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Biomedical subjects

B L Hart

Publications and source records attributed to B L Hart.

At least 37 records · Page 2Linked to original sources
PubMed1998

Brain injury and neurometabolic abnormalities in systemic lupus erythematosus.

PURPOSE: To investigate with statistical analysis the relationship between brain injury measured with magnetic resonance (MR) imaging and that measured with proton (hydrogen-1) MR spectroscopy. MATERIALS AND METHODS: Forty-two patients (34 female, eight male; mean age +/- SD, 38.7 years +/- 13.1; age range, 6-60 years) with systemic lupus erythematosus (SLE) were examined with H-1 MR spectroscopy to measure N-acetylaspartate (NAA), creatine (Cr), and choline (Cho) levels in normal-appearing white matter and with MR imaging to detect anatomic abnormalities. RESULTS: Results of linear regression analysis revealed an association between the NAA/Cr ratio and anatomic abnormalities (P = .03). However, only small focal lesions were independently related to NAA/Cr ratio changes (P = .04). Results of a similar analysis showed associations between the Cho/Cr ratio and anatomic abnormalities (P = .002). An elevated Cho/Cr ratio and cerebral infarction were independently associated (P = .02), as were a decreased Cho/Cr ratio and severe cortical atrophy (P = .02). CONCLUSION: Cerebrovascular abnormalities underlie diffuse cerebral injury in SLE, with small vessel injury (i.e., small focal lesions) primarily associated with a decreased NAA/Cr ratio and medium vessel injury (i.e., infarct) primarily associated with an increased Cho/Cr ratio. Statistical integration of H-1 MR spectroscopic and MR imaging findings over large data sets provides insights into the relevance of individual MR imaging-visible brain abnormalities in SLE. This statistical approach may be applicable to other systemic diseases complicated by brain injury.

Adolescent↗
PubMed1998

Autosomal dominant cerebral arteriopathy: neuropsychiatric syndrome in a family.

Though familial vascular leukoencephalopathy was described two decades ago, recent studies focus on a disorder termed Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL), a dominantly inherited disorder causing recurrent strokes and eventual dementia. The phenotypic boundaries of CADASIL remain indistinct and novel clinical features continue to arise in the literature. However, the associated histopathology is fairly consistent, typically demonstrating granular thickening of cerebral arterioles. The authors evaluated a 38-year-old man who suffered from progressive change in personality and intellect. His father, paternal aunt, and older sister had succumbed to a similar disorder. The authors examined relatives from three generations, including another sister with transient focal symptoms followed by persisting psychiatric disorder, and reviewed the radiographic studies from the propositus and his siblings. All the siblings showed diffuse white matter signal change on magnetic resonance imaging. Brain biopsy from the propositus revealed normal cortex and white matter but granular sclerosis of leptomeningeal arterioles. While the family's illness likely represents another instance of CADASIL, their presentation is unique because neuropsychiatric disorders predominate over focal ischemic symptoms.

Adult↗
PubMed1998

Neurologic, MR imaging, and MR spectroscopic findings in eosinophilia myalgia syndrome.

BACKGROUND AND PURPOSE: Eosinophilia myalgia syndrome (EMS), a multisystemic disease induced by exposure to L-tryptophan, may result in serious CNS abnormalities. The purpose of this study was to determine the pattern of neurologic characteristics, MR imaging abnormalities, and brain neurometabolites in EMS. METHODS: Sixteen patients with EMS and CNS abnormalities (CNS-EMS) and 12 control subjects underwent evaluation, including medical and neurologic examination, proton MR spectroscopy, and MR imaging. RESULTS: Neurologic findings that were increased in CNS-EMS included minor depression (100%), amnesia (88%), and intermittent confusion (38%), although fatigue (31%), motor disorders (31%), recurrent headache (19%), major depression (13%), and dementia (6%) also occurred, but at a lesser significance. Self-reported disability was markedly increased in CNS-EMS. MR imaging findings included subcortical focal lesions, focal lesions in deep white matter, cortical atrophy, ventricular dilatation, and diffuse and periventricular white matter abnormalities. MR spectroscopic findings established two distinct spectral patterns: 1) increased choline-containing compounds, decreased N-acetylaspartate, and increased lipid-macromolecules, consistent with inflammatory cerebrovascular disease; and 2) increased glutamine, decreased myo-inositol, and decreased choline, consistent with acute CNS injury or metabolic encephalopathy. CONCLUSION: Neurologic abnormalities, self-reported disability, brain lesions, and MR spectroscopic abnormalities are common in CNS-EMS. The pattern of cerebral lesions and neurometabolites is consistent with widespread inflammatory cerebrovascular disease. However, a subgroup of patients with CNS-EMS have neurometabolic changes consistent with a metabolic encephalopathy identical or similar to hepatic encephalopathy. The neurologic abnormalities in EMS and related hypereosinophilic syndromes should be interpreted cautiously, with the recognition that both cerebrovascular injury and secondary metabolic encephalopathies may be involved.

Adult↗
PubMed1997

Brain abnormalities in schizophrenia-spectrum children: implications for a neurodevelopmental perspective.

Children with symptoms of schizophrenia-spectrum disorder (N = 20) were compared to controls (N = 20) matched for age and socioeconomic status. Structural brain abnormalities were assessed with magnetic resonance imaging and functional brain abnormalities with neuropsychological tests. Children with schizophrenia-spectrum disorder had smaller amygdala and temporal cortex volumes, along with reduced callosal areas and an unusual pattern of neuroanatomic asymmetries. No differences were noted in overall brain volume, ventricular volume, hippocampal volume, or frontal area. Schizophrenia-spectrum children were also characterized by deficits in all neuropsychological functions examined. Some types of verbal memory and frontal lobe skills were especially deficient. These results support the hypothesis that children with schizophrenia-spectrum disorder have significant brain abnormalities, similar in some ways to those seen in adult schizophrenics. In conjunction with recent primate studies, the current results draw attention to the role of the amygdala as one relevant factor in the pathogenesis of schizophrenia.

Brain↗
PubMed1997

The management of unilateral lateral mass/facet fractures of the subaxial cervical spine: the use of magnetic resonance imaging to predict instability.

STUDY DESIGN: Retrospective review of the clinical course and cervical spine plain radiographs, computed tomography, and magnetic resonance imaging of 24 consecutive patients for a 2-year period with a unilateral lateral mass/facet fracture. OBJECTIVE: To propose a treatment algorithm for the management of unilateral lateral mass/facet fractures of the subaxial cervical spine based on ligamentous injury detected by magnetic resonance imaging. SUMMARY OF BACKGROUND DATA: There have been no previous reports of the use of magnetic resonance imaging to predict clinical instability. METHODS: A retrospective review of the clinical course of all unilateral mass/facet fractures identified over a 2-year period was conducted. All cervical spine plain radiographs, computed tomography scans, and magnetic resonance images were reviewed by a neuroradiologist blinded to the clinical course of the patient. Magnetic resonance T1-weighted and inversion recovery images were used to evaluate the integrity of the facet region, interspinous ligament, anterior longitudinal ligament, and posterior longitudinal ligament. RESULTS: Twenty-four unilateral lateral mass/facet fractures were identified. Only six initial cervical spine series demonstrated a bony abnormality at the level of the fracture. The fractures were identified by computed tomography and were almost all nondisplaced or minimally displaced. Less than half of the fractures extended ventrally to involve the transverse process or foramen transversarium or dorsally to involve the lamina. Twelve fractures were nonoperatively treated and 12 were treated surgically for stabilization. Ten patients in the operative group presented with or developed a subluxation. Nine of these patients had injury to at least three of the four ligaments evaluated by magnetic resonance imaging. In the nonoperative group, only three patients had extensive ligamentous injury at the level of the fracture. All three of these patients were lost to follow-up. CONCLUSIONS: Plain radiographs of the cervical spine lack sensitivity to detect the presence of lateral mass/ facet fractures. The appearance of the fracture on computed tomography does not indicate instability. The degree of ligamentous injury at the level of the fracture demonstrated on magnetic resonance imaging correlates with instability in this series. Operative stabilization may be indicated for unilateral lateral mass fractures that present with a subluxation or that have injury to at least three of the following ligaments: the facet region, the interspinous ligament, the anterior longitudinal ligament, and the posterior longitudinal ligament. However, before a definitive management plan can be formulated, results from this small series require further validation.

Adult↗
PubMed1997

Effects of castration on problem behaviors in male dogs with reference to age and duration of behavior.

OBJECTIVE: To determine whether 9 problem behaviors in adult male dogs were affected by castration and to examine the influence of age and duration of problem behavior on behavioral effects of castration. DESIGN: Cohort study. ANIMALS: 57 male dogs > 2 years old at the time of castration that had > or = 1 of the targeted problem behaviors. PROCEDURE: Data were collected by telephone contact with owners to identify dogs that had > or = 1 problem behavior before castration and to estimate the improvement (ie, decrease) in the objectionable behaviors after castration. Problem behaviors of interest included urine marking in the house, mounting, roaming, fear of inanimate stimuli, aggression toward human family members, aggression toward unfamiliar people, aggression toward other dogs in the household, aggression toward unfamiliar dogs, and aggression toward human territorial intruders. RESULTS: Effects of castration on fear of inanimate stimuli or aggression toward unfamiliar people were not significant. For urine marking, mounting, and roaming, castration resulted in an improvement of > or = 50% in > or = 60% of dogs and an improvement of > or = 90% in 25 to 40% of dogs. For remaining behaviors, castration resulted in an improvement of > or = 50% in < 35% of dogs. Significant correlations were not found between the percentage of improvement and age of the dog or duration of the problem behavior at the time of castration. CLINICAL IMPLICATIONS: Castration was most effective in altering objectionable urine making, mounting, and roaming. With various types of aggressive behavior, including aggression toward human family members, castration may be effective in decreasing aggression in some dogs, but fewer than a third can be expected to have marked improvement. Age of the dog or duration of the problem behavior does not have value in predicting whether castration will have a beneficial effect.

Aggression↗
PubMed1997

Cerebellar hypoplasia and frontal lobe cognitive deficits in disorders of early childhood.

A developmental chronometry hypothesis of early brain damage is suggested in which regions of the brain with a protracted course of postnatal development will be more vulnerable than earlier maturing areas to deleterious effects of early insult and, therefore, may become common sites of abnormality across many disorders originating in early childhood. Initial investigations of the cerebellum and frontal lobes are presented using MRI and neuropsychological measures. Planimetric measures of the cerebellar vermis (lobuli I-V and VI-VII) and pons, and neuropsychological frontal lobe measures were obtained from high functioning individuals with autism (A), survivors of acute lymphoblastic leukemia (ALL) with brain sequelae following radiation and chemotherapy, and from rigorously selected healthy controls (C). The neuropsychological results were clustered according to functions commonly related to frontal brain, posterior brain, and left and right hemispheres. The A and ALL groups, as compared to C, yielded modest but consistently reduced MRI measures for vermal lobuli I-V and VI-VII. Hypoplasia of lobuli VI-VII was more marked than I-V. Performance on neuropsychological tests for frontal lobe functions was generally depressed in both groups, with more severe deficits in A. Between-group differences in verbal, visual-spatial, and emotional-social skills are discussed. The cerebellar and frontal brain deficits that are present in both clinical groups (A and ALL) may be common to other developmental and acquired disorders of early childhood. Such joint manifestation of cerebellar and frontal lobe abnormalities is in agreement with the concept of cerebellar significance for the development of higher cognitive functions.

Adolescent↗
PubMed1996

Hemangiopericytoma: a rare pineal mass.

We describe a hemangiopericytoma of the pineal region in a young woman. The striking radiologic features were intense, homogeneous contrast enhancement on MRI and a dense blush on angiography.

Adult↗
PubMed1996

Behavioral and pharmacologic approaches to problem urination in cats.

Problem urination is the most frequent feline behavior problem for which veterinary consultation is sought. The first step is to differentiate between inappropriate urination and urine marking. This is an array of behavioral approaches that are particularly useful with inappropriate urination and may also be useful with urine marking. Anti-anxiety drugs may be used if behavioral approaches are not effective in treating urine marking or inappropriate urination.

Animals↗
PubMed1996

Postmortem cranial MRI and autopsy correlation in suspected child abuse.

We investigated the correlation between postmortem magnetic resonance imaging (MRI) of the head and autopsy findings in suspected child abuse. Postmortem MRI was performed within 24 h of death and before autopsy in 11 children 2 years old or younger whose deaths were unexplained or suspected to be due to child abuse. MRI findings were available to the pathologist at the time of autopsy. In eight cases of death from non-accidental trauma, cerebral edema, contusion, shearing injury, ischemia, and infarction were well demonstrated on MRI. In the three deaths determined not to be due to trauma, there were no false-positive MRI findings. Autopsy was superior in detection of subarachnoid hemorrhage, suture separation, extracranial injuries, and very small subdural hematomas. MRI findings were useful in directing the autopsy and brain-cutting to focal areas of abnormality. Postmortem MRI and autopsy are complementary, and each may disclose abnormalities missed by the other. In half of the eight cases of child abuse examined, the combination of MRI and autopsy added valuable information compared with the results of autopsy alone. Postmortem MRI can be a valuable addition to autopsy findings in the investigation of fatalities potentially due to child abuse.

Autopsy↗
PubMed1996

Magnetic resonance imaging for the evaluation of patients with occult cervical spine injury.

Because it is often difficult to diagnose accurately the structurally intact cervical spine after acute trauma, a series of patients was evaluated with magnetic resonance (MR) imaging to assess its efficacy for the evaluation and clearance of the cervical spine in a trauma victim in the early posttrauma period. Ultralow-field MR imaging was used to evaluate 174 posttraumatic patients in whom physical findings indicated the potential for spine injury or minor radiographic findings indicated injury. This series includes only those patients who did not appear to harbor disruption of spinal integrity on the basis of a routine x-ray film. None had clinically obvious injury. Of the 174 patients, 62 (36%) had soft-tissue abnormalities identified by MR imaging, including disc interspace disruption in 27 patients (four with ventral and dorsal ligamentous injury, three with ventral ligamentous injury alone, 18 with dorsal ligamentous injury alone, and two without ventral or dorsal ligamentous injury). Isolated ligamentous injury was observed in 35 patients (eight with ventral and dorsal ligamentous injury, five with ventral ligamentous injury alone, and 22 with dorsal ligamentous injury alone). One patient underwent a surgical fusion procedure, 35 patients (including the one treated surgically) were placed in a cervical collar for at least 1 month, and 27 patients were placed in a thermoplastic Minerva jacket for at least 2 months. All had a satisfactory outcome without evidence of instability. The T2-weighted sagittal images were most useful in defining acute soft-tissue injury; axial images were of minimal assistance. Posttraumatic soft-tissue cervical spine injuries and disc herniations (most likely proexisting the trauma) are more common than expected. A negative MR image should be considered as confirmation of a negative or "cleared" subaxial cervical spine. Diagnostic and patient management algorithms may be appropriately tailored by this information. Thus, MR imaging is useful for early acute posttrauma assessment in a very select group of patients.

Adolescent↗
PubMed1995

A locus for cerebral cavernous malformations maps to chromosome 7q in two families.

Cavernous malformations (angiomas) affecting the central nervous system and retina can be inherited in autosomal dominant pattern (OMIM 116860). These vascular lesions may remain clinically silent or lead to a number of neurological symptoms including seizure, intracranial hemorrhage, focal neurological deficit, and migraine. We have mapped a gene for this disorder in two families, one of Italian-American origin and one of Mexican-American origin, to markers on proximal 7q, with a combined maximum lod score of 3.92 (theta of zero) with marker D7S479. Haplotype analysis of these families places the locus between markers D7S502 proximally and D7S515 distally, an interval of approximately 41 cM. The location distinguishes this disorder from an autosomal dominant vascular malformation syndrome where lesions are primarily cutaneous and that maps to 9p21.

Adolescent↗
PubMed1995

Spin-spin relaxation of brain tissues in systemic lupus erythematosus. A method for increasing the sensitivity of magnetic resonance imaging for neuropsychiatric lupus.

OBJECTIVE: To correlate the spin-spin relaxation time (T2) of brain tissue in neuropsychiatric systemic lupus erythematosus (NPSLE) with the patient's clinical condition. METHODS: T2 values were determined in 54 SLE patients and 45 non-SLE controls at 1.5 Tesla, using intensity from multi-echo magnetic resonance (MR) images fitted to an exponential decay curve with rate-constant T2. RESULTS: The T2 of white matter was increased in SLE patients compared with controls (P = 0.01) and was increased in those patients who had previously experienced major NPSLE: Patients with acute diffuse neurologic manifestations (seizures, psychosis, coma) demonstrated a longer T2 of the gray matter (mean +/- SD 92.75 +/- 6.35 ms, n = 10) than did other SLE patients (mean +/- SD 79.61 +/- 5.04 ms, n = 44) (P = 0.02 by t-test), which suggests acute cerebral edema. The mean T2 values of reversible and nonreversible focal lesions were significantly different (P < 0.02), indicating different microenvironments and micropathology. CONCLUSION: Quantitative T2 measurement extends the utility and sensitivity of conventional MR imaging for evaluating NPSLE:

Adolescent↗
PubMed1995

Refined localization of the cerebral cavernous malformation gene (CCM1) to a 4-cM interval of chromosome 7q contained in a well-defined YAC contig.

Cerebral cavernous malformations (CCM) are vascular lesions present in some 20 million people worldwide that are responsible for seizures, migraine, hemorrhage, and other neurologic problems. Familial cases ofCCM can be inherited as an autosomal dominant disorder with variable expression. A gene for CCM (CCM/)was recently mapped to a 33-cM segment of chromosome 7q in a large Hispanic family (Dubovsky et al.1995). Here, the collection of several new short tandem repeat polymorphisms (STRPs) within the region of interest on 7q and the refinement of the marker order in this region using both linkage analysis in CEPH families and especially YAC-based STS content mapping are described. Affected members of three Hispanic families share allele haplotypes indicating a common ancestral mutation within these families. Using the shared haplotype information along with analysis of crossovers in affected individuals from both the Hispanic and Caucasian families, the region likely to contain the CCMI gene has been reduced to a 4-cM segment of 7q between D7S2410 and D7S689. All markers within the refined chromosomal segment were located on a single YAC contig estimated to be approximately 2 Mb in size. Four potential candidate genes have been mapped to this region.

Base Sequence↗