F-waves persistence in peripheral sensory syndromes.

BACKGROUND: The distinction between sensory neuronopathies (SN), which is by definition purely sensory, and sensory polyneuropathies (SP) and sensory multineuropathies (SM) is important for etiologic investigation and prognosis estimation. However, this task is often challenging in clinical practice. We hypothesize that F-wave assessment might be helpful, since it is able to detect subtle signs of motor involvement, which are found in SP and SM, but not in SN. OBJECTIVE: The aim of the present study was to determine whether F-waves are useful to distinguish SN from SP and SM. METHODS: We selected 21 patients with SP (12 diabetes mellitus, 4 transthyretin familial amyloid polyneuropathy, 4 others), 22 with SM (22 leprosy), and 26 with SN (13 immune-mediated, 10 idiopathic, 3 others) according to clinical-electrophysiological-etiological criteria. For every subject, we collected data on height and performed 20 supramaximal distal stimuli in median, ulnar, peroneal, and tibial nerves, bilaterally, to record F-waves. Latencies (minimum and mean) and persistences were compared across groups using the Kruskal-Wallis and Bonferroni tests. P-values < 0.05 were considered significant. RESULTS: All groups were age, gender, and height-matched. Overall, there were no significant between-group differences regarding F-wave latencies. In contrast, F-wave persistence was able to stratify the groups. Peroneal F-wave persistence was higher, bilaterally, in the SN group compared to SM and SP (p < 0.05). In addition, F-waves persistence of the ulnar and tibial nerves was also helpful to separate SN from SP (p < 0.05). CONCLUSION: F-wave persistence of the peroneal nerves might be an additional and useful diagnostic tool to differentiate peripheral sensory syndromes.

ANTECEDENTES: A distinção entre neuronopatias sensitivas (SN) e polineuropatias sensitivas (SP) e multineuropatias sensitivas (SM) é importante para a investigação etiológica e para o prognóstico. Contudo, esta tarefa é desafiadora na prática clínica. Hipotetizou-se que a avaliação das ondas-F pode ser útil, por ser capaz de detectar envolvimento motor nas SP e SM, mas não nas SN. OBJETIVO: Determinar se as ondas-F podem ajudar a distinguir entre SN, SP e SM. MéTODOS: Selecionou-se 21 pacientes com SP (12 diabetes mellitus, 4 ATTR-FAP e 4 com outras neuropatias), 22 com SM (22 hanseníases) e 26 com SN (13 imunomediadas, 10 idiopáticas e 3 com outras neuronopatias), de acordo com critérios clínicos, etiológicos e eletrofisiológicos. Para cada indivíduo, foi aferida a altura e foram aplicados 20 estímulos distais supramáximos nos nervos mediano, ulnar, fibular e tibial, bilateralmente, para registrar as ondas-F. Uma comparação foi feita, por grupo, das latências (mínimas e médias) e persistências pelos testes Kruskal-Wallis e Bonferroni. Valores de p < 0.05 foram considerados estatisticamente significativos. RESULTADOS: Todos os grupos foram pareados por idade, sexo e altura. Não houve diferença estatística significativa entre os grupos quanto às latências das ondas-F. A persistência da onda-F foi capaz de estratificar os grupos, sendo as dos nervos fibulares bilateralmente maiores no grupo SN que nos grupos SM e SP (p < 0.05). Adicionalmente, a persistência das ondas-F dos nervos ulnares e tibiais também foi útil para distinguir SN de SP (p < 0.05). CONCLUSãO: A persistência das ondas-F dos nervos fibulares pode ser uma ferramenta adicional e útil para diferenciar síndromes sensitivas periféricas.

Autonomic function in sporadic and familial ALS type 8.

OBJECTIVE: To characterize and compare autonomic function in patients with sporadic (sALS) and familial ALS type 8 (fALS8). METHODS: We selected 11 patients with sALS (7 men), 14 with fALS8 (8 men) and 26 controls (15 men). All groups were gender and age-matched. For each subject, Scale for Outcomes in Parkinson's Disease for Autonomic Symptoms (SCOPA-AUT) was applied and data from heart rate variability, Quantitative Sudomotor Axon Reflex Test (QSART) and skin sympathetic response (SSR) were collected. These data were compared across groups using nonparametric tests. P-values < 0.05 were considered significant. RESULTS: SCOPA-AUT revealed predominant clinical complaints in thermoregulatory, pupillomotor and sexual domains in fALS8 relative to sALS as well as controls. Neurophysiological tests demonstrated significant differences in Valsalva ratio, Expiratory:Inspiratory index and RR minimum values in both ALS groups relative to controls. Sudomotor dysfunction was also observed in sALS and fALS8 groups, as shown by reduced medial forearm and foot QSART volumes and absence of SSR in lower limbs. CONCLUSIONS: Dysautonomia - cardiac and sudomotor - is part of the phenotype in sALS and fALS8. The profile of autonomic symptoms, however, is different in each group. SIGNIFICANCE: Patients with fALS8 and sALS have autonomic dysfunction involving both sympathetic and parasympathetic divisions.

F-waves persistence in peripheral sensory syndromes / Persistência das ondas-F nas síndromes sensitivas periféricas

Abstract Background The distinction between sensory neuronopathies (SN), which is by definition purely sensory, and sensory polyneuropathies (SP) and sensory multineuropathies (SM) is important for etiologic investigation and prognosis estimation. However, this task is often challenging in clinical practice. We hypothesize that F-wave assessment might be helpful, since it is able to detect subtle signs of motor involvement, which are found in SP and SM, but not in SN. Objective The aim of the present study was to determine whether F-waves are useful to distinguish SN from SP and SM. Methods We selected 21 patients with SP (12 diabetes mellitus, 4 transthyretin familial amyloid polyneuropathy, 4 others), 22 with SM (22 leprosy), and 26 with SN (13 immune-mediated, 10 idiopathic, 3 others) according to clinical-electrophysiological-etiological criteria. For every subject, we collected data on height and performed 20 supramaximal distal stimuli in median, ulnar, peroneal, and tibial nerves, bilaterally, to record F-waves. Latencies (minimum and mean) and persistences were compared across groups using the Kruskal-Wallis and Bonferroni tests. P-values < 0.05 were considered significant. Results All groups were age, gender, and height-matched. Overall, there were no significant between-group differences regarding F-wave latencies. In contrast, F-wave persistence was able to stratify the groups. Peroneal F-wave persistence was higher, bilaterally, in the SN group compared to SM and SP (p < 0.05). In addition, F-waves persistence of the ulnar and tibial nerves was also helpful to separate SN from SP (p < 0.05). Conclusion F-wave persistence of the peroneal nerves might be an additional and useful diagnostic tool to differentiate peripheral sensory syndromes.

Resumo Antecedentes A distinção entre neuronopatias sensitivas (SN) e polineuropatias sensitivas (SP) e multineuropatias sensitivas (SM) é importante para a investigação etiológica e para o prognóstico. Contudo, esta tarefa é desafiadora na prática clínica. Hipotetizou-se que a avaliação das ondas-F pode ser útil, por ser capaz de detectar envolvimento motor nas SP e SM, mas não nas SN. Objetivo Determinar se as ondas-F podem ajudar a distinguir entre SN, SP e SM. Métodos Selecionou-se 21 pacientes com SP (12 diabetes mellitus, 4 ATTR-FAP e 4 com outras neuropatias), 22 com SM (22 hanseníases) e 26 com SN (13 imunomediadas, 10 idiopáticas e 3 com outras neuronopatias), de acordo com critérios clínicos, etiológicos e eletrofisiológicos. Para cada indivíduo, foi aferida a altura e foram aplicados 20 estímulos distais supramáximos nos nervos mediano, ulnar, fibular e tibial, bilateralmente, para registrar as ondas-F. Uma comparação foi feita, por grupo, das latências (mínimas e médias) e persistências pelos testes Kruskal-Wallis e Bonferroni. Valores de p < 0.05 foram considerados estatisticamente significativos. Resultados Todos os grupos foram pareados por idade, sexo e altura. Não houve diferença estatística significativa entre os grupos quanto às latências das ondas-F. A persistência da onda-F foi capaz de estratificar os grupos, sendo as dos nervos fibulares bilateralmente maiores no grupo SN que nos grupos SM e SP (p < 0.05). Adicionalmente, a persistência das ondas-F dos nervos ulnares e tibiais também foi útil para distinguir SN de SP (p < 0.05). Conclusão A persistência das ondas-F dos nervos fibulares pode ser uma ferramenta adicional e útil para diferenciar síndromes sensitivas periféricas.

Update of the Brazilian consensus recommendations on Duchenne muscular dystrophy.

In the last few decades, there have been considerable improvements in the diagnosis and care of Duchenne muscular dystrophy (DMD), the most common childhood muscular dystrophy. International guidelines have been published and recently reviewed. A group of Brazilian experts has developed a standard of care based on a literature review with evidence-based graded recommendations in a two-part publication. Implementing best practice management has helped change the natural history of this chronic progressive disorder, in which the life expectancy for children of the male sex in the past used to be very limited. Since the previous publication, diagnosis, steroid treatment, rehabilitation, and systemic care have gained more significant insights with new original work in certain fields. Furthermore, the development of new drugs is ongoing, and some interventions have been approved for use in certain countries. Therefore, we have identified the need to review the previous care recommendations for Brazilian patients with DMD. Our objective was to create an evidence-based document that is an update on our previous consensus on those topics.

Nas últimas décadas, houve progressos significativos no diagnóstico e no tratamento da distrofia muscular de Duchenne (DMD), considerada a distrofia muscular mais comum na infância. Diretrizes internacionais foram publicadas e revisadas recentemente. Um grupo de especialistas brasileiros desenvolveu um padrão de atendimento baseado em revisão de literatura, com recomendações graduadas pautadas em evidências compiladas em uma publicação dividida em duas partes. A implementação de melhores práticas de manejo ajudou a modificar a história natural desta doença crônica, progressiva, que, no passado, oferecia uma expectativa de vida muito limitada para crianças do sexo masculino. Desde a publicação desse consenso anterior, o diagnóstico, o tratamento com esteroides, a reabilitação e os cuidados sistêmicos ganharam novas possibilidades a partir da divulgação dos resultados de trabalhos originais em algumas dessas áreas. Além disso, as pesquisas e o desenvolvimento de novos fármacos estão em andamento, e algumas intervenções já foram aprovadas para uso em determinados países. Nesse contexto, identificamos a necessidade de rever as recomendações anteriores sobre o manejo dos pacientes brasileiros com DMD. Nosso objetivo principal foi elaborar uma atualização baseada em evidências sobre esses tópicos do consenso.

Update of the Brazilian consensus recommendations on Duchenne muscular dystrophy / Atualização das recomendações do consenso brasileiro para distrofia muscular de Duchenne

Abstract In the last few decades, there have been considerable improvements in the diagnosis and care of Duchenne muscular dystrophy (DMD), the most common childhood muscular dystrophy. International guidelines have been published and recently reviewed. A group of Brazilian experts has developed a standard of care based on a literature review with evidence-based graded recommendations in a two-part publication. Implementing best practice management has helped change the natural history of this chronic progressive disorder, in which the life expectancy for children of the male sex in the past used to be very limited. Since the previous publication, diagnosis, steroid treatment, rehabilitation, and systemic care have gained more significant insights with new original work in certain fields. Furthermore, the development of new drugs is ongoing, and some interventions have been approved for use in certain countries. Therefore, we have identified the need to review the previous care recommendations for Brazilian patients with DMD. Our objective was to create an evidence-based document that is an update on our previous consensus on those topics.

Resumo Nas últimas décadas, houve progressos significativos no diagnóstico e no tratamento da distrofia muscular de Duchenne (DMD), considerada a distrofia muscular mais comum na infância. Diretrizes internacionais foram publicadas e revisadas recentemente. Um grupo de especialistas brasileiros desenvolveu um padrão de atendimento baseado em revisão de literatura, com recomendações graduadas pautadas em evidências compiladas em uma publicação dividida em duas partes. A implementação de melhores práticas de manejo ajudou a modificar a história natural desta doença crônica, progressiva, que, no passado, oferecia uma expectativa de vida muito limitada para crianças do sexo masculino. Desde a publicação desse consenso anterior, o diagnóstico, o tratamento com esteroides, a reabilitação e os cuidados sistêmicos ganharam novas possibilidades a partir da divulgação dos resultados de trabalhos originais em algumas dessas áreas. Além disso, as pesquisas e o desenvolvimento de novos fármacos estão em andamento, e algumas intervenções já foram aprovadas para uso em determinados países. Nesse contexto, identificamos a necessidade de rever as recomendações anteriores sobre o manejo dos pacientes brasileiros com DMD. Nosso objetivo principal foi elaborar uma atualização baseada em evidências sobre esses tópicos do consenso.

Dysautonomia in RFC1-related disorder: Clinical and neurophysiological evaluation.

OBJECTIVE: To characterize and quantify autonomic involvement in patients with RFC1-related disorder of adult-onset cerebellar ataxia and idiopathic sensory neuropathy. METHODS: We enrolled 16 subjects with biallelic RFC1 (AAGGG)n expansions and 16 age and sex-matched healthy controls that underwent comprehensive clinical and neurophysiological evaluation. Scales for Outcomes in Parkinson's Disease Autonomic Dysfunction (SCOPA-AUT) score was used to assess autonomic symptoms. Electrophysiological testing included assessment of heart rate variability and quantitative sudomotor axon reflex test (QSART). Between-group comparisons were assessed using non-parametric tests. RESULTS: In the patient group, there were 9 men/7 women and the median age was 60.5 years. SCOPA-AUT scores were significantly higher in the RFC1 group compared to controls (22 vs 10, p < 0.001). Half of patients had cardiac autonomic neuropathy. In neurophysiology, there was resting tachycardia combined with abnormal responses during Valsalva maneuver and deep breathing among patients. QSART responses were also significantly reduced in the RFC1 group, especially in the lower limbs. CONCLUSIONS: Autonomic dysfunction is frequent, clinically relevant and involves multiple domains in RFC1-related disorder. Patients have both sympathetic and parasympathetic involvement. From a topographical perspective, this condition is characterized by a small fiber autonomic axonopathy. SIGNIFICANCE: Dysautonomia is frequent, severe and related to peripheral damage in RFC1-related disorder.

Intrafamilial phenotypic heterogeneity related to a new DMD splice site variant.

Dystrophinopathies are a group of X-linked neuromuscular disorders that result from pathogenic variants in the DMD gene. Their pathophysiological substrate is the defective expression of dystrophin in many tissues. While patients from the same pedigree usually present similar dystrophin expression and clinical course, the extent of cardiac and skeletal muscle involvement may not correlate in the same individual. We identified a new splice site variant c.2803+5G>C (NM_004006) ClinVar VCV000803902, located in intron 22 of DMD in a Brazilian family that present a broad phenotypic and histological heterogeneity. One of the subjects had a typical Duchenne muscular dystrophy (DMD) phenotype, whereas the others had Becker muscular dystrophy (BMD). Cardiac involvement was remarkable in some of the BMD patients, but not in the DMD patient. Western blot analysis of skeletal muscle revealed much lower levels of calsequestrin in the most severely affected patient compared to his brother, whose phenotype is BMD, highlighting the potential role of proteins involved in skeletal muscle calcium homeostasis in differential degrees of dystrophinopathies.

A Novel Multisystem Proteinopathy Caused by a Missense ANXA11 Variant.

OBJECTIVE: Protein misfolding plays a central role not only in amyotrophic lateral sclerosis (ALS), but also in other conditions, such as frontotemporal dementia (FTD), inclusion body myopathy (hIBM) or Paget's disease of bone. The concept of multisystem proteinopathies (MSP) was created to account for those rare families that segregate at least 2 out of these 4 conditions in the same pedigree. The calcium-dependent phospholipid-binding protein annexin A11 was recently associated to ALS in European pedigrees. Herein, we describe in detail 3 Brazilian families presenting hIBM (isolated or in combination with ALS/FTD) caused by the novel p.D40Y change in the gene encoding annexin A11 (ANXA11). METHODS: We collected clinical, genetic, pathological and skeletal muscle imaging from 11 affected subjects. Neuroimaging was also obtained from 8 patients and 8 matched controls. RESULTS: Clinico-radiological phenotype of this novel hIBM reveals a slowly progressive predominant limb-girdle syndrome, but with frequent axial (ptosis/dropped head) and distal (medial gastrocnemius) involvement as well. Muscle pathology identified numerous rimmed vacuoles with positive annexin A11, TDP-43 and p62 inclusions, but no inflammation. Central nervous system was also involved: two patients had FTD, but diffusion tensor imaging uncovered multiple areas of cerebral white matter damage in the whole group (including the corticospinal tracts and frontal subcortical regions). INTERPRETATION: These findings expand the phenotypic spectrum related to ANXA11. This gene should be considered the cause of a novel multisystem proteinopathy (MSP type 6), rather than just ALS. ANN NEUROL 2021;90:239-252.

Genetic epidemiology of familial ALS in Brazil.

Many genes associated with familial forms of the amyotrophic lateral sclerosis (fALS) have been identified in European and North American cohorts. However, little is known about the genetic bases of fALS in Latin America and Brazil, in particular. To address this question, we recruited 107 patients with fALS from 93 unrelated families from Southeastern, Southern, and Northeastern regions of the country. A 3-step diagnostic approach was used: 1) Triplet repeat primed polymerase chain reaction to search for C9orf72 expansions, then 2) fragment digestion to search for the c.166 C>T VAPB variant, and finally, 3) whole exome sequencing for those who tested negative. We identified the genetic cause for fALS in 70% of the families. VAPB and C9orf72 were the most frequent genes (30% and 22%, respectively), followed by SOD1, TARDBP, ANXA11, and FUS. Five novel variants in known ALS genes were found, including the SOD1 Val120Leu and ANXA11 Asp40Tyr, which were seen in 2 unrelated families each. In conclusion, VAPB and then C9orf72 are the genes most commonly related to fALS in Brazil.

Randomized Trial of Botulinum Toxin Type A in Hereditary Spastic Paraplegia - The SPASTOX Trial.

BACKGROUND: Hereditary spastic paraplegia presents spasticity as the main clinical manifestation, reducing gait quality and producing incapacity. Management with botulinum toxin type A (BoNT-A) is not well elucidated. The objective of the current study was to evaluate the efficacy and safety of BoNT-A in patients with hereditary spastic paraplegias. METHODS: This was a double-blind, randomized, placebo-controlled crossover trial. Each participant was randomly assigned to receive 1 injection session of either BoNT-A (100 IU/2 mL of Prosigne in each adductor magnus and each triceps surae) or saline 0.9% (2 mL). The primary outcome measure was change from baseline in maximal gait velocity, and secondary outcome measures included changes in gait at self-selected velocity, spasticity, muscle strength, Spastic Paraplegia Rating Scale, pain, fatigue, and subjective perception of improvement. We also looked at adverse events reported by the patients. RESULTS: We enrolled 55 patients, 36 of whom were men and 41 with the pure phenotype. Mean age was 43 ± 13.4 years (range, 19-72 years), mean age of onset waws 27 ± 13.1 years (range, <1 to 55 yars), and mean disease duration was 17 ± 12.7 years (range, 1-62 years). Compared with baseline, we did not find significant differences between groups in primary and secondary outcomes, except for reduction in adductor tone (P = 0.01). The adverse events were transient and tolerable, and their incidence did not significantly differ between treatments (P = 0.17). CONCLUSIONS: BoNT-A was safe in patients with hereditary spastic paraplegias and reduced the adductor tone, but it was not able to produce functional improvement considering the doses, injection protocol, measures, and instruments used. © 2021 International Parkinson and Movement Disorder Society.

Laryngeal electromyography in amyotrophic lateral sclerosis.

BACKGROUND: Bulbar involvement is a hallmark of amyotrophic lateral sclerosis (ALS), but surprisingly very few studies have addressed the frequency, pattern and clinical relevance of laryngeal involvement in the disease. METHODS: Twenty-six patients with spinal-onset ALS underwent nasofibroscopy (NF), followed by laryngeal electromyography (LEMG). We also studied resting activity and motor unit potentials of the genioglossus and masseter muscles. RESULTS: Twenty-four patients presented neurogenic changes in at least one laryngeal muscle. There were fibrillation and/or fasciculation potentials associated with chronic neurogenic changes in the same muscle in 16 patients; of these, 9 had no alteration in the genioglossus. We found no patient with tongue neurogenic changes and normal LEMG. NF was abnormal in 14 patients; in the remaining 12, LEMG identified neurogenic changes in 11 of them. CONCLUSION: LEMG is able to identify laryngeal denervation in patients with ALS, sometimes before clinical manifestations are noticed. This technique may be a useful diagnostic tool for selected patients with suspicion of ALS.

CAG repeats ≥ 34 in Ataxin-1 gene are associated with amyotrophic lateral sclerosis in a Brazilian cohort.

Little is known about the genetic basis of amyotrophic lateral sclerosis (ALS) outside Europe and US. In this study, we investigated whether intermediate CAG expansions at ATXN1 were associated to ALS in the Brazilian population. To accomplish that, representative samples from 411 unrelated patients and 436 neurologically normal controls from 6 centers spread over the territory were genotyped to quantify ATXN1 expansions. We found that ATXN1 intermediate-length expansion (≥34 CAG repeats) are associated with the disease (odds ratio = 2.19, 95% CI = 1.081-4.441, p = .026). Most ATXN1-positive patients had classical phenotype, but some of them presented predominant lower motor neuron involvement. None of them had associated ataxia. Frontotemporal dementia was concomitantly found in 12.5% of patients carrying the intermediate ATXN1 expansion. Further studies are needed to validate these findings and to understand the pathophysiological mechanisms that connect ataxin-1 and ALS.

Misdiagnosis and diagnostic delay in non-paraneoplastic sensory neuronopathies.

METHODS: Sensory neuronopathies (SN) are a group of peripheral nerve disorders characterized by multifocal non-length-dependent sensory deficits and sensory ataxia. Its recognition is essential not only for proper management but also to guide the etiological investigation. The uncommon SN clinical picture and its rarity set the conditions for the misdiagnosis and the diagnostic delay, especially in non-paraneoplastic SN. Therefore, our objectives were to characterize the diagnostic odyssey for non-paraneoplastic SN patients, as well as to identify possible associated factors. We consecutively enrolled 48 non-paraneoplastic SN patients followed in a tertiary neuromuscular clinic at the University of Campinas (Brazil). All patients were instructed to retrieve their previous medical records, and we collected the data regarding demographics, disease onset, previous incorrect diagnoses made and the recommended treatments. RESULTS: There were 34 women, with a mean age at the diagnosis of 45.9 ± 12.2 years, and 28/48 (58%) of the patients were idiopathic. Negative sensory symptoms were the heralding symptoms in 25/48 (52%); these were asymmetric in 36/48 (75%) and followed a chronic course in 35/48 (73%). On average, it took 5.4 ± 5.3 years for SN to be diagnosed; patients had an average of 3.4 ± 1.5 incorrect diagnoses. A disease onset before the age of 40 was associated to shorter diagnosis delay (3.7 ± 3.4 vs. 7.8 ± 6.7 years, p = 0.01). CONCLUSIONS: These results suggest that diagnostic delay and misdiagnosis are frequent in non-paraneoplastic SN patients. As in other rare conditions, increased awareness in all the healthcare system levels is paramount to ensure accurate diagnosis and to improve care of these patients.

Clinical and molecular findings in a cohort of ANO5-related myopathy.

OBJECTIVE: ANO5-related myopathy is an important cause of limb-girdle muscular dystrophy (LGMD) and hyperCKemia. The main descriptions have emerged from European cohorts, and the burden of the disease worldwide is unclear. We provide a detailed characterization of a large Brazilian cohort of ANO5 patients. METHODS: A national cross-sectional study was conducted to describe clinical, histopathological, radiological, and molecular features of patients carrying recessive variants in ANO5. Correlation of clinical and genetic characteristics with different phenotypes was studied. RESULTS: Thirty-seven patients from 34 nonrelated families with recessive mutations of ANO5 were identified. The most common phenotype was LGMD, observed in 25 (67.5%) patients, followed by pseudometabolic presentation in 7 (18.9%) patients, isolated asymptomatic hyperCKemia in 4 (10.8%) patients, and distal myopathy in a single patient. Nine patients presented axial involvement, including one patient with isolated axial weakness. The most affected muscles according to MRI were the semimembranosus and gastrocnemius, but paraspinal and abdominal muscles, when studied, were involved in most patients. Fourteen variants in ANO5 were identified, and the c.191dupA was present in 19 (56%) families. Sex, years of disease, and the presence of loss-of-function variants were not associated with specific phenotypes. INTERPRETATION: We present the largest series of anoctaminopathy outside Europe. The most common European founder mutation c.191dupA was very frequent in our population. Gender, disease duration, and genotype did not determine the phenotype.

Misdiagnosis and diagnostic delay in non-paraneoplastic sensory neuronopathies / Erro e atraso diagnóstico nas neuronopatias sensitivas não paraneoplásicas

ABSTRACT Sensory neuronopathies (SN) are a group of peripheral nerve disorders characterized by multifocal non-length-dependent sensory deficits and sensory ataxia. Its recognition is essential not only for proper management but also to guide the etiological investigation. The uncommon SN clinical picture and its rarity set the conditions for the misdiagnosis and the diagnostic delay, especially in non-paraneoplastic SN. Therefore, our objectives were to characterize the diagnostic odyssey for non-paraneoplastic SN patients, as well as to identify possible associated factors. Methods We consecutively enrolled 48 non-paraneoplastic SN patients followed in a tertiary neuromuscular clinic at the University of Campinas (Brazil). All patients were instructed to retrieve their previous medical records, and we collected the data regarding demographics, disease onset, previous incorrect diagnoses made and the recommended treatments. Results There were 34 women, with a mean age at the diagnosis of 45.9 ± 12.2 years, and 28/48 (58%) of the patients were idiopathic. Negative sensory symptoms were the heralding symptoms in 25/48 (52%); these were asymmetric in 36/48 (75%) and followed a chronic course in 35/48 (73%). On average, it took 5.4 ± 5.3 years for SN to be diagnosed; patients had an average of 3.4 ± 1.5 incorrect diagnoses. A disease onset before the age of 40 was associated to shorter diagnosis delay (3.7 ± 3.4 vs. 7.8 ± 6.7 years, p = 0.01). Conclusions These results suggest that diagnostic delay and misdiagnosis are frequent in non-paraneoplastic SN patients. As in other rare conditions, increased awareness in all the healthcare system levels is paramount to ensure accurate diagnosis and to improve care of these patients.

RESUMO As neuronopatias sensitivas (NS) representam um grupo de doenças caracterizadas por ataxia sensitiva e déficits sensitivos multifocais e não-comprimento dependentes. O seu reconhecimento é fundamental para o tratamento apropriado e para a investigação de doenças associadas. O quadro clínico pouco frequente aliado à baixa prevalência, especialmente das formas não-paraneoplásicas (NSnp), colaboram para o atraso e erro no diagnóstico. Os objetivos desse trabalho são descrever a odisseia diagnóstica dos pacientes com NSnp e tentar identificar possíveis fatores associados. Métodos Foram incluídos consecutivamente 48 pacientes com NSnp acompanhados no ambulatório de doenças neuromusculares da Universidade Estadual de Campinas (Brasil). Dados demográficos e sobre o início da NS (incluindo diagnósticos que lhes foram dados e tratamentos prescritos) foram coletados. Resultados Na coorte descrita havia 34 mulheres e a idade ao diagnóstico era de 45,9 ± 12,2 anos. Os sintomas inaugurais eram sensitivos deficitários em 25/48 (52%) dos pacientes, sendo assimétricos em 36/48 (75%) e de evolução crônica em 35/48 (73%). Para 28/48 (58%) dos pacientes a NS era idiopática. Em média, os pacientes com NSnp tiveram um atraso diagnóstico de 5,4 ± 5,3 anos com uma média de 3,4 ± 1,5 diagnósticos incorretos. Pacientes com início antes dos 40 anos tiveram diagnóstico mais precoce que aqueles com início tardio (3,7 ± 3,4 vs. 7,8 ± 6,7 anos, p = 0,01). Conclusão Os dados ora apresentados sugerem que o erro e o atraso diagnóstico são frequentes e impactam os pacientes com NS. A importância do diagnóstico das NS deve ser constante em todos os níveis do sistema de saúde para o diagnóstico correto e a consequente melhora no cuidado a esses pacientes.

Sensory ataxia rating scale: Development and validation of a functional scale for patients with sensory neuronopathies.

Sensory neuronopathies (SN) result from dorsal root ganglia damage and manifest with a combination of sensory deficits and proprioceptive ataxia. Characterization of the natural history and development of therapeutic trials are hampered by the lack of clinical scales that capture the whole spectrum of SN-related manifestations. We propose and validate a rating instrument for SN. Three experienced neuromuscular specialists developed items to rate SN. The resultant instrument was later validated by the assessment of the intra-class correlation coefficient, for inter-rater validity in 48 SN patients, and later in a smaller subset of 16 patients to assess its intra-rater validity. Standardized Crombach's alpha and Oblimin rotation analysis were performed to verify internal consistency and items' relationship, respectively. Evaluation of Sensory Ataxia Rating Scale (SEARS)'s external validity was performed by comparison to: scale for the assessment and rating of ataxia (SARA), Beck balance scale (BBS), and INCAT sensory sum score (ISS). A 10-item scale with an intra-class correlation coefficient >0.95 for intra- and inter-rating measurements with a good internal consistency (standardized Cronbach's alpha of 0.83) were observed. There was a normal distribution of the scores without a floor or ceiling effect. A moderate to good correlation between SEARS and SARA, BBS, and ISS was observed. SEARS is a reliable, easy-to-perform and consistent instrument to rate SN. Larger cohorts and multicenter studies are needed to validate its usefulness towards possible treatment trials.

Autonomic dysfunction is frequent and disabling in non-paraneoplastic sensory neuronopathies.

INTRODUCTION: Sensory neuronopathies (SN) are characterized by asymmetric non-length dependent sensory deficits and sensory ataxia. Autonomic dysfunction in SN was not yet evaluated regarding its frequency, characteristics and relationship to sensory deficits. To address these issues, we performed a comprehensive clinical and neurophysiological evaluation of a large cohort of patients with non-paraneoplastic SN (np-SN). METHODS: We enrolled 50 consecutive patients with npSN and 32 age/sex-matched healthy controls. They were clinically evaluated (SCOPA-Aut scale) and underwent neurophysiological autonomic assessment (quantitative sudomotor axon reflex test, heart rate variability and sympathetic skin response). RESULTS: Mean age of patients was 50.9 ±â€¯10.3 years and there were 18 men. npSN patients had higher SCOPA-Aut scores than controls (26.63 ±â€¯12.72 vs. 12.66 ±â€¯9.11, p < .001). QSART was abnormal in 92% of the patients - sweat volumes in all examined sites were smaller among patients (p < .001). Cardiovascular autonomic neuropathy was more frequent in these patients as well (p < .001). CONCLUSION: Altogether our results suggest that autonomic dysfunction in distinct domains is frequent in npSN patients. These findings suggest that the clinical picture of npSN is related to a double neuronopathy: sensory and autonomic.

Analysis of motor and respiratory function in Duchenne muscular dystrophy patients.

INTRODUCTION: Duchenne muscular dystrophy(DMD) shows motor and respiratory impairment. METHODS: 19 DMD patients (DMDG) (nine ambulatory and 10 non-ambulatory) were evaluated through motor function measure (MFM), 6-minute walk test (6MWT), respiratory muscle strength, cough peak flow, spirometry and volumetric capnography (VCap) tools. Control group that performed spirometry and VCap (CG1-n = 17) were different from those that performed the 6MWT (CG2-n = 8). RESULTS: The follow tools were assessed (p < 0.05): (i) MFM: Ambulatory patients showed higher values than non-ambulatory patients; (ii) 6MWT: DMDG walked a shorter distance and showed higher respiratory rate at rest and heart rate (HR) at rest than CG2; (iii) Spirometry: DMDG and non-ambulatory patients had minor values achieved in spirometry when compared with CG1 and ambulatory patients, respectively; (iv) VCap: DMDG when compared with CG1 showed: (<11 years-old) lower values in VCap parameters; (>11 years-old): higher HR and lower slope 2. There was correlation between spirometry, mainly for zFEV1/FVC, and MFM. CONCLUSION: DMDG showed motor (MFM/6MWT) and respiratory (spirometry/VCap) deterioration when compared with CG. Non-ambulatory condition was associated with worse MFM and spirometry.