Atypical Presentations of Huntington Disease-like 2 in South African Individuals.

BACKGROUND: Huntington disease-like 2 (HDL2) is a neurodegenerative disorder, affecting only individuals of African ancestry. Full penetrance occurs in individuals with 40 repeats or more. OBJECTIVE: To describe the phenotypic variability of HDL2 in a group of mixed ancestry individuals from South Africa. METHODS: Eight patients were assessed with analysis of repeat size and magnetic resonance brain imaging. We applied the Unified Huntington's Disease Rating Scale (UHDRS), but in deceased patients (4), this was estimated from video material. RESULTS: Cognitive domains were more severely affected than motor; UHDRS motor scores were notable for bradykinesia, and to a slightly lesser extent, for rigidity and dystonia; a single patient had marked chorea. Repeat lengths ranged from 45 to 63 (median, 52). CONCLUSION: This South African group of mixed ancestry HDL2 individuals presented with severe cognitive and behavioral impairments, with lesser degrees or absence of chorea. This presentation is possibly related to large repeat sizes.

Identification of novel mutations by targeted NGS in Moroccan families clinically diagnosed with a neuromuscular disorder.

BACKGROUND AND AIMS: The identification of underlying genes of genetic conditions has expanded greatly in the past decades, which has broadened the field of genes responsible for inherited neuromuscular diseases. We aimed to investigate mutations associated with neuromuscular disorders phenotypes in 2 Moroccan families. MATERIAL AND METHODS: Next-generation sequencing combined with Sanger sequencing could assist with understanding the hereditary variety and underlying disease mechanisms in these disorders. RESULTS: Two novel homozygous mutations were described in this study. The SIL1 mutation is the first identified in the Moroccan population, the mutation was identified as the main cause of Marinesco-Sjogren syndrome in one patient. While the second mutation identified in the fatty acid 2-hydroxylase gene (FA2H) was associated with the Spastic paraplegia 35 in another patient, both transmitted in an autosomal recessive pattern. DISCUSSION AND CONCLUSIONS: These conditions are extremely rare in the North African population and may be underdiagnosed due to overlapping clinical characteristics and heterogeneity of these diseases. We have reported in this study mutations associated with the diseases found in the patients. In addition, we have narrowed the phenotypic spectrum, as well as the diagnostic orientation of patients with neuromuscular disorders, who might have very similar symptoms to other disease groups.

The diagnostic odyssey: our family's story.

Danny is the father of two boys with MEPAN syndrome and a member of Global Genes' RARE Foundation Alliance Leadership Council.

Charcot-Marie-Tooth Disease and Other Hereditary Neuropathies.

PURPOSE OF REVIEW: This article provides an overview of Charcot-Marie-Tooth disease (CMT) and other inherited neuropathies. These disorders encompass a broad spectrum with variable motor, sensory, autonomic, and other organ system involvement. Considerable overlap exists, both phenotypically and genetically, among these separate categories, all eventually exhibiting axonal injury and neurologic impairment. Depending on the specific neural and non-neural localizations, patients experience varying morbidity and mortality. Neurologic evaluations, including neurophysiologic testing, can help diagnose and predict patient disabilities. Diagnosis is often complex, especially when genetic and acquired components overlap. RECENT FINDINGS: Next-generation sequencing has greatly improved genetic diagnosis, with many third-party reimbursement parties now embracing phenotype-based panel evaluations. Through the advent of comprehensive gene panels, symptoms previously labeled as idiopathic or atypical now have a better chance to receive a specific diagnosis. A definitive molecular diagnosis affords patients improved care and counsel. The new classification scheme for inherited neuropathies emphasizes the causal gene names. A specific genetic diagnosis is important as considerable advances are being made in gene-specific therapeutics. Emerging therapeutic approaches include small molecule chaperones, antisense oligonucleotides, RNA interference, and viral gene delivery therapies. New therapies for hereditary transthyretin amyloidosis and Fabry disease are discussed. SUMMARY: Comprehensive genetic testing through a next-generation sequencing approach is simplifying diagnostic algorithms and affords significantly improved decision-making processes in neuropathy care. Genetic diagnosis is essential for pathogenic understanding and for gene therapy development. Gene-targeted therapies have begun entering the clinic. Currently, for most inherited neuropathy categories, specific symptomatic management and family counseling remain the mainstays of therapy.

Screening for the C9ORF72 expansion in Greek Huntington Disease phenocopies and controls and meta-analysis of current data.

Background: Several European studies examined the role of C9orf72 repeat expansion in patients with Huntington-disease like phenotypes (HD-L). The scope of our study is to investigate the expansion frequency in a Greek HD-L cohort and the meta-analysis of all published cases. This will be of use in genetic counseling of these cases. Methods: A cohort of 74 patients with HD-L and 67 healthy controls were screened for the C9orf72 expansion status. Case-controls comparison was assessed with the Pearson's chi-square statistic for a 2 × 2 table.A systematic database search was conducted and seven studies, including the current study, were considered eligible for inclusion in a meta-analysis considering a total of 812 patients with HD phenocopies. Pooled mutation frequency was calculated using a Random Effects model or the Mantel-Haezsel fixed effects model, depending on the observed heterogeneity. Results: In our cohort, one patient was found to have a pathologic expansion of C9orf72, and none from the control group (chi-square: 0.91, p-value: 0.34). Pooled mutation frequency was found at 2% (CI: 1-3%) with low heterogeneity (I2:15%). Discussion: Based on this meta-analysis the recommendation for genetic testing for C9orf72 expansions is further solidified.

Investigations of Huntington's Disease and Huntington's Disease-Like Syndromes in Indian Choreatic Patients.

BACKGROUND: The diagnostic workup for choreiform movement disorders including Huntington's disease (HD) and those mimicking HD like phenotype is complex. OBJECTIVE: The aim of the present study was to genetically define HD and HD-like presentations in an Indian cohort. We also describe HTT-CAG expansion manifesting as neuroferritinopathy-like disorder in four families from Punjab in India. MATERIALS AND METHODS: 159 patients clinically diagnosed as HD and HD-like presentations from various tertiary neurology clinics were referred to our centre (CSIR-IGIB) for genetic investigations. As a first tier test, CAG-TNR for HTT was performed and subsequently HD-negative samples were screened for JPH3 (HDL2), TBP (SCA17), ATN1 (DRPLA), PPP2R2B (SCA12) and GGGGCC expansion in C9orf72 gene. Four families presenting as neuroferritinopathy-like disorder were also investigated for HTT-CAG expansion. RESULTS: 94 of 159 (59%) patients were found to have expanded HTT-CAG repeats. Pathogenic repeat expansion in JPH3, TBP, ATN1 and C9orf72 were not found in HD negative cases. Two patients were positive for SCA12-CAG expansion in pathogenic length, whereas 5 cases harboured TBP-CAG repeats falling in reduced penetrance range of 41- 48 repeats for SCA17. Four unrelated families, presented with atypical chorea and brain MRI findings suggestive of basal ganglia abnormalities mimicking neuroferritinopathy were found to harbour HTT-CAG expansion. CONCLUSION: We present SCA12 as a new reported phenocopy of HD which should be considered for diagnostic workout along with SCA17 for HD-like syndromes. This study also illustrates the necessity, to consider evolving HD like phenotype, as a clinical diagnosis for cases with initial manifestations depicting neuroferritinopathy.

Familial intestinal degenerative neuropathy with chronic intestinal pseudo-obstruction linked to a gene locus with duplication in chromosome 9.

Background: Intestinal degenerative neuropathy without extra-intestinal involvement occurs as familial forms (FIDN) but the genetics behind is unknown. We studied a Swedish family with autosomal dominant disease and several cases of chronic intestinal pseudo-obstruction (CIP).Methods: We included 33 members of a family sharing a male ancestor. Chronic intestinal symptoms including diarrhoea occurred in 11, four had severe CIP. DNA was analysed with SNP-microarray (Affymetrix), linkage (Allegro Software) and gene dosage (CNAG 3.0).Results: Genetic linkage was found to the short arm of Ch9 to a 9.7 Mb region with 45 protein-coding genes, 22 of which were duplicated (1.2 Mb duplication) (dup(9)(p21.3) with breaking point in the FOCAD-gene. Lod score for the region was 3.4. Fourteen subjects were duplication carriers including all 11 subjects having severe chronic symptoms/CIP. Nineteen subjects had no duplication. The occurrence of gastrointestinal symptoms in the family was strongly linked to duplication carrier-ship (p = .0005). The two branches of the family had separate maternal ancestors (A and B). Including the previous generation, severe disease (overt CIP and/or death from intestinal failure) was assessed to occur in 100% (5/5) of duplication carriers in branch A and in 21% (3/14) in branch B (p = .005). In branch B the onset of symptoms was later (median 38 vs. 24 yrs) and three duplication carriers were symptom-free.Conclusions: In this family with autosomal dominant hereditary intestinal neuropathy, the disorder is linked to a 9.7 Mb region in Ch9 including a 1.2 Mb duplication. There is a significant difference in disease expressivity between family branches, seemingly related to separate maternal ancestors.

Twenty Years of a Pre-Symptomatic Testing Protocol for Late-Onset Neurological Diseases in Portugal.

INTRODUCTION: The national protocol of genetic counselling and pre-symptomatic testing for late-onset neurological diseases began in Portugal in 1995. Initially, it was accessible only to adults at-risk for Machado-Joseph disease, but was later extended to other hereditary ataxias, to Huntington's disease and to familial amyloid polyneuropathy caused by Val30Met mutation at the transthyretin gene. The aim of this study was to describe the profile of the population seeking pre-symptomatic testing, while also reflecting on the experience of conducting the protocol of multidisciplinary sessions since 1996. MATERIAL AND METHODS: We conducted a retrospective study and collected data from clinical records of consultands who requested pre-symptomatic testing at our centre in Porto (Portugal) during the first twenty years of practice (1996 - 2015). RESULTS: A total of 1446 records were reviewed. The most common reason for testing was to reduce uncertainty (41.7%). The rate of withdrawals before results disclosure was lower (16%) than reported in other international experiences with pre-symptomatic testing, while 45% of the consultands dropped out the protocol after learning the test results (73.5% of them were non-carriers). As far as the mutation carriers were concerned, 29.6% adhered to the protocol a year after test disclosure. Consultands that had learned about presymptomatic testing through healthcare professionals tended to adhere more to pre-symptomatic testing consultations. DISCUSSION: The profile of Portuguese consultands at risk for late-onset neurological diseases is similar to those reported in other international programs. The largest group in this data set was the one comprising the subjects at risk for familial amyloid polyneuropathy caused by Val30Met mutation at the transthyretin gene, and it is likely that therapeutic options for this condition may have influenced this result. Adherence to pre-symptomatic testing may change in the future since effective therapies are available (or given the fact that people think effective treatments are imminent). CONCLUSION: This study reflects the first comprehensive description of a Portuguese experience with pre-symptomatic testing for late onset neurological diseases. The development of innovative approaches to improve the consultands' experience with pre-symptomatic testing and their engagement in genetic departments is still a challenge in Portuguese genetics healthcare departments. A better coordination among primary care and genetics healthcare services is needed.

Introdução: Em 1995 foi iniciado em Portugal um protocolo nacional para o aconselhamento genético e teste pré-sintomático de doenças neurológicas de início tardio. Inicialmente, foi disponibilizado para indivíduos adultos em risco para a doença de Machado-Joseph e posteriormente estendido a outras ataxias hereditárias, doença de Huntington e polineuropatia amiloidótica familiar ATTR Val30Met. O objetivo deste estudo é descrever o perfil dos consultandos envolvidos no teste pré-sintomático desde 1996, e refletir no protocolo de sessões multidisciplinares. Material e Métodos: Realizámos um estudo retrospetivo com recolha de dados dos processos clínicos dos utentes que solicitaram teste pré-sintomático ao longo dos primeiros 20 anos do Centro de Genética Preditiva e Preventiva (1996 - 2015), localizado no Porto, Portugal. Resultados: Analisámos um total de 1446 processos clínicos; a principal motivação para a realização do teste pré-sintomático foi o alívio da incerteza (41,7%). A taxa de abandono do protocolo antes da comunicação dos resultados do pré-sintomático (16% dos casos) foi mais baixa do que em outras experiências internacionais; 45% dos consultandos abandonaram o protocolo depois de saberem o resultado do teste pré-sintomático (73,5% dos quais eram não-portadores). 29,6% de consultandos portadores continuaram envolvidos no protocolo um ano após saberem o resultado do teste pré-sintomático. Os consultandos encaminhados para o protocolo através de outros profissionais de saúde revelaram maior adesão ao protocolo. Discussão: O perfil sociodemográfico dos consultandos no Centro de Genética Preditiva e Preventiva é similar ao reportado noutras experiências internacionais. Os consultandos em risco para polineuropatia amiloidótica familiar ATTR Val30Met representaram o maior grupo nos nossos dados, sendo provável que as opções terapêuticas disponíveis para esta doença tenham influenciado este resultado. A adesão ao teste pré-sintomático poderá alterar-se no futuro quando terapias eficazes estiverem disponíveis (ou as pessoas as percepcionem como estando iminentes). Conclusão: Este trabalho constitui a descrição mais completa até ao momento publicada acerca da realização de teste pré-sintomático em Portugal. O desenvolvimento de abordagens com vista à melhoria da experiência dos consultandos com os testes pré-sintomáticos e ao seu envolvimento nos serviços de genética é um desafio atual, assim como a melhor articulação dos mesmos com os cuidados de saúde primários.

Huntington's disease-like 2 with an expansion mutation of the Junctophilin-3 gene; first reported case from Botswana.

Huntington's disease-like 2 (HDL2) is a rare autosomal dominant progressive neurodegenerative disorder commonly seen in adults. It was first described in a large African-American family in the United States. HDL2 clinically resembles Huntington's disease (HD) and causes adult-onset relentlessly progressive movement, emotional and cognitive dysfunction. Onset is usually in the fourth decade with slow progression to death. We present a 47-year-old male Botswana native, with a four-year-history of chorea, slurred speech, mood instability, cognitive impairment and weight loss. Genetic testing reveals normal HTT gene but a heterozygous expansion mutation at the JPH3 locus, confirmatory of HDL2. Though some cases of HDL2 have been reported from neighboring South Africa, this is the first instance from Botswana. This report draws attention to the fact that HDL2 exists among native Batswana, and even though clinically indistinguishable from HD, molecular testing can result in positive case identification.

MPV17-related mitochondrial DNA maintenance defect: New cases and review of clinical, biochemical, and molecular aspects.

Mitochondrial DNA (mtDNA) maintenance defects are a group of diseases caused by deficiency of proteins involved in mtDNA synthesis, mitochondrial nucleotide supply, or mitochondrial dynamics. One of the mtDNA maintenance proteins is MPV17, which is a mitochondrial inner membrane protein involved in importing deoxynucleotides into the mitochondria. In 2006, pathogenic variants in MPV17 were first reported to cause infantile-onset hepatocerebral mtDNA depletion syndrome and Navajo neurohepatopathy. To date, 75 individuals with MPV17-related mtDNA maintenance defect have been reported with 39 different MPV17 pathogenic variants. In this report, we present an additional 25 affected individuals with nine novel MPV17 pathogenic variants. We summarize the clinical features of all 100 affected individuals and review the total 48 MPV17 pathogenic variants. The vast majority of affected individuals presented with an early-onset encephalohepatopathic disease characterized by hepatic and neurological manifestations, failure to thrive, lactic acidemia, and mtDNA depletion detected mainly in liver tissue. Rarely, MPV17 deficiency can cause a late-onset neuromyopathic disease characterized by myopathy and peripheral neuropathy with no or minimal liver involvement. Approximately half of the MPV17 pathogenic variants are missense. A genotype with biallelic missense variants, in particular homozygous p.R50Q, p.P98L, and p.R41Q, can carry a relatively better prognosis.

Human Cochlear Histopathology Reflects Clinical Signatures of Primary Neural Degeneration.

Auditory neuropathy is a significant and understudied cause of human hearing loss, diagnosed in patients who demonstrate abnormal function of the cochlear nerve despite typical function of sensory cells. Because the human inner ear cannot be visualized during life, histopathological analysis of autopsy specimens is critical to understanding the cellular mechanisms underlying this pathology. Here we present statistical models of severe primary neuronal degeneration and its relationship to pure tone audiometric thresholds and word recognition scores in comparison to age-matched control patients, spanning every decade of life. Analysis of 30 ears from 23 patients shows that severe neuronal loss correlates with elevated audiometric thresholds and poor word recognition. For each ten percent increase in total neuronal loss, average thresholds across patients at each audiometric test frequency increase by 6.0 dB hearing level (HL). As neuronal loss increases, threshold elevation proceeds more rapidly in low audiometric test frequencies than in high frequencies. Pure tone average closely agrees with word recognition scores in the case of severe neural pathology. Histopathologic study of the human inner ear continues to emphasize the need for non- or minimally invasive clinical tools capable of establishing cellular-level diagnoses.

[Infantile epileptic encephalopathies: what matters is genetics]. / Encefalopatias epilepticas del lactante: lo prioritario es el estudio genetico.

INTRODUCTION: Epileptic encephalopathies in infancy are defined as conditions where the sustained epileptic activity itself may contribute to the severe neurological and cognitive impairment. These epileptic encephalopathies include Ohtahara syndrome, early myoclonic epileptic encephalopathy, West syndrome, Dravet syndrome, and malignant migrating epilepsy in infancy. These syndromes result from identifiable primary causes, such as structural, neurodegenerative, metabolic, or genetic defects. AIM: To present and discuss current knowledge regarding genetic findings in epileptic encephalopathies in infancy, phenotype-genotype correlations in different forms of paediatric epileptic encephalopathies, and the impact of these new findings in clinical practice. DEVELOPMENT: Patients with unclear etiologies after performing a brain magnetic resonance imaging should be considered for a further workup, which should include an evaluation for genetic defects. Nowadays, more than 50 genes have been associated with epileptic encephalopathies in infancy. Targeted next-generation sequencing panels show a high diagnostic yield in patients with epileptic encephalopathies. CONCLUSIONS: Genetic knowledge about epileptic encephalopathies in infancy has revolutionized the diagnostic approach to these disorders, and an increasing number of gene mutations have been related to their pathogenesis. A more detailed classification of epileptic encephalopathies genotypes will improve the accuracy of genotype-phenotype correlation and genetic counseling. All these developments could yield therapeutic applications such as gene therapy or antiepileptic drugs 'tailored' to the specific genetic markers or targets.

TITLE: Encefalopatias epilepticas del lactante: lo prioritario es el estudio genetico.Introduccion. Las encefalopatias epilepticas del lactante constituyen un grupo de entidades donde la actividad epileptica mantenida contribuye por si misma al deterioro neurologico y cognitivo del paciente. Entre ellas se incluyen el sindrome de Ohtahara, la encefalopatia mioclonica precoz, el sindrome de West, el sindrome de Dravet y la epilepsia migratoria maligna del lactante. Estos sindromes se originan por etiologias variadas, incluyendo lesiones estructurales cerebrales, enfermedades metabolicas y heredodegenerativas, y alteraciones geneticas, entre otras. Objetivo. Presentar y discutir el conocimiento actual sobre los hallazgos geneticos en las encefalopatias epilepticas del lactante, el potencial correlato genotipo-fenotipo en las distintas formas de encefalopatias epilepticas y el impacto de estos nuevos hallazgos en la practica clinica. Desarrollo. En los lactantes con encefalopatias epilepticas, sin una etiologia definida tras realizar una resonancia magnetica cerebral, debe considerarse un abordaje etiologico que excluya patologias geneticas. En la actualidad, mas de 50 genes se han asociado con la etiologia de las encefalopatias epilepticas del lactante. Los paneles de multiples genes analizados por tecnicas de secuenciacion masiva son una herramienta util para el diagnostico genetico de estos pacientes. Conclusiones. El conocimiento sobre la genetica de las encefalopatias epilepticas del lactante ha revolucionado el abordaje diagnostico y cada vez se implican mas genes y distintos tipos de mutaciones en la patogenia de estas patologias. El desarrollo de clasificaciones especificas para las encefalopatias epilepticas geneticas puede contribuir a un mejor correlato genotipo-fenotipo, a orientar mejor el consejo genetico y a considerar terapias especificas.

Plasma metabolomics reveals a diagnostic metabolic fingerprint for mitochondrial aconitase (ACO2) deficiency.

Mitochondrial respiratory chain dysfunction has been identified in a number of neurodegenerative disorders. Infantile cerebellar-retinal degeneration associated with mutations in the mitochondrial aconitase 2 gene (ACO2) has been recently described as a neurodegenerative disease of autosomal recessive inheritance. To date there is no biomarker for ACO2 deficiency and diagnosis relies on genetic analysis. Here we report global metabolic profiling in eight patients with ACO2 deficiency. Using an LC-MS-based metabolomics platform we have identified several metabolites with affected plasma concentrations including the tricarboxylic acid cycle metabolites cis-aconitate, isocitrate and alpha-ketoglutarate, as well as phosphoenolpyruvate and hydroxybutyrate. Taken together we report a diagnostic metabolic fingerprint for mitochondrial aconitase 2 deficiency.

[Trends and expectations the research on the molecular background of epileptic encephalopathies - state of the art in 2017].

Epilepsy is common neurological condition affecting 0.8-1% of the human population. Since 80% of patients are under 20 years of age, it is mainly a disease of the developmental period. The causes of epilepsy are heterogeneous, but the disease has always been considered a genetic disorder, which no longer doubted. Epilepsy genetics has undergone a revolution since the discovery of the first gene responsible for epilepsy. This is mainly because of introduction of the next generation sequencing as research and diagnostic tool, and transition from studies of pedigrees with epilepsy to the analysis of cases of epileptic encephalopathies. In a short time more than 50 early infantile epileptic encephalopathies were recognized due to the causative genes. Whole exome or targeted panel sequencing has been used as a diagnostic tool with a diagnostic yield of about 30-40%. The "genetic diagnosis" that is obtained makes it possible to introduce targeted treatment in an increasing number of cases. Since epileptic encephalopaties are often regarded as the model disease for epilepsy, these therapeutic strategies can provide treatment for patients with common epilepsies.

Management of degenerative cervical myelopathy - An update.

INTRODUCTION: Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord dysfunction in adult patients. Patients generally present with a slow, progressive neurological decline or a stepwise deterioration pattern. In this paper, we discuss the most important factors involved in the management of DCM, including a discussion about the surgical approaches. METHOD: The authors performed an extensive review of the peer-reviewed literature addressing the aforementioned objectives. RESULTS: Although the diagnosis is clinical, magnetic resonance imaging (MRI) is the study of choice to confirm stenosis and also to exclude the differential diagnosis. The severity the clinical symptoms of DCM are evaluated by different scales, but the modified Japanese Orthopedic Association (mJOA) and the Nürick scale are probably the most commonly used. Spontaneous clinical improvement is rare and surgery is the main treatment form in an attempt to prevent further neurological deterioration and, potentially, to provide some improvement in symptoms and function. Anterior, posterior or combined cervical approaches are used to decompress the spinal cord, with adjunctive fusion being commonly performed. The choice of one approach over the other depends on patient characteristics (such as number of involved levels, site of compression, cervical alignment, previous surgeries, bone quality, presence of instability, among others) as well as surgeon preference and experience. CONCLUSION: Spine surgeons must understand the advantages and disadvantages of all surgical techniques to choose the best procedure for their patients. Further comparative studies are necessary to establish the superiority of one approach over the other when multiple options are available.

Management of degenerative cervical myelopathy - An update / Manejo da mielopatia cervical degeneratiiva - Uma atualização

SUMMARY Introduction Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord dysfunction in adult patients. Patients generally present with a slow, progressive neurological decline or a stepwise deterioration pattern. In this paper, we discuss the most important factors involved in the management of DCM, including a discussion about the surgical approaches. Method The authors performed an extensive review of the peer-reviewed literature addressing the aforementioned objectives. Results Although the diagnosis is clinical, magnetic resonance imaging (MRI) is the study of choice to confirm stenosis and also to exclude the differential diagnosis. The severity the clinical symptoms of DCM are evaluated by different scales, but the modified Japanese Orthopedic Association (mJOA) and the Nürick scale are probably the most commonly used. Spontaneous clinical improvement is rare and surgery is the main treatment form in an attempt to prevent further neurological deterioration and, potentially, to provide some improvement in symptoms and function. Anterior, posterior or combined cervical approaches are used to decompress the spinal cord, with adjunctive fusion being commonly performed. The choice of one approach over the other depends on patient characteristics (such as number of involved levels, site of compression, cervical alignment, previous surgeries, bone quality, presence of instability, among others) as well as surgeon preference and experience. Conclusion Spine surgeons must understand the advantages and disadvantages of all surgical techniques to choose the best procedure for their patients. Further comparative studies are necessary to establish the superiority of one approach over the other when multiple options are available.

RESUMO Introdução a mielopatia cervical degenerativa (MCD) é uma das causas mais comuns de disfunção medular em adultos. Os pacientes em geral apresentam declínio neurológico lento e progressivo, ou deterioração escalonada. No presente artigo, discutimos os mais importantes fatores envolvidos no manejo da MCD, incluindo considerações sobre os aspectos relacionados à escolha da abordagem cirúrgica. Método realizou-se extensa revisão da literatura de artigos peer-reviewed relacionados ao tema. Resultados embora o diagnóstico seja realizado clinicamente, a ressonância magnética (RM) é o estudo de imagem de escolha para confirmá-lo e excluir eventuais diagnósticos diferenciais. A gravidade do quadro clínico pode ser avaliado utilizando-se diferentes escalas, como a modified Japanese Orthopedic Association (mJOA) ou a de Nürick, provavelmente as mais comuns. Uma vez que a melhora clínica espontânea é rara, a cirurgia é a principal forma de tratamento, em uma tentativa de evitar dano neurológico adicional ou deterioração e, potencialmente, aliviar alguns sintomas e melhorar a função dos pacientes. Abordagens cirúrgicas por via anterior, posterior ou combinada podem ser usadas para descomprimir o canal, concomitantemente a técnicas de fusão. A escolha da abordagem depende das características dos pacientes (número de segmentos envolvidos, local de compressão, alinhamento cervical, cirurgias prévias, qualidade óssea, presença de instabilidade, entre outras), além da preferência e experiência do cirurgião. Conclusão os cirurgiões de coluna devem compreender as vantagens e desvantagens de todas as técnicas cirúrgicas para escolher o melhor procedimento para seus pacientes. Estudos futuros comparando as abordagens são necessários para orientar o cirurgião quando múltiplas opções forem possíveis.

Degenerative Encephalopathy in Nova Scotia Duck Tolling Retrievers Presenting with a Rapid Eye Movement Sleep Behavior Disorder.

BACKGROUND: Neurodegenerative diseases are a heterogeneous group of disorders characterized by loss of neurons and are commonly associated with a genetic mutation. HYPOTHESIS/OBJECTIVES: To characterize the clinical and histopathological features of a novel degenerative neurological disease affecting the brain of young adult Nova Scotia Duck Tolling Retrievers (NSDTRs). ANIMALS: Nine, young adult, related NSDTRs were evaluated for neurological dysfunction and rapid eye movement sleep behavior disorder. METHODS: Case series review. RESULTS: Clinical signs of neurological dysfunction began between 2 months and 5 years of age and were progressive in nature. They were characterized by episodes of marked movements during sleep, increased anxiety, noise phobia, and gait abnormalities. Magnetic resonance imaging documented symmetrical, progressively increasing, T2-weighted image intensity, predominantly within the caudate nuclei, consistent with necrosis secondary to gray matter degeneration. Abnormalities were not detected on clinicopathological analysis of blood and cerebrospinal fluid, infectious disease screening or urine metabolite screening in most cases. Postmortem examination of brain tissue identified symmetrical malacia of the caudate nuclei and axonal dystrophy within the brainstem and spinal cord. Genealogical analysis supports an autosomal recessive mode of inheritance. CONCLUSIONS AND CLINICAL IMPORTANCE: A degenerative encephalopathy was identified in young adult NSDTRs consistent with a hereditary disease. The prognosis is guarded due to the progressive nature of the disease, which is minimally responsive to empirical treatment.