Spontaneous intracranial hypotension (SIH) is a syndrome that was unknown until the advent of magnetic resonance imaging (MRI). It is a cause of orthostatic headache, which remains underdiagnosed and, rarely, can result in several complications including dural venous sinus thrombosis, subdural hematoma and subarachnoid hemorrhage. Some of these complications are potentially life-threatening and should be recognized promptly, mainly by imaging studies. We reviewed the MRI of nine patients with SIH and describe the complications observed in three of these patients. Two of them had subdural hematoma and one had a dural venous sinus thrombosis detected by computed tomography and MRI. We concluded that MRI findings are of great importance in the diagnosis of SIH and its complications, which often influence the clinical-surgical treatment of the patient.

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.

Spinocerebellar ataxias (SCA) are a clinically and genetically heterogeneous group of monogenic diseases that share ataxia and autosomal dominant inheritance as the core features. An important proportion of SCAs are caused by CAG trinucleotide repeat expansions in the coding region of different genes. In addition to genetic heterogeneity, clinical features transcend motor symptoms, including cognitive, electrophysiological and imaging aspects. Despite all the progress in the past 25 years, the mechanisms that determine how neuronal death is mediated by these unstable expansions are still unclear. The aim of this article is to review, from an historical point of view, the first CAG-related ataxia to be genetically described: SCA 1.

Diagnostic imaging techniques play an important role in assessing the exact location, cause, and extent of a nerve lesion, thus allowing clinicians to diagnose and manage more effectively a variety of pathological conditions, such as entrapment syndromes, traumatic injuries, and space-occupying lesions. Ultrasound and nuclear magnetic resonance imaging are becoming useful methods for this purpose, but they still lack spatial resolution. In this regard, recent phase contrast x-ray imaging experiments of peripheral nerve allowed the visualization of each nerve fiber surrounded by its myelin sheath as clearly as optical microscopy. In the present study, we attempted to produce high-resolution x-ray phase contrast images of a human sciatic nerve by using synchrotron radiation propagation-based imaging. The images showed high contrast and high spatial resolution, allowing clear identification of each fascicle structure and surrounding connective tissue. The outstanding result is the detection of such structures by phase contrast x-ray tomography of a thick human sciatic nerve section. This may further enable the identification of diverse pathological patterns, such as Wallerian degeneration, hypertrophic neuropathy, inflammatory infiltration, leprosy neuropathy and amyloid deposits. To the best of our knowledge, this is the first successful phase contrast x-ray imaging experiment of a human peripheral nerve sample. Our long-term goal is to develop peripheral nerve imaging methods that could supersede biopsy procedures.

RESUMO Objetivo Avaliar a inteligibilidade de fala e disartria, correlacionando com a avaliação funcional da ELA. Método Estudo quantitativo-descritivo aprovado pelo CEP, sob nº CAAE 62912416.4.0000.5404, constituído por 19 pessoas com ELA, esporádica ou familiar. Para coleta, aplicou-se o Protocolo de Disartria e Escala de Avaliação Funcional da Esclerose Lateral Amiotrófica (ALSFRS-Re). Para análise, foi utilizada escala visual analógica para inteligibilidade de fala e medidas de resumo e correlação dos instrumentos pelo Coeficiente de Spearman com nível de significância de 5%. Resultados A inteligibilidade de fala está comprometida (41,37±39,73) em graus variados com correlação positiva com o grau geral de disartria (p=<,0001) e com todos os parâmetros de fala analisados, indicando impacto na deterioração da fala do grupo estudado. Há correlação negativa entre inteligibilidade de fala e resultados das seções bulbar – fala e deglutição (p=0,0166), braço – atividades com membro superior (p=0,0064) e perna – atividades com membro inferior (p=0,0391). Os parâmetros de respiração (p=0,0178), fonação (p=0,0334) e ressonância (p=0,0053) apresentaram correlação negativa com o item “fala” do ALSFRS-Re. Conclusão Os achados mostram prejuízo da inteligibilidade de fala e disartria e evidenciam respiração, fonação e ressonância como importantes marcadores da progressão da doença. Uma avaliação criteriosa e precoce da produção motora oral permite melhor gerenciamento das alterações na ELA.