflect localized neuronal and synaptic loss that is specific to the epileptogenic zone. [11C]Flumazenil imaging may be useful in presurgical evaluation of refractory complex partial seizures.

Adult↗
PubMed1993

Correlation of evoked potential and MRI findings in Wilson's disease.

We recorded brainstem auditory evoked potentials (BAEPs) and somatosensory evoked potentials to median nerve stimulation (MSEPs) within 10 days of brain MRI in 20 patients with Wilson's disease (WD). MRI was abnormal in 90% of patients, demonstrating symmetric striatum and brainstem lesions with or without thalamic lesions. MSEPs were abnormal in 65% of patients, usually showing bilaterally prolonged N/P13-N20 latencies. BAEPs were abnormal in 40%, most often with bilateral prolongation of the III-V latency. The III-V and N/P13-N20 interpeak latencies correlated significantly with the severity of MRI lesions in the caudal pons, rostral pons, and caudal midbrain. Our results indicate that subclinical sensory dysfunction is common in WD, and that auditory and somatosensory pathways are most severely affected at the brainstem level. Both the localization and severity of evoked potential abnormalities correspond closely to the morphologic changes in the pons and caudal midbrain shown by MRI.

Adult↗
PubMed1991

Quantitative measurement of tissue perfusion and diffusion in vivo.

Magnetic resonance imaging techniques designed for sensitivity to microscopic motions of water diffusion and blood flow in the capillary network are also exceptionally sensitive to bulk motion properties of the tissue, which may lead to contrast artifact and large quantitative errors. The magnitude of bulk motion error that exists in human brain perfusion/diffusion imaging and the inability of cardiac gating to adequately control this motion are demonstrated by direct measurement of phase stability of voxels localized in the brain. Two methods are introduced to reduce bulk motion phase error. The first, a postprocessing phase correction algorithm, reduces coarse phase error but is inadequate by itself for quantitative perfusion/diffusion MRI. The second method employs orthogonal slice selection gradients to define a column of tissue in the object, from which echoes may be combined in a phase-insensitive manner to measure more reliably the targeted signal attenuation. Applying this acquisition technique and a simplistic model of perfusion and diffusion signal attenuations yields an estimated perfusion fraction of 3.4 +/- 1.1% and diffusion coefficient of 1.1 +/- 0.2 x 10(-5) cm2/s in the white matter of one normal volunteer. Successful separation of perfusion and diffusion effects by this technique is supported in a dynamic study of calf muscle. Periods of normal blood flow, low flow, and reactive hyperemia are clearly distinguished in the quantitative perfusion results, whereas measured diffusion remained nearly constant.

Algorithms↗
PubMed1991

Intramedullary lesions of the pediatric spinal cord: correlation of findings from MR imaging, intraoperative sonography, surgery, and histologic study.

Findings of preoperative magnetic resonance (MR) imaging and radiologist-directed intraoperative sonography (IOS) were correlated with surgical and pathologic findings in 11 pediatric patients with intramedullary spinal cord lesions. There were seven gliomas and one each of primitive neuroectodermal tumor, venous vascular malformation, neuroenteric cyst, and active schistosomiasis. MR imaging provided discrete preoperative anatomic localization and excluded multicentric lesions but did not reliably distinguish between solid and cystic lesions. IOS helped (a) define the limits of intramedullary mass before the dura mater was opened and (b) differentiate cystic from solid components. The internal architecture of intramedullary lesions, as shown with MR imaging and sonography, was strikingly similar, allowing discrete correlative localization for biopsy or tissue resection. Gadolinium-enhanced MR imaging and IOS are complementary imaging techniques that should be used in concert for the evaluation and management of intramedullary lesions of the pediatric spinal cord. Both techniques display regions of cord abnormality, but neither definitively characterizes underlying tissue histology.

Adolescent↗
PubMed1991

Arytenoid subluxation: diagnosis and treatment.

Both arytenoid subluxation and recurrent laryngeal nerve paralysis (RLNP) may result from injury to the larynx, and they may be difficult to distinguish clinically. A patient with arytenoid subluxation who was initially believed to have RLNP was treated with medialization laryngoplasty 1 year after the injury. Preoperative magnetic resonance imaging and computed tomography effectively demonstrated the cricoarytenoid subluxation, which was confirmed by intraoperative electromyography (EMG) showing normal electrical activity in the thyroarytenoid muscle. Photographs from preoperative fiberoptic laryngoscopy are presented to identify the appearance of arytenoid subluxation. Computed tomographic findings and photographs from laryngoscopy of two patients with RLNP documented by intraoperative EMG evaluation are presented to help distinguish the clinical appearance of this disorder from arytenoid subluxation. An integrated approach to the diagnosis and treatment of arytenoid subluxation is presented.

Adult↗
PubMed1991

Spinal cord schistosomiasis: a pediatric case mimicking intrinsic cord neoplasm.

We present the clinical, myelographic, MRI, and histologic data on a 7-year-old girl with confirmed Schistosoma mansoni infection of the spinal cord. MRI of the granulomatous spinal lesion revealed extensive enlargement of the cord in the T11-12 area, with some intramedullary swelling extending to T-5 through T-7. The clinical manifestations of spinal schistosomiasis can be diverse, and there should be a high index of suspicion for all patients from endemic areas.

Adult↗
PubMed1990

Cerebellar and frontal hypometabolism in alcoholic cerebellar degeneration studied with positron emission tomography.

Local cerebral metabolic rate for glucose was studied utilizing 18F-2-fluoro-2-deoxy-D-glucose and positron emission tomography (PET) in 14 chronically alcohol-dependent patients and 8 normal control subjects of similar age and sex. Nine of the 14 patients (Group A) had clinical signs of alcoholic cerebellar degeneration, and the remaining 5 (Group B) did not have signs of alcoholic cerebellar degeneration. PET studies of Group A revealed significantly decreased local cerebral metabolic rates for glucose in the superior cerebellar vermis in comparison with the normal control subjects. Group B did not show decreased rates in the cerebellum. Both Groups A and B showed decreased local cerebral metabolic rates for glucose bilaterally in the medial frontal area of the cerebral cortex in comparison with the normal control subjects. The severity of the clinical neurological impairment was significantly correlated with the degree of hypometabolism in both the superior cerebellar vermis and the medial frontal region of the cerebral cortex. The degree of atrophy detected in computed tomography scans was significantly correlated with local cerebral metabolic rates in the medial frontal area of the cerebral cortex, but not in the cerebellum. The data indicate that hypometabolism in the superior cerebellar vermis closely follows clinical symptomatology in patients with alcoholic cerebellar degeneration, and does not occur in alcohol-dependent patients without clinical evidence of cerebellar dysfunction. Hypometabolism in the medial frontal region of the cerebral cortex is a prominent finding in alcohol-dependent patients with or without alcoholic cerebellar degeneration.

Adult↗
PubMed1990

Anisotropic diffusion in human white matter: demonstration with MR techniques in vivo.

Quantitative measurements of perfusion and molecular diffusion were made in human white matter in two orientations of the motion-sensitization gradient to document anisotropy of these parameters. Measurements were localized to a 10 X 10-mm tissue column oriented in an anterior-to-posterior direction in the left cerebral hemisphere just above the body of the left ventricle. This region was selected because of the relatively high directionality of white matter fibers. In this study of five healthy volunteers, strong diffusion anisotropy was observed in all cases. Twofold or greater anisotropy was commonly observed, with the higher diffusion value associated with motion sensitivity along the fiber directions. By combining data from both gradient orientations in all cases, diffusion values of solid tissue ranged from 0.38 X 10(-3) mm2/sec to 1.12 X 10(-3) mm2/sec, and measured perfusion fractions were in the range of 2%-5% (excluding areas highly contaminated by cerebrospinal fluid). Little or no perfusion-fraction anisotropy was observed; however, perfusion measurements were limited by noise. Data were collected without cardiac gating by using a technique that offers good immunity to bulk tissue motion artifacts.

Adult↗
PubMed1988

Diagnosis of tethered cords by magnetic resonance imaging.

Thirty children presented with signs and/or symptoms of tethered spinal cord, 13 in association with spina bifida occulta and 17 after myelomeningocele repair. Preoperative magnetic resonance imaging (MRI) of 27 children showed tethering (27), intradural fat (17), distal syrinxes (8), and thickened filum terminale (2). There was an excellent correlation between MRI and the surgical findings. Postoperative MRI was obtained within 1 year after operation in 14 children; spinal cord ascent was seen on only four studies and retethering was suspected on five studies. We consider MRI the procedure of choice to diagnose a tethered cord because this technique accurately defines anatomical relationships without risk to the patient. In addition, we conclude that cord ascent is seen less often than expected and that retethering may occur, especially to cadaveric dura mater.

Adolescent↗
PubMed1988

Magnetic resonance imaging of spinal dysraphism.

MR imaging has become the definitive diagnostic procedure for the evaluation of suspected spinal dysrhaphic processes. Techniques for spinal MR imaging are discussed and MR findings in patients with surgically verified dysrhaphic spinal lesions are reviewed.

Child↗