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Biomedical subjects

G J Harris

Publications and source records attributed to G J Harris.

At least 55 records · Page 3Linked to original sources
PubMed1996

Normal caudate nucleus in obsessive-compulsive disorder assessed by quantitative neuroimaging.

BACKGROUND: Prior neuroimaging studies have not consistently demonstrated a structural or functional abnormality of the caudate nucleus in patients with obsessive-compulsive disorder (OCD). However, there is theoretical support for some associated dysfunction of the caudate nucleus. METHODS: We examined volumes of the caudate nucleus and putamen with magnetic resonance imaging in 24 patients with adult-onset OCD and 21 control subjects, group-matched on age, race, education, and sex. Patients were relatively free from tics. To evaluate function (metabolism or blood flow) of the caudate nucleus, we performed a quantitative review, including a meta-analysis, of normalized data from functional neuroimaging studies that compared patients who had OCD with normal control subjects. RESULTS: All structural basal ganglia measures failed to exhibit differences between patients with OCD and matched normal control subjects. Patients did not demonstrate evidence of ventricular enlargement. Quantitative meta-analysis of the functional neuroimaging literature did not demonstrate a consistent abnormality of the caudate nucleus. CONCLUSIONS: We did not observe evidence of a structural abnormality of the caudate nucleus in patients with OCD. Prior reports of a structural aberration of the caudate nucleus were mixed. We also did not find strong support for relative caudate metabolic or perfusion dysfunction in the literature, although increased function in the frontal cerebral cortex was identified. The heterogeneous nature of this disorder may account for inconsistencies between studies. For example, ventricular enlargement or reduced caudate volume or blood flow might be evident in patients with soft neurological signs (eg, tics), while patients in the current study were relatively free from tics. Although theories of OCD suggest a dysfunction of the caudate nucleus, the structural and functional neuroimaging literature has not consistently verified this.

Adult↗
PubMed1996

Subperiosteal abscess of the orbit: computed tomography and the clinical course.

In an earlier study, a trial of i.v. antibiotics, with surgical drainage reserved for failure to respond, was recommended for children aged < 9 years with medial subperiosteal abscesses (SPAs) of modest size and without compromised vision. Careful monitoring is mandatory in these cases, and comparison of serial computed tomography (CT) scans frequently guides therapy. The present study examines how the CT findings actually relate to the clinical course of SPA. Initial and subsequent CT scans in 37 cases were analyzed with respect to the subperiosteal material encountered at surgery and the response to treatment. The subperiosteal material could not be predicted from the size or relative radiodensity of the collections in CT scans. Initial scans were not predictive of the clinical course. Serial scans showed enlargement of abscesses during the first few days of i.v. antibiotic therapy, regardless of the ultimate response to treatment. It is concluded that expansion of an SPA in serial CT scans during the first few days of treatment should not be equated to failure of the infection to respond to antibiotics alone. In interpreting serial scans, the time-dependent pharmacokinetics of antibiotic therapy should be considered.

Abscess↗
PubMed1996

Dynamic susceptibility contrast MRI of regional cerebral blood volume in Alzheimer's disease.

OBJECTIVE: The purpose of this study was to investigate the potential effectiveness of dynamic susceptibility contrast magnetic resonance imaging (MRI) to discriminate elderly patients with Alzheimer's disease from normal matched comparison subjects. METHOD: Images of regional cerebral blood volume (CBV) were generated from echo-planar MRI with the dynamic susceptibility contrast method in 13 Alzheimer's disease patients and 13 comparison subjects group-matched on age and gender. RESULTS: Temporoparietal cerebral blood volume, expressed as a percentage of the cerebellum value, was reduced 17% bilaterally in the patients with Alzheimer's disease. Blood volume in sensorimotor regions was reduced only 8.5% in the patients. Discriminant function analysis based on left and right temporoparietal measures correctly classified 88.5% of the subjects as patients or comparison subjects. Temporoparietal CBV was reduced even in mildly affected Alzheimer's disease patients (Mini-Mental State scores > 24). CONCLUSIONS: Dynamic susceptibility contrast MRI of regional CBV is promising as a nonradioactive, potentially lower-cost alternative to other functional neuroimaging methods for evaluating Alzheimer's disease.

Aged↗
PubMed1995

Structural differences in the cerebral cortex of healthy female and male subjects: a magnetic resonance imaging study.

There are both reproductive and nonreproductive behavioral differences between men and women. Brain regions involved in determining sexual behavior have been reported to differ between the sexes. Nonreproductive, cognitive functional differences between sexes might be reflected in higher-order cortical structural dimorphisms, which have not previously been studied. We hypothesized that cortical regions involved in verbal behavior (which is sexually dimorphic) would differ between sexes. Using magnetic resonance imaging, we assessed gray matter volumes in several cortical regions in 17 women and 43 men. Women had 23.2% (dorsolateral prefrontal cortex) and 12.8% (superior temporal gyrus) greater gray matter percentages (corrected for overall brain size and age) than men in a language-related cortical region, but not in a more visuospatially related cortical region. These data seem to establish sexually dimorphic structural differences in the cerebral cortex, consistent with prior cerebral blood flow reports.

Adult↗
PubMed1995

Posterior superior temporal gyrus in schizophrenia: grey matter changes and clinical correlates.

We report an MRI morphometric study of the posterior segment of the superior temporal gyrus (STG) in twenty young male schizophrenics and their individually matched normal controls. In particular the more posterior segment of STG was examined, since it has been identified as the approximate site of Wernicke's language area and is a marker for the planum temporale, a region believed to be abnormal in schizophrenia. Total volumes and grey and white matter volumes were measured in middle and posterior STG in each hemisphere. STG grey matter volumes and percentages were significantly reduced bilaterally in both regions in schizophrenic subjects. No significant differences between patients and controls were noted in STG white matter volumes. A significant correlation was detected between delusion scores in schizophrenics and the total volume of the left dominant posterior STG. Replicating the findings of a recent study (Shenton et al., 1992), we found an inverse correlation between thought disorder scores and grey matter reduction in the left posterior STG in schizophrenia.

Adult↗
PubMed1995

Echographic monitoring of response of extraocular muscles to irradiation in Graves' ophthalmopathy.

PURPOSE: Confirmation of the efficacy of orbital irradiation in Graves' ophthalmopathy is needed due to the unpredictable natural history of the disease, the variation in individual clinical presentations, the contribution of other simultaneous treatments, and the lack of controlled studies using objective criteria to classify and assess response over time. Orbital echography before and at select intervals following orbital irradiation is proposed as an objective parameter of tissue response to orbital irradiation over time. METHODS AND MATERIALS: From January, 1983 to September, 1993, 55 patients with progressive Graves' ophthalmopathy underwent 20 Gy retrobulbar irradiation. On retrospective review, standardized orbital echography was performed randomly prior to irradiation in 37 of the 55 patients to assess the acoustic characteristics of the extraocular muscles and to quantitate their individual and summed diameters. Twenty-one patients had at least one follow-up echographic evaluation at random intervals of 0 to 27.5 months following completion of irradiation. Twelve patients received steroids before or during irradiation, which were tapered in proximity to completion of radiation. Follow-up ranged from 2 to 65 months with the majority followed at least 6 months (18 patients). RESULTS: Of the 21 patients with serial studies, 18 showed an interval decrease in individual and summed muscle size over time and return of symmetry. Interval improvement was documented as early as the 1 month follow-up study, with continued improvement seen during the 3-9-month studies, with stability typically achieved within 12 months. One patient had further changes between the 21 and 27.5 month follow-up studies. Exacerbation of disease was, however, echographically demonstrated in three patients at 6.5, 8.5, and 13 months. Follow-up studies in two of these patients again revealed improvement, one following tapered steroids. The third patient required orbital decompression. CONCLUSION: Objective parameters of response are needed to document both the immediate and long-term outcome of orbital irradiation on the course of Graves' ophthalmopathy and confirm its efficacy. Serial echography is proposed as a new technique for providing parameters to judge response.

Follow-Up Studies↗
PubMed1995

Bone wax template for the correction of enophthalmos with porous polyethylene implants.

PURPOSE: We used a technique that facilitates the custom contouring of porous polyethylene implants. METHODS: Bone was was molded in the subperiosteal space of the orbit. The wax then served as a model for free-hand sculpting of the rigid implant. RESULTS: Bone wax templates have been used successfully in seven patients with enophthalmos or superior sulcus depression. CONCLUSIONS: This technique has increased the precision of custom contouring subperiosteal alloplastic implants.

Enophthalmos↗
PubMed1995

Subgaleal hematoma with delayed proptosis and corneal ulceration.

We report the delayed occurrence in a child of proptosis caused by a subgaleal hematoma. A corneal ulcer resulted from the proptosis, which developed 9 days after mild head trauma. Evaluation revealed a heterozygous factor VII deficiency. The coagulopathy and, more likely, the use of the nonsteroidal antiinflammatory drug ibuprofen may have contributed to the extension of the hematoma into the orbital space. Careful follow-up of patients with subgaleal hematomas is necessary because the development of proptosis may be delayed.

Child↗
PubMed1995

Noninfectious inflammatory response to gold weight eyelid implants.

We describe three patients with noninfectious inflammatory reactions to gold weight eyelid implants, a complication not previously reported. Eyelid edema and erythema developed gradually in each patient, and maximal inflammation that prompted treatment was present at 12, 3, and 5 weeks, respectively, after surgery in the three patients. Management involved removal of the implant in the first patient, oral corticosteroids followed by replacement of the implant by a platinum weight in the second patient, and a local corticosteroid injection with retention of the implant in the third. Histopathological features included a thick eosinophilic coagulum at the tissue-gold interface and an intense, predominantly lymphocytic infiltrate in the collagenous capsule that surrounded the implants. Gold weight eyelid implants can elicit a gradually progressive inflammatory response. In at least some cases, local corticosteroid injection may suppress the inflammation and permit retention of the implant.

Aged↗
PubMed1995

Magnetic resonance imaging measurement of gray matter volume reductions in HIV dementia.

OBJECTIVE: The authors recently reported smaller basal ganglia volumes for patients with HIV-associated dementia than for HIV-infected patients without dementia and a seronegative comparison group. The purpose of the current study was to determine whether HIV dementia is associated with volume reductions in other brain regions. METHOD: The authors measured volumes of CSF and gray and white tissue on cranial magnetic resonance images from homosexual men who were 1) infected with HIV with HIV-associated dementia complex, 2) infected with HIV without dementia, and 3) HIV seronegative. RESULTS: Results suggest that loss of white matter occurs with HIV infection and is more severe in HIV-positive patients with dementia than in those without dementia. There was some generalized volume reduction in gray matter in HIV-positive demented patients, although group differences did not reach significance when adjusted for age. Volume of posterior cortex, however, was significantly smaller among HIV-positive patients with dementia than in either remaining group. There were no significant differences between HIV-positive nondemented patients and HIV-negative subjects in these regions. CONCLUSIONS: In conjunction with findings from previous research, the authors conclude that HIV dementia is associated with specific gray matter volume reduction in basal ganglia and posterior cortex, as well as with generalized volume reduction of white matter.

AIDS Dementia Complex↗
PubMed1994

Lacrimal collecting system lymphomas: integration of magnetic resonance imaging and therapeutic irradiation.

Lymphomas arising within the lacrimal collecting system are rare tumours and unusual causes of lacrimal obstructive symptoms. The presentation, diagnosis, and treatment of this disease in five patients are described, as well as a review of the existing literature. Emphasized in this series is the efficacy of magnetic resonance imaging of these presentations and the importance of irradiation in their treatment.

Adult↗
PubMed1994

Orbital myositis as a paraneoplastic syndrome.

We describe a patient with bilateral orbital myositis, multiple cranial neuropathies, a sensory polyneuropathy, serum and cerebrospinal fluid paraproteins, and high-grade non-Hodgkin's lymphoma. Neurologic symptoms began more than 1 year before diagnosis of the lymphoma. Results of extraocular muscle biopsy showed extensive destruction of myofibers and granulomatous features, with no evidence of direct tumor involvement. The cranial neuropathies and orbital myositis improved with immunosuppressive therapy, while the patient's tumor progressed. We believe the orbital myositis and the multiple neurologic abnormalities were paraneoplastic effects of the lymphoma. To our knowledge, this is the first case of orbital myositis identified as a paraneoplastic syndrome.

Adult↗
PubMed1994

Subperiosteal abscess of the orbit. Age as a factor in the bacteriology and response to treatment.

BACKGROUND: Earlier studies of subperiosteal abscess secondary to sinusitis showed considerable variation in the clinical course and bacteriology. At one extreme, patients recovered with intravenous antibiotics alone; at the other extreme, complex pathogens persisted despite early surgical drainage and appropriate antibiotics, and visual or intracranial complications occurred. To better direct management of individual patients, this study evaluates the role of patient age in the complexity and responsiveness of subperiosteal abscess. METHODS: The records of 37 patients with a computed tomography diagnosis of subperiosteal abscess were reviewed. Initial and follow-up culture results were evaluated in the context of prior treatment of individual patients. Responses to therapy and pathogens were compared among three age groups. RESULTS: Among patients younger than 9 years, 83% either cleared without drainage (25%) or had negative cultures at the time of drainage (58%). In the culture-positive cases, single aerobes were found, and anaerobes were not isolated. Patients 9 to 14 years old showed a transition toward more complex infections. Patients 15 years of age or older all had positive cultures after more than 3 days of antibiotics, which were frequently effective in vitro. Polymicrobial infections were the rule, including anaerobes in every case. CONCLUSION: Variations in the complexity and responsiveness of subperiosteal abscesses appear to be age-associated. Treatment protocols should consider visual compromise, pain, location of the abscess, which sinuses are involved, intracranial complications, and the age of the patient.

Abscess↗
PubMed1994

Altered cortical blood flow in HIV-seropositive individuals with and without dementia: a single photon emission computed tomography study.

OBJECTIVE: To quantitatively demonstrate the pattern of cerebral perfusion abnormalities in HIV-1-infected individuals described as 'patchiness' or inhomogeneity in previous qualitative emission tomographic imaging studies. DESIGN: We aimed to create a quantitative measure of inhomogeneity in HIV-infected individuals. High-frequency variance in cortical profiles is an indication of inhomogeneity in the distribution of radiotracer in the cerebral cortex. Therefore, the study analysis was designed to enable the estimation of variance frequencies in cortical profiles. METHODS: Regional cerebral blood flow was examined in nine mildly demented and 10 cognitively normal HIV-1-seropositive individuals and eight seronegative normal controls using single photon emission computed tomography with the radiotracer [I-123]-N-isopropyl-p-iodoamphetamine. Quantitative analysis was performed using circumferential profiles of cerebral cortical perfusion. Fourier transform power spectra of the profiles were examined as an index of patchiness in tracer distribution. RESULTS: Normal controls were characterized by strong middle frequency and weak high-frequency power. Both HIV-1-infected groups showed a significant power shift from middle to high frequencies. CONCLUSIONS: Increased high-frequency variations in both HIV-1-infected groups indicates diffuse cortical perfusion changes compared with normal controls. This study suggests that there are cerebral bloodflow abnormalities in HIV-1-infected individuals both with and without clinically severe dementia.

AIDS Dementia Complex↗
PubMed1994

Magnetic resonance imaging evaluation of the effects of ageing on grey-white ratio in the human brain.

A previous neuropathological report noted a non-linear pattern of change in cerebral grey-white matter ratio during ageing. In that report, grey-white ratio decreased from age 20 to age 50, then increased in elderly subjects. The objective of the current study was to attempt to replicate this pattern of age-related change in the grey-white ratio in living human subjects using quantitative magnetic resonance imaging segmentation analysis. We measured the grey-white ratio in 78 subjects between the ages of 19 and 77 years, using a computer segmentation algorithm with magnetic resonance images. In agreement with the previous neuropathological report, the current in vivo magnetic resonance study found that the grey-white ratio declined from age 20 to age 50, then increased in elderly subjects.

Adult↗
PubMed1994

Basal ganglia volumes and white matter hyperintensities in patients with bipolar disorder.

OBJECTIVE: Accumulating evidence suggests an association between abnormalities of the basal ganglia and affective disorders. The authors hypothesized that patients with bipolar disorder would demonstrate smaller basal ganglia volumes and a greater number of hyperintensities on magnetic resonance imaging than comparison subjects who were matched on age, race, sex, and education. METHOD: Volumes of the caudate, putamen, and globus pallidus were measured in 30 patients with bipolar disorder and 30 matched normal comparison subjects. The presence, number, and location of hyperintensities were also assessed. RESULTS: Male patients with bipolar disorder demonstrated larger caudate volumes than male comparison subjects. Older, but not younger, patients with bipolar disorder demonstrated more hyperintensities than comparison subjects, primarily in frontal lobe white matter. CONCLUSIONS: These results are not consistent with those of previous studies showing reduced basal ganglia volume in subjects with affective disorders, but they are consistent with previous findings of increased white matter hyperintensities, especially in older patients with bipolar disorder. Considered together with results from other studies, the findings suggest that the nature of basal ganglia/subcortical white matter involvement may differ according to the type of depression (unipolar versus bipolar) and the age and sex of the patient.

Adult↗