SNR - Artigos publicados em revistas indexadas na Pubmed/Medline
Permanent URI for this collection
Browse
Browsing SNR - Artigos publicados em revistas indexadas na Pubmed/Medline by Issue Date
Now showing 1 - 10 of 20
Results Per Page
Sort Options
- [Choroidal type aneurysmal malformation of the vein of Galen associated with Dandy‐Walker malformation in an adult]Publication . Ribeiro, V.; Botelho, L.; Lopes, A.; Ribeiro, P.; Xavier, J.; Teixeira, J.; Cruz, R.A distrofia muscular congénita (DMC) é uma das distrofias mais frequentes da infância, caracterizada por fraqueza muscular neonatal, com ou sem envolvimento do Sistema Nervoso central (SNC). As DMCs foram classificadas em cinco tipos clínicos diferentes: as duas formas de DMC clássica, com e sem défice da cadeia a2- laminina da merosina, causada por mutações do gene no cromossoma 6q2, a DMC de Fukuyama (forma clinicamente severa, inicialmente descrita em Japoneses e ligada ao cromossoma 9q31-33), a síndrome Walker-Warburg e a Doença músculoolhos- cérebro, descrita em doentes Finlandeses. A maioria destas formas tem envolvimento clínico e imagiológico severo do SNC. Este aspecto, raramente é observado na DMC clássica, particularmente na forma merosina positiva. Descrevemos o caso de uma doente de 28 anos, com sinais clínicos e histopatológicos de DMC clássica, não deficiente em merosina (merosina positiva). Não tem atraso mental, mas apresenta epilepsia. A RM revela, nas ponderações de TR longo, hipersinal difuso e simétrico da substância branca de ambos os hemisférios cerebrais, atingindo também o corpo caloso, braços posteriores das cápsulas internas e a via piramidal até ao mesencéfalo. O sinal dos gânglios da base é também anormal, observando-se hipersinal difuso e simétrico dos corpos estriados, sobretudo da cabeça dos núcleos caudados. Associa-se displasia cortical occipital posterior bilateral. Este padrão imagiológico poderá corresponder a um novo subtipo de DMC, híbrido entre a DMC clássica e as formas graves, embora não se saiba qual o seu lugar no espectro. Além disso, o nosso caso relembra o possível envolvimento do SNC em doentes merosinapositivos, pelo que sugerimos a realização de RM a todos os doentes com DMC não deficientes em merosina.
- [Merosin‐positive congenital muscular dystrophy, white matter abnormalities, and bilateral posterior occipital cortical dysplasia]Publication . Ribeiro, V.; Moreira, N.; Teixeira, J.; Guimarães, A.; Cruz, R.; Lima, L.A distrofia muscular congénita (DMC) é uma das distrofias mais frequentes da infância, caracterizada por fraqueza muscular neonatal, com ou sem envolvimento do Sistema Nervoso central (SNC). As DMCs foram classificadas em cinco tipos clínicos diferentes: as duas formas de DMC clássica, com e sem défice da cadeia a2- laminina da merosina, causada por mutações do gene no cromossoma 6q2, a DMC de Fukuyama (forma clinicamente severa, inicialmente descrita em Japoneses e ligada ao cromossoma 9q31-33), a síndrome Walker-Warburg e a Doença músculoolhos- cérebro, descrita em doentes Finlandeses. A maioria destas formas tem envolvimento clínico e imagiológico severo do SNC. Este aspecto, raramente é observado na DMC clássica, particularmente na forma merosina positiva. Descrevemos o caso de uma doente de 28 anos, com sinais clínicos e histopatológicos de DMC clássica, não deficiente em merosina (merosina positiva). Não tem atraso mental, mas apresenta epilepsia. A RM revela, nas ponderações de TR longo, hipersinal difuso e simétrico da substância branca de ambos os hemisférios cerebrais, atingindo também o corpo caloso, braços posteriores das cápsulas internas e a via piramidal até ao mesencéfalo. O sinal dos gânglios da base é também anormal, observando-se hipersinal difuso e simétrico dos corpos estriados, sobretudo da cabeça dos núcleos caudados. Associa-se displasia cortical occipital posterior bilateral. Este padrão imagiológico poderá corresponder a um novo Congenital muscular dystrophy merosin positive, white-matter abnormalities and bilateral occipital cortical dysplasia Congenital muscular dystrophy (CMD) is one of the most frequent dystrophies of childhood, which is commonly characterized by neonatal muscle impairment with or without clinical evidence of central nervous system involvement. CMDs were classified into five clinically distinct forms: the two classical CMDs with and without deficit of the a2 laminin chain (merosin) caused by mutations on chromosome 6q2, the Fukuyama CMD (severe form, initialy described in Japanese patients and recently linked to the chromosome 9q31-33), Walker-Warburg syndrome and the muscle-eyebrain disease described in Finnish patients. The majoraty of these forms have severe clinical and imagiological involvement of SNC. This aspect is rarely observed on classical CMD, particularly in the merosin-positive form. We descrive a case of a 28 year-old woman, with clinical and histopathological signs of classical CMD merosin-positive (no deficient), without mental retardation, but with epilepsy. MRI T2 weighted images, revealed diffuse and simetrical high signal white matter of both cerebral hemispheres, affecting corpos calosum, posterior arms of internal capsules and the piramidal tract to mesencephalon. It also disclosed diffuse and simetrical high signal of basal ganglia, specially, the head of caudate nuclei. These were associated with bilateral occipital posterior cortical dysplasia. The 190 VALENTINA T. RIBEIRO et al subtipo de DMC, híbrido entre a DMC clássica e as formas graves, embora não se saiba qual o seu lugar no espectro. Além disso, o nosso caso relembra o possível envolvimento do SNC em doentes merosinapositivos, pelo que sugerimos a realização de RM a todos os doentes com DMC não deficientes em merosina.
- Enfermedad de Schilder: dos nuevos casosPublication . Garrido, C.; Levy-Gomes, A.; Teixeira, J.; Temudo, T.Summary. Introduction. Schilder’s disease, or diffuse myelinoclastic sclerosis, is an infrequent disease that presents clinically as a pseudotumoural demyelinating lesion, which makes its diagnosis more complicated as it can be mistaken for a tumour or an abscess. Case reports. We examine the case of a male who was healthy up to the age of 8 years, when symptoms of a left hemiparesis appeared with a subacute onset and which were associated to symptoms of intracranial hypertension. A brain CAT scan showed a hypodense lesion in the right temporoparietal region, and the hypothesis of a tumoural lesion (astrocytoma) was suggested. Treatment was started with dexamethasone and furosemide, and a complete regression of the symptoms and a considerable decrease in the cerebral lesion were observed. The second case is that of a female adolescent who, at the age of 11, developed a clinical picture of subacute onset of left hemiplegia. A brain CAT scan revealed hypodense lesions with ring-shaped contrast enhancement. In view of the histological diagnosis of an astrocytoma, radiotherapy and corticotherapy were started. After two months’ treatment, a sharp involution of the lesions was observed, which led to the acceptance of the diagnostic hypothesis of Schilder’s disease. Both children presented recurrence of the lesions three years and nine months, in the first and second case respectively, after the first episode. Treatment with corticoid therapy was started with good clinical and radiological responses. Conclusions. In the presence of a neurological deficit with a subacute onset, associated to a brain image showing a ‘tumoural’ lesion containing an important amount of oedema and little mass effect, diagnoses other than that of a brain tumour must be taken into account. It thus becomes possible to avoid invasive forms of treatment, such as surgical resection, which entail a number of sequelae.
- Thalamic Lesions in Vascular Dementia: Low Sensitivity of Fluid-Attenuated Inversion Recovery (FLAIR) ImagingPublication . Bastos-Leite, A.; Straaten, E.; Scheltens, P.; Lycklama, G.; Barkhof, F.Background and Purpose—The criteria of the National Institute of Neurological Disorders and Stroke (NINDS)– Association Internationale pour la Recherche et l’Enseignement en Neurosciences (AIREN) include thalamic lesions for the diagnosis of vascular dementia (VaD). Although studies concerning VaD and brain aging advocate the use of fluid-attenuated inversion recovery (FLAIR) or T2-weighted images (T2-WI) to detect ischemic lesions, none compared the sensitivity of these sequences to depict thalamic lesions. Methods—We performed a blinded review of T2-WI and FLAIR images in 73 patients fulfilling the radiological part of the NINDS-AIREN criteria (mean age, 71 years; range, 49 to 83 years). This sample was drawn from a large multicenter trial on VaD and was expected to have a high prevalence of thalamic lesions. In a side-by-side review, including T1-weighted images as well, lesions were classified according to presumed underlying pathology. Results—The total number of thalamic lesions was 214. Two hundred eight (97%) were detected on T2-WI, but only 117 (55%) were detected on FLAIR ( 2 5.1; P 0.05). Although the mean size of lesions detected on T2-WI and not on FLAIR (4.4 mm) was significantly lower than the mean size of lesions detected on both sequences (6.7 mm) (P 0.001), 5 of the 29 lesions 10 mm on T2-WI were not visible on FLAIR. FLAIR detected only 81 (51%) of the 158 probable ischemic lesions and 30 (60%) of the 50 probable microbleeds. Conclusions—FLAIR should not be used as the only T2-weighted sequence to detect thalamic lesions in patients suspected of having VaD.
- Infratentorial Abnormalities in Vascular DementiaPublication . Bastos-Leite, A.; Flier, W.; Straaten, E.; Scheltens, P.; Barkhof, F.Background and Purpose—Infratentorial abnormalities may cause cognitive deficits, but current research criteria for vascular dementia (VaD) do not consider them. Our purposes were to determine the prevalence of infratentorial abnormalities in VaD, their relation with supratentorial abnormalities, and whether they are relevant to cognition. Methods—We examined 182 patients (120 men, mean age 73 years, SD 8) with probable VaD at inclusion into a multicenter clinical trial. MRI scans were evaluated for infratentorial vascular abnormalities, midbrain atrophy, cerebellar atrophy, basilar artery diameter and tortuosity, and supratentorial abnormalities. Cognitive testing included the mini–mental state examination (MMSE) and the vascular dementia assessment scale (VaDAS-cog). Results—One hundred forty-one (77.5%) patients had infratentorial abnormalities: 119 (65.4%) had focal infratentorial vascular lesions, 65 (35.7%) had diffuse pontine vascular abnormalities hyperintense on T2-weighted images, 20 (11.0%) had midbrain atrophy, and 16 (8.8%) had cerebellar atrophy. Significant correlations were found between number of infratentorial vascular lesions and basilar artery diameter (rs 0.26; P 0.0001), infratentorial and basal ganglia (including thalamus) vascular abnormalities (rs 0.30; P 0.0001), as well as between midbrain atrophy and global supratentorial atrophy (rs 0.27; P 0.0001). Infratentorial vascular abnormalities and cerebellar atrophy were not significantly associated with cognitive impairment. Patients with midbrain atrophy performed worse on cognitive tests than those without midbrain atrophy. After correction for sex, age, education, supratentorial abnormalities, and center, midbrain atrophy remained significantly associated with lower MMSE scores (P 0.05). Conclusions—Infratentorial abnormalities often occur in patients with VaD, but only midbrain atrophy was found to be relevant to cognition
- Wernicke Encephalopathy: the importance of the diagnosisPublication . Ramos, C.G.; Pereira, C.Acta Med Port. 2006 Nov-Dec;19(6):442-5. Epub 2007 May 14. [Wernicke Encephalopathy: the importance of the diagnosis] [Article in Portuguese] Ramos CG, Pereira C. Serviço de Neurorradiologia, Hospital Geral Santo António, Porto, Portugal. Abstract Wernicke Encephalopathy (WE) is a severe neurological disease caused by vitamin B1 (thiamine) deficiency, which is potentially treatable if early diagnosed. This is the clinical case of a young female patient, with renal insufficiency on haemodialysis, who has been submitted to an abdominal surgery. After the intervention, there were difficulties on beginning with enteric nutrition. Some days later she developed gait imbalance. A Brain Magnetic Resonance (MR) was performed and disclosed abnormalities suggestive of WE. After treatment with thiamine, the patient became asymptomatic. Brain MR is crucial for the confirmation of the diagnosis and early detection of WE, as the imagiologic pattern is typical and the clinical diagnosis is frequently difficult to obtain. PMID: 17583600 [PubMed - indexed for MEDLINE]Free Article
- Neuro-Behçet: MR study of a group of patientsPublication . Ramos, C.; Sá, G.; Tedim Cruz, V.; Lopes, A.; Xavier, J.; Cruz, R.Acta Med Port. 2006 Nov-Dec;19(6):494-8. Epub 2007 May 14. [Neuro-Behçet: MR study of a group of patients] [Article in Portuguese] Ramos C, Sá G, Tedim Cruz V, Lopes A, Xavier J, Cruz R. Serviço de Neurorradiologia, Hospital Geral de Santo António, Porto, Portugal. Abstract Behçet's disease is a chronic inflammatory, multisystemic disease of unknown aetiology. Central nervous system involvement occurs in a variable proportion of cases (4 to 49%) and is due to intracranial hypertension secondary to dural sinus thrombosis, inflammatory parenquimal lesions or recurrent meningoencephalitis. We reviewed 12 patients, 7 men and 5 women, aged between 27 to 40 years at the time of diagnosis. Neurological manifestations were secondary to parenquimal lesions in 7 patients, meningoencephalitis in 3 patients (including one with extensive medullary lesion) and dural sinus thrombosis in 2. Magnetic Resonance (MR) findings in Neuro-Behçet are non-specific. Nevertheless, MR has a role in characterizing brain lesions topography, helping in the diagnosis and in the follow-up of these patients. PMID: 17583610 [PubMed - indexed for MEDLINE]Free Article
- A case of haemophagocytic syndrome presenting with oculogyric crisesPublication . Taipa, R.; Moreira, B.; França, M.; Maia, L.Haemophagocytic lymphohistiocytosis (HLH), also called haemophagocytic syndrome (HPS), is a rare disorder resulting in abnormal proliferation of histiocytes in tissues and organs, including the CNS. HLH can present as a primary disease or occur as a secondary reactive disease. Clinical features are high fever, splenomegaly, cytopenia of two or more cell lines, hypertriglyceridaemia and haemophagocytosis. CNS involvement varies between 10% and 73%, and clinical manifestations include seizures, decreased sensorium, brainstem symptoms, ataxia or demyelinating peripheral neuropathy.
- Tratamento Suboclusivo por via transvenosa de fístulas arteriovenosas duraisPublication . Pinto, P.; Moreira, B.; Alves, V.; Caixeiro, T.; Stocker, A.; Cruz, R.; Xavier, J.Introdução: As fístulas arteriovenosas durais (FAVd) são usualmente adquiridas e quando apresentam drenagem venosa cortical estão associadas a um risco elevado de hemorragia. Podem ser tratadas por embolização (transarterial ou transvenosa), cirurgicamente ou pela combinação das duas técnicas. A embolização por via transvenosa induz uma trombose iatrogénica do seio venoso, acarretando risco de enfarte venoso e/ou hemorragia. Objectivo: Rever os casos de FAVd do seio lateral submetidas a embolização transvenosa. O nosso principal objectivo é avaliar a eficácia e a morbilidade deste tipo de tratamento e o segundo é discutir as possíveis vantagens de uma abordagem suboclusiva na primeira sessão de tratamento. Resultados: Os autores apresentam seis casos clínicos de FAVd, cujas formas de apresentação foram: diminuição da acuidade visual (3); sopro pulsátil no ouvido (3); cefaleias (2); hemorragia subaracnoideia (1); hipoacusia subjectiva (1); edema da papila (1); défice motor (1). Angiograficamente: Cognard IIa (3), IIab (2) e IV (1), todas com envolvimento dos seios laterais. As principais aferências eram: ACE ipsilateral (6); ACI ipsilateral (6); AV ipsilateral (6); ACE contralateral (5); AV contralateral (5); ACI contralateral (3); ACP ipsilateral (1). O tratamento inicial foi sempre a abordagem transarterial, com resultados angiográficos aceitáveis, embora transitórios. Posteriormente optou-se pela via transvenosa com preenchimento do seio lateral com GDC coils. Em cinco dos doentes decidiu-se pela suboclusão, com persistência de algumas aferências. Em quatro, a angiografia subsequente demonstrou trombose “espontânea” do seio lateral com resolução clínica e angiográfica da doença. Num deles a trombose ocorreu ainda durante a sessão inicial. Todos os procedimentos decorreram sem complicações e nenhum dos doentes desenvolveu novos défices neurológicos focais. Conclusões: A abordagem transvenosa das FAVd obteve um sucesso técnico e clínico assinalável, sem presença de complicações. Pensamos que a suboclusão do seio venoso com coils poderá induzir menor alteração hemodinâmica aguda, possibilitando uma trombose mais lenta, diminuindo o risco de complicações, mas com resolução angiográfica ulterior da FAVd.
- Arterial Spin Labeling: Experiência Inicial, Indicações Clínicas e DificuldadesPublication . Carneiro, A.; Pina, S.; Moreira, B.RESUMO O arterial spin labeling (ASL) é uma técnica de perfusão por ressonância magnética (RM) que usa os protões das moléculas de água do sangue arterial como marcador endógeno. As suas principais vantagens residem no facto de ser um método não invasivo, rápido e que dispensa a administração de contraste. Actualmente os seus resultados são reprodutíveis de modo robusto, o que o torna uma ferramenta cada vez mais utilizada na prática clínica. O objectivo deste trabalho é apresentar a nossa experiência inicial com o ASL, salientando os aspectos técnicos, as principais solicitações clínicas, os resultados obtidos e as dificuldades experimentadas. Métodos: Foi efectuada uma revisão dos exames realizados durante um período de oito meses, usando uma técnica de ASL pulsado, num aparelho de 3T. A avaliação dos mapas de perfusão foi realizada de modo qualitativo. Resultados: As principais indicações clínicas para a realização de ASL foram epilepsia, doenças neuro-degenerativas e tumores intra-parenquimatosos. Embora o ASL não tenha sido, em nenhum dos casos, a principal ferramenta diagnóstica, contribuiu, por vezes, com dados fisiológicos importantes para o diagnóstico e para a orientação terapêutica. Salientam-se os casos de doentes com múltiplas crises epilépticas nos quais foi possível identificar focos de hiperperfusão pós-ictal (cujos resultados foram concordantes com o SPECT). Destacam-se ainda casos de doenças neuro-degenerativas nos quais o ASL identificou áreas de hipoperfusão típicas das respectivas entidades nosológicas. As principais dificuldades estiveram relacionadas com o carácter qualitativo da avaliação e com a valorização clínica dos achados. Conclusão: O estudo da perfusão cerebral por ASL tem um potencial diagnóstico importante. Com este trabalho mostramos que, com uma aquisição rápida e pós-processamento simples, pode facilmente integrar os estudos de RM de rotina. Abstract Arterial spin labelling (ASL) is a MR perfusion technique that uses protons from water molecules of the arterial blood as an endogenous tracer. It is fast, non-invasive and does not require gadolinium administration. Due to the increasing robustness of the results, it is becoming an important clinical tool. In this article we present our initial experience with ASL, highlighting some technical aspects, the main clinical applications, some achieved results and most important difficulties. Methods: Review of the examinations performed during eight months, using a pulsating ASL technique in a 3T machine. Perfusion maps were evaluated qualitatively. Results: The most frequent clinical applications were epilepsy, neurodegenerative disorders and tumours. Although perfusion data from ASL had never been crucial for diagnosis, it still provided substantial information. We highlight two epileptic patients who had had recent seizures, in which ASL depicted distinct post-ictal hyperperfusion areas (with the results being confirmed by SPECT studies). The impact was also remarkable in patients with neurodegenerative disorders in which ASL depicted hypoperfusion areas, typical of each nosological entity. The main difficulties were related to the lack of quantitative evaluation and to the clinical interpretation of the results obtained. Conclusion: ASL perfusion studies have a great potential in several clinical conditions. In this article we show that, with a fast acquisition and easy post-processing, it can integrate routine MRI examinations.