Acurácia de fasciculações musculares para o diagnóstico de formas tardias de atrofia muscular espinhal 5q

Introdução A AME-5q é uma doença genética de herança autossômica recessiva causada por variantes patogênicas no gene SMN1. A presença de fasciculações parece ajudar na diferenciação da AME (especialmente em suas formas tardias) de seus diagnósticos diferenciais. Apesar disso, a frequência de fasciculações em pacientes com AME nunca foi estudada de maneira sistemática. Objetivo: Este estudo visou determinar a acurácia diagnóstica de fasciculações na língua para diagnóstico de AME tipos II e III em paciente com fraqueza muscular simétrica proximal sem herança autossômica dominante. Métodos: realizou-se um estudo transversal de acurácia diagnóstica em que 19 indivíduos (10 com AME e 9 com diagnóstico de outras doenças genéticas musculares) foram avaliados quanto a presença de fasciculações pelo exame clínico e pela ultrassonografia muscular, 11 indivíduos (5 com AME e 6 com outras doenças musculares) foram avaliados também com eletromiografia. O exame físico e ultrassom foram gravados a avaliados por avaliadores externos. Resultados: Dos 10 pacientes com AME, 5 eram do tipo II e 5 do tipo III; dos pacientes do grupo controle, 6 possuem diagnóstico de distrofia de cinturas, 1 com mutação do gene COL6A1, 1 com diagnóstico de miopatia nemalínica e 2 sem diagnóstico molecular definido (mas com biópsia compatível com distrofia muscular). O intraclass correlation coeficient (ICC) para o exame físico foi de 0,59 (p < 0,0001), e para a ultrassonografia muscular de 0,8 (p < 0.0001). A presença de fasciculações em mais de um grupo muscular foi percebida em todos os pacientes com AME e um paciente do grupo controle (p=0,001 – teste exato de Fisher); o valor de sensibilidade foi de 100%(IC 95% 69-100), especificidade de 89% (IC 95% 52-100%), valor preditivo positivo de 91%(IC 95% 52-100%) e negativo de 100%(IC 95% 63-100). Conclusão: Concluímos que o método empregado, especialmente o uso de exame físico direcionado à busca de fasciculações seguido da ultrassonografia muscular, também direcionada, tem grande sensibilidade e especificidade para diagnóstico de formas tardias de AME em cenário de grupo controle não saudável. Houve moderada correlação para o achado de exame físico pelo método empregado (gravação de vídeo) e correlação boa a excelente para ultrassonografia. Trabalhos adicionais com amostras maiores são encorajados para redução do intervalo de confiança dos dados que obtivemos.Background: SMA-5q is a genetic disease of autosomal recessive inheritance caused by pathogenic variants in the SMN1 gene. The presence of fasciculations seems to help differentiate SMA (especially in its late forms) from its differential diagnoses. Despite this, the frequency of fasciculations in patients with SMA has never been studied in a systematic way. Objective: This study aimed to determine the diagnostic accuracy of tongue fasciculations for the diagnosis of SMA types II and III in a patient with proximal symmetric muscle weakness without autosomal dominant inheritance. Methods: a cross-sectional diagnostic accuracy study was conducted in which 19 individuals (10 with SMA and 9 with a diagnosis of other genetic muscle diseases) were assessed for the presence of fasciculations by clinical examination and muscle ultrasound, individuals (5 with EBF and 6 with other muscle diseases) were also evaluated with electromyography. The physical examination and ultrasound were recorded and evaluated by external evaluators. Results: Of the 10 patients with SMA, 5 were type 2 and 5 were type 3; of the patients in the control group, 6 had a diagnosis of waist dystrophy, 1 with a COL6A1 gene mutation, 1 with a diagnosis of nemaline myopathy and 2 without a defined molecular diagnosis (but with a biopsy compatible with muscular dystrophy). The intraclass correlation coefficient (ICC) for physical examination was 0.59 (p <0.0001), and for muscle ultrasonography 0.8 (p <0.0001). The presence of fasciculations in more than one muscle group was noticed in all patients with SMA and one patient in the control group (p = 0.001 - Fisher's exact test); the sensitivity value was 100% (95% CI 69-100), 89% specificity (95% CI 52-100%), a positive predictive value of 91% (95% CI 52-100%) and a negative predictive value of 100 % (95% CI 63-100). Conclusion: We conclude that the method employed, especially the use of physical examination directed at the search for fasciculations followed by muscle ultrasound, also directed, has great sensitivity and specificity for the diagnosis of late forms of SMA in a scenario of unhealthy control group. There was a moderate correlation for the finding of physical examination by the method employed (video recording) and a good to excellent correlation for ultrasound. Additional work with larger samples is encouraged to reduce the confidence interval of the data we obtained

Evoked potentials as biomarkers of hereditary spastic paraplegias : a case-control study

Introduction: The Hereditary Spastic Paraplegias (HSP) are a group of genetic diseases that lead to slow deterioration of locomotion. Clinical scales seem to have low sensitivity in detecting disease progression, making the search for additional biomarkers a paramount task. This study aims to evaluate the role of evoked potentials (EPs) as disease biomarkers of HSPs. Methods: A single center cross-sectional case-control study was performed, in which 18 individuals with genetic diagnosis of HSP and 21 healthy controls were evaluated. Motor evoked potentials (MEP) obtained with transcranial magnetic stimulation and somatosensory evoked potentials (SSEP) were performed in lower (LL) and upper limbs (UL). Results: Central motor conduction time in lower limbs (CMCT-LL) was prolonged in HSP subjects, with marked reductions in MEP-LL amplitudes when compared to the control group (p<0.001 for both comparisons). CMCT-UL was 3.59ms (95% CI: 0.73 to 6.46; p = 0.015) prolonged and MEP-UL amplitudes were reduced (p = 0.008) in the HSP group. SSEP-LL latencies were prolonged in HSP subjects when compared to controls (p<0.001), with no statistically significant differences for upper limbs (p = 0.147). SSEP-UL and SSEP-LL latencies presented moderate to strong correlations with age at onset (Rho = 0.613, p = 0.012) and disease duration (Rho = 0.835, p<0.001), respectively. Similar results were obtained for the SPG4 subgroups of patients. Conclusion: Motor and somatosensory evoked potentials can adequately differentiate HSP individuals from controls. MEP were severely affected in HSP subjects and SSEP-LL latencies were prolonged, with longer latencies being related to more severe disease. Future longitudinal studies should address if SSEP is a sensitive disease progression biomarker for HSP

Pharyngeal-cervical-brachial : a rare variant of the Guillain-Barré syndrome spectrum

A Síndrome de Guillain-Barré (SGB) é uma polineuropatia autolimitada, na maioria das vezes de mecanismo autoimune pós-infeccioso. Este caso tem por objetivo relatar uma variante rara do espectro da SGB. O método utilizado foi o acompanhamento clinico do paciente e revisão de prontuário. Conclui-se que conhecimento acerca da FCB e alto grau de suspeição são importantes para o diagnóstico diferencial de pacientes que apresentam sintomas bulbares e fraqueza de membros superiores, principalmente pela gama de diagnósticos diferenciais que os sintomas podem sugerir