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Dive into the research topics where Karthik Muthusamy is active.

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Featured researches published by Karthik Muthusamy.


Neurology India | 2015

Natural history of multiple sclerosis from the Indian perspective: Experience from a tertiary care hospital.

SubhransuS Jena; Mathew Alexander; Sanjith Aaron; Vivek Mathew; MayaMary Thomas; AnilK Patil; Ajith Sivadasan; Karthik Muthusamy; Sunithi Mani; JGrace Rebekah

CONTEXT Multiple sclerosis (MS) has a spectrum of heterogeneity, as seen in western and eastern hemispheres, in the clinical features, topography of involvement and differences in natural history. AIM To study the clinical spectrum, imaging, and electrophysiological as well as cerebrospinal fluid (CSF) characteristics and correlate them with outcome. SETTINGS AND DESIGN Retrospective analysis of MS patients during a period of 20 years. SUBJECTS AND METHODS Cases were selected according to recent McDonalds criteria (2010), They were managed in the Department of Neurology, Christian Medical College, Vellore. STATISTICAL ANALYSIS USED Chi-square and Fishers exact tests were used for categorical variables. Multiple binary logistic regressions were done to assess significance. Kaplan-Meier curves were drawn to estimate the time to irreversible disability. RESULTS A total of 157 patients with female preponderance (55%) were included. The inter quartile range duration of follow-up was 9.1 (8.2, 11) years for 114 patients, who were included for final outcome analysis. Relapsing remitting MS (RRMS) (54.1%) was the most common type of MS seen. RRMS had a significantly better outcome (odds ratio: 0.12, 95% confidence interval: 0.02-0.57, P = 0.008) compared to progressive form of MS (primary progressive, secondary progressive). The Expanded Disability Status Scale score of patients at presentation and at final follow-up was 4.4 ± 1.31 and 4.1 ± 2.31, respectively. During the first presentation, polysymptomatic manifestations like motor and sphincteric involvement, incomplete recovery from the first attack; and, during the disease course, bowel, bladder, cerebellar and pyramidal affliction, predicted a worse outcome. CONCLUSION A high incidence of optico-spinal presentation, predominance of RRMS and a low yield on cerebrospinal fluid (CSF) studies are the major findings of our study. A notable feature was the analysis of prognostic markers of disability.


Journal of Pediatric Neurosciences | 2014

Siblings with fucosidosis

Karthik Muthusamy; Maya Thomas; Renu George; Mathew Alexander; Sunithi Mani; Rohit Ninan Benjamin

Fucosidosis is a rare lysosomal storage disorder due to deficiency of fucosidase enzyme, with around 100 cases reported worldwide. Here, we describe the clinical and imaging features in two siblings with fucosidosis. An 8-year-old girl presented with global developmental delay, followed by regression of acquired milestones from 3 years of age with bipyramidal, extrapyramidal involvement, coarse facies, telangiectatic lesions, dysostosis multiplex, characteristic magnetic resonance imaging finding along with undetectable levels of the fucosidase activity, which confirmed the diagnosis. Younger sibling has mild developmental delay with autistic traits with no neuroregression until now. He also has undetectable level of fucosidase enzyme activity and is being considered for stem cell transplantation. New case reports would expand the clinical spectrum, early diagnosis and help formulating appropriate therapy. Early diagnosis is crucial and hence sibling screening can be done, and those in the presymptomatic stage can undergo hematopoietic stem cell transplantation, which is potentially curable.


Indian Journal of Pediatrics | 2016

Imaging in Pediatric Demyelinating and Inflammatory Diseases of the Brain- Part 1.

Sniya Valsa Sudhakar; Karthik Muthusamy; Sunithi Mani; Sridhar Gibikote; Manohar Shroff

Imaging plays an important role in the diagnosis, management, prognostication and follow up of pediatric demyelinating and inflammatory diseases of the brain and forms an integral part of the diagnostic criteria. Conventional and advanced MR imaging is the first and only reliable imaging modality. This article reviews the typical and atypical imaging features of common and some uncommon demyelinating and inflammatory diseases with emphasis on the criteria for categorization. Imaging protocols and the role of advanced imaging techniques are also covered appropriately.


Neurology | 2016

Pearls & Oy-sters: Mitochondrial neurogastrointestinal encephalomyopathy: Diagnosis and response to peritoneal dialysis.

Ajith Sivadasan; Karthik Muthusamy; Anil Kumar B Patil; Vivek Mathew; Mathew Alexander

A 26-year-old man born to nonconsanguineous parents was admitted with complaints of muscle cramps, fatigue, recurrent abdominal pain, and vomiting since 10 years of age. Since 16 years of age, he noted progressive weakness of the proximal and distal muscles of all 4 limbs with intermittent worsening precipitated by febrile illnesses. He reported dysesthesias of the extremities and gait unsteadiness, which worsened in the dark. There was deterioration of symptoms with progressive dyspnea, orthopnea, dysphagia, early satiety, abdominal pain, and postprandial vomiting associated with a weight loss of 13 kg in the 6 months prior to presentation. Previous treatment received elsewhere included intermittent oral corticosteroids and azathioprine with suboptimal benefit. There was history of proximal weakness, recurrent abdominal pain, and respiratory involvement in his younger sibling (age at onset 20 years), who had died of the illness within 4 years of disease onset.


Molecular genetics and metabolism reports | 2015

Cerebrotendinous xanthomatosis: Possibility of founder mutation in CYP27A1 gene (c.526delG) in Eastern Indian and Surinamese population

Atanu Kumar Dutta; Sumita Danda; Karthik Muthusamy; Mathew Alexander; Sniya Valsa Sudhakar; Samuel George Hansdak; Rini Bandyopadhyay; G.B. Bakhya Shree; L.Rekha

Cerebrotendinous xanthomatosis is a lipid storage disease characterized by diarrhea, cataract, tendon xanthoma and neurological regression if untreated. CYP27A1 is the only gene in which mutations are known to cause Cerebrotendinous xanthomatosis. We report two Indian families from different regions of India who underwent molecular testing of CYP27A1. The first family from Eastern India consisting of two affected individuals was found to have the c.526delG homozygous mutation in exon 3, previously reported from our laboratory, also in a patient from Eastern India. However the second affected individual from Southern India that we studied and two previously reported cases from Northern India have different mutations. Interestingly the only previous report of c.526delG mutation was in a Surinamese individual from the Netherlands. To date most of the pathogenic mutations for Cerebrotendinous xanthomatosis have been confined to single population except for R362C mutation which was reported from the Netherlands and the USA (Black). To our knowledge this is the second causal mutation for Cerebrotendinous xanthomatosis which has been reported in two different populations. As human trading was prevalent from Eastern India to Surinam by the Dutch settlers this mutation might suggest a common founder mutation in these populations.


Journal of Child Neurology | 2015

Hypomyelination, Hypodontia, Hypogonadotropic Hypogonadism (4H) Syndrome With Vertebral Anomalies: A Novel Association.

Karthik Muthusamy; Sniya Valsa Sudhakar; Sangeetha Yoganathan; Maya Thomas; Mathew Alexander

Hypomyelination, hypodontia, hypogonadotropic hypogonadism (4H) syndrome is a rare hypomyelination disorder with around 40 cases reported worldwide. Children with hypomyelination, hypodontia, hypogonadotropic hypogonadism syndrome present with varying degrees of developmental delay with a spastic ataxic syndrome with delayed eruption of teeth along with disruption in the eruption sequence, hypogonadotropic hypogonadism, and a fluctuating clinical course with intercurrent infections and varying periods of stability. The disorder is caused by mutations in POL3A and POL3B genes and is collectively termed as pol III–related leukodystrophies. Here we describe 2 children with hypomyelination, hypodontia, hypogonadotropic, hypogonadism syndrome and the association of multiple vertebral fusion anomalies in one of them, which has not been previously described in the literature. We conclude that the spectrum of the disorder is not limited to brain parenchyma alone and involves all the structures arising from neural ectoderm, and this needs further research.


European Journal of Medical Genetics | 2018

A family with floppy neonates with severe respiratory insufficiency: A lethal phenotype of RFT1 -CDG due to a novel mutation

Thangaraj Abiramalatha; Gautham Arunachal; Karthik Muthusamy; Niranjan Thomas

Congenital disorders of glycosylation (CDG) are a rapidly expanding group of inborn errors of metabolism with around 100 types described so far. Because of the limited number of reported cases in each type except PMM2-CDG, the complete clinical picture of other types is not known. RFT1-CDG is a rare type, with ten cases reported in the literature. Our patient presented as a floppy neonate with severe respiratory insufficiency and ventilator dependence in the newborn period. He had fetal growth restriction, facial dysmorphism, high arched palate, bilateral cryptorchidism, hypoplastic pons and cerebellum and probable hearing impairment. He succumbed to the illness on day 24 of life. There was a similar history of two previous sibling deaths in the early neonatal period due to respiratory insufficiency and history of multiple neonatal and infant deaths in the extended family. Transferrin iso-electric focusing was normal. Clinical exome sequencing revealed a novel homozygous missense mutation (c.1018 G > A) in RFT1 gene [NM_052859; c.1018G > A; p.G340S; ENST00000296292] and the parents were heterozygous for the same (ClinVar SVC000778540). The pathogenic variants so far reported are all missense variants affecting the luminal loops; whereas the variant in our case is in the trans-membrane helical domain. A strong family history of neonatal deaths and similar presentations in the previous 2 siblings suggests the homogenous phenotype of this mutation. Severe respiratory insuffiency and ventilator dependence shows the lethality of the disease phenotype and incompatibility with survival beyond the neonatal period.


Neurology India | 2017

Sonothrombolysis for acute ischemic stroke - Break on through to the other side.

Sanjith Aaron; Sunithi Mani; At Prabhakar; P Suresh Babu; Sanjeev Kumar; Rohith Ninan Benjamin; Ajith Sivadasan; Karthik Muthusamy; Anil Kumar B Patil; Vivek Mathew; Mathew Alexander

Background: Intravenous (IV) tissue plasminogen activator (tPA) infusion combined with transcranial low-frequency ultrasound waves targeted on the occluded arterial segment (sonothrombolysis) can increase recanalization in large artery-acute ischemic stroke (LA-AIS). Aims: To evaluate the benefits of sonothrombolysis in LA-AIS. Settings and Designs: An open-labeled observational study done in a quaternary care teaching hospital. Methodology: Patients with LA-AIS within the window period (<4.5 h) with no contraindications for IV-recombinant tPA were sonothrombolysed. Recanalization was monitored and graded using the transcranial Doppler thrombolysis in brain ischemia (TIBI) flow criteria and also by time of flight magnetic resonance angiography using a modified thrombolysis in myocardial infarction score. Parenchymal changes were assessed using computed tomography (CT) or diffusion-weighted imaging-Alberta Stroke Programme Early CT Score. National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) were used to assess the outcome. Results: Eighteen patients underwent sonothrombolysis and the mean onset to needle time was 138 min (range 65–256). TIBI residual flow grade of ≥2 was seen in 15 of 18 patients (83%). Immediate dramatic improvement (NIHSS score ≤3 points or improvement by ≥10 points) was seen in 6 of 18 patients (30%) and in 9 of 18 patients (50%) within the next 24 h. Two patients (one with TIBI 0, another with re-occlusion) underwent mechanical thrombectomy post-sonothrombolysis. Symptomatic hemorrhage occurred in 5.5% of the patients. At 6 months, 2 of 18 patients (11%) died and 10 of 16 patients (63%) achieved mRS ≤2. Conclusions: Sonothrombolysis appears to be a safe way to augment the effect of tPA without increasing the door to needle time with the added advantage of observing flow through the occluded artery in real time.


Annals of Indian Academy of Neurology | 2017

Clinical spectrum, therapeutic outcomes, and prognostic predictors in sjogren's syndrome-associated neuropathy

Ajith Sivadasan; Karthik Muthusamy; Bimal Patel; Rohit Ninan Benjamin; At Prabhakar; Vivek Mathew; Sanjith Aaron; Mathew Alexander

Objectives: There are limited data regarding long-term follow-up and therapeutic outcomes in Sjogrens syndrome (SS)-associated peripheral neuropathy. In this study, we aim to study the clinical, electrophysiological spectrum and therapeutic responses among the different subtypes of SS-associated neuropathy. The predictors of suboptimal treatment response will be identified. Methods: The study included a retrospective cohort of patients with SS-associated neuropathy between January 2012 and November 2015. Baseline clinical, laboratory, electrophysiological data and details of treatment were noted. Therapeutic outcomes were assessed at follow-up and compared among the different subtypes. Prognostic predictors were determined using logistic regression analysis. Results: Fifty-four patients were included in the study. Sensory ataxic neuropathy (17, including 9 with sensory ganglionopathy) and radiculoneuropathy (11) were the main subtypes. Notable atypical presentations included acute neuropathies, pure motor neuropathies, and hypertrophic neuropathy. Concomitant autoimmune disorders were present in 24 (44.4%) patients. Most presentations were subacute-chronic (51, 94.4%). Minor salivary gland biopsy had a higher yield compared to serological markers (81.5 vs. 44.4%). Sensory ataxic neuropathy was associated with greater severity and autonomic dysfunction. Improvement was noted in 33 (61%) patients. Cranial neuropathy and radiculoneuropathy subtypes were associated with the best treatment responses. Chronicity, orthostatic hypotension, baseline severity, and marked axonopathy (nerve biopsy) were predictive of a suboptimal therapeutic response. Conclusions: The study highlights the heterogeneous spectrum, atypical presentations, and differential therapeutic responses. SS-associated neuropathy remains underdiagnosed. Early diagnosis and prompt initiation of immunotherapy before worsening axonal degeneration is paramount. SS-associated neuropathy need not necessarily be associated with a poor prognosis.


Journal of clinical and diagnostic research : JCDR | 2016

Ocular Features and Visual Outcome in Children with Moyamoya Disease and Moyamoya Syndrome: A Case Series.

Deepa John; Karthik Muthusamy; Bhavagna Bandla; Sniya Valsa Sudhakar; Maya Thomas

Moya Moya Disease (MMD) is characterised by idiopathic vasculopathy affecting the terminal internal carotid arteries resulting in the formation of extensive collaterals at the base of the brain, leptomeninges and parenchymal regions with resultant infarcts and bleeds. Four children presented with clinico-radiological features suggestive of Moyamoya disease/syndrome. This includes global developmental delay, recurrent seizures, transient ischaemic attacks and impaired vision. The first patient had vision of 6/15 in both eyes with bilateral optic disc pallor. Second case also had bilateral optic disc pallor with arteriolar attenuation, but had vision of perception of light only in both eyes. The third child had vision of 6/60 with alternate divergent squint and clinical features suggestive of Neurofibromatosis 1 (NF 1). Fourth patient presented with poor fixation in both eyes with bilateral total cataract. He underwent bilateral cataract surgery with intraocular lens implantation and vision improved to 2/60 with good fixation. We also describe their medical and neurosurgical interventions in this report.

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Sunithi Mani

Christian Medical College

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Ajith Sivadasan

Christian Medical College

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Maya Thomas

Christian Medical College

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Sanjith Aaron

Christian Medical College

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Vivek Mathew

Christian Medical College

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At Prabhakar

Christian Medical College

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