Nitrous Oxide-induced Myeloneuropathy Due to Recreational Abuse.

BACKGROUND: The recreational use of nitrous oxide (N2O) has increased in recent years with a noticeable surge in the incidence of nitrous oxide-related myeloneuropathy. OBJECTIVES: To raise awareness of increasing myeloneuropathy due to recreational nitrous oxide misuse in Israel. METHODS: We conducted a case series documenting the clinical and investigative features of eight patients presenting with nitrous oxide-induced myeloneuropathy who were admitted to our departments. RESULTS: Paresthesia was the chief complaint in all patients, with sensory gait ataxia being a common feature, which was often accompanied by Romberg's sign and mild lower limb weakness. Vitamin B12 levels were below the normal range in seven patients, accompanied by elevated homocysteine and methylmalonic acid levels. Magnetic resonance imaging scans revealed hyperintense signals in the dorsal columns of the cervical spine. All patients improved following vitamin B12 injections. CONCLUSIONS: Enhancing awareness, prompting the use of appropriate investigations, and advocating for timely treatment are needed to overcome the risks associated with nitrous oxide misuse.

Roussy-Lévy Syndrome: Pes Cavus, Tendon Areflexia, Amyotrophy, Gait Ataxia, and Upper Limb Tremor in a Patient with CMT Neuropathy.

Background: Roussy-Lévy syndrome (RLS) is characterized by postural hand tremor seen in patients with familial autosomal dominant Charcot-Marie-Tooth (CMT) neuropathy. Phenomenology Shown: This video demonstrates irregular, jerky bilateral kinetic, postural, rest tremor affecting the right > left hand, along with pes cavus and gait ataxia in a patient with CMT disease. Educational Value: Pes cavus, tendon areflexia, sensory ataxia, and upper limb tremor should prompt consideration of CMT neuropathy. Highlights: This video abstract depicts a bilateral hand tremor characteristic of Roussy-Lévy syndrome seen in patients with Charcot-Marie-Tooth disease neuropathy. The significance of the abstract lies in the phenomenology and the physiology of the tremor seen in patients with genetically confirmed duplication of PMP22 gene.

Consensus Paper: Ataxic Gait.

The aim of this consensus paper is to discuss the roles of the cerebellum in human gait, as well as its assessment and therapy. Cerebellar vermis is critical for postural control. The cerebellum ensures the mapping of sensory information into temporally relevant motor commands. Mental imagery of gait involves intrinsically connected fronto-parietal networks comprising the cerebellum. Muscular activities in cerebellar patients show impaired timing of discharges, affecting the patterning of the synergies subserving locomotion. Ataxia of stance/gait is amongst the first cerebellar deficits in cerebellar disorders such as degenerative ataxias and is a disabling symptom with a high risk of falls. Prolonged discharges and increased muscle coactivation may be related to compensatory mechanisms and enhanced body sway, respectively. Essential tremor is frequently associated with mild gait ataxia. There is growing evidence for an important role of the cerebellar cortex in the pathogenesis of essential tremor. In multiple sclerosis, balance and gait are affected due to cerebellar and spinal cord involvement, as a result of disseminated demyelination and neurodegeneration impairing proprioception. In orthostatic tremor, patients often show mild-to-moderate limb and gait ataxia. The tremor generator is likely located in the posterior fossa. Tandem gait is impaired in the early stages of cerebellar disorders and may be particularly useful in the evaluation of pre-ataxic stages of progressive ataxias. Impaired inter-joint coordination and enhanced variability of gait temporal and kinetic parameters can be grasped by wearable devices such as accelerometers. Kinect is a promising low cost technology to obtain reliable measurements and remote assessments of gait. Deep learning methods are being developed in order to help clinicians in the diagnosis and decision-making process. Locomotor adaptation is impaired in cerebellar patients. Coordinative training aims to improve the coordinative strategy and foot placements across strides, cerebellar patients benefiting from intense rehabilitation therapies. Robotic training is a promising approach to complement conventional rehabilitation and neuromodulation of the cerebellum. Wearable dynamic orthoses represent a potential aid to assist gait. The panel of experts agree that the understanding of the cerebellar contribution to gait control will lead to a better management of cerebellar ataxias in general and will likely contribute to use gait parameters as robust biomarkers of future clinical trials.

Case Report: Homozygous DNAJC3 Mutation Causes Monogenic Diabetes Mellitus Associated With Pancreatic Atrophy.

Introduction: DNAJC3, abundant in the pancreatic cells, attenuates endoplasmic reticulum stress. Homozygous DNAJC3 mutations have been reported to cause non-immune juvenile-onset diabetes, neurodegeneration, hearing loss, short stature, and hypothyroidism. Case Description: We report a case of homozygous DNAJC3 mutation in two siblings of a consanguineous family. A 3-year-old boy presented with short stature and a thyroid nodule. Laboratory findings confirmed hypothyroidism. Subsequently, levothyroxine was administered. Growth hormone (GH) stimulation test results were within the normal limits. His stature was exceedingly short (80.5 cm) (-3.79 SDS). The patient developed sensorineural hearing loss at age 6 years; his intellectual functioning was impaired. Recombinant Human Growth Hormine (rhGH) treatment was postponed until the age of 6.9 years due to a strong family history of diabetes. At age 9 years, he developed an ataxic gait. Brain magnetic resonance imaging (MRI) revealed neurodegeneration. The patient developed diabetes at the age of 11 years-5 years after the initiation of rhGH treatment. Tests for markers of autoimmune diabetes were negative. Lifestyle modification was introduced, but insulin therapy was eventually required. Whole-exome-sequencing (WES) revealed a homozygous DNAJC3 mutation, which explained his clinical presentation. MRI revealed a small, atrophic pancreas. At the age of 17, his final adult height was 143 cm (-4.7 SDS). His elder brother, who had the same mutation, had a similar history, except that he had milder ataxia and normal brain MRI finding at the age of 28 years. Conclusion: We propose that DNAJC3 mutation can be considered as a cause of maturity onset diabetes of the young. Patients with DNAJC3 mutations may possess a small atrophic pancreas.

Complement Component C3 Loss leads to Locomotor Deficits and Altered Cerebellar Internal Granule Cell In Vitro Synaptic Protein Expression in C57BL/6 Mice.

Complement component 3 (C3) expression is increased in the cerebellum of aging mice that demonstrate locomotor impairments and increased excitatory synapse density. However, C3 regulation of locomotion, as well as C3 roles in excitatory synapse function, remains poorly understood. Here, we demonstrate that constitutive loss of C3 function in mice evokes a locomotor phenotype characterized by decreased speed, increased active state locomotor probability, and gait ataxia. C3 loss does not alter metabolism or body mass composition. No evidence of significant muscle weakness or degenerative arthritis was found in C3 knockout mice to explain decreased gait speeds. In an enriched primary cerebellar granule cell culture model, loss of C3 protein results in increased excitatory synaptic density and increased response to KCl depolarization. Our analysis of excitatory synaptic density in the cerebellar internal granule cell and molecular layers did not demonstrate increased synaptic density in vivo, suggesting the presence of compensatory mechanisms regulating synaptic development. Functional deficits in C3 knockout mice are therefore more likely to result from altered synaptic function and/or connectivity than gross synaptic deficits. Our data demonstrate a novel role for complement proteins in cerebellar regulation of locomotor output and control.

Cerebellar Long Noncoding RNA Expression Profile in a Niemann-Pick C Disease Mouse Model.

Niemann-Pick type C (NP-C) disease is a neurodegenerative lysosomal storage disorder primarily caused by mutations in NPC1. However, its pathogenesis remains poorly understood. While mounting evidence has demonstrated the involvement of long noncoding RNAs (lncRNAs) in the pathogenesis of neurodegenerative disorders, the lncRNA expression profile in NP-C has not been determined. Here, we used RNA-seq analysis to determine lncRNA and mRNA expression profiles of the cerebella of NPC1-/- mice. We found that 272 lncRNAs and 856 mRNAs were significantly dysregulated in NPC1-/- mice relative to controls (≥ 2.0-fold, p < 0.05). Quantitative real-time PCR (qRT-PCR) was utilized to validate the expression of selected lncRNAs and mRNAs. Next, a lncRNA-mRNA coexpression network was employed to examine the potential roles of the differentially expressed (DE) lncRNAs. Functional analysis revealed that mRNAs coexpressed with lncRNAs are mainly linked to immune system-related processes and neuroinflammation. Moreover, knockdown of the lncRNA H19 ameliorated changes in ROS levels and cell viability and suppressed the lipopolysaccharide (LPS)-induced inflammatory response in vitro. Our findings indicate that dysregulated lncRNA expression patterns are associated with NP-C pathogenesis and offer insight into the development of novel therapeutics based on lncRNAs.

Neurological Evaluation of Patients with Newly Diagnosed Coeliac Disease Presenting to Gastroenterologists: A 7-Year Follow-Up Study.

We have previously shown that 67% of patients with newly diagnosed coeliac disease (CD) presenting to gastroenterologists have evidence of neurological dysfunction. This manifested with headache and loss of co-ordination. Furthermore 60% of these patients had abnormal brain imaging. In this follow-up study, we re-examined and re-scanned 30 patients from the original cohort of 100, seven years later. There was significant reduction in the prevalence of headaches (47% to 20%) but an increase in the prevalence of incoordination (27% to 47%). Although those patients with coordination problems at baseline reported improvement on the gluten free diet (GFD), there were 7 patients reporting incoordination not present at baseline. All 7 patients had positive serology for one or more gluten-sensitivity related antibodies at follow-up. In total, 50% of the whole follow-up cohort were positive for one or more gluten-related antibodies. A comparison between the baseline and follow-up brain imaging showed a greater rate of cerebellar grey matter atrophy in the antibody positive group compared to the antibody negative group. Patients with CD who do not adhere to a strict GFD and are serological positive are at risk of developing ataxia, and have a significantly higher rate of cerebellar atrophy when compared to patients with negative serology. This highlights the importance of regular review and close monitoring.

Double Vision and Gait Ataxia in an Immunocompetent 9-Year-Old Girl With Intracranial Phaeohyphomycosis.

ABSTRACT: A 9-year-old girl presented with morning headaches associated with vomiting, gait ataxia, and facial and ocular motor nerve palsies. Her initial imaging was concerning for demyelinating disease. After extensive infectious and rheumatologic workup returned negative, she was treated twice with intravenous immunoglobulin and intravenous steroids with near-complete resolution each time. She returned, however, with worsening neurologic deficits and imaging revealing focal ischemic infarction in the brainstem as well as new-onset hydrocephalus. A multispecialty workup was initiated without conclusive diagnosis. A novel, noninvasive test for plasma cell-free DNA established a diagnosis of Cladophialophora bantiana that was confirmed and validated by a brain biopsy taken during a clinical decompensation. Treatment was initiated with systemic voriconazole and intraventricular amphotericin B.

Methotrexate-associated lymphoproliferative disorders in the central nervous system and stomach: A case report.

RATIONALE: Methotrexate-associated lymphoproliferative disorder (MTX-LPD) is a serious complication in patients treated using methotrexate. It occasionally develops in extra-nodal sites, but rarely in the central nervous system (CNS) or in 2 different sites at the same time. We present the rare case of a patient with rheumatoid arthritis who developed lymphoma in the CNS and stomach during MTX therapy. PATIENT CONCERNS: A 75-year-old Japanese man with rheumatoid arthritis who received methotrexate was admitted to our hospital because of gait ataxia and anorexia. DIAGNOSES: Imaging findings and biopsy led to a diagnosis of 2 different types of MTX-LPD in the central nervous system and stomach. INTERVENTIONS: The lesion in his stomach improved after methotrexate withdrawal, whereas the cerebellar mass required high-dose methotrexate and rituximab therapy. OUTCOMES: Complete remission has been maintained for the 2 years following the initiation of chemotherapy. LESSONS: In patients with RA who receive MTX and develop new neurological symptoms, CNS lymphoma as an MTX-LPD may be considered as a differential diagnosis.

A man in his sixties with gait ataxia, dysarthria and mild cognitive impairment. / En mann i 60-årene med gangvansker, dysartri og lett kognitiv svikt.

BACKGROUND: Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) syndrome is an immune-mediated, treatable and inflammatory CNS disease first reported by Pittock et al. (2010). CASE PRESENTATION: We describe a 66-year-old man with previous history of diabetes, atrial fibrillation and hypertension, who was admitted to hospital with reduced general condition. He had experienced dizziness and unstable gait for a year, and had been periodically confused, especially in the previous month. MR imaging showed characteristic punctuate and curvilinear gadolinium enhancements in the pons. Our patient was diagnosed with CLIPPERS and was given corticosteroid treatment, initially methylprednisolone intravenously and then prednisone orally. Other differential diagnoses, such as CNS lymphoma, high-grade glioma, CNS vasculitis, neurosarcoidosis, demyelinating disease, Bickerstaff brainstem encephalitis, and acute disseminated encephalomyelitis were ruled out. The patient's condition improved dramatically after corticosteroid treatment. INTERPRETATION: In 2017, the diagnostic criteria for CLIPPERS were published. Based on these criteria we were able to diagnose this patient with possible CLIPPERS, consistent with clinical symptoms, MRI findings, absence of better explanations for the condition, and clinical and radiological improvement after treatment with corticosteroids. An unequivocal diagnosis of CLIPPERS can only be established by characteristic pathological findings.

Adult-onset methylenetetrahydrofolate reductase deficiency.

Severe hyperhomocysteinemia (>100 µmol/L) is often associated with inborn errors of homocysteine metabolism. It manifests typically in neonatal period with developmental delay, hypotonia, feeding problems or failure to thrive. Adult-onset forms are rare and include less severe manifestations. Early diagnosis is crucial because effective treatment is available. A 23-year-old man presented with a 3-week history of speech and gait impairment, and numbness in lower limbs. Neurological examination revealed dysarthria, decreased vibratory sensation in both legs and appendicular and gait ataxia. Brain MRI revealed T2-hyperintense symmetric white matter lesions and cortical atrophy. He had folate and vitamin B12 deficiency, a markedly elevated serum homocysteine and low methionine. Despite vitamin supplementation homocysteine levels remained elevated. Molecular studies of 5,10-methylenetetrahydrofolate reductase (MTHFR) gene revealed a new pathogenic mutation (c.1003C>T (p.Arg335Cys)) and a polymorphism (C677T (p.Ala222Val)) associated with hyperhomocysteinemia, both in homozygosity. The patient started betaine with clinical and biochemical improvement.

Nueva variante asociada a enfermedad de Niemann-Pick tipo C: manifestaciones neurológicas y caracterización bioquímica, molecular y celular / New variant associated with Niemann-Pick disease type C: Neurological manifestations and biochemical, molecular, and cellular characterisation

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Progressive myeloneuropathy with symptomatic anaemia.

Hypocupremia is a rare and under-recognised cause of bone marrow dysplasia and myeloneuropathy. A 47-year-old Caucasian woman had progressive ascending peripheral neuropathy and gait ataxia over 3 months and fatigue, dyspnoea and unintentional weight loss over 8 months. She had profound macrocytic anaemia and neutropenia. Initial workup included normal serum vitamin B12 Bone marrow biopsy was suggestive of copper deficiency. Serum copper levels were later confirmed to be undetectable. The patient received oral copper repletion which resulted in complete normalisation of haematological abnormalities 16 weeks later. However, neurological deficits persisted. This case describes a delayed diagnosis of hypocupremia as initially suggested through invasive testing. Associating myeloneuropathy with cytopenia is imperative for accurate and prompt diagnosis of hypocupremia, which can be confirmed by serum analysis alone. Developing an accurate differential diagnosis can help prevent unnecessary procedures. Furthermore, initiating prompt copper repletion prevents further neurological impairment. Neurological deficits are often irreversible.

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.

Mutación del gen MMADHC de la cobalamina D con comienzo en el adulto: a propósito de 2 casos potencialmente tratables / Mutation of the MMADHC gene in adult-onset cobalamin D deficiency: A report of 2 potentially treatable cases

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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.

Vestibular dysfunction in acute traumatic brain injury.

Traumatic brain injury (TBI) is the commonest cause of disability in under-40-year-olds. Vestibular features of dizziness (illusory self-motion) or imbalance which affects 50% of TBI patients at 5 years, increases unemployment threefold in TBI survivors. Unfortunately, vestibular diagnoses are cryptogenic in 25% of chronic TBI cases, impeding therapy. We hypothesized that chronic adaptive brain mechanisms uncouple vestibular symptoms from signs. This predicts a masking of vestibular diagnoses chronically but not acutely. Hence, defining the spectrum of vestibular diagnoses in acute TBI should clarify vestibular diagnoses in chronic TBI. There are, however, no relevant acute TBI data. Of 111 Major Trauma Ward adult admissions screened (median 38-years-old), 96 patients (87%) had subjective dizziness (illusory self-motion) and/or objective imbalance were referred to the senior author (BMS). Symptoms included: feeling unbalanced (58%), headache (50%) and dizziness (40%). In the 47 cases assessed by BMS, gait ataxia was the commonest sign (62%) with half of these cases denying imbalance when asked. Diagnoses included BPPV (38%), acute peripheral unilateral vestibular loss (19%), and migraine phenotype headache (34%), another potential source of vestibular symptoms. In acute TBI, vestibular signs are common, with gait ataxia being the most frequent one. However, patients underreport symptoms. The uncoupling of symptoms from signs likely arises from TBI affecting perceptual mechanisms. Hence, the cryptogenic nature of vestibular symptoms in TBI (acute or chronic) relates to a complex interaction between injury (to peripheral and central vestibular structures and perceptual mechanisms) and brain-adaptation, emphasizing the need for acute prospective, mechanistic studies.

Waldenstrom-associated anti-MAG paraprotein polyneuropathy with neurogenic tremor.

A 71-year-old female patient presented with a 14-year history of slowly progressive distal limb numbness, paraesthesia and reduced vibration perception, ataxic gait and intentional tremor. Examination revealed with a length-dependent sensory neuropathy. Nerve conduction studies showed a chronic sensorimotor inflammatory demyelinating polyneuropathy. Intravenous immunoglobulin treatment (on two occasions) proved ineffective. Serum electrophoresis showed increased monoclonal IgM with kappa light chains. Anti-myelin-associated glycoprotein (MAG) levels were extremely elevated, >70 000 BTU. Bone marrow biopsy revealed 15%-20% small B cells and positive MYD88 mutation, indicative of Waldenstrom macroglobulinaemia. A diagnosis of Waldenstrom-associated anti-MAG paraprotein neuropathy with intentional (neurogenic) tremor was made. Repeat nerve conduction study showed a severe sensory demyelinating neuropathy with no axonal lesion. Treatment with rituximab was given for 1 month with minimal improvement. Repeat anti-MAG levels dropped to 53 670 BTU, with minimal clinical improvement.