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1.
Neuroophthalmology ; 41(5): 284-286, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29339964

RESUMO

A 60-year-old woman with history of multiple myeloma was in remission after stem cell transplant 6 years prior. She was undergoing work-up for headaches that were thought to be secondary to a right mastoiditis seen on magnetic resonance imaging (MRI). On routine eye exam, papilloedema was noted. A lumbar puncture was performed, with elevated opening pressure with normal constituents. She was an atypical age for idiopathic intracranial hypertension, and her mastoiditis raised concern for secondary cerebral venous sinus thrombosis. Magnetic resonance venography (MRV) was performed showing poor flow in the right sigmoid sinus, and computed tomography venography (CTV) showed lack of contrast enhancement distal to the right sigmoid sinus, consistent with occlusion. There was also an enhancing mass inferior to the right occipital bone. Biopsy confirmed recurrent plasma cell myeloma. She was treated with chemotherapy, radiation, and warfarin for presumed cerebral venous sinus thrombosis.

2.
Hum Brain Mapp ; 30(5): 1705-22, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-18972392

RESUMO

We studied the neural correlates of rapid eye movement during sleep (REM) by timing REMs from video recording and using rapid event-related functional MRI. Consistent with the hypothesis that REMs share the brain systems and mechanisms with waking eye movements and are visually-targeted saccades, we found REM-locked activation in the primary visual cortex, thalamic reticular nucleus (TRN), 'visual claustrum', retrosplenial cortex (RSC, only on the right hemisphere), fusiform gyrus, anterior cingulate cortex, and the oculomotor circuit that controls awake saccadic eye movements (and subserves awake visuospatial attention). Unexpectedly, robust activation also occurred in non-visual sensory cortices, motor cortex, language areas, and the ascending reticular activating system, including basal forebrain, the major source of cholinergic input to the entire cortex. REM-associated activation of these areas, especially non-visual primary sensory cortices, TRN and claustrum, parallels findings from waking studies on the interactions between multiple sensory data, and their 'binding' into a unified percept, suggesting that these mechanisms are also shared in waking and dreaming and that the sharing goes beyond the expected visual scanning mechanisms. Surprisingly, REMs were associated with a decrease in signal in specific periventricular subregions, matching the distribution of the serotonergic supraependymal plexus. REMs might serve as a useful task-free probe into major brain systems for functional brain imaging.


Assuntos
Encéfalo/irrigação sanguínea , Imageamento por Ressonância Magnética , Sensação/fisiologia , Sono REM/fisiologia , Sono/fisiologia , Adulto , Vias Aferentes/irrigação sanguínea , Vias Aferentes/fisiologia , Encéfalo/fisiologia , Mapeamento Encefálico , Eletroculografia , Feminino , Dedos/fisiologia , Lateralidade Funcional/fisiologia , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Oxigênio/sangue , Percepção/fisiologia , Polissonografia , Desempenho Psicomotor , Gravação em Vídeo , Adulto Jovem
3.
Ann Clin Transl Neurol ; 5(5): 630-639, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29761125

RESUMO

OBJECTIVE: We conducted a retrospective, case-control study of neurocysticercosis patients to ascertain early markers that identify subjects likely to develop treatment-resistant seizures. METHODS: Clinical histories and imaging studies from 38 neurocysticercosis patients who had been followed for 18 months after treatment were evaluated. Both pairwise and multifactorial analyses were conducted to identify factors associated with continued seizures. RESULTS: Eleven of 38 patients continued to have seizures during the follow-up period. On univariate analysis, the number of neurocysticercosis lesions, number of bands on the baseline neurocysticercosis western blot, edema volumes on follow-up MRI scans, edema volume changes between baseline and follow-up images, and proportion of calcified lesions with perilesional edema were all significantly increased in subjects who had persistent seizures during the 18-month follow-up period. On multivariate analyses using recursive partition and random forest algorithms, variables associated with persistent seizures included: the number of total and calcified lesions, presence of perilesional edema, the rate of change in the lesion and edema volumes from baseline to follow-up, and the number of bands on the neurocysticercosis western blot. INTERPRETATION: Measures of both inflammation and disease burden are key risk factors for persistent seizures despite anticonvulsant treatments in patients with neurocysticercosis. Inflammation is therefore a potentially modifiable risk factor for the frequently seen severe seizure disorders in patients with neurocysticercosis.

4.
J Orthop Sports Phys Ther ; 47(9): 691, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28859596

RESUMO

A 57-year-old man with insidious onset of progressive bilateral upper extremity weakness was referred to physical therapy by his primary care physician. Following examination, the physical therapist referred the patient back to his primary care physician with a request for cervical magnetic resonance imaging (MRI) and neurology consultation. Cervical radiographs demonstrated multilevel degenerative changes, while cervical spine MRI revealed compressive myelopathy, significant spinal canal stenosis, and severe spondylosis J Orthop Sports Phys Ther 2017;47(9):691. doi:10.2519/jospt.2017.7287.


Assuntos
Paresia/etiologia , Compressão da Medula Espinal/diagnóstico por imagem , Estenose Espinal/diagnóstico por imagem , Espondilose/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Compressão da Medula Espinal/fisiopatologia , Compressão da Medula Espinal/terapia , Estenose Espinal/fisiopatologia , Estenose Espinal/terapia , Espondilose/fisiopatologia , Espondilose/terapia , Resultado do Tratamento , Extremidade Superior/fisiopatologia
5.
Biol Psychiatry ; 58(12): 921-9, 2005 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-16043134

RESUMO

BACKGROUND: Diffusion tensor imaging (DTI) is a relatively new neuroimaging technique that can be used to examine the microstructure of white matter in vivo. A systematic review of DTI studies in schizophrenia was undertaken to test the hypothesis that DTI can detect white matter differences between schizophrenia patients and normal control subjects. METHODS: EMBASE, PubMed, Medline, and PsychInfo were searched online and key journals were searched manually for studies comparing anisotropy (a measure of white matter integrity) between patients and control subjects. Nineteen articles were systematically reviewed. RESULTS: Though 16 studies found differences, methodological and data differences prevented a meta-analysis. Fourteen studies found reduced anisotropy in patients; two studies found only a loss of normal asymmetry. The region of investigation varied across studies, however, and when the same region (for example, the cingulum) was examined in different studies, as many failed to find a difference as found one. These inconsistencies may be the result of small sample sizes and differences in methodology. CONCLUSIONS: Diffusion tensor imaging has yet to provide consistent findings of white matter abnormalities in schizophrenia. Its potential as a means of examining anatomical connectivity may be realized with the study of larger, more homogenous groups of subjects and with ongoing improvements in image analysis.


Assuntos
Esquizofrenia/patologia , Adulto , Idoso , Anisotropia , Encéfalo/patologia , Corpo Caloso/patologia , Imagem de Difusão por Ressonância Magnética , Eletroencefalografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
6.
Psychiatry Res ; 131(1): 23-30, 2004 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-15246452

RESUMO

The aim of this study was to investigate pathophysiological changes at an early stage of clinical Huntington's disease (HD) using a functional magnetic resonance imaging (fMRI) study and a serial reaction time task paradigm. Mildly affected and presymptomatic HD subjects (n = 8) and healthy normal controls (NC, n = 12) were studied. A group behavioral effect of implicit learning was seen only in the control population. Individual statistical parametric mapping (SPM) analysis showed more consistent activation of the caudate nucleus and putamen in the NC group. In the HD group, the group average SPM showed significant activation in the right head of caudate nucleus, as well as bilateral thalami, left middle temporal, right superior temporal, right superior frontal, right middle and inferior frontal and right postcentral gyri. In the comparison of between-group differences (NC-HD), reduced activation in the HD group relative to NC was observed in the right middle frontal, left middle occipital, left precuneus, and left middle frontal gyri. The variable striatal activity in the Huntington's group suggests early functional loss possibly associated with previously demonstrated early atrophy of these same neural structures.


Assuntos
Doença de Huntington/fisiopatologia , Aumento da Imagem , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Desempenho Psicomotor/fisiologia , Tempo de Reação/fisiologia , Aprendizagem Seriada/fisiologia , Adulto , Atenção/fisiologia , Mapeamento Encefálico , Núcleo Caudado/fisiopatologia , Córtex Cerebral/fisiopatologia , Dominância Cerebral/fisiologia , Diagnóstico Precoce , Feminino , Humanos , Doença de Huntington/diagnóstico , Masculino , Memória de Curto Prazo/fisiologia , Pessoa de Meia-Idade , Vias Neurais/fisiopatologia , Oxigênio/sangue , Putamen/fisiopatologia , Valores de Referência , Tálamo/fisiopatologia
7.
AJR Am J Roentgenol ; 179(3): 783-9, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12185064

RESUMO

OBJECTIVE: Relative cerebral blood flow has rarely been studied as part of the preoperative assessment of tumor grade, although relative cerebral blood volume is known to be useful for this assessment. The purpose of our study was to determine the usefulness of relative cerebral blood flow in assessing the histopathologic grade of cerebral gliomas. SUBJECTS AND METHODS: MR imaging was performed in 17 patients with proven cerebral gliomas (11 high-grade gliomas and six low-grade gliomas), using a first-pass gadopentetate dimeglumine-enhanced T2-weighted echoplanar perfusion sequence. The perfusion data were deconvoluted with an arterial input function, using singular value decomposition to obtain a color map of relative cerebral blood volume and flow; the relative cerebral blood volume and flow ratios were expressed relative to values measured in the contralateral white matter. The Wilcoxon's rank sum test was performed to test the difference between the mean of the relative cerebral blood volume (or flow) ratio in high-grade gliomas and that in low-grade gliomas. Receiver operating characteristic curve analysis was used to evaluate the association between the relative cerebral blood volume (or flow) ratio and the grade of the glioma, as well as to calculate the relative cerebral blood volume and flow ratio cutoff value permitting discrimination between high- and low-grade gliomas. The correlation between relative cerebral blood volume and flow ratios was evaluated using Spearman's rank correlation analysis. We also made a qualitative assessment regarding the match or mismatch of areas of maximal contrast enhancement with the areas of highest color perfusion maps. RESULTS: The mean of the relative cerebral blood volume ratio was 4.91 in the high-grade gliomas and 2.00 in the low-grade gliomas. The mean relative cerebral blood flow ratio was 4.82 in the high-grade gliomas and 1.83 in the low-grade gliomas. A significant difference in each relative cerebral blood volume and flow ratio was found between the high- and low-grade gliomas (Wilcoxon's rank sum test, p < 0.05). Both the relative cerebral blood volume and flow ratios strongly matched the grade of the glioma, but the difference between the two areas was not significant (receiver operating characteristic curve analysis, p > 0.05). The desired cutoff value was 2.93 in the relative cerebral blood volume ratio and 3.57 in the relative cerebral blood flow ratio. Additionally, there was a strong correlation between the relative cerebral blood volume and flow ratios (Spearman's rank correlation coefficient = 0.762; p < 0.05). There was frequent mismatch (33%) between the qualitative assessment of the contrast-enhanced T1-weighted MR images and the perfusion maps. CONCLUSION: First-pass gadopentetate dimeglumine-enhanced T2-weighted echoplanar perfusion MR imaging is useful for the preoperative assessment of tumor grade. A relative cerebral blood flow ratio, in addition to a relative cerebral blood volume ratio, can be a useful tool in the evaluation of the histopathologic grade of cerebral gliomas.


Assuntos
Volume Sanguíneo/fisiologia , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/fisiopatologia , Circulação Cerebrovascular/fisiologia , Glioma/patologia , Glioma/fisiopatologia , Adolescente , Adulto , Idoso , Encéfalo/patologia , Encéfalo/fisiopatologia , Encéfalo/cirurgia , Neoplasias Encefálicas/cirurgia , Feminino , Glioma/cirurgia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Cuidados Pré-Operatórios , Sensibilidade e Especificidade , Índice de Gravidade de Doença
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