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1.
J Clin Oncol ; 17(9): 2804-10, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10561356

RESUMO

PURPOSE: Cytarabine (ara-C) is one of the most effective chemotherapeutic agents in patients with acute leukemia (AL), with a clear dose effect. Use of high-dose ara-C is hampered, however, by a noticeable toxicity, particularly to the CNS. We investigated the usefulness of CNS perfusion imaging with technetium-99m ((99m)Tc)-hexamethyl-propylene-amine oxime (HMPAO) single-photon emission computed tomography (SPECT) concurrent to magnetic resonance imaging (MRI) to specifically assess the effects of standard- and high-dose ara-C in children with AL. PATIENTS AND METHODS: Twenty-six perfusion studies using (99m)Tc-HMPAO SPECT were performed in 12 children (age range, 4 to 15 years) with AL after induction therapy, which consisted of a standard-dose ara-C, immediately after consolidation with high-dose ara-C, and later during follow-up (range, 6 to 44 months). The chemotherapy-related adverse events were monitored and correlated to SPECT and MRI. RESULTS: After the induction phase, all children were neurologically normal on MRI. On SPECT imaging, four children displayed a slightly heterogeneous perfusion. After high-dose ara-C (4 to 36 g/m(2)), five children had regressive neurologic signs of potential toxic origin. Of these five children, only one had an abnormal MRI scan, whereas all patients showed evidence of diffuse cerebral and/or cerebellar heterogeneous perfusion on SPECT. The seven other patients without any neurologic symptoms had normal MRI scans; SPECT was normal for three patients and abnormal for four patients. On follow-up, for four children who had presented with clinical neurologic toxicity, SPECT improved in three patients and remained unchanged in one patients. In two of these four children, delayed abnormalities (T2 white matter hypersignal and cerebellar atrophy) appeared on MRI scans. CONCLUSION: In our series, diffuse heterogeneous brain hypoperfusion is often the sole early objective imaging feature identified by SPECT of high-dose ara-C neurotoxicity, where MRI still demonstrates normal pictures.


Assuntos
Antimetabólitos Antineoplásicos/efeitos adversos , Encéfalo/efeitos dos fármacos , Citarabina/efeitos adversos , Compostos Radiofarmacêuticos , Tecnécio Tc 99m Exametazima , Tomografia Computadorizada de Emissão de Fóton Único , Adolescente , Antimetabólitos Antineoplásicos/administração & dosagem , Encéfalo/diagnóstico por imagem , Encefalopatias/induzido quimicamente , Encefalopatias/diagnóstico , Cerebelo/diagnóstico por imagem , Cerebelo/efeitos dos fármacos , Criança , Pré-Escolar , Citarabina/administração & dosagem , Monitoramento de Medicamentos/métodos , Feminino , Seguimentos , Humanos , Imageamento por Ressonância Magnética , Masculino , Exame Neurológico
2.
J Neuroradiol ; 32(1): 63-6, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15798617

RESUMO

We report the cases of 2 severely disabled patients with large inflammatory lesions suggestive of demyelination treated with mitoxantrone. Clinical condition was improved and brain lesions volume was reduced. On serial MR spectroscopy, there were variations in peaks between 0.9 and 1.4 ppm, suggestive of free lipids and amino acids. These variations may represent neurochemical markers of clinical recovery of large inflammatory lesions in multiple sclerosis.


Assuntos
Encefalopatias/tratamento farmacológico , Doenças Desmielinizantes/tratamento farmacológico , Mitoxantrona/uso terapêutico , Doença Aguda , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Masculino
3.
Arch Neurol ; 55(4): 517-21, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9561980

RESUMO

OBJECTIVES: To evaluate in patients with multiple sclerosis (MS) the occurrence of clinical systemic signs and biological autoimmune abnormalities, including positive titers of antinuclear antibodies and antiphospholipid antibodies, suggestive of autoimmune diseases that may affect the central nervous system. Also, to compare the clinical and magnetic resonance imaging features and evolution of MS in patients with and without autoimmune abnormalities. DESIGN AND PATIENTS: Prospective study of 161 patients fulfilling the criteria of having probable or definite MS hospitalized in our institution between November 1990 and June 1992. RESULTS: Among the 161 patients, 84 (52.1%) had at least 1 clinical and/or biological general sign suggestive of an autoimmune disease; 64 were followed up for 4 to 5 years. The diagnosis of MS was confirmed in 50 patients and is still pending in 14 of them. No significant difference was found between patients with MS who were free of autoimmune features and those with autoimmune abnormalities (MS plus) concerning the age of disease onset, the presenting symptoms and signs, symptoms found on neurologic examination, and the course of the disease. For all patients with confirmed MS, general signs were found in 13.3%, positive titers of antinuclear antibodies in 26%, and positive titers of antiphospholipid antibodies in 6.2%. CONCLUSIONS: Patients with MS with autoimmune features, including those with titers of antinuclear antibodies of 1:100 or less and/or antiphospholipid antibodies, are not different than others with MS, and therefore should not be excluded from clinical trials.


Assuntos
Anticorpos Antinucleares/imunologia , Anticorpos Antifosfolipídeos/imunologia , Esclerose Múltipla/imunologia , Adolescente , Adulto , Idade de Início , Estudos de Casos e Controles , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/diagnóstico , Estudos Prospectivos , Titulometria
4.
Arch Neurol ; 54(5): 586-92, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9152115

RESUMO

OBJECTIVES: To describe the changes in the results of magnetic resonance imaging and spectroscopy occurring in the normal-appearing white matter of patients with adult adrenoleukodystrophy and to present evidence of a particular change that may serve as a marker for the follow-up of the disease. DESIGN: Neurologic, magnetic resonance imaging, and localized proton spectroscopic examinations were performed in 11 patients with adult adrenoleukodystrophy and compared with 11 sex- and age-matched controls. PATIENTS: Eleven patients with adult adrenoleukodystrophy participated in a trial of dietary therapy with glyceryl trioleate and glyceryl trierucate (Lorenzo's oil) in the Fédération de Neurologie and the Institut National de la Santé et de la Recherche Médicale, Unité 134, at the Hôpital de la Salpêtrière in Paris, France. RESULTS: The results of magnetic resonance imaging of the white matter were normal in 2 patients and showed areas of mild symmetrical hypersignals on T2-weighted images and fluid attenuated inversion recovery sequences, localized in the posterior white matter in 9 patients. The results of spectroscopy indicated that the peak of the area of choline-containing compounds was increased at long echo times in patients with adult adrenoleukodystrophy, which may reflect very long-chain fatty acid accumulation in this disease. The peak of the area of myo-inositol-containing compounds was increased at short echo times in patients with adult adrenoleukodystrophy, which may indicate a rise in this metabolite concentration. The N-acetylaspartate-creatine amplitude ratio was significantly decreased in patients with motor deficit. The significance of this finding remains to be established. CONCLUSIONS: The results of localized proton magnetic resonance spectroscopy show abnormalities in the cerebral white matter of patients with adult adrenoleukodystrophy, which may contribute to the understanding of the pathophysiologic characteristics of the disease. Although changes in the results of spectroscopy found in this disease are not specific, the increase of choline-containing compounds may reflect the accumulation of very long-chain fatty acids in the central nervous system. Localized proton magnetic resonance spectroscopy may prove a valuable technique, in addition to magnetic resonance imaging, for noninvasive investigation of patients with adult adrenoleukodystrophy undergoing future clinical trials.


Assuntos
Adrenoleucodistrofia/diagnóstico , Adrenoleucodistrofia/metabolismo , Encéfalo/metabolismo , Colina/metabolismo , Adrenoleucodistrofia/dietoterapia , Adulto , Encéfalo/patologia , Gorduras Insaturadas na Dieta/uso terapêutico , Combinação de Medicamentos , Ácidos Erúcicos/uso terapêutico , Feminino , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Trioleína/uso terapêutico
5.
Neurology ; 53(5): 1091-7, 1999 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-10496272

RESUMO

OBJECTIVE: To determine the efficacy of MRS in discriminating between relapsing remitting (RR) and secondary progressive (SP) MS. METHODS: MRS at long and short echo times was carried out in 104 patients with MS stratified for clinical course (RR or SP), and the results were compared with those of 15 control subjects. Normal-appearing white matter (NAWM) was studied in 55 patients, and a high-T2-signal area on MRI in 49 others. RESULTS: At long echo times, there was a highly significant decrease in the ratios N-acetyl-aspartate/creatine (NAA/Cr) and NAA/ choline (Cho) in high-T2-signal areas and in the NAWM in patients with an SP course compared with control subjects and patients with an RR course. There was a significant negative correlation between these ratios and clinical disability measured by Expanded Disability Status Scale score, which was independent of disease duration. Discriminant values between patients with RR and SP courses were found in the NAWM (NAA/Cr = 1.75 and NAA/Cho = 1.5), but not in high-T2-signal areas. At short echo times, there was a significant increase in the ratio myoinositol/Cr in high-signal areas of patients with an SP course compared with control subjects, and the presence of abnormal resonances in the lesions and NAWM for free amino acids and lipids (in 30% and 8%, respectively) and GLX complex (glutamine, glutamate, gamma-aminobutyric acid; 16% and 20%, respectively). CONCLUSIONS: Studying normal-appearing white matter on MRI with MRS allows discrimination between relapsing remitting and secondary progressive patients. In the NAWM of patients with MS and an SP course, severe axonal loss/dysfunction is negatively correlated to clinical disability and independent of the duration of the disease.


Assuntos
Espectroscopia de Ressonância Magnética , Esclerose Múltipla Recidivante-Remitente/metabolismo , Esclerose Múltipla/metabolismo , Adolescente , Adulto , Idoso , Encéfalo/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prótons
6.
Neurology ; 56(1): 112-5, 2001 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-11148248

RESUMO

To assess the impact of highly active antiretroviral therapy (HAART) on AIDS-associated cognitive impairment, 22 patients with AIDS with (n = 11) and without (n = 11) cognitive deficit were evaluated clinically and by MRS every 3 months for 9 months. Nineteen patients were on HAART at study entry, 21 after 2 months. Cognitively impaired patients presented with a subcorticofrontal deficit and decreased N-acetyl-aspartate in frontal white matter. These clinical and metabolic abnormalities reversed partially on HAART, whereas they remained within normal limits in cognitively unimpaired patients.


Assuntos
Complexo AIDS Demência/diagnóstico , Complexo AIDS Demência/tratamento farmacológico , Terapia Antirretroviral de Alta Atividade , Espectroscopia de Ressonância Magnética , Adulto , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Estudos Prospectivos , Resultado do Tratamento
7.
J Nucl Med ; 40(5): 786-92, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10319751

RESUMO

UNLABELLED: Ictal SPECT studies are increasingly used to localize seizure foci in children with refractory epilepsy, but few studies have reported on ictal-interictal subtraction images co-registered to MRI at this age. METHODS: Twenty-seven children with partial epilepsy (aged 3 mo-18 y) underwent ictal ethyl cysteinate dimer (ECD) SPECT (20 mCi/1.73 m2) combined with video-electroencephalography (EEG) and interictal ECD SPECT followed 2 d later by three-dimensional MRI. Ictal-interictal and interictal-ictal subtraction images were computed by registering and normalizing the ictal to the interictal SPECT scans for each child. The ictal, interictal SPECT and subtraction images were registered to each child's MRI. Difference images (ictal-interictal) were then superimposed on MRI for anatomic localization of the perfusion changes. Intra- and interobserver reproducibility and "facility of interpretation" of overlay images were compared with standard analysis of the non-coregistered ictal and interictal scans. RESULTS: Overlay images allowed the detection of at least one hyperperfused focus in 93% of the children, compared with 74% using ictal and interictal scans separately. Seizure onset was suspected clinically, on EEG or on MRI in 20 children. Overlay images were concordant (n = 11) or larger (n = 7) than the suspected focus in 18 of 20 (90%), whereas these images failed to show any abnormality in 1 child and were discordant with MRI in another patient. In the remaining 7, images showed cortical localization in 6 patients. Among the 5 patients who underwent electrocorticography, overlay images were concordant in 3, larger in 1 and absent in 1. The intra- and interobserver reproducibility and facility of interpretation were significantly higher using overlay images than standard analysis, even when ictal and interictal SPECT were co-registered. CONCLUSION: The co-registration of ictal-interictal subtraction SPECT images to MRI seems to be a helpful technique in localizing the onset of seizure and guiding the intracranial recording in childhood epilepsy. Moreover, this method improves sensitivity, enhances intra- and interobserver reproducibility and makes interpretation easier.


Assuntos
Encéfalo/diagnóstico por imagem , Epilepsias Parciais/diagnóstico por imagem , Imageamento por Ressonância Magnética , Tomografia Computadorizada de Emissão de Fóton Único , Adolescente , Encéfalo/patologia , Criança , Pré-Escolar , Cisteína/análogos & derivados , Eletroencefalografia , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Lactente , Masculino , Variações Dependentes do Observador , Compostos de Organotecnécio , Compostos Radiofarmacêuticos , Técnica de Subtração , Tomografia Computadorizada de Emissão de Fóton Único/métodos
8.
Brain Res Bull ; 44(2): 117-24, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9292200

RESUMO

The aim of this magnetic resonance imaging study was to find a geometrical characterization of the deeper part of the corpus callosum. Its shape was studied in 12 middle-aged persons free of white matter pathology. Profiles of curvatures were measured showing that this surface was close to a minimal one, especially at the genu and near the splenium. To assess the effect of a white matter pathology on these geometrical features, the same measurements were performed in an extra group of nine patients with definite multiple sclerosis. The hypothesis of curvatures profiles parallelism for the two groups could be rejected at the 0.05 confidence level for the mean curvatures but not for the Gaussian ones. Curvatures profiles may give indications on balance between the cortex and the fiber bundles growth rates during the development and on large scale modifications co-occurring with multilocular white matter pathologies.


Assuntos
Corpo Caloso/anatomia & histologia , Adulto , Análise Fatorial , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Modelos Neurológicos , Esclerose Múltipla/patologia
9.
Nucl Med Commun ; 18(12): 1122-9, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9481758

RESUMO

Four methods of brain edge detection on brain SPET perfusion (99Tcm-hexamethylpropylene amine oxime) images were compared: ellipse adaptation, simple thresholding (four threshold values), a low threshold (40%) followed by 1, 2 or 3 pixel erosion, and the Deriche 3D adaptive cut-off frequency method (four filter widths: alpha = 1, 2, 3 or 4). The SPET data of six patients were reconstructed to obtain 10 axial slices, each 10 mm thick, covering the whole brain. On the 60 axial slices, the methods were compared based on automaticity, computation time and accuracy of edge detection compared with morphological edges drawn manually on the patients' 3D co-registered magnetic resonance imaging (MRI) scans. The proportion of pixels inside the contour defined by the MRI scan but outside the SPET edge (p(i)), and the proportion of pixels inside the contour defined by the SPET image but outside the MRI contour (pe), were calculated. The thresholding methods provided interesting results, particularly the application of a low threshold value (40%), followed by a 2 pixel erosion, which required a computation time of 12 s (p(i) = 5.7 +/- 2.2%; pe = 2.7 +/- 0.9%). Because of adjustments to each slice of the ellipse axis, the processing time of this method was about 3 min (p(i) = 1.5 +/- 1.4%; pe = 11.3 +/- 3.4%). The Deriche 3D filter was time-consuming (6 min for 10 slices on a NXT workstation, SMV International). With this method, the best edge fitting was found with a filter width of 3 and 4 (p(i) = 9.6 +/- 11.1%; pe = 14.1 +/- 23.2%; alpha = 3). Three-dimensional filtering methods must be refined to reduce the computation time and to improve brain edge fitting accuracy when compared with the eroded thresholding method.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Transtornos Cerebrovasculares/diagnóstico por imagem , Compostos Radiofarmacêuticos , Tecnécio Tc 99m Exametazima , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Transtornos Cerebrovasculares/diagnóstico , Câmaras gama , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/métodos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
10.
Seizure ; 1(3): 203-6, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1344769

RESUMO

Reflex epilepsy constitutes a rare form of epileptic seizures. We observed a 20-year-old man who presented with seizures induced by immersion in hot water. The trigger stimulus was specific. Contrast CT scan and MRI were all normal, not revealing any structural lesion. Ictal EEG recorded during a hot bath showed focal epileptic discharges in the left temporo-occipital area. Interictal SPECT showed a hypometabolism in the same cerebral region. Neuroimaging studies were rarely performed in this uncommon type of epilepsy. Nevertheless, in our case the result of the SPECT suggests a localized functional disturbance in the emergence of the disorder.


Assuntos
Banhos , Eletroencefalografia , Epilepsias Parciais/fisiopatologia , Temperatura Alta , Imageamento por Ressonância Magnética , Tomografia Computadorizada de Emissão de Fóton Único , Adulto , Isquemia Encefálica/fisiopatologia , Mapeamento Encefálico , Potenciais Evocados/fisiologia , Humanos , Masculino , Lobo Occipital/irrigação sanguínea , Lobo Occipital/fisiopatologia , Lobo Temporal/irrigação sanguínea , Lobo Temporal/fisiopatologia
11.
Rev Neurol (Paris) ; 151(11): 619-33, 1995 Nov.
Artigo em Francês | MEDLINE | ID: mdl-8745625

RESUMO

Brain single photon emission tomography is a functional imaging modality in constant evolution. Tracers belong to 4 categories; blood pool tracers, perfusion tracers, ligands of receptors, "metabolic" tracers. Examination conditions must be accurately described since they may cause specific cerebral activation. The interpretation must be done in comparison with a morphological examination (CT or NMR). Cerebrovascular diseases, temporal lobe epilepsy and dementia were the first domains of application. Now many studies concentrate on cerebral cognitive or pharmacological activation procedure before the tracer injection to capture an aspect of the brain functioning. It is mandatory to clearly state what is expected from the examination: an answer for a given patient and a specific question or a study of an homogeneous group of patients. In order to yield relevant results, such studies must rely on a rigorous methodology.


Assuntos
Doenças do Sistema Nervoso/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único , Transtornos Cerebrovasculares/diagnóstico por imagem , Demência/diagnóstico por imagem , Epilepsia/diagnóstico por imagem , Humanos , Transtornos Mentais/diagnóstico por imagem , Doenças do Sistema Nervoso/fisiopatologia
12.
Rev Neurol (Paris) ; 156(12): 1078-86, 2000 Dec.
Artigo em Francês | MEDLINE | ID: mdl-11139723

RESUMO

Magnetic resonance spectroscopy allows in vivo neurochemical exploration of multiple sclerosis (MS) lesions and normal appearing white matter on MRI. It gives insights into pathophysiology: inflammation (increase of choline), recent demyelination (increase in lipids and choline), axonal dysfunction (decrease of NAA), gliosis (increase of myoinositol). The spectroscopic profile of lesions is not specific to MS. Therefore MRI remains the first investigation to perform when MS is suspected. However, spectroscopy is a sensitive, reproducible, non invasive tool which may provide an index of activity. In the future, spectroscopy may contribute in homogenizing patient selection for clinical trials and might be used, in association with MRI, to evaluate therapeutic efficiency. Spectroscopy might also influence therapeutic choices by identifying the prevailing lesional mechanism: inflammation, demyelination, axonal destruction, or gliosis.


Assuntos
Encéfalo/metabolismo , Espectroscopia de Ressonância Magnética , Esclerose Múltipla/diagnóstico , Esclerose Múltipla/metabolismo , Encéfalo/patologia , Humanos , Imageamento por Ressonância Magnética , Sensibilidade e Especificidade
13.
Rev Neurol (Paris) ; 157(1): 35-44, 2001 Jan.
Artigo em Francês | MEDLINE | ID: mdl-11240546

RESUMO

We have analyzed with localized proton magnetic resonance spectroscopy (MRS) 31 lesions in 28 patients with multiple sclerosis (MS). The course of the disease was either relapsing remitting, secondary progressive, or primary progressive. Four patients had an isolated neurological syndrome suggestive of MS. The decrease in the NAA/Cre ratio and the raise of the Cho/Cre ratio were more pronounced in patients with an acute isolated neurological syndrome, suggesting the predominance of an inflammatory process, and the presence of an axonal dysfunction in the initial course of the lesion. The NAA/Cre ratio was negatively correlated with clinical disability and thus could be used as an index of disease activity. Patients with a secondary progressive course exhibited a significant increase in the Myo/Cre ratio compared to those with a relapsing remitting course. Thus, there may be an association between the evolution towards a progressive disease and axonal loss or the development of gliosis. The isointense lesions to the cerebrospinal fluid on MRI T1 weighted sequences were characterized by a sharp raise in the Cho/Cre ratio suggesting demyelination and/or intense inflammation. Gadolinium enhanced lesions were not characterized by a specific neurochemical profile.


Assuntos
Imageamento por Ressonância Magnética , Esclerose Múltipla/patologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
14.
Rev Neurol (Paris) ; 155(6-7): 477-81, 1999 Jul.
Artigo em Francês | MEDLINE | ID: mdl-10472663

RESUMO

Ictal SPECT is a highly sensitive method to localize the epileptogenic focus in refractory temporal lobe epilepsy in adults. In extratemporal epilepsy, sensitivity can be improved by subtracting interictal from ictal images and superimposing subtraction images on MRI. In children, such a procedure is potentially interesting because most epilepsies are extratemporal and ictal SPECT not yet routinely developed. The aim of this study was to test the feasibility of ictal SPECT with subtraction image processing in a pediatric population. Twenty-six children with refractory partial epilepsy and aged from 3 months to 18 years underwent ictal ECD-SPECT (20 mCi/1.73 m2) combined with video-EEG and interictal ECD-SPECT plus 3D-MRI two days later. Ictal-interictal subtraction images were computed by registering and normalizing the ictal to the interictal SPECT scans for each child. The ictal, interictal SPECT and subtraction images were registered to the children's MRI. Difference images were then superimposed to MRI for anatomical localization of the perfusion changes (overlay images). Looking for perfusion changes, overlay images allowed to detect at least one hyperperfused focus in 92 p. 100 of the 26 children compared to 73 p. 100 visually comparing ictal and interictal scans separately. Seizure onset was suspected on clinical and/or EEG and/or MRI in 19 children. Positive overlay images were concordant (n = 11) or larger (n = 7) than the suspected focus in 17/19 (90 p. 100), whereas they failed to show any abnormality in 1 child and were discordant with MRI in another one. In the 7 remaining patients, images showed cortical localization in 6 cases. Ictal SPECT is therefore faisable in very young children. Ictal-interictal subtraction SPECT images co-registered to MRI improves sensitivity compared to classical visual analysis. It seems therefore to be a helpful technique to localize the onset of seizure and to guide the intracranial recording in childhood epilepsy.


Assuntos
Encéfalo/fisiopatologia , Epilepsias Parciais/diagnóstico por imagem , Epilepsias Parciais/patologia , Imageamento por Ressonância Magnética , Tomografia Computadorizada de Emissão de Fóton Único , Adolescente , Adulto , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Criança , Pré-Escolar , Cisteína/análogos & derivados , Eletroencefalografia , Epilepsias Parciais/etiologia , Epilepsias Parciais/fisiopatologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Lactente , Masculino , Compostos de Organotecnécio , Compostos Radiofarmacêuticos , Sensibilidade e Especificidade , Gravação em Vídeo
15.
J Neuroradiol ; 23(2): 49-55, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8948157

RESUMO

We used a rapid long TE proton magnetic resonance spectroscopic (MRS) sequence in the normal appearing white matter of 11 patients with definite multiple sclerosis (MS) localizing the volume of interest in the centrum semi-ovale. The metabolic changes were compared to the same area in 11 normal brains. We found a significant decrease in NAA/Cr ratios and a borderline significance of increase in Cho/Cr ratios in patients with MS. A discriminant analysis was performed on these data. This allowed to obtain a simple ratio, NAA/(Cho+Myo), which discriminated MS patients from controls. Our results indicate that normal appearing white matter on MRI is biochemically abnormal in patients with MS. In addition MRS could be routinely used after a standard MRI examination in patients with MS for clinical correlations, total load of the disease assessment and monitoring clinical trials.


Assuntos
Encéfalo/metabolismo , Espectroscopia de Ressonância Magnética , Esclerose Múltipla/metabolismo , Adulto , Análise de Variância , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Encéfalo/patologia , Encefalopatias/metabolismo , Encefalopatias/patologia , Colina/metabolismo , Ensaios Clínicos como Assunto , Creatina/metabolismo , Análise Discriminante , Humanos , Aumento da Imagem , Inositol/metabolismo , Pessoa de Meia-Idade , Esclerose Múltipla/diagnóstico , Esclerose Múltipla/patologia , Prótons
16.
J Neuroradiol ; 23(4): 217-22, 1996 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9107108

RESUMO

Fifty six patients among whom 39 had white matter diseases had MRI of the brain comparing FLAIR sequence to a conventional proton density sequence. Flair sequence allowed to detect 18 additional hypersignal (HS) that were not present on T2 sequence. These HS were located in the periventricular areas for 5 of them, near the cortical sulci in 10, and in the centrum semi-ovale for 3. FLAIR sequence permitted analyze 41 other lesions that were not obvious on proton density sequences. Thirty five of them were thus confirmed to be HS : 31 in the paracortical areas, 3 in the paraventricular regions and one in the internal capsule, whereas the remaining 6 were normal sulci of the brain. FLAIR sequence increases the sensitivity of MRI in white matter diseases.


Assuntos
Encefalopatias/diagnóstico , Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Adolescente , Adulto , Síndrome Antifosfolipídica/diagnóstico , Córtex Cerebral/patologia , Ventrículos Cerebrais/patologia , Transtornos Cerebrovasculares/diagnóstico , Corpo Caloso/patologia , Feminino , Doença de Graves/diagnóstico , Humanos , Lúpus Eritematoso Sistêmico/diagnóstico , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/diagnóstico , Neurite Óptica/diagnóstico , Paraparesia Espástica Tropical/diagnóstico
17.
J Fr Ophtalmol ; 26(9): 941-51, 2003 Nov.
Artigo em Francês | MEDLINE | ID: mdl-14631278

RESUMO

Water diffusion analysis in magnetic resonance imaging (MRI) provides an elective visualization of fiber tract orientations in cerebral white matter, especially for optic tracts. We explored 25 patients from 18 to 45 years of age, with normal MRI in 20 subjects, and radiological anomalies in five. On a 1.5 Tesla MRI apparatus, diffusion tensor acquisitions were performed in 5 minutes 58 seconds with an EPI Single Shot sequence covering the entire brain. Image displacements were precluded by patient information and adequate fixation, then digitally corrected on workstations. Volume merging and fiber tract extraction were achieved using dedicated software (Volume-One and dTV). A directional depiction was obtained for all areas in the white matter, in particular for white matter junctions. Coming from the lateral geniculate body, the optic tracts were directed posteriorly toward the occipital cortex, with numerous connections to extrastriate associative areas, and through the corpus callosum and the fornix. Diffusion tractography requires optimization of volume displacements, before and secondary to MRI acquisitions. Our diffusion tensor acquisition, with image optimization in a short-duration sequence can be routinely applied to all patients, for a specific analysis of functional connections between cortical areas of cerebral white matter.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Vias Visuais/patologia , Adolescente , Adulto , Anisotropia , Estudos de Casos e Controles , Corpo Caloso/patologia , Imagem de Difusão por Ressonância Magnética/instrumentação , Imagem de Difusão por Ressonância Magnética/normas , Feminino , Fórnice/patologia , Corpos Geniculados/patologia , Humanos , Aumento da Imagem/instrumentação , Aumento da Imagem/métodos , Aumento da Imagem/normas , Masculino , Programas de Rastreamento/instrumentação , Programas de Rastreamento/métodos , Programas de Rastreamento/normas , Pessoa de Meia-Idade , Lobo Occipital/patologia , Radiografia , Sensibilidade e Especificidade , Software/normas , Fatores de Tempo , Vias Visuais/diagnóstico por imagem
18.
J Fr Ophtalmol ; 27(9 Pt 2): 3S65-71, 2004 Nov.
Artigo em Francês | MEDLINE | ID: mdl-15602408

RESUMO

PURPOSE: To evaluate the cortical response to visual stimulation in patients with age-related macular degeneration (ARMD). MATERIAL AND METHODS: We conducted a prospective functional MRI study at 1.5 Testa in ten patients presenting with unilateral or bilateral ARMD and five age-matched controls. The visual stimulus was a sequence of resting phase (presentation of a fixation point on a black background) followed by an activation phase (flashes at 2 Hz). Functional data were recorded with anatomy; significant hemodynamic response secondary to neuronal activation was statistically determined using the SPM 99 software. RESULTS: The first objective was to estimate the feasibility of a functional study in the elderly. Controls and patients complained about the duration of the examination, although each of the two active functional sessions lasted only 4.5 min. The central point fixation was impaired for the patients; some deviated their gaze to center the fixation point on a perimacular retinal area. Because of substantial movement during MRI acquisitions, the data from two patients and one control were withdrawn from statistic processing. DISCUSSION AND CONCLUSION: This study is one of the few evaluations reported on functional MRI in the elderly, because of technical constraints, patient fragility and their ophthalmologic pathology. Optimizing the visual stimulus and the paradigm of stimulation, repeating patient information and support have helped demonstrate significant cortical hemodynamic response in most subjects, even in the most affected patients. Evaluation of the visual cortex by functional MRI appears feasible in the ophthalmologic pathology of the elderly, providing an adapted management of the subject's conditions.


Assuntos
Degeneração Macular/fisiopatologia , Imageamento por Ressonância Magnética , Córtex Visual/fisiologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Artefatos , Mapeamento Encefálico , Interpretação Estatística de Dados , Imagem Ecoplanar , Feminino , Fixação Ocular , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Estimulação Luminosa , Fatores de Tempo
19.
J Fr Ophtalmol ; 27(9 Pt 2): 3S72-86, 2004 Nov.
Artigo em Francês | MEDLINE | ID: mdl-15602409

RESUMO

UNLABELLED: PURPOSE AND MATERIALS: To evaluate the cortical response to visual stimulation in patients with age-related macular degeneration (ARMD), we conducted a functional MRI study in ten patients presenting unilateral or bilateral ARMD and five age-matched controls, using white flashes during activation phases (see Part I). RESULTS: After anatomical conformation, eight patients and four controls showed significant cortical hemodynamic response to monocular stimulations. Individual analysis was preferred to group evaluation, because of the differences in visual loss in a small number of patients. In controls, we observed cortical response in the primary visual cortex, especially at occipital poles corresponding to the macula. Patients showed a qualitative and quantitative restriction in cortical response and exclusion of occipital poles after stimulation of the affected eye, whereas activation was found in the peripheral striate and peristriate cortex. Cortical response showed hemispheric asymmetry in some patients. DISCUSSION: Our study demonstrated an activation defect in the macular projected striate cortex, corresponding to visual impairment in ARMD patients. Nevertheless, at a given visual acuity, cortical response may vary among subjects. Patients' subjective apprehension may account for such variations, as well as objective visual capacity stemming from residual functional retinal areas within the affected macula. The hemispheric asymmetry in cortical activation may result from gaze deviation onto the new fixation area in the perimacular retina, thus altering the global visual field. Enhancement in the peripheral striate and peristriate areas suggests changes in cortical interactions, possibly by a lowering of the feedback from macular projected V1. Finally, cortical evaluations must take into account degenerative phenomena delaying the hemodynamic response in the elderly. CONCLUSION: Aiming at a specific population of weakened patients with a serious visual impairment, we obtained significant results concerning cortical plasticity for visual perception in central vision deletion. Our preliminary findings must be confirmed in a larger population and correlated with other techniques exploring vision, in particular with multifocal electroretinography for retinal evaluation.


Assuntos
Degeneração Macular/fisiopatologia , Imageamento por Ressonância Magnética , Córtex Visual/fisiologia , Percepção Visual , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Mapeamento Encefálico , Interpretação Estatística de Dados , Retroalimentação , Feminino , Fixação Ocular , Hemodinâmica , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Estimulação Luminosa , Fatores de Tempo , Acuidade Visual , Campos Visuais
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