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1.
Am J Med Genet B Neuropsychiatr Genet ; 153B(3): 775-85, 2010 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-19908235

RESUMO

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a neurodegenerative disorder occurring in male and occasional female carriers of a premutation expansion (55-200 CGG repeats) of the fragile X mental retardation 1 gene (FMR1). This study assessed the relationship between hippocampal volume and psychological symptoms in carriers, both with and without FXTAS, and controls. Volumetric MRI measures, clinical staging, cognitive testing, molecular analysis, and measures of psychological symptoms were performed for female premutation carriers both with FXTAS (n = 16, age: 57.50 + or - 12.46) and without FXTAS (n = 17, age: 44.94 + or - 11.23), in genetically normal female controls (n = 8, age: 50.63 + or - 11.43), male carriers with FXTAS (n = 34, age: 66.44 + or - 6.77) and without FXTAS (n = 21, age: 52.38 + or - 12.11), and genetically normal male controls (n = 30, age: 57.20 + or - 14.12). We examined the relationship between psychological symptom severity and hippocampal volume, as well as correlations with molecular data. We found a significant negative correlation between total hippocampal volume and anxiety in female carriers, with and without FXTAS. This finding was mainly driven by the significant negative correlation between right hippocampal volume and anxiety. Other anxiety-related subscales also correlated with the right hippocampus in females. In male carriers with and without FXTAS, only paranoid ideation negatively correlated with hippocampal volume. Female premutation carriers demonstrated a negative association between hippocampal volume and the severity of anxiety-related psychological symptoms. Though the presentation of FXTAS symptoms is less common in females, anxiety-related problems are common both prior to and after the onset of FXTAS, and may be related to hippocampal changes.


Assuntos
Proteína do X Frágil da Deficiência Intelectual/genética , Síndrome do Cromossomo X Frágil/genética , Síndrome do Cromossomo X Frágil/psicologia , Heterozigoto , Hipocampo/patologia , Mutação/genética , Adulto , Idoso , Ansiedade/psicologia , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão
3.
Neurology ; 69(9): 851-9, 2007 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-17724287

RESUMO

BACKGROUND: Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder occurring in male and rare female carriers of a premutation expansion (55 to 200 CGG repeats) of the fragile X mental retardation 1 (FMR1) gene. METHODS: Volumetric MRI studies, clinical staging, cognitive testing, and molecular analysis were conducted in 15 female premutation carriers affected by FXTAS (age 59.5 +/- 10.3 years), 20 unaffected female carriers (43.3 +/- 11.2 years), 11 genetically normal female controls (51.0 +/- 10.3 years), 36 affected male carriers (65.0 +/- 5.6 years), 25 unaffected male carriers (53.5 +/- 12.5 years), and 39 male controls (58.0 +/- 15.0 years). Female and male carriers with FXTAS were matched on duration of disease. RESULTS: We found less pronounced reductions of cerebellar volume and a lower incidence of involvement (symmetric high T2 signal) of the middle cerebellar peduncles (MCP sign) in females affected by FXTAS (13%) compared with affected males (58%). We found reduced brain volumes and increased white matter disease associated with the presence of FXTAS in females compared with female controls. We also observed significant associations between reduced cerebellar volume and both increased severity of FXTAS symptoms and increased length of the CGG repeat expansion in male premutation carriers, but not in females. CONCLUSIONS: Females affected by fragile X-associated tremor/ataxia syndrome (FXTAS) demonstrated milder brain changes than affected males, although they showed a similar pattern of radiologic findings consistent with brain atrophy and white matter disease. FXTAS should be considered (by ordering fragile X DNA testing) in females who present with late-onset ataxia, action tremor, or neuropathy, particularly in those with a family history of mental retardation, autism, or premature ovarian failure.


Assuntos
Ataxia/patologia , Atrofia/patologia , Doenças Cerebelares/patologia , Síndrome do Cromossomo X Frágil/patologia , Caracteres Sexuais , Tremor/patologia , Adulto , Idoso , Ataxia/genética , Ataxia/fisiopatologia , Atrofia/genética , Doenças Cerebelares/genética , Doenças Cerebelares/fisiopatologia , Análise Mutacional de DNA , Feminino , Proteína do X Frágil da Deficiência Intelectual/genética , Síndrome do Cromossomo X Frágil/genética , Síndrome do Cromossomo X Frágil/fisiopatologia , Predisposição Genética para Doença/genética , Testes Genéticos , Genótipo , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Fibras Nervosas Mielinizadas/patologia , Tremor/genética , Tremor/fisiopatologia , Expansão das Repetições de Trinucleotídeos/genética
5.
Am J Hum Genet ; 74(5): 1051-6, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15065016

RESUMO

We describe five female carriers of the FMR1 premutation who presented with symptoms of tremor and ataxia and who received a diagnosis of definite or probable fragile-X-associated tremor/ataxia syndrome (FXTAS). Unlike their male counterparts with FXTAS, none of the women had dementia. Females had not been reported in previous studies of FXTAS, suggesting that they may be relatively protected from this disorder. Brain tissue was available from one of the five subjects, a women who died at age 85 years; microscopic examination revealed intranuclear neuronal and astrocytic inclusions, in accord with the findings previously reported in males with FXTAS. The work-up of families with the FMR1 mutation should include questions regarding neurological symptoms in both older male and female carriers, with the expectation that females may also manifest the symptoms of FXTAS, although more subtly and less often than their male counterparts.


Assuntos
Ataxia/genética , Síndrome do Cromossomo X Frágil/genética , Heterozigoto , Proteínas do Tecido Nervoso/genética , Proteínas de Ligação a RNA , Tremor/genética , Adulto , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Ataxia/patologia , Feminino , Proteína do X Frágil da Deficiência Intelectual , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Tremor/patologia , Repetições de Trinucleotídeos/genética
6.
Acta Radiol ; 44(3): 343-6, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12752010

RESUMO

Diffusion-weighted (DW) MR imaging usually identifies acute cerebral infarction injury in symptomatic patients. We report a patient with severe hypoxic brain injury following suicide attempt by hanging, but with normal DW MR imaging 5-6 h after the event. Follow-up DW MR imaging 3 days after the event, and subsequent autopsy, revealed extensive cerebral anoxic injury.


Assuntos
Encéfalo/patologia , Imagem de Difusão por Ressonância Magnética , Hipóxia Encefálica/patologia , Tentativa de Suicídio , Adolescente , Feminino , Humanos , Hipóxia Encefálica/etiologia , Fatores de Tempo
7.
Neurology ; 59(3): 383-91, 2002 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-12177372

RESUMO

BACKGROUND: Previous studies have found that hippocampal atrophy and white matter hyperintensities (WMH) on MRI are linked to cognitive impairment and dementia. The authors measured these variables in a population-based cohort of older Mexican Americans with a wide spectrum of cognitive ability, ranging from normal cognition to dementia. OBJECTIVE: To investigate whether these structural brain changes were seen in individuals prior to the development of dementia and how these changes were related to the presence of dementia. METHODS: A sample of 122 subjects was selected from the Sacramento Area Latino Study on Aging, and subjects were categorized into four groups of increasing levels of cognitive impairment: normal, memory impaired (MI), cognitively impaired but not demented (CIND), and demented. Hippocampal volume was quantified using a region of interest approach. WMH was rated on a semiquantitative scale as the percent of total volume of white matter. RESULTS: Hippocampal volume was significantly reduced in CIND and demented individuals, and WMH were significantly increased in demented subjects. MI subjects did not have any significant changes in hippocampal volume or WMH. The risk for developing dementia was significantly and comparably increased in subjects with either hippocampal atrophy or high WMH. However, the risk for dementia increased dramatically in subjects with both hippocampal atrophy and a high degree of WMH. CONCLUSION: Reductions in hippocampal volume may be present before dementia but not until cognitive impairment is relatively severe. Because there is a synergistic effect between high WMH and hippocampal atrophy, interactions between vascular and degenerative processes may be important determinants of dementia.


Assuntos
Envelhecimento/fisiologia , Envelhecimento/psicologia , Encéfalo/patologia , Transtornos Cognitivos/diagnóstico , Coleta de Dados , Americanos Mexicanos , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Atrofia , Distribuição de Qui-Quadrado , Transtornos Cognitivos/epidemiologia , Estudos de Coortes , Intervalos de Confiança , Coleta de Dados/métodos , Coleta de Dados/estatística & dados numéricos , Feminino , Hipocampo/patologia , Humanos , Modelos Logísticos , Imageamento por Ressonância Magnética , Masculino , Americanos Mexicanos/psicologia , Americanos Mexicanos/estatística & dados numéricos , Pessoa de Meia-Idade , Razão de Chances
8.
Psychiatry Res ; 108(2): 79-87, 2001 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-11738542

RESUMO

The hippocampus and amygdala are believed to be involved in the pathology of schizophrenia. In this study, we attempted to replicate the reported bilateral volume reduction of the hippocampus and amygdala and to study the relationship of the volumes of these structures to the symptoms of schizophrenia. The hippocampus-amygdala complex (HAC) was manually traced on 3-mm coronal T(1)-weighted MRIs, resampled into 1-mm coronal slices, from 20 male patients with schizophrenia and 20 age-matched male controls. The complex was divided into three parts: anterior one-third representing the amygdala and middle and posterior thirds representing the anterior and posterior halves of the hippocampus. Positive and negative symptoms and severity of hallucinations and thought disorder (conceptual disorganization) were quantified using the Brief Psychiatric Rating Scale (BPRS). None of the above structures, controlled for brain volume, differed significantly in patients compared with normal controls. When the relationship between volumes and symptoms was examined, the left HAC was found to inversely correlate with thought disorder and negative symptoms. Specifically, significant inverse correlations were found between (i) left amygdala and thought disorder, (ii) left hippocampus and negative symptoms, and (iii) left anterior and posterior hippocampus volumes and positive and negative symptoms, respectively. Our findings further support the role of the HAC in the pathophysiology of schizophrenia and suggest unique associations between individual structures and specific symptoms of the illness.


Assuntos
Tonsila do Cerebelo/patologia , Hipocampo/patologia , Imageamento por Ressonância Magnética , Esquizofrenia/diagnóstico , Psicologia do Esquizofrênico , Adulto , Dominância Cerebral/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Valores de Referência , Pensamento/fisiologia
9.
J Pediatr ; 137(5): 646-52, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11060530

RESUMO

OBJECTIVE: To compare neurodevelopmental outcome (NDO) in patients with hypoplastic left heart syndrome (HLHS), other functional single ventricle lesions, and the standard population and to investigate predictors of NDO in the population of children with functional single ventricle (FSV). STUDY DESIGN: A time- and age-defined cohort of patients with the Fontan circulation was recruited to participate in neurodevelopmental testing, behavioral evaluation, and imaging of the central nervous system. The Wechsler Intelligence test was the primary measure of NDO. Analysis included comparison of patients with HLHS with other patients with functional single ventricles. Other potential clinical predictors of NDO were investigated. RESULTS: The mean Full Scale Wechsler Intelligence score was 101.4+/-5.4. For the HLHS subgroup the mean Full Scale Wechsler score was 93.8+/-7.3, and for the non-HLHS subgroup it was 107.0+/-7.0. Although the HLHS group had significantly lower scores than the non-HLHS subgroup, neither subgroup scored significantly different from the standard population on the Wechsler Scales. Socioeconomic status, circulatory arrest, and perioperative seizures also were predictive of neurodevelopmental outcome. CONCLUSION: Neurodevelopmental and behavioral outcome in patients who have undergone the Fontan procedure including patients with HLHS is good in the preschool and early school years, with Wechsler Intelligence scores generally in the normal range.


Assuntos
Desenvolvimento Infantil , Deficiências do Desenvolvimento , Técnica de Fontan , Síndrome do Coração Esquerdo Hipoplásico/cirurgia , Inteligência , Desempenho Psicomotor , Disfunção Ventricular/cirurgia , Sistema Nervoso Central/patologia , Comportamento Infantil , Pré-Escolar , Feminino , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , Exame Neurológico , Resultado do Tratamento , Escalas de Wechsler
10.
Invest Radiol ; 35(7): 412-9, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10901102

RESUMO

RATIONALE AND OBJECTIVES: The objective of the two pivotal phase 3 studies was to evaluate the safety and efficacy of OptiMARK (Gd-DTPA-bis(methoxyethylamide) [Gd-DTPA-BMEA]) compared with Magnevist (Gd-DTPA) in magnetic resonance imaging of the central nervous system. METHODS: Two multicenter, randomized, double-blind, parallel group studies were conducted in 395 patients with known or suspected central nervous system pathology. Subjects were randomized to receive a single 0.1 mmol/kg intravenous injection of either Gd-DTPA-BMEA or Gd-DTPA. The safety of Gd-DTPA-BMEA and Gd-DTPA was monitored for up to 72 hours after study drug administration. Precontrast and postcontrast administration magnetic resonance scans were acquired using identical imaging planes and techniques. RESULTS: No deaths or unexpected adverse events were reported in either group. A comparison of adverse events by intensity and relation demonstrated no statistically significant differences between the two groups. Gd-DTPA-BMEA and Gd-DTPA were equivalent with respect to confidence in diagnosis, conspicuity, and border delineation. CONCLUSIONS: Gd-DTPA-BMEA and Gd-DTPA demonstrated comparable efficacy profiles, and the safety profiles were considered similar.


Assuntos
Doenças do Sistema Nervoso Central/patologia , Meios de Contraste , Gadolínio DTPA , Compostos Organometálicos , Adulto , Idoso , Encéfalo/patologia , Meios de Contraste/efeitos adversos , Método Duplo-Cego , Feminino , Gadolínio , Gadolínio DTPA/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Compostos Organometálicos/efeitos adversos , Medula Espinal/patologia
11.
Neuroradiology ; 40(10): 664-8, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9833898

RESUMO

Imaging studies in eight patients with surgically-confirmed spinal arachnoid cysts were analyzed retrospectively. All patients had preoperative MRI of the spine and seven preoperative myelography with postmyelographic CT. In all cases the correct diagnosis could be made preoperatively on the basis solely of MRI. The diagnosis could also be established from myelography and postmyelographic CT in six of the seven cases. In one case myelography and CT simply demonstrated an intradural extramedullary mass.


Assuntos
Cistos Aracnóideos/diagnóstico , Imageamento por Ressonância Magnética , Mielografia , Doenças da Medula Espinal/diagnóstico , Tomografia Computadorizada por Raios X , Adulto , Idoso , Cistos Aracnóideos/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Doenças da Medula Espinal/diagnóstico por imagem
12.
J Lab Clin Med ; 132(4): 264-78, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9794697

RESUMO

Wilson's disease is an inherited disease of copper accumulation caused by a failure of biliary excretion of excess copper. Accumulated copper causes liver disease in these patients, and in perhaps two thirds of patients, it causes brain damage leading to clinical neurologic or psychiatric dysfunction. Maintenance treatment involves reversing the positive copper balance. The earliest approaches have used chelators, such as penicillamine or trientine, which increase the urinary excretion of copper. A more recent approach has used zinc, which blocks the absorption of copper and increases copper excretion in the stool. Because of the high level of endogenously secreted copper in alimentary secretions, the reabsorption of which is partially blocked by zinc therapy, zinc acts to remove accumulated copper from the body as well as prevent its reaccumulation. In the present article we present data on the long-term follow-up (up to 10 years) of maintenance zinc treatment of 141 patients with Wilson's disease. The data presented document that zinc is effective as a sole therapy in the long-term maintenance treatment of Wilson's disease and that it has a low toxicity. The results demonstrate the efficacy of zinc therapy in treating the presymptomatic patient from the beginning of therapy. We also present limited data on the use of zinc in the treatment of pregnant patients and children who have Wilson's disease; these data also indicate efficacy and low toxicity. The median follow-up period for the group as a whole is 4.8 years; for the presymptomatic patients it is 6.5 years; for the children it is 3.6 years.


Assuntos
Degeneração Hepatolenticular/tratamento farmacológico , Acetato de Zinco/uso terapêutico , Adolescente , Adulto , Encéfalo/patologia , Ceruloplasmina/análise , Criança , Pré-Escolar , Cobre/metabolismo , Cobre/farmacologia , Radioisótopos de Cobre , Feminino , Seguimentos , Degeneração Hepatolenticular/sangue , Degeneração Hepatolenticular/urina , Humanos , Fígado/metabolismo , Testes de Função Hepática , Imageamento por Ressonância Magnética , Masculino , Doenças do Sistema Nervoso/tratamento farmacológico , Doenças do Sistema Nervoso/fisiopatologia , Exame Neurológico , Gravidez , Medida da Produção da Fala , Resultado do Tratamento , Acetato de Zinco/sangue , Acetato de Zinco/urina
13.
AJNR Am J Neuroradiol ; 19(2): 341-8, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9504492

RESUMO

PURPOSE: Our purpose was to describe the MR findings and evolution of spinal cord abscess and to define those MR features that allow differentiation of cord infection from other intramedullary abnormalities. METHODS: We retrospectively reviewed the MR studies of all patients in whom intramedullary spinal cord abscess was proved either by blood or cerebrospinal fluid culture or by serologic examination at our institution between January 1988 and January 1996. The study group included four adults and two children, 7 to 74 years old (mean age, 38 years). RESULTS: Initial MR studies showed intramedullary high signal on T2-weighted sequences with poorly defined marginal enhancement on T1-weighted images. On follow-up contrast-enhanced T1-weighted studies, the lesions had well-defined enhancing margins with central low signal intensity. After the initiation of therapy, T2 signal abnormalities decreased markedly and contrast-enhanced studies showed ring enhancement. These T1 findings resolved with treatment over serial studies in four patients. The organisms identified were Streptococcus milleria, S pyogenes, atypical mycobacteria, Mycobacterium tuberculosis, and Schistosoma mansoni (both children). CONCLUSION: A characteristic sequence of imaging findings aids in the differentiation of cord infection from other intramedullary lesions.


Assuntos
Abscesso/diagnóstico , Imageamento por Ressonância Magnética , Mielite/diagnóstico , Doenças da Medula Espinal/diagnóstico , Adolescente , Adulto , Idoso , Criança , Diagnóstico Diferencial , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Mycobacterium não Tuberculosas/diagnóstico , Estudos Retrospectivos , Esquistossomose mansoni/diagnóstico , Medula Espinal/patologia , Infecções Estreptocócicas/diagnóstico , Streptococcus pyogenes , Tuberculose da Coluna Vertebral/diagnóstico
14.
J Neurosurg ; 88(2): 226-31, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9452228

RESUMO

OBJECT: The authors designed a blinded prospective study comparing patients with essential hypertension to patients without hypertension in which magnetic resonance (MR) imaging was used to evaluate the role of lateral medullary compression by adjacent vascular structures as a cause of neurogenic hypertension. METHODS: Patients with documented essential hypertension were recruited to undergo thin-slice axial brainstem MR imaging evaluation. Nonhypertensive (control) patients scheduled to undergo MR imaging for other reasons also underwent thin-slice MR imaging to form a basis for comparison. Magnetic resonance images obtained in patients from the hypertensive (30 patients) and the control (45 patients) groups were then compared by four independent reviewers (two neuroradiologists and two neurosurgeons) who were blinded to the patients' diagnosis and hypertensive status. Images were reviewed with regard to left versus right vertebral artery (VA) dominance, compression of the medulla on the left and/or right side, and brainstem rotation. Medullary compression was graded as either vessel contact without associated brainstem deformity or vessel contact with associated brainstem deformity. CONCLUSIONS: There was a tendency toward left VA dominance in the hypertensive group compared with the control group, although a significant difference was shown by only one of the four reviewers. There were no differences in brainstem compression or rotation between the hypertensive and nonhypertensive groups. These results are contrary to those of recently published studies in which MR imaging and/or MR angiography revealed lateral brainstem vascular compression in hypertensive patients but not in nonhypertensive (control) patients. Reasons for this discrepancy are discussed. On the basis of their own experience and that of others, the authors believe that neurogenic hypertension does exist. However, thin-slice MR imaging may not be a reliable method for detecting neurovascularly induced essential hypertension and the prevalence of neurovascular compression as the source of hypertension may be overestimated when using current imaging techniques.


Assuntos
Hipertensão/patologia , Hipertensão/cirurgia , Bulbo/patologia , Bulbo/cirurgia , Adolescente , Adulto , Idoso , Tronco Encefálico/patologia , Estudos de Avaliação como Assunto , Feminino , Humanos , Hipertensão/etiologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Síndromes de Compressão Nervosa/complicações , Síndromes de Compressão Nervosa/patologia , Variações Dependentes do Observador , Estudos Prospectivos , Rotação , Método Simples-Cego , Artéria Vertebral/patologia
16.
Interv Neuroradiol ; 4(1): 51-5, 1998 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-20673390

RESUMO

SUMMARY: The purpose of this paper was to evaluate the utility of continuous electroencephalography (EEG) during balloon test occlusion (BTO) of the internal carotid artery (ICA). Continuous EEG monitoring and [O-15] H2O PET cerebral blood flow (CBF) studies were completed in 34 patients undergoing BTO of the ICA. CBF determinations were obtained as a baseline without carotid occlusion, and following balloon occlusion, with continuous EEG monitoring. Patients were divided into three groups based on clinical and CBF response to BTO. Group I had no clinical signs or symptoms and had a CBF decrease less than 10 ml/l00 g/min ipsilateral to the occlusion. Group II had no symptoms but CBF fell to 35 to 25 ml/l00 g/min on the occluded side. Group III were clinically unable to tolerate occlusion or CBF fell to less than 25 ml/l00 g/min on the occluded side. The results of continuous 21 channel EEG monitoring were assessed at the time of the examination and retrospectively reviewed for changes in the EEG pattern indicative of ischaemia. On the basis of PET CBF, eighteen patients were classified as Group I, four as Group II, and twelve as Group III. EEG evidence of ischaemia was seen in three patients, all members of Group III. Of the three patients, only one patient had clinical signs or symptoms of ischaemia. All four patients in Group II had PET quantitated CBF levels indicating carotid sacrifice should be done with caution or following a presacrifice by-pass procedure, and nine patients in Group III with PET quantitated CBFs below eligibility for carotid sacrifice, were not identified by EEG monitoring. Even when CBF falls below 25 ml/100 g/minute continuous EEG monitoring is insensitive to reduction in perfusion. Reliance upon EEG for detection of cerebral hypoperfusion in interventionl neuroradiological procedures will significantly underestimate ischaemic risk.

17.
Interv Neuroradiol ; 4(1): 57-62, 1998 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-20673391

RESUMO

SUMMARY: The purpose of this paper was to evaluate the effects of acetazolamide on cerebral blood flow (CBF) measured by [O-15]H2O positron emission tomography (PET) during balloon test occlusion (BTO) of the internal carotid artery (ICA). [O-15]H2O PET cerebral blood flow studies were completed in 20 patients undergoing BTO CBF determinations were obtained without carotid occlusion as a baseline, following balloon occlusion, and as a third scan with balloon occlusion after an intravenous acetazolamide bolus. The balloon was left deflated between scans, and was only inflated immediately before and during the 90 second period of time needed for CBF determination. Significance was determined at the P < 0.05 level. Two of twenty studies were technical failures. Prior to acetazolamide there was a significant decrease in CBF (P < 0.0007) ipsilateral to the occlusion. After acetazolamide administration there was no statistically significant change in flow on the occluded side (P < 0.3047); however, there was a significant increase in cerebral blood flow (P < 0.0002) on the non-occluded side. In this patient population, there was no acetazolamide-induced CBF decompensation (steal) phenomenon or haemodynamically significant risk in CBF ipsilateral to the occlusion.

18.
J Magn Reson Imaging ; 7(5): 774-83, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9307901

RESUMO

Therapeutic outcome of head and neck cancer is influenced strongly by the presence of nodal metastases. Sensitivity and specificity of the physical examination for the diagnosis of nodal metastasis is unsatisfactory, resulting in both false negatives and false positives of 25 to 40%. Preoperative detection of nodal metastases therefore becomes one of the important goals of imaging studies of patients with head and neck cancer. Despite several advanced techniques and the wide clinical use of MR, MR has surprisingly added little to the diagnostic accuracy of contrast-enhanced CT. Although CT and MR allow detection of abnormally enlarged nodes or necrotic nodes, neither borderline-sized nodes without necrosis nor extracapsular spread are reliably differentiated from reactive or normal nodes in patients with head and neck cancer. Lack of definitive diagnostic methods of metastatic lymph nodes is a serious shortcoming in the preoperative workup for patients with head and neck cancer. To avoid missing small metastatic nodes, a large number of patients clinically staged as N0 have undergone elective neck dissection to exclude metastases. With development of more tissue-specific imaging techniques, patients can be better characterized according to the status of nodal disease so that an appropriate therapeutic protocol can be designed for an individual case.


Assuntos
Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/secundário , Diagnóstico por Imagem/métodos , Neoplasias de Cabeça e Pescoço/patologia , Aumento da Imagem/métodos , Linfonodos , Adulto , Idoso , Biópsia por Agulha , Meios de Contraste , Feminino , Compostos Férricos , Humanos , Excisão de Linfonodo/métodos , Linfonodos/diagnóstico por imagem , Linfonodos/patologia , Linfonodos/cirurgia , Metástase Linfática , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Pescoço , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Tomografia Computadorizada de Emissão , Tomografia Computadorizada por Raios X
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