Acquired hyperexcitable peripheral nerve disorders: Clinical and laboratory features, therapeutic responses, and long-term follow-up.

INTRODUCTION/AIMS: Hyperexcitable peripheral nerve disorders (HPNDs) are rare. Although their clinical and laboratory features have been well studied, information on treatment and follow-up is limited. The aim of this study is to explore the long-term clinical, investigative, and therapeutic profile of patients with acquired HPNDs. METHODS: This study retrospectively analyzed patients from a single tertiary care center with HPND (January 2012 to January 2022). Patients were recruited according to published inclusion and exclusion criteria. Details of clinical features, diagnostic tests, therapeutic interventions, and follow-up were recorded. This study included patients with follow-up of 2 or more years. RESULTS: A total of 32 patients (M = 26, F = 6) were studied. The common clinical features included myokymia, neuropathic or shock-like pain, cramps, sleep disturbances, encephalopathy, cerebellar ataxia, and seizures. A total of 81.25% of patients responded favorably to corticosteroids and membrane stabilizers. Among the nonresponders, five received intravenous immunoglobulin (IVIG), and one received plasma exchange (PLEX). Two patients required rituximab due to poor responses to the above treatments. The mean duration of response was 6 weeks (4-24 weeks) from the initiation of treatment. All patients had favorable outcomes, reaching clinical remission within 1-5 years from the initiation of treatment. Only two patients had relapses. Immunotherapy could be stopped in 78% of patients within 3 years and 100% by 5 years. DISCUSSION: Chronic immunosuppression starting with corticosteroids is required for satisfactory outcomes of HPNDs. These disorders usually run a monophasic course, and relapses are uncommon.

Clinical Recommendations for the use of Neurotropic B vitamins (B1, B6, and B12) for the Management of Peripheral Neuropathy: Consensus from a Multidisciplinary Expert Panel.

INTRODUCTION: Peripheral neuropathy (PN) is an insidious disease that is often asymptomatic during the early stages but which can have a significant impact on quality of life at later stages when nerve damage occurs. There is currently no guidance on the use of neurotropic B vitamins (B1, B6, and B12) for the management of asymptomatic and symptomatic PN. OBJECTIVE: To provide guidance to primary care physicians on an integrated approach to managing PN with neurotropic B vitamins (B1, B6, and B12). MATERIALS AND METHODS: A multidisciplinary panel of eight experts participated in an iterative quasi-anonymous Delphi survey consisting of two rounds of questions and a virtual meeting. A literature review formed the basis of the survey questions. The first round included multiple select, qualitative, and Likert Scale questions; the subsequent round consisted of 2-point scale (agree or disagree) questions that sought to develop consensus-based statements refined from the first round and recommendations derived from discussions during the virtual expert panel meeting. RESULTS: Clinical recommendations for the use of neurotropic B vitamins (B1, B6, and B12) have been developed for the prevention of PN progression or to delay onset in patients at high risk of developing PN. Recommendations have also been provided for the assessment of PN etiology and considerations for the use of loading dose (high dose) and maintenance dose (lower dose) of these neurotropic B vitamins (B1, B6, and B12). CONCLUSION: These clinical recommendations provide an initial step towards formulating comprehensive guidelines for the early and long-term management of PN with neurotropic B vitamins (B1, B6, and B12) and move beyond addressing only neuropathic pain associated with the late stages of PN.

Chronic immune polyradiculopathies: Three clinical variants of one disease?

INTRODUCTION: Chronic immune polyradiculopathies (sensory, motor, and mixed) are uncommon. METHODS: In this single-center, retrospective study, the inclusion criteria for participants were progressive sensory ataxia and/or areflexic limb weakness; tibial somatosensory evoked potential (SSEP) abnormalities of the N22 and P40 potentials with normal sensory and motor nerve conduction studies or root involvement, according to magnetic resonance imaging (MRI); and albuminocytological dissociation. RESULTS: Eight patients were included in our study. Two had weakness, two had sensory ataxia, and four had both weakness and ataxia. Patients with weakness had abnormal SSEPs and patients with sensory ataxia also had absent F waves. Electromyography showed chronic denervation. MRI scans confirmed thickening and enhancement of roots. The patients responded to corticosteroid treatment. DISCUSSION: The overlapping clinicoelectrophysiological findings and similarities in radiological and therapeutic responses suggest that these entities are clinical variants of the same disease. The terms CIS(m)P, CI(s)MP, and CISMP (for chronic immune sensory motor polyradiculopathy) could be used to denote the predominant clinical involvement.

Early and consistent pattern of proximal weakness in GNE myopathy.

BACKGROUND: GNE myopathy is widely regarded as a distal myopathy. Involvement of proximal musculature in this condition has not been systematically studied. METHODS: The phenotype of genetically confirmed patients with GNE myopathy was analyzed. Fourteen groups of muscles were evaluated with Medical Research Council (MRC) grading and the average muscle scores (AMS:1-10) were calculated. RESULTS: Fully documented AMS data was available in 31 of 65 patients. It showed a consistent pattern of severe weakness of hip adductors, hip flexors, knee flexors, and foot dorsiflexors, with milder weakness of the hip extensors and abductors. The knee extensors were largely unaffected. The proximal weakness appeared early in the course of the disease. Proximal muscle weakness was also present in the remaining 34 patients in whom the data were limited. A variant in exon 13 (c.2179G > A) was very common (81.5%). CONCLUSIONS: The GNE phenotype in this Indian cohort exhibited mixed proximal and distal involvement. Weakness of adductors and flexors of the hip formed an integral part of the phenotype.

Between the Person and the Pill: Factors Affecting Medication Adherence in Epilepsy Patients.

BACKGROUND: The majority of people afflicted with epilepsy live in developing countries. Poor adherence to prescribed medication is considered the main cause of unsuccessful drug treatment for epilepsy. Our study aims to evaluate the factors influencing medication adherence in epilepsy patients at a public hospital in Mumbai, India. METHOD: This cross-sectional study was carried out on a cohort of 313 epilepsy patients regularly attending an out-patient clinic at a tertiary-care hospital. A semi-structured questionnaire was used to assess demographic information, the level of medication adherence, and various factors that could influence adherence. Brief Illness Perception Questionnaire and WHO QoL-BREF Scale were also administered to the study population. RESULTS: Patients on anti-epilepsy medication reported an overall good quality of life and a good level of adherence. 90.1% of study participants reported being adherent with their treatment regimen. The main factors found to impact medication adherence were the duration of non-availability of medications in the public sector, and the monthly cost of the medications in the private sector. Other therapy-related, health system-related, socioeconomic, and psychosocial variables were not found to be significant determinants of medication nonadherence in our setting. CONCLUSION: Ensuring that anti-epilepsy drugs remain available in the public sector, and/or making them more affordable in the private sector are the main interventions likely to improve medication adherence in clinical settings such as ours.

Making sense of the clinical spectrum of limb girdle muscular dystrophies.

The expansion of the spectrum of limb girdle muscular dystrophies (LGMDs) in recent years means that neurologists need to be familiar with the clinical clues that can help with their diagnosis. The LGMDs comprise a group of genetic myopathies that manifest as chronic progressive weakness of hip and shoulder girdles. Their inheritance is either autosomal dominant (LGMD1) or autosomal recessive (LGMD2). Their prevalence varies in different regions of the world; certain ethnic groups have documented founder mutations and this knowledge can facilitate the diagnosis. The clinical approach to LGMDs uses the age at onset, genetic transmission and clinical patterns of muscular weakness. Helpful clinical features that help to differentiate the various subtypes include: predominant upper girdle weakness, disproportionate respiratory muscle involvement, distal weakness, hip adductor weakness, 'biceps lump' and 'diamond on quadriceps' sign, calf hypertrophy, contractures and cardiac involvement. Almost half of patients with LGMD have such clinical clues. Investigations such as serum creatine kinase, electrophysiology, muscle biopsy and genetic studies can complement the clinical examination. In this review, we discuss diagnostic clinical pointers and comment on the differential diagnosis and relevant investigations, using illustrative case studies.

Two cases of chronic immune sensorimotor polyradiculopathy: Expanding the spectrum of chronic immune polyradiculopathies.

INTRODUCTION: Immune-mediated demyelinating radiculopathies restricted to proximal sensory or motor roots are uncommon. METHODS: We report the clinical, electrophysiological, biochemical, and radiological features in 2 patients with chronic immune sensorimotor polyradiculopathy (CISMP). RESULTS: The patients presented with sensory ataxia, weakness of the lower limbs, and areflexia. Electrophysiological studies revealed involvement of proximal sensorimotor roots, as evidenced by changes in somatosensory evoked potentials, F-waves, and H-reflexes. In contrast, the distal nerve segments were normal. Magnetic resonance neurography findings of thickened and enhanced roots supported the electrophysiological findings. The response to immunosuppressive therapy was favorable in both patients. CONCLUSION: The findings from these 2 patients further expand the knowledge spectrum of immune polyradiculopathies. Muscle Nerve 55:135-137, 2017.

Myotonic Dystrophy Type 1 Clinical, Electrophysiological and Molecular Characterization: Experience at Tertiary Care Centre.

OBJECTIVE: Myotonic dystrophy type 1 (DM1) is the most common myotonic disorder. Molecular genetic testing of the Dystrophia Myotonica-Protein Kinase DMPK gene to detect expansion of CTG repeats is confirmatory. TP-PCR (Triplet Primed-Polymerase Chain Reaction) is rapid and effective screening for the CTG repeat expansions in myotonic dystrophy. Indian data regarding clinical and genetic evaluation of DM1 are sparse. MATERIAL AND METHODS: This was a prospective observational study at a tertiary neurology centre. It included subjects having clinical and electrophysiological evidence of myotonia with CTG repeat expansion of DMPK gene demonstrated by TP-PCR. Diagnostic molecular assessment was done by two-step procedure; conventional PCR and Fragment length analysis followed by TP-PCR. RESULTS: Seventeen patients fulfilled the inclusion criteria. There were fifteen males and two females, with age ranging from 19 to 53 years (mean age 33years). In the phenotype, large calves were seen in three patients and ophthalmoparesis and scapular winging were seen in one patient each. Screening of patients by PCR-Fragment analysis identified all 17 cases to be of DM1. Further confirmatory test by TP-PCR also successfully identified the cases to be of DM1. TP-PCR technique using forward combination primers was used successfully in detecting expansion of CTG repeats in 13 cases whereas in remaining 4 cases reverse primer combination was used successfully. CONCLUSIONS: This series establishes that a combination of PCR- Fragment analysis and TP-PCR is simple and cost effective in determining the diagnosis of Myotonic dystrophy type 1. This study also documents a new clinical observation of calf hypertrophy in genetically confirmed patients with DM1.

Approach to Chronic Lymphocytic Meningitis.

Chronic meningitis is a common clinical problem. Early diagnosis and appropriate therapy is important in improving the overall outcome and to prevent long-lasting sequels. As many etiological agents lead to the development of chronic lymphocytic meningitis, it is important to develop a systematic approach to the diagnosis; taking clues from history, examination and laboratory tests, to make an accurate diagnosis and institute appropriate therapy. This review focuses on the diagnostic approach towards the commonly encountered situation of chronic lymphocytic meningitis. Chronic meningitis is defined as meningeal inflammation that persists for more than 4 weeks. Chronic meningitis accounts for less than 10% of all the cases of meningitis.1 Causes of chronic lymphocytic meningitis are mainly divided into infectious and non-infectious listed in Table 1.2 Due to advancement in investigations, diseases causing chronic meningitis may be diagnosed earlier than 4 weeks and hence the definition should be considered as a rough guideline.

A practical approach to enlargement of nerves, plexuses and roots.

Detecting enlargement of accessible nerves is very helpful in assessing patients with peripheral nerve disorders, as only a few types of neuropathy lead to nerve thickening. The three leading causes are leprosy, hereditary motor and sensory neuropathies (types 1 and 3) and chronic inflammatory demyelinating neuropathies. MRI, neurography and ultrasonography allow assessment of clinically inaccessible portions of deep-seated nerves, plexuses and roots. As a result, isolated proximal segment thickenings, as found in chronic inflammatory sensory polyradiculopathy, can now be better evaluated and managed. Similarly, focal nerve enlargements due to infection, inflammation, infiltration and neoplasm are being identified and treated effectively. We present a practical approach to the diagnosis and management of patients with enlarged peripheral nerves, plexuses and roots, including cranial nerves.

Role of local thrombolysis in cerebral hemorrhagic venous infarct.

BACKGROUND: Chemical thrombolysis in cerebral venous thrombosis (CVT) is one of the treatment options and the data is limited. SETTINGS AND DESIGN: Prospective observational nonrandomized study. SUBJECTS AND METHODS: This is a prospective study of 10 patients (six females and four males) admitted between May 2007 and June 2013. Grading system proposed by Department of Interventional Neuroradiology (INR), King Edward Memorial Hospital (KEM), Mumbai was used to grade the clinical status at admission. There were six patients with clinical Grade 3, two with Grade 4, and two with Grade 5. Patients with either Grade less than 3 or more than Grade 5 were excluded. Those patients, who were diagnosed with Cerebral venoussinous thrombosis (CSVT) but without hemorrhagic venous infarct and treated  according to INR KEM criteria, were excluded from the study. Average duration of thrombolysis was 13 hours (range 10-18 hours). Average dose of urokinase was 12.2 lakh units (range 9.2-16.8 lakh units). RESULTS: Six patients presented with clinical Grade 3 had modified Rankin Scale (mRS) sore of 1 at 30-day follow-up. Of the two patients with Grade 4, one had mRS 1 and the other had mRS 2 at 30-day follow-up. Of the two patients with Grade 5, one had mRS 2 at 30-day follow-up and the other did not respond to local thrombolysis and succumb to intracranial hemorrhagic infarct within 48 hours. CONCLUSION: This small prospective single-center study showed local dural venous thrombolysis significantly improves clinical and radiological outcome in patients with CVT. A randomized control trial with large sample size is needed to substantiate our findings.

Once myasthenic, always myasthenic? observations on the behavior and prognosis of myasthenia gravis in a cohort of 100 patients.

BACKGROUND: The natural history of myasthenia gravis [MG] is unpredictable: In the first few years the disease course is worst with subsequent gradual disease stabilization. However, some patients tend to have continued disease activity or resurgence of the disease many years into the illness. The factors correlating with disease course need further evaluation. AIMS: To study the patterns of remissions, worsening and exacerbations in patients with MG and correlate various factors affecting them. SETTINGS AND DESIGN: Retrospective, Institute Review Board (IRB) approved study in tertiary referral neurology center. MATERIALS AND METHODS: Hundred patients with acquired MG confirming the inclusion criteria were studied. Pharmacological remissions, complete stable remissions, exacerbations, worsening episodes were analyzed with respect to age of onset, disease extent, disease severity at onset and worst of illness, acetyl choline receptor antibody positivity, thymectomy status, period of disease, pharmacotherapy and crisis episodes. RESULTS AND CONCLUSIONS: In this cohort the percentage of new remission rates per year steadily declined after the first year. Ocular myasthenia had lesser clinical worsening episodes and high chance of complete stable remission. Generalized disease had less chance drug free remission. The risk of episodes of worsening persisted at a steady rate over a period of time, being maximum in the first year. The risk of exacerbations was unpredictable and could occur after prolonged clinical quiescence, often was related to reduction of immunosuppression. The disease course did not differ significantly in the juvenile and adult age-groups. There was a strong case for permanent immunomodulation in MG.

Diagnostic Tests in Neoplastic Meningitis: Lessons Learnt from Three Patients.

Neoplastic meningitis (NM) poses diagnostic challenges and investigations need to be chosen carefully. We present three cases of NM with distinct learning points. In case 1, MRI was diagnostic of melanosis; in case 2, ventricular CSF showed malignant cells when lumbar CSF repeatedly failed to show them; and in the third, whole body PET scan diagnosed the tumour when other tests were negative. A comparative evaluation of various diagnostic modalities used in suspected NM is provided.

Life-Saving Treatments for Spinal Muscular Atrophy: Global Access and Availability.

Background and Objectives: Spinal muscular atrophy (SMA) is a neurodegenerative disorder manifesting with progressive muscle weakness and atrophy. SMA type 1 used to be fatal within the first 2 years of life, but is now treatable with therapies targeting splicing modification and gene replacement. Nusinersen, risdiplam, and onasemnogene abeparvovec-xioi improve survival, motor strength, endurance, and ability to thrive, allowing many patients to potentially attain a normal life; all have been recently approved by major regulatory agencies. Although these therapies have revolutionized the world of SMA, they are associated with a high economic burden, and access to these therapies is limited in some countries. The primary objective of this study was to compare the availability and implementation of treatment of SMA from different regions of the world. Methods: In this qualitative study, we surveyed health care providers from 21 countries regarding their experiences caring for patients with SMA. The main outcome measures were provider survey responses on newborn screening, drug availability/access, barriers to treatment, and related questions. Results: Twenty-four providers from 21 countries with decades of experience (mean 26 years) in treating patients with SMA responded to the survey. Nusinersen was the most available therapy for SMA. Our survey showed that while genetic testing is usually available, newborn screening is still unavailable in many countries. The provider-reported treatment cost also varied between countries, and economic burden was a major barrier in treating patients with SMA. Discussion: Overall, this survey highlights the global inequality in managing patients with SMA. The spread of newborn screening is essential in ensuring improved access to care for patients with SMA. With the advancement of neurotherapeutics, more genetic diseases will soon be treatable, and addressing the global inequality in clinical care will require novel approaches to mitigate such inequality in the future.

Ancestral founder mutations in calpain-3 in the Indian Agarwal community: historical, clinical, and molecular perspective.

INTRODUCTION: Clinical heterogeneity of limb-girdle muscular dystrophies (LGMDs, 24 known subtypes), which includes overlapping phenotypes and varying ages of onset and morbidity, adds complexity to clinical and molecular diagnoses. METHODS: To diagnose LGMD subtype, protein analysis, using immunohistochemistry (IHC) and immunoblotting, was followed by gene sequencing through a panel approach (simultaneous sequencing of known LGMD genes) in 9 patients from unrelated families of the Indian Agarwal community. Haplotype studies were performed by targeted SNP genotyping to establish mutation segregation. RESULTS: We identified 2 founder mutations in CAPN3, a missense (c.2338G>C; p.D780H) and a splice-site (c.2099-1G>T) mutation, on 2 different haplotype backgrounds. The patients were either heterozygous for both or homozygous for either of these mutations. CONCLUSIONS: Founder mutations have immediate clinical application, at least in selected population groups. Clinically available gene panels may provide a definitive molecular diagnosis for heterogeneous disorders such as LGMD.