Phenotypic features of epilepsy due to sodium channelopathies - A single center experience from India

Objectives

Nearly 40% of pediatric epilepsies have a genetic basis. There is significant phenotypic and genotypic heterogeneity, especially in epilepsy syndromes caused by sodium channelopathies. Sodium channel subunit 1A (SCN1A)-related epilepsy represents the archetypical channel-associated gene that has been linked to a wide spectrum of epilepsies of varying severity. Subsequently, other sodium channels have also been implicated in epilepsy and other neurodevelopmental disorders. This study aims to describe the phenotypes in children with sodium channelopathies from a center in Southern India.

Materials and Methods

This is a retrospective, descriptive, and single-center study. Out of 112 children presenting with epilepsy who underwent genetic testing between 2017 and 2021, 23 probands (M: F = 12:11) were identified to have clinically significant sodium channel mutations. Clinical presentation, electroencephalography, and imaging features of these patients were recorded. The utility of genetic test results (e.g., in planning another child, withdrawal of medications, or change in treatment) was also recorded.

Results

Age at onset of seizures ranged from day 4 of life to 3.5 years. Clinical epilepsy syndromes included generalized epilepsy with febrile seizures plus (n = 3), Dravet syndrome (n = 5), early infantile epileptic encephalopathy (n = 7), drug-resistant epilepsy (n = 5), and epilepsy with associated movement disorders (n = 3). The most common type of seizure was focal with impaired awareness (n = 18, 78.2%), followed by myoclonic jerks (n = 8, 34.78%), epileptic spasms (n = 7, 30.4%), bilateral tonic-clonic seizures/generalized tonic-clonic seizures (n = 3, 13%), and atonic seizures (n = 5, 23.8%). In addition to epilepsy, other phenotypic features that were discerned were microcephaly (n = 1), cerebellar ataxia (n = 2), and chorea and dystonia (n = 1).

Conclusion

Sodium channelopathies may present with seizure phenotypes that vary in severity. In addition to epilepsy, patients may also have other clinical features such as movement disorders. Early clinical diagnosis may aid in tailoring treatment for the given patient.

Surgical Management of Vision Loss in Cerebral Venous Thrombosis: Case Series from a Tertiary Care Stroke Center

Background and Purpose

Cerebral venous thrombosis (CVT) presenting as vision loss is uncommon. Raised intracranial tension in CVT is proposed as one of the mechanisms (13.2%). There are still unknown underlying mechanisms to explain vision loss in CVT. The safety and outcome of the surgery (optic nerve sheath fenestration [ONSF] or theco-peritoneal shunt [TPS]) to reduce intracranial hypertension and prevent vision loss has not been studied.

Methods

A retrospective case record review of CVT patients with impending vision loss who underwent ONSF/TPS from 2007 to 2019 was performed from the stroke registry. All patients had formal neuro-ophthalmological evaluation and documentation of visual acuity, supplemented by visual field assessments by perimetry in a subset of patients. Safety and outcomes were assessed based on vision improvement and adverse effects after the surgery.

Results

Among approximately 1400 patients with CVT admitted in the stroke ward over 12 years, surgery for rescuing vision was done in 18. Among these, the males were 6, and the females were 12. The mean age of presentation was 24 (range 18-52 years). All of them had headaches and progressive blurring of vision with papilledema. The number of patients who underwent TPS was 13, ONSF was 1, and both were 4. In the TPS group (26 eyes), vision improved in 15 eyes (57.7%), remained status-quo in 8 eyes (30.7%), and worsened in 3 eyes (11.5%). Four patients underwent both surgeries; three eyes improved, two remained status quo, and three worsened. One patient underwent ONSF, and his vision remained status quo (no perception of light). Three patients (17.6%) of the TPS group had minor complications (low-pressure headache, subdural hygroma), and five (29.4%) had major complications like subdural hemorrhage, abdominal wound infection, and meningitis.

Conclusion and Implications

In patients with CVT, adequate vision monitoring is mandatory. Shunt surgeries (especially TPS) may help in stabilizing/improving vision in CVT patients with impending vision loss, despite adequate anti-edema measures (53.8% improved). Early diagnosis and precise decisions in referring for surgery are crucial.

Characterisation of Patients with SH3TC2 Associated Neuropathy in an Indian Cohort

Background

SH3TC2 variations lead to demyelinating recessive Charcot-Marie-Tooth (CMT) disease, which is commonly associated with early-onset scoliosis and cranial neuropathy. Data from Indian ethnicity is limited.

Objective

We aim to report the characteristics of patients with SH3TC2-associated neuropathy from an Indian cohort.

Patients and Methods

Data of five unrelated subjects with SH3TC2 variations were analyzed.

Results

Clinical features included female predominance (n = 4), early-onset neuropathy (n = 2), pes cavus and hammer toes (n = 4), kyphoscoliosis (n = 1), impaired vision and hearing (n = 1), facial muscle weakness (n = 1), impaired kinaesthetic sense (n = 3), tremor (n = 2), and ataxia (n = 1). Four patients had the "CMT" phenotype, while one patient had Roussy-Levy syndrome. All had demyelinating electrophysiology with conduction velocities being "very slow" in one, "slow" in one, "mildly slow" in two, and "intermediate" in one patient. Brain stem auditory evoked potentials were universally abnormal though only one patient had symptomatic deafness. Seven variants were identified in SH3TC2 [homozygous = 3 (c.1412del, c.69del, c.3152G>A), heterozygous = 4 (c.1105C>T, c.3511C>T, c.2028G>C, c.254A>T)]. Except for c.3511C>T variant, the rest were novel. Three patients had additional variations in genes having pathobiological relevance in other CMTs or amyotrophic lateral sclerosis.

Conclusion

We provide data on a cohort of patients of Indian origin with SH3TC2 variations and highlight differences from other cohorts. Though the majority were not symptomatic for hearing impairment, evoked potentials disclosed abnormalities in all. Further studies are required to establish the functional consequences of novel variants and their interacting molecular partners identified in the present study to strengthen their association with the phenotype.

Rituximab in Myasthenia Gravis- Experience from a Low- and Middle-Income Country (LMIC) Setting

BACKGROUND

Myasthenia gravis (MG) is an immune-mediated disorder of the neuromuscular junction. About 10% are refractory to immunosuppressive therapy.

AIMS

To analyze the response of patients with generalized MG to rituximab.

METHODS AND MATERIALS

A retrospective review of patients with MG who received rituximab was carried out (n = 13, M:F = 6:7, mean age: 44.84 ± 15.73 years). Myasthenia Gravis Foundation of America (MGFA), MGFA post-intervention status (MGFA-PIS), and Myasthenia Gravis Status and Treatment Intensity (MGSTI) were assessed before and after rituximab.

RESULTS

The duration of MG was 104.07 ± 92.25 months. Before rituximab, the MGFA was IIA/IIB/IIIA/IIIB/IVB/V in 1/1/2/6/2/1 patients and MGSTI was four in eight patients and six in three patients. The mean duration of follow up was 20.92 ± 14.06 months (range, 4 to 42 months). Dose reduction or discontinuation of cholinesterase inhibitors could be achieved 12 patients. Complete stable remission (CSR) and pharmacologic remission (PR) were achieved in one and four patients respectively and five patients had minimal manifestations. Most patients attained level 0, 1 or 2 MGSTI at last follow up. No rituximab infusion-related adverse events were noted. Three patients had exacerbation of MG between one to five weeks after rituximab administration. Three patients died, one each due to a cardiac event unrelated to MG or treatment, complications related to myasthenic crisis, and coronavirus disease.

CONCLUSIONS

Rituximab was effective in bringing about remission in MG and can be considered as a first-line agent. However, it has to be administered under close supervision as some patients develop exacerbation of MG akin to steroid-induced worsening.

Role of altered IL-33/ST2 immune axis in the immunobiology of Guillain-Barré syndrome

BACKGROUND

IL-33/ST2 immune axis plays crucial roles in infection and immunity. A dysregulated IL-33/ST2 axis can induce autoimmune reaction and inflammatory responses. Guillain-Barré Syndrome (GBS) is an acute peripheral neuropathy, mostly caused by post-infection autoimmunity. The role of IL-33/ST2 axis is not known in GBS. This study aimed to explore the role of IL-33/ST2 axis in GBS.

METHODS

Three single nucleotide polymorphisms (SNPs) of Il33 gene (rs16924159; rs7044343; rs1342336) and three SNPs of Il1rl1 gene (rs10192157, rs1041973, rs10206753), coding for ST2 were genotyped in 179 GBS patients and 186 healthy controls by TaqMan Allelic Discrimination Assay. Plasma levels of IL-33 and sST2 were measured in a subset of GBS (n=80) and healthy controls (n=80) by ELISA.

RESULTS

The frequencies of CC genotype of rs10192157 (p=0.043) and TT genotype of rs10206753 (p=0.036) SNPs of Il1rl1 gene differed significantly between GBS patients and healthy subjects. Gene-gene interaction between Il33 and Il1rl1 genes also conferred significant risk to GBS. In addition, the plasma sST2 levels were significantly elevated in GBS patients compared to healthy subjects (24,934.31 ± 1.81 pg/ml vs. 12,518.97 ± 1.51 pg/ml, p<0.001). Plasma sST2 levels showed a significant correlation with the disability scores at the peak of neurological deficit in GBS patients.

CONCLUSIONS

IL-33/ST2 axis is suggested to influence the immunopathogenesis of GBS. Genetic variants of Il1rl1 gene might serve as a risk determinant of GBS and plasma sST2 levels might emerge as a biomarker of severity of GBS, if replicated further by other studies.

The Spectrum of Neuro-COVID: A Study of a Comprehensively Investigated Large Cohort from India

Background:

Though reports of neurological manifestations of COVID-19 have emerged from various parts of the world, the cohorts reported are from the West and mostly derived from electronic databases. Much remains unknown regarding neuro-COVID in developing countries. India is the second-worst affected country, and this study reports the neurological manifestations of COVID-19 in a comprehensively evaluated cohort.

Objective:

The aim of this study was to describe the range of neurological manifestations of COVID-19 in India with an emphasis on the risk factors, laboratory and imaging findings and short-term outcome.

Methods:

Retrospective review of hospital records of all confirmed COVID-19 patients with neurological manifestations, receiving inpatient care in two neurology referral hospitals were done. All demographic, clinical details, investigations, and treatment were analysed.

Results:

A total of 120 confirmed COVID-19 cases presenting with neurological symptoms were included. The mean age of illness and duration of illness was 48.03 ± 17.3 years and 10.9 ± 17.3 days respectively. New onset of neurological symptoms occurred in 100 cases while 20 patients had worsening of pre-existing neurological illness. Stroke was the commonest neurological disorder (43%), followed by encephalopathy (23%) and Guillain-Barre syndrome (10%). Other unusual neurological manifestations included new-onset headache (7%), seizures including denovo status epilepticus (5%) and meningo-encephalitis (5%). Nearly half of the patients had preceding COVID-19 symptoms. Poor outcome at discharge was seen in 40% and mortality occurred in 15%.

Conclusion:

Stroke and encephalopathy constitute the most common neurological manifestations. The absence of preceding COVID-19 symptoms in nearly half the cases is striking. Poor outcome was seen in nearly 50% despite early recognition and management.

Vogt-Koyanagi-Harada Syndrome - A Neurologist's Perspective

Vogt-Koyanagi-Harada (VKH) syndrome is an immune-mediated granulomatous disease which affects melanin-rich organs like eyes, skin, nervous system, and ears. Neurological and auditory manifestations usually precede the involvement of other sites. Patients may manifest with “complete” or “incomplete” syndrome. We report two patients who presented with acute headache and impaired vision. Fundus examination revealed optic disc hyperemia and exudative retinal detachment which provided a clue for the diagnosis at the bedside. Fundus fluorescein angiogram (FFA) revealed abnormal dye leakage, whereas B scan showed choroid thickening. Cerebrospinal fluid (CSF) pleocytosis contrasted with unremarkable brain magnetic resonance imaging and lack of meningeal signs. Melanophagocytosis was evidenced by melanin-laden macrophages in CSF and skin biopsy. This finding is specific for VKH syndrome and helps to clinch the diagnosis even when the complete syndrome is not present cross-sectionally. VKH syndrome should be suspected in patients with aseptic meningitis if tests for common infectious and immune-mediated diseases are negative.

Clinical Profile and Treatment Response in Patients with CASPR2 Antibody-Associated Neurological Disease

Background:

The clinical spectrum of contactin-associated protein-like 2 (CASPR2) antibody-associated disease is wide and includes Morvan syndrome. Studies describing treatment and long-term outcome are limited.

Aims:

We report the clinical profile and emphasize response to treatment and long-term outcome in eight patients with CASPR2-antibody-associated disease.

Methods:

Clinical, radiological, electrophysiological, treatment, follow-up, and outcome data were collected by retrospective chart review.

Results:

Clinical manifestations included Morvan syndrome (n = 7) and limbic encephalitis (n = 1). None of the patients were positive for LGI1 antibody. Associated features included myasthenia (n = 1), thymoma (n = 1), and dermatological manifestations (n = 4). Patients were treated with intravenous methylprednisolone and plasma exchange during the acute symptomatic phase followed by pulsed intravenous methyl prednisolone to maintain remission. Mean-modified Rankin score at admission (pre-treatment), discharge, and last follow-up were 3.75, 2.5, and 0.42, respectively. One patient with underlying thymoma and myasthenic crisis died. The other seven patients were followed up for a mean duration of 19.71 months. All of them improved completely. Relapse occurred in one patient after 13 months but responded favorably to steroids.

Conclusion:

CASPR2 antibody-associated disease has favorable response to immunotherapy with complete improvement and good outcome. Underlying malignancy may be a marker for poor prognosis.

Role of pulse methylprednisolone in epileptic encephalopathy: A retrospective observational analysis

OBJECTIVES

To study the effect of monthly pulses of intravenous methylprednisolone (IVMP) on seizure and global outcomes in children with epileptic encephalopathy (EE).

METHODS

This retrospective study was undertaken in a tertiary care epilepsy center in India. Consecutive patients with EE who had received IVMP as adjunctive therapy for a minimum of 3 months and had at least one pre-and post-steroid EEG each, were identified and a structured questionnaire was used to collect information including outcomes at 3 months post-steroid course completion and beyond, as available.

RESULTS

Ninety-seven patients (M:F=71:26) fulfilling the inclusion criteria with a mean age at onset of seizures being 20.52 ± 25.69 months were included. Commonest seizure types were myoclonic (66%); Lennaux-Gastaut and West Syndromes accounted for 57 % and 24 % patients respectively. The etiology was unknown in 52 %. All children were on a combination of standard anti-seizure drugs. The duration of IVMP pulse therapy was 7.72 ± 6.25 months. One-fourth (26 %) patients experienced minor adverse events. Greater than 50 % seizure burden reduction was seen in 66 % patients at 3 months with seizure-freedom in 25 %. A total of 45 (46 %) patients became seizure-free in the cohort eventually with continuation of steroids beyond 3 months. Children with idiopathic EEs, normal neuroimaging, myoclonic jerks, and West syndrome showed the best response. The presence of burst-suppression and generalized paroxysmal fast activity (GPFA) predicted inadequate response.

CONCLUSIONS

Adjunct pulse doses of IVMP are safe, well-tolerated, and effective in reducing seizures and improving global outcomes in children with idiopathic EEs, West syndrome, normal neuroimaging, and myoclonic jerks. Seizure freedom might be delayed in a subset of these patients, hence duration of therapy beyond 3 months may be warranted.

Optokinetic nystagmus in patients with SCA: A bedside test for oculomotor dysfunction grading

OBJECTIVE

To characterize the clinical features in patients with spinocerebellar ataxia (SCA) type 1, SCA2, and SCA3 and to evaluate the oculomotor dysfunction by using optokinetic nystagmus (OKN) testing, which may be a sensitive marker.

METHODS

In this prospective observational study, all patients underwent detailed neurologic examination with special emphasis on eye movements. OKN was evaluated with a tape. Disease severity was measured with the International Co-Operative Ataxia Rating Scale (ICARS).

RESULTS

A total of 73 genetically confirmed patients were included, of whom 28, 30, and 15 patients were positive for SCA1, SCA2, and SCA3, respectively. Dystonia was more common in patients with SCA3 (46%), and absent ankle jerk was more common in those with SCA2 (21.4%). Brisk deep tendon reflexes were common in patients with SCA1 (46.6%), followed by patients with SCA3 (26.6%) and SCA2 (7.1%). Vertical OKN was impaired in all patients and absent in 86.6% of patients with SCA1, 96% of those with SCA2, and 80% of those with SCA3. Horizontal OKN was absent in 30% of patients with SCA1, 57% of patients with SCA2, and 33% of those with SCA3. Higher motor disability (posture and gait, kinetic functions [Motor Disability] subscore on the ICARS) was associated with higher oculomotor dysfunction measured by OKN-saccades impairment grading but not with the Ocular Disorder subscore of ICARS (ICARS-OD).

CONCLUSION

OKN-saccades are a better and sensitive bedside clinical tool to quantify oculomotor dysfunction in neurodegenerative ataxias. Its role needs to be tested further in presymptomatic carriers. The current ICARS-OD scale to grade oculomotor dysfunction in degenerative ataxias need to be modified.