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Biomedical subjects

D Eidelberg

Publications and source records attributed to D Eidelberg.

104 records · Page 6Linked to original sources

The metabolic anatomy of Parkinson's disease: complementary [18F]fluorodeoxyglucose and [18F]fluorodopa positron emission tomographic studies.

We studied the metabolic anatomy of typical Parkinson's disease (PD) using [18F]fluorodeoxyglucose (FDG) and [18F]fluorodopa (FDOPA) and positron emission tomography (PET). Fourteen PD patients (mean age 49 years) had FDG/PET scans, of which 11 were scanned with both FDOPA and FDG. After the injection of FDOPA, brain uptake and arterial plasma radioactivity were monitored for 2 h. Striatal FDOPA uptake was analyzed with regard to a two-compartment model, and target-to-background ratios (TBRs) and TBR-versus-time slopes were also calculated. Regional patterns of metabolic covariation were extracted from FDG/PET data using the Scaled Subprofile Model (SSM). SSM pattern weights, FDOPA uptake constants (Ki), TBRs, and TBR slopes were correlated with clinical measures for bradykinesia, rigidity, tremor, gait disturbance, left-right asymmetry, dementia, and overall disease severity. In PD patients, rate constants for FDOPA uptake correlated with individual measures of bradykinesia (p = 0.001) and gait disability (p less than 0.05). SSM analysis revealed a distinct pattern of regional metabolic asymmetries, which correlated with motor asymmetries (p less than 0.001) and left-right differences in Ki (p less than 0.01). Our data suggest that in PD patients, FDG/PET and FDOPA/PET may provide unique and complementary information about underlying disease processes.

Adult↗

Chronic unilateral optic neuropathy: a magnetic resonance study.

We studied the clinical, electrophysiological, and magnetic resonance imaging (MRI) features of 20 patients with chronic unilateral optic neuropathy (CUON): progressive unilateral visual failure lasting a minimum of 6 months. The patients, 10 male and 10 female, ranged in age from 12 to 77 years (mean 44) and had a mean duration of symptoms of 22 months. All had signs of optic nerve dysfunction. Each patient was studied with MRI using a short TI inversion recovery (STIR) sequence to delineate the optic nerve from surrounding orbital tissue. Three distinct groups of patients with CUON were identified using MRI. In the first group (8/20) the optic nerve was compressed by an extrinsic mass, whereas in the second group (5/20) CUON resulted from an intrinsic tumor of the optic nerve or sheath. In both groups STIR sequences compared favorably with computed tomography in identifying mass lesions. MRI was superior in delineating distortion of the optic nerve by mass or tumor extension beyond the orbit. In the third group (7/20) no mass was evident on MRI. However, STIR sequences revealed altered signal (long T1) in clinically symptomatic nerves. In 4 of the patients T2-weighted cerebral MRI disclosed periventricular lesions suggestive of disseminated white matter disease. We conclude that MRI complements clinical and electrophysiological testing in the assessment of CUON.

Adolescent↗

19F NMR imaging of blood oxygenation in the brain.

Perfluorocarbon (PFC) emulsions have been developed as oxygen carrying blood substitutes. High fluorine concentrations allow them to be used in 19F NMR imaging of blood vessels. Furthermore, 19F relaxation times in PFCs are dependent on oxygen tension (pO2) so that NMR imaging may provide a noninvasive method of measuring spatially localized pO2 values in vivo. Using these principles, we have formed 19F images and calculated pO2 maps of the cat brain.

Animals↗

19F imaging of cerebral blood oxygenation in experimental middle cerebral artery occlusion: preliminary results.

Fluorine (19F) nuclear magnetic resonance may be used to image cerebral perfusion in cats receiving perfluorocarbon blood substitutes. 19F relaxation times in these blood substitutes are dependent on oxygen tension (PO2) and may be used to calculate and spatially map cerebrovascular PO2 values in vivo. We have applied this noninvasive method to experimental middle cerebral artery (MCA) occlusion. Following MCA occlusion a perfusion defect is evident in the sylvian region, followed by the appearance of collaterals. Signal from the ipsilateral rete mirabilis is increased. Calculated cortical vascular PO2 values indicate a relative reduction in oxygenation in the ischaemic hemisphere. PO2 maps show a perfused hypoxaemic zone adjacent to the perfusion defect. These changes are partly reversed with reperfusion.

Animals↗

Adult onset Hallervorden-Spatz disease with neurofibrillary pathology. A discrete clinicopathological entity.

Three adults with progressive cognitive decline and extrapyramidal dysfunction were studied. They were all mentally retarded women without known chromosomal abnormalities, ranging in age at the time of onset from 31 to 42 yrs with an average duration of illness of 6 yrs. Neurological signs were stereotyped and consisted of a unilateral equinovarus foot posture followed by progressive dementia, rigidity and quadriparesis. Identical pathological findings were noted in all cases. There was marked deposition of iron-containing pigments in the globus pallidus and reticulate zone of the substantia nigra. Numerous axonal spheroids were noted in these areas and in the gracile and cuneate nuclei. In addition to these typical changes of Hallervorden-Spatz disease (HSD), abundant neurofibrillary tangles (NFTs) were found within the hippocampus, neocortex, nuclei of basal forebrain, subthalamic nucleus and brainstem reticular formation. Rare Hirano bodies and granulovacuolar degeneration were noted within the hippocampus; neuritic plaques and amyloid deposits were absent. Ultrastructurally the NFTs were mostly paired helical filaments (PHFs) with a diameter of 20 to 25 nm and a half-periodicity of 80 nm. Straight filaments and incompletely twisted forms were also seen. Immunocytochemistry with polyclonal antibodies to PHFs was positive in a distribution identical to that of Bodian-positive NFTs. Biochemical analysis of frozen frontal cortex from 1 case revealed a 94% depletion of the cholinergic marker enzyme choline acetyltransferase. Somatostatin-like immunoreactivity was within normal range. Study of 1 case with laser microprobe mass analysis revealed evidence of aluminium accumulation in tangle-bearing hippocampal neurons. Adjacent tangle-free neurons failed to show comparable accumulations. These findings indicate that adult onset HSD occurring in mentally retarded individuals may represent a distinct clinicopathological entity associated with neurofibrillary pathology without amyloid deposition.

Adult↗

Thrombotic cerebral vasculopathy associated with herpes zoster.

We describe the clinical, radiographic, and pathological findings in 3 patients with large-vessel cerebral vasculopathy following herpes zoster. Two of the patients were studied at postmortem examination, and a brain biopsy was performed in the third. Each of the 3 patients suffered thrombotic occlusions of large vessels without notable inflammatory or granulomatous changes following trigeminal or segmental herpes zoster infection. In the 2 autopsied patients, varicella-zoster virus (VZV) antigens were detected by immunoperoxidase staining within the media of the affected cerebral arteries. Little or no inflammation was associated with the foci of the VZV antigens. These studies provide evidence that the vasculopathy following herpes zoster may result from direct VZV infection of the artery and the in situ thrombosis can develop within the infected vessels in the absence of clear inflammatory vasculitis.

Adult↗

Progressive polyradiculopathy in acquired immune deficiency syndrome.

We studied three patients with acquired immune deficiency syndrome (AIDS) and progressive polyradiculopathy. Postmortem examination of one patient disclosed extensive necrosis, inflammatory infiltrates, and focal vasculitis of spinal roots. Typical cytomegaloviral (CMV), intranuclear, and intracytoplasmic inclusions were noted within enlarged endoneurial and endothelial cells. Progressive polyradiculopathy is an unusual complication of AIDS; CMV may be the causative agent in certain cases.

Acquired Immunodeficiency Syndrome↗

Inferior parietal lobule. Divergent architectonic asymmetries in the human brain.

Architectonic parcellation of the parietal lobes of eight human brains, with special attention paid to the inferior parietal lobule, resulted in a map that bore a close relationship to previous maps and took into consideration modern data on physiology and connections. Two general parietal zones were distinguished, one above and the other below the intraparietal sulcus, similar to the dorsal-ventral distinction suggested for the frontal lobe. Five areas were recognized in the inferior parietal lobule, of which areas parietal areas EG (PEG), G (PG), and occipitoparietal G (OPG) were in the angular gyrus. A lateralization toward the right was found for area PEG, an area structurally similar to the visually related cortices of the posterior superior parietal region. A lateralization toward the left was found for area PG, but only in brains with a larger left planum temporale. The asymmetry in area PG seemed to be linked to other asymmetries present in language areas, whereas the right-sided area PEG preponderance showed no relation to the language asymmetries.

Adult↗

Symmetry and asymmetry in the human posterior thalamus. I. Cytoarchitectonic analysis in normal persons.

We parceled the posterior thalami of nine normal human brains according to cytoarchitectonic criteria, measured relevant nuclear volumes, and sought left-right asymmetries. We found that thalamic zones with multiple projections to the cerebral cortex, using the centromedian-parafascicular nucleus as a prototype, were mostly symmetric. This group includes the medial, lateral, and inferior pulvinar nuclei. Thalamic zones that project discretely to a few, clearly defined cortical receptor fields (using the medial geniculate nucleus [MG] as a prototype) closely reflected the asymmetry of the cortical fields to which they project. Hence, the MG showed a slight right-sided bias, and the lateralis posterior nucleus (related to the grossly asymmetric inferior parietal lobule) showed a significant leftsided bias in eight of the nine brains measured. This asymmetry may partially explain the apparent language specialization of the dominant thalamus.

Adolescent↗

Symmetry and asymmetry in the human posterior thalamus. II. Thalamic lesions in a case of developmental dyslexia.

The cytoarchitecture of the brain of a patient with developmental dyslexia was analyzed. The cortical abnormalities, consisting of micropolygyria encompassing most of posterior temporoparietal area and ectopic cell collections elsewhere have been described previously. In this study, the posterior thalamus was likewise analyzed, and a bilateral disruption of cytoarchitecture was noted in the medial geniculate nucleus and the lateralis posterior nucleus, a nuclear group of probable relevance to language found to be asymmetric.

Cerebral Cortex↗

Visualizing the evolution of abnormal metabolic networks in the brain using PET.

By applying novel statistical methods and visualization techniques to PET data obtained from combined groups of patients and normals, we are able to illustrate topographic covariance profiles unique to neurodegenerative disorders such as Parkinson's Disease at various stages of progression. Each profile represents a neuroanatomical network of metabolically covarying regions. The expression of the profile in each patient is characterized by a subject score which can correlate with independent clinical disease severity measures. To visualize these profiles, a semi-automatic routine is used (3D) animation of the metabolic topography as it evolves from initial to final stages of the disease.

Adult↗

Contralateral temporal hypometabolism on positron emission tomography in temporal lobe epilepsy.

INTRODUCTION: No detailed case studies report lateralised hypometabolism on positron emission tomography (PET) contralateral to the epileptogenic focus in temporal lobe epilepsy (TLE). MATERIAL AND METHODS: We performed 18F fluorodeoxyglucose (FDG) PET in two intractable TLE patients. RESULTS: One had right temporal interictal spikes on electroencephalography (EEG) and a right medial temporal lobe lesion on magnetic resonance imaging (MRI). FDG-PET showed decreased uptake in the left temporal lobe. Right temporal ictal onset, with bilateral interictal epileptiform activity, occurred on intracranial EEG. He is seizure free after right temporal lobectomy and ganglioglioma resection. The second had right temporal lobe interictal and ictal EEG activity. MRI demonstrated right anteriomedial temporal increased T2 signal. Neuropsychology revealed bilateral cognitive dysfunction. FDG-PET showed left anterior temporal and lateral frontal hypometabolism. He is seizure free after right temporal lobectomy. CONCLUSION: These findings suggest that regional uptake asymmetry on FDG-PET may be give misleading lateralising information in TLE.

Adult↗