Objective
Machado–Joseph disease (SCA3/MJD) is the most frequent spinocerebellar ataxia worldwide and characterized by brainstem, basal ganglia, and cerebellar damage. However, little is known about ...the natural history of the disease. This motivated us to determine the extension and progression of central nervous system involvement in SCA3/MJD using multimodal magnetic resonance imaging (MRI)‐based analyses in a large cohort of patients (n = 79) and presymptomatic subjects (n = 12).
Methods
All subjects underwent MRI in a 3T device to assess gray and white matter. To evaluate the cerebral and cerebellar cortices, we used measures from FreeSurfer and SUIT. T1‐multiatlas assessed deep gray matter. Diffusion tensor imaging multiatlas was used to investigate cerebral white matter (WM) and SpineSeg to assess the cervical spinal cord.
Results
There was widespread WM and cerebellar damage, in contrast to the restricted motor cortex involvement when all patients are compared to age‐ and sex‐matched controls. Presymtomatic patients showed WM microstructural abnormalities mainly in the cerebellar and cerebral peduncles and volumetric reduction of midbrain, spinal cord, and substantia nigra. To assess the disease progression, we divided patients into four subgroups defined by time from ataxia onset. There was a clear pattern of evolving structural compromise, starting in infratentorial structures and progressing up to the cerebral cortex.
Conclusion
Structural damage in SCA3/MJD begins in the spinal cord, cerebellar peduncles, as well as substantia nigra and progresses to cerebral areas in the long term. These structural differences reveal some insights into the pathogenesis of SCA3/MJD and suggest a staging scheme to map the progression of the disease. Ann Neurol 2018;84:401–408
Autoimmune encephalitis (AIE) is one of the most common causes of noninfectious encephalitis. It can be triggered by tumors, infections, or it may be cryptogenic. The neurological manifestations can ...be either acute or subacute and usually develop within six weeks. There are a variety of clinical manifestations including behavioral and psychiatric symptoms, autonomic disturbances, movement disorders, and seizures. We reviewed common forms of AIE and discuss their diagnostic approach and treatment.
ABSTRACT
Background:
As the COVID-19 pandemic unfolds worldwide, different forms of reports have described its neurologic manifestations.
Objective:
To review the literature on neurological ...complications of SARS-CoV-2 infection.
Methods:
Literature search performed following systematic reviews guidelines, using specific keywords based on the COVID-19 neurological complications described up to May 10
th
, 2020.
Results:
A total of 43 articles were selected, including data ranging from common, non-specific symptoms, such as hyposmia and myalgia, to more complex and life-threatening conditions, such as cerebrovascular diseases, encephalopathies, and Guillain-Barré syndrome.
Conclusion:
Recognition of neurological manifestations of SARS-CoV-2 should be emphasized despite the obvious challenges faced by clinicians caring for critical patients who are often sedated and presenting other concurrent systemic complications.
ABSTRACT
Professor Ângelo Barbosa Monteiro Machado (May 22, 1934 to April 6, 2020) was one of the most outstanding and respected professors in the Brazilian history. He worked broadly as a professor, ...neuroscientist, writer, dramaturgist, neurobiologist, and entomologist. The publication of the neuroanatomy book is pioneer, revolutionary, and iconic in the history of academic medical education in Brazil. In the literature field, he also wrote many books in which he adapted scientific knowledge to children. In this article, the authors approach the academic life of Professor Ângelo Machado and the steps that culminated in the most renowned Brazilian textbook of neuroanatomy:
Neuroanatomia Funcional
.
Hereditary spastic paraplegias (HSP) are a large group of genetic diseases characterized by progressive degeneration of the long tracts of the spinal cord, namely the corticospinal tracts and dorsal ...columns. Genotypic and phenotypic heterogeneity is a hallmark of this group of diseases, which makes proper diagnosis and management often challenging. In this scenario, magnetic resonance imaging (MRI) emerges as a valuable tool to assist in the exclusion of mimicking disorders and in the detailed phenotypic characterization. Some neuroradiological signs have been reported in specific subtypes of HSP and are therefore helpful to guide genetic testing/interpretation. In addition, advanced MRI techniques enable detection of subtle structural abnormalities not visible on routine scans in the spinal cord and brain of subjects with HSP. In particular, quantitative spinal cord morphometry and diffusion tensor imaging look promising tools to uncover the pathophysiology and to track progression of these diseases. In the current review article, we discuss the current use and future perspectives of MRI in the context of HSP.
Abstract
Establishing the definitive diagnosis of a neurogenetic disease is usually a complex task. However, like any type of clinical diagnostic reasoning, an organized process of development and ...consideration of diagnostic hypotheses may guide neurologists and medical geneticists to solve this difficult task. The aim of the present review is to propose a general method for diagnostic reasoning in neurogenetics, with the definition of the main neurological syndrome and its associated topographical diagnosis, followed by the identification of major and secondary neurological syndromes, extraneurological findings, and inheritance pattern. We also discuss general rules and knowledge requirements of the ordering physician to request genetic testing and information on how to interpret genetic variants in a genetic report. By guiding the requests for genetic testing according to an organized model of diagnostic reasoning and with the availability of specific treatments, clinicians may find greater resoluteness and efficacy in the diagnostic investigation, shortening the struggle of patients for a definitive diagnosis.
A biallelic pentanucleotide expansion in the
gene has been reported to be a common cause of late-onset ataxia. In the general population, four different repeat conformations are observed: wild type ...sequence AAAAG (11 repeats) and longer expansions of either AAAAG, AAAGG or AAGGG sequences. However only the biallelic AAGGG expansions were reported to cause late-onset ataxia. In this study, we aimed to assess the prevalence and nature of
repeat expansions in three cohorts of adult-onset ataxia cases: Brazilian (n = 23) and Canadian (n = 26) cases that are negative for the presence of variants in other known ataxia-associated genes, as well as a cohort of randomly selected Canadian cases (n = 128) without regard to a genetic diagnosis. We identified the biallelic AAGGG expansion in only one Brazilian family which presented two affected siblings, and in one Canadian case. We also observed two new repeat conformations, AAGAG and AGAGG, which suggests the pentanucleotide expansion sequence has a dynamic nature. To assess the frequency of these new repeat conformations in the general population, we screened 163 healthy individuals and observed the AAGAG expansion to be more frequent in cases than in control individuals. While additional studies will be necessary to asses the pathogenic impact of biallelic genotypes that include the novel expanded conformations, their occurrence should nonetheless be examined in future studies.
A brief history of the syndrome discovered by Andreas Rett is reported in this paper.
Although having been described in 1966, the syndrome was only recognized by the international community after a ...report by Hagberg et al. in 1983. Soon, its importance was evident as a relatively frequent cause of severe encephalopathy among girls.
From the beginning it was difficult to explain the absence of male patients and the almost total predominance of sporadic cases (99%), with very few familial cases. For these reasons, it was particularly difficult to investigate this condition until 1997, when a particular Brazilian family greatly helped in the final discovery of the gene, and in the clarification of its genetic mechanism.
Brief references are made to the importance of the MECP2 gene, 18 years later, as well as to its role in synaptogenesis and future prospects.
A 64-year-old man presented with involuntary oromandibular movements since the start of the COVID-19 pandemics. Whenever the patient has worn a mask, he started the abnormal movements of the jaw, ...that promptly improved when he took off the mask. The patient was unaware of the movements and did not feel any urge to perform them, no tongue movement was observed, and there were no other relieving maneuvers. Apart from the oromandibular dyskinesia (OMD), neurological examination was normal. Surgical mask-induced dyskinesia phenomenology is uncertain, and somewhat similar to task-induced dystonia, a focal, isolated disorder that occurs only with specific actions. Although, it is thought to be choreic rather than dystonic, since the patients are not self-aware of the phenomenon. Absence of use of antipsychotics and the exacerbation with sensory input help distinguishing from other forms of OMD.
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