Clinical features and stroke etiology in 10 patients with bilateral middle cerebellar peduncle infarctions: a preliminary study / 中华神经科杂志

Objective:To characterize clinical and neuroimaging features, etiologies, and mechanisms of bilateral middle cerebellar peduncle (MCP) infarctions.Methods:Consecutive patients with bilateral MCP infarctions treated in the Beijing Tiantan Hospital, Capital Medical University between January 1, 2020 and April 30, 2022 were enrolled in this retrospective study. The demographic data, vascular risk factors, clincial manifestations and the National Institutes of Health Stroke Scale (NIHSS) scores were collected. Brain diffusion-weighted imaging was used to assess the regions of cerebral infarction, and the extracranial and intracranial segments of the vertebrobasilar artery were evaluated using magnetic resonance angiography, or computed tomography angiography. The stroke etiology and underlying mechanism were evaluated according to the Chinese Ischemic Stroke Subclassification.Results:Ten patients with bilateral MCP infarctions (8 men and 2 women) were analyzed ultimately. The onset age were 51.0-86.0 (64.8±11.4) years. NIHSS scores were 2.0-12.0 (4.9±2.9) points at admission. All patients had vascular risk factors, most of which were hypertension (10 cases) and dyslipoproteinemia (8 cases). The most common clinical manifestations were vertigo (10 cases), followed by ataxia (9 cases) and dysarthria (8 cases). Four cases were isolated bilateral MCP infarctions, while 6 patients were combined with other vertebrobasilar artery infarctions, 4 of which were combined with cerebellar hemisphere infarctions, consistent with the clinical symptoms. The etiology in all patients was large atherosclerosis (severe stenosis or occlusion of V4 segment of vertebral artery and anterior inferior cerebellar artery; 9 cases). Five patients were classified as hypoperfusion/impaired emboli clearance, while 4 patients were considered as artery-to-artery embolism, and 1 was considered as the parent artery (plaque or thrombosis) occluding penetrating artery.Conclusions:Bilateral MCP infarctions are an extremely rare cerebrovascular disease characterized by vertigo, ataxia, and dysarthria. Cerebral infarction can be isolated or often combined with cerebellar hemisphere infarction. The etiology was mostly stenosis or occlusion of V4 segment of vertebral artery and anterior inferior cerebellar artery.

Transaxonal degenerations of cerebellar connections: the value of anatomical knowledge / Degenerações transaxonais das conexões cerebelares: o valor do conhecimento anatômico

ABSTRACT Transaxonal degenerations result from neuronal death or the interruption of synaptic connections among neuronal structures. These degenerations are not common but may be recognized by conventional magnetic resonance imaging. Objective: The learning objectives of this review include recognition of the imaging characteristics of transaxonal degenerations involving cerebellar connections, the identification of potential encephalic lesions that can lead to these degenerations and correlation of the clinical manifestations with imaging findings that reflect this involvement. Methods: In this report, we review the neuroanatomical knowledge that provides a basis for identifying potential lesions that can result in these degenerations involving cerebellar structures. Results: Hypertrophic olivary degeneration results from an injury that interrupts any of the components of the Guillain-Mollaret triangle. In this work, we describe cases of lesions in the dentate nucleus and central tegmental tract. The crossed cerebellar diaschisis presents specific imaging findings and clinical correlations associated with its acute and chronic phases. The Wallerian degeneration of the middle cerebellar peduncle is illustrated by fiber injury of the pontine cerebellar tracts. A T2-hyperintensity in the dentate nucleus due to a thalamic acute lesion (in ventral lateral nuclei) is also described. Each condition described here is documented by MRI images and is accompanied by teaching points and an anatomical review of the pathways involved. Conclusion: Neurologists and radiologists need to become familiar with the diagnosis of these conditions since their presentations are peculiar and often subtle, and can easily be misdiagnosed as ischemic events, degenerative disease, demyelinating disease or even tumors.

RESUMO Degenerações transaxonais resultam da morte neuronal ou da interrupção de conexões sinápticas entre estruturas neurais. Essas degenerações não são comuns, mas podem ser reconhecidas por imagens de ressonância magnética convencional. Objetivo: Os objetivos de aprendizado desta revisão incluem o reconhecimento das características de imagem de degenerações transaxonais envolvendo conexões cerebelares, a identificação de possíveis lesões encefálicas que podem levar a essas degenerações e a correlação das manifestações clínicas com os achados de imagem que refletem esse envolvimento. Métodos: Neste artigo, revisamos conhecimentos neuroanatômicos que fornecem a base para identificar possíveis lesões que podem resultar nessas degenerações envolvendo estruturas cerebelares. Resultados: A degeneração olivar hipertrófica resulta de uma lesão que interrompe algum dos componentes do triângulo de Guillain-Mollaret. Neste trabalho, descrevemos casos de lesões no núcleo denteado e no trato tegmentar central. A diásquise cerebelar cruzada apresenta achados de imagem específicos e correlações clínicas associadas às suas fases aguda e crônica. A degeneração walleriana dos pedúnculos cerebelares médios é ilustrada pela lesão dos tratos pontino-cerebelares. Uma hiperintensidade em T2 do núcleo denteado devido a uma lesão talâmica aguda (no núcleo ventrolateral) também é descrita. Cada condição aqui descrita é documentada por imagens de ressonância magnética e é acompanhada por pontos didáticos e uma revisão anatômica das vias envolvidas. Conclusão: Neurologistas e radiologistas precisam estar familiarizados com o diagnóstico dessas condições, uma vez que suas apresentações são peculiares e frequentemente sutis, e podem ser facilmente equivocadamente diagnosticadas como lesões isquêmicas, doenças degenerativas, desmielinizantes, ou mesmo tumorais.

Primary infratentorial diffuse large b-cell lymphoma: a challenging diagnosis in an immunocompetent patient

SUMMARY We describe the case of a female patient, 52 years old, with dizziness and left motor incoordination for 2 weeks. Brain MRI magnetic resonance imaging) revealed a hyperintense lesion on T2-weighted images, without restricted diffusion, in the left middle cerebellar peduncle. Spectroscopy demonstrated peak of lipids and perfusion did not show any elevation in relative cerebral blood volume (rCBV). The patient underwent an open biopsy and resection, and the diagnosis of diffuse large B-cell lymphoma (DLBCL) was established. The patient received intravenous dexamethasone with symptoms remission, followed by four cycles of methotrexate plus cytarabine. After 3 months, the patient returned with decreased consciences level and a new MRI revealed a right superior frontal gyrus lesion with features suggesting a lymphomatous lesion. The patient died five days after her relapse.

RESUMO Descrevemos o caso de uma paciente do sexo feminino, de 52 anos, apresentando história de tontura e perda da coordenação motora do lado esquerdo há duas semanas. A RM (ressonância magnética) de crânio revelou uma lesão hiperintensa nas imagens ponderadas em T2, sem restrição à difusão, localizada no pedúnculo cerebelar médio esquerdo. A espectroscopia demonstrou pico de lipídeos, sem elevação do volume sanguíneo cerebral relativo (rCBV) à perfusão. A paciente foi submetida à biópsia a céu aberto, estabelecendo o diagnóstico de linfoma difuso de grandes células B (DLBCL). Houve remissão dos sintomas após o início do tratamento com dexametasona endovenosa, seguida de quatro ciclos de metotrexato associado à citarabina. Após três meses, a paciente retornou apresentando rebaixamento do nível de consciência, e a RM de crânio revelou uma nova lesão de origem linfomatosa no giro frontal superior direito. A paciente faleceu após cinco dias.

Increased Signal in the Superior Cerebellar Peduncle of Patients with Progressive Supranuclear Palsy

OBJECTIVE: The provisional diagnosis of progressive supranuclear palsy (PSP) depends on a combination of typical clinical features and specific MRI findings, such as atrophy of the tegmentum in the midbrain. Atrophy of the superior cerebellar peduncle (SCP) distinguishes PSP from other types of parkinsonism. Histological factors affect the conventional fluid-attenuated inversion recovery (FLAIR) signals, such as the extent of neuronal loss and gliosis. METHODS: We investigated patients with PSP to verify the percentage of patients with various PSP phenotypes presenting a high signal intensity in the SCP. Three interviewers, who were not informed about the clinical data, visually inspected the presence or absence of a high signal intensity in the SCP on the FLAIR images. We measured the pixel value in the SCP of each patient. Clinical characteristics were evaluated using the Mann-Whitney test, followed by the χ² test. RESULTS: Ten of the 51 patients with PSP showed a high signal intensity in the SCP on FLAIR MRI. Higher pixel values were observed within the SCP of patients with a high signal intensity in the SCP than in patients without a high signal intensity (p < 0.001). The sensitivity and specificity of the high signal intensity in the SCP of patients with PSP was 19.6% and 100%, respectively. This finding was more frequently observed in patients with PSP with Richardson's syndrome (PSP-RS) (25.7%) than other phenotypes (6.2%). CONCLUSION: The high signal intensity in the SCP on FLAIR MRI might be an effective diagnostic tool for PSP-RS.

Appearances of decussation of superior cerebellar peduncle in DTT FACT with different reconstruct parameters / 中国医学影像技术

Objective To observe the appearances of decussation of superior cerebellar peduncle (SCP) on MR diffusion tensor imaging (DTI) with different parameters of scanning and reconstruction. Methods Twenty healthy volunteers were examined on Siemens 3.0T MR DTI (b=0, 1000 s/mm~2), post processing were made in Siemens Leonardo workstation using Siemens Standar 6 dirs software to reconstruct the white matter fibers with different fractional anisotropy (FA) threshold value (0.04-0.20), angle threshold value (20°-89°) and voxel size (1.2 mm×1.2 mm×3.0 mm-1.6 mm×1.6 mm×5.0 mm). Results Crossing fiber was presented each voxel group on diffusion tensor tractography (DTT). The types of crossing fiber in the small voxel were more than those of big voxel image obviously. Reduced along with the FA threshold value, the number of crossing fiber increased gradually. After the peak value (FA=0.08), the number of crossing fiber reduced along with the FA threshold value reduced gradually. Increased along with the angle threshold value, the number of crossing fiber increased gradually. The number of crossing fiber reduced along with the angle threshold value increased gradually after the peak value (the angle threshold value＝80°). There were 5 kinds of MR fiber tracking appearances at the level of decussation of SCP on DTT. The fiber crossed to the opposited red nucleus in anterior-posterior style, superior-inferior style and single main bundle fiber. Kissing fiber and missing fiber sign was shouw in all subjects, which mainly located in the center of the decussation. Conclusion DTT FACT can show the descussation of SCP in most health subjects with five typical appearance. The descussation of SCP has the obvious appearances, may be causing by individual difference. For the crossing fiber of SCP, voxel size 1.2 mm×1.2 mm×3.0 mm, FA 0.08 and the angle 80° are recommended.

Asymptomatic Extrapontine Myelinolysis in Diabetic Woman

Osmotic myelinolysis syndrome in central nervous system is classified into central pontine myelinolysis(CPM) and extrapontine myelinolysis(EPM). The former can cause a spastic quadriplegia, pseudobulbar palsy, and varying degree of mental disorder, but the latter a movement disorder(tremor, dystonia, parkinsonism, and chorea, etc), behavior change(mood instability, personality change, agitated delirium, and disinhibition, etc), and cognitive dysfunction. Although a few cases of asymptomatic CPM have been reported, asymptomatic EPM were rare. A 67-year-old woman with diabetes mellitus and old cerebral infarction has suffered from the common bile duct stone. She had hyponatremia(Na=126mEq/L) on admission and was corrected rapidly. Incidental findings of her brain MRI showed EPM. We experienced a case of bilateral middle cerebellar peduncle myelinolysis incidentally without neurological presentations and report a rare case of asymptomatic EPM recoverd in diabetic woman after rapid correction of hyponatremia.