Displaying publications 21 - 40 of 54 in total

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  1. Viswanathan S
    Mult Scler Relat Disord, 2020 Sep;44:102353.
    PMID: 32653804 DOI: 10.1016/j.msard.2020.102353
    The Covid-19 pandemic poses a grave health management challenge globally of unprecedented nature. Management of idiopathic Central Nervous system inflammatory disorders (iCNSID) such as Multiple sclerosis, Neuromyelitis optica and its spectrum disorders and related conditions during this pandemic needs to be addressed with affirmative and sustainable strategies in order to prevent disease related risks, medication related complications and possible COVID-19 disease associated effects. Global international iCNSIDs agencies and recent publications are attempting to address this but such guidance is not available in South East Asia. Here we outline prospectively qualitatively and quantitatively novel strategies at a tertiary center in Malaysia catering for neuroimmunological disorders despite modest resources during this pandemic. In this retrospective study with longitudinal follow-up, we describe stratification of patients for face to face versus virtual visits in the absence of formal teleneurology, stratification of patients for treatment according to disease activity, rescheduling, deferring initiation or extending treatment intervals of certain disease modifying therapies(DMT's) or immunosuppressants(IS), especially those producing lymphocyte depletion in MS and the continuation of IS in patients with NMO/NMOSD. Furthermore, we highlight the use off-label treatments such as Intravenous immunoglobulins/rituximab,bridging interferons/Teriflunomide temporarily replacing more potent DMT choices,supply challenges of IS/DMT's and tailoring blood watches and neuroimaging surveillance based on the current health needs to stave off the pandemic and prevent at risk patients with iCNSID/health care workers from possibly being exposed to the COVID-19.
  2. Ooi HS, Viswanathan S, Botross NP, Eow GB, Chin YT, Kanesalingam R, et al.
    Neurol India, 2020 8 30;68(4):850-855.
    PMID: 32859827 DOI: 10.4103/0028-3886.293469
    Background: The association between appendectomy and multiple sclerosis (MS) is unknown. In this study, we explored the association between appendectomy and MS and neuromyelitis optica spectrum disorder (NMOSD).

    Patients and Methods: MS and NMOSD patients older than 40 were identified from neurology records from hospitals in Malaysia. The diagnoses were based on the Revised McDonald (2010) and Wingerchuk (2015) criteria. Controls were sampled from Malaysia's normal population. Individuals were interviewed telephonically or face-to-face. The age inclusion criterion (over 40) differentiated high or low lifetime risk of appendicitis, as appendicitis incidence is rare after 40.

    Results: 49 MS, 71 NMOSD, and 880 controls met the inclusion criteria. Seventy-two individuals (9 MS, 4 NMOSD, 59 control) had undergone appendectomy. Appendectomy rates were 18.37% in the MS group (95% CI 7.5-29.2%), 5.6% in the NMOSD group (0.3%, 11%), and 6.7% among controls (5.1%, 8.4%), (MS vs NMOSD P = 0.036, MS vs controls P = 0.007). Binary regression analysis showed that MS was an independent risk factor for appendectomy (OR 2.938, 95% CI 1.302, 6.633, P = 0.009). NMOSD showed no association with appendectomy.

    Conclusion: MS is positively associated with appendectomy, unlike ulcerative colitis, which is negatively associated. We hypothesize that there is a commonality in the microflora in persons who have had these two illnesses.

  3. Ong ZM, Schee JP, Viswanathan S
    Ther Apher Dial, 2020 Jun;24(3):312-323.
    PMID: 31654607 DOI: 10.1111/1744-9987.13446
    We evaluated therapeutic plasma exchange (TPE) efficiency in treatment of a single relapse in steroid-refractory patients with neuromyelitis optica spectrum disorders (NMOSD) in a multi-ethnic resource-limited setting. This was a historical cohort study on the clinical outcomes post-TPE in a multiethnic cohort of 53 steroid-refractory NMOSD patients at a single Malaysian tertiary center. Primary outcomes, assessed both pre- and post-TPE, were Medical Research Council scale of muscle power, Modified Rankin Scale, Expanded Disability Status Scale (EDSS), and visual acuity. Secondary outcomes were ambulatory status and target neurological deficit (TND)-based TPE response. Significant improvements in Medical Research Council, Modified Rankin Scale, EDSS, and visual acuity (P 14 days (P = 0.047) were significantly associated with improved EDSSΔ6. TND-based TPE response was significant in absence of cord atrophy (P = 0.030). TPE is an effective treatment for steroid-refractory acute relapses of NMOSD in a multiethnic Malaysian population despite its resource-limited setting. The predictive factors of EDSSΔ6 improvement were anti-aquaporin 4 seronegativity, longer cord lesions, and higher pre-TPE EDSS. Absence of cord atrophy was predictive of better TND-based TPE response. Unexpectedly, our study showed that delayed TPE initiation of more than 14 days and up to 60 days may also be beneficial.
  4. Ching YM, Viswanathan S, Mohamed Nor N, Shuib S, Kamarudin B, Mansor S, et al.
    Auto- immunity highlights, 2019 Dec;10(1):13.
    PMID: 32257069 DOI: 10.1186/s13317-019-0123-7
    Background: Multiple sclerosis is an immune mediated disease targeting the central nervous system. Association of non-human leukocyte antigen gene, CD58, with multiple sclerosis has been reported in several populations but is unclear among Southeast Asians. This pilot study was conducted to explore the association between CD58 polymorphism and multiple sclerosis among the Malay population in Malaysia.

    Methods: Blood samples were collected from 27 multiple sclerosis patients, and compared with 58 age- and gender matched healthy individuals. All patients were tested negative for anti-aquaporin 4. DNA was extracted from the blood and genotyped for 3 single nucleotide polymorphisms rs12044852, rs2300747 and rs1335532 of gene CD58 by real-time PCR.

    Results: The majority of multiple sclerosis patients were female (85.2%). The general mean age of onset was 30.5 years. Genotyping results showed that frequencies of the alleles were between 40 and 50% for MS patients and healthy individuals. Association (allelic model) between multiple sclerosis and CD58 gene polymorphism alleles rs12044852 (p = 0.410), rs2300747 (p = 0.881) and rs1335532 (p = 0.407) were indistinct.

    Conclusions: The impact of the CD58 gene polymorphism was not prominent in this pilot study, implying that genetic composition contributing to multiple sclerosis may be different between different populations, thus results in a heterogeneity of disease manifestation and distribution.

  5. Gopalai AA, Lim JL, Li HH, Zhao Y, Lim TT, Eow GB, et al.
    Mol Genet Genomic Med, 2019 Nov;7(11):e604.
    PMID: 31487119 DOI: 10.1002/mgg3.604
    BACKGROUND: The LRRK2 gene is associated with Parkinson's disease (PD) as a number of mutations within the gene have been shown to be susceptibility factors. Studies on various global populations have determined that mutations such as G2019S, G2385R, and R1628P in LRRK2 increase the risk of developing PD while the N551K-R1398H haplotype is associated with conferring protection against developing PD. Here we report a study looking at the N551K and R1398H variants for the first time in the Malaysian population.

    METHODS: Cases (523) which conformed to the United Kingdom PD Brain Bank Criteria for PD were recruited through trained neurologists and age- and ethnically matched controls (491) were individuals free of any neurological disorder. The N551K and R1398H mutations were genotyped using the Taqman SNP genotyping assay.

    RESULTS: A significant protective association for N551K was found in those of Malay ancestry, with a protective trend seen for R1398H. A meta-analysis of Chinese individuals in this cohort with other published cohorts of Chinese ancestry indicated a significant protective role for N551K and R1398H.

    CONCLUSION: This study reports that the N551K-R1398H haplotype is also relevant to the Malaysian population, with a significant protective effect found in those of Malay and Chinese ancestries.

  6. Viswanathan S, Wah LM
    Mult Scler, 2019 10;25(11):1452-1461.
    PMID: 30113245 DOI: 10.1177/1352458518792430
    OBJECTIVES: This study looked at observed crude prevalence/incidence of multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) in Malaysia and identified any inter-ethnic differences for MS/NMOSD.

    METHODS: This was a nationwide tertiary hospital-based retrospective cross-sectional study using the capture-recapture method. It looked at the estimated crude prevalence of confirmed MS and NMOSD and annual incidence on 29 December 2017. Recapture of data was done between February and March 2018 on 1 March 2018. Public and referring private institutions were accessed.

    RESULTS: The survey identified 767 MS and 545 NMOSD subjects, with crude prevalence rates of 2.73 per 100,000 (95% confidence interval (CI): 2.53; 2.92 per 100,000 population) and 1.94 per 100,000 (95% CI: 1.77; 2.10 per 100,000 population) with observed crude annual incidence of 0.55 (95% CI: 0.43; 0.58) for MS and 0.39 per 100,000 (95% CI: 0.35; 0.47) for NMOSD. The MS:NMOSD ratios were 1.4:1.0. The capture-recapture method revealed 913 MS (95% CI: 910; 915.9) and 580 (95% CI: 578.8; 581.2) NMOSD with prevalence per 100,000 of 3.26 (95% CI: 3.05; 3.47) and 2.07 (95% CI: 1.90; 2.24), respectively. In the MS group, 59.4% were Malay, 16.6% Chinese, 20.5% Indian, and 3.5% were from indigenous groups. In the NMOSD group, 47.3% were Malay, 46.9% Chinese, 3.5% Indian, and 2.3% were from other indigenous groups. The ratio of NMOSD to MS among the Chinese was 2:1, but the ratio of MS to NMOSD among the Malays was 1.8:1, and that in Indians was 8.3:1.

    CONCLUSION: There is a modest increase in the prevalence of MS and NMOSD in Malaysia with inter-ethnic differences for MS/NMOSD.

  7. Pittock SJ, Berthele A, Fujihara K, Kim HJ, Levy M, Palace J, et al.
    N Engl J Med, 2019 08 15;381(7):614-625.
    PMID: 31050279 DOI: 10.1056/NEJMoa1900866
    BACKGROUND: Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing, autoimmune, inflammatory disorder that typically affects the optic nerves and spinal cord. At least two thirds of cases are associated with aquaporin-4 antibodies (AQP4-IgG) and complement-mediated damage to the central nervous system. In a previous small, open-label study involving patients with AQP4-IgG-positive disease, eculizumab, a terminal complement inhibitor, was shown to reduce the frequency of relapse.

    METHODS: In this randomized, double-blind, time-to-event trial, 143 adults were randomly assigned in a 2:1 ratio to receive either intravenous eculizumab (at a dose of 900 mg weekly for the first four doses starting on day 1, followed by 1200 mg every 2 weeks starting at week 4) or matched placebo. The continued use of stable-dose immunosuppressive therapy was permitted. The primary end point was the first adjudicated relapse. Secondary outcomes included the adjudicated annualized relapse rate, quality-of-life measures, and the score on the Expanded Disability Status Scale (EDSS), which ranges from 0 (no disability) to 10 (death).

    RESULTS: The trial was stopped after 23 of the 24 prespecified adjudicated relapses, given the uncertainty in estimating when the final event would occur. The mean (±SD) annualized relapse rate in the 24 months before enrollment was 1.99±0.94; 76% of the patients continued to receive their previous immunosuppressive therapy during the trial. Adjudicated relapses occurred in 3 of 96 patients (3%) in the eculizumab group and 20 of 47 (43%) in the placebo group (hazard ratio, 0.06; 95% confidence interval [CI], 0.02 to 0.20; P<0.001). The adjudicated annualized relapse rate was 0.02 in the eculizumab group and 0.35 in the placebo group (rate ratio, 0.04; 95% CI, 0.01 to 0.15; P<0.001). The mean change in the EDSS score was -0.18 in the eculizumab group and 0.12 in the placebo group (least-squares mean difference, -0.29; 95% CI, -0.59 to 0.01). Upper respiratory tract infections and headaches were more common in the eculizumab group. There was one death from pulmonary empyema in the eculizumab group.

    CONCLUSIONS: Among patients with AQP4-IgG-positive NMOSD, those who received eculizumab had a significantly lower risk of relapse than those who received placebo. There was no significant between-group difference in measures of disability progression. (Funded by Alexion Pharmaceuticals; PREVENT ClinicalTrials.gov number, NCT01892345; EudraCT number, 2013-001150-10.).

  8. Viswanathan S, Hiew FL
    J Clin Apher, 2019 Aug;34(4):434-444.
    PMID: 30829434 DOI: 10.1002/jca.21696
    There has been an increase in the use of therapeutic plasma exchange (TPE) in immune-mediated neurological disorders in recent years. However, accessibility and availability of TPE remains low and costly, especially for a country with limited healthcare funding like Malaysia. With expanding clinical indications in neurological disorders, and increasingly expensive conventional immunomodulatory treatment such as intravenous immunoglobulin and monoclonal antibodies, TPE remains an effective part of first or second-line treatment. In this article, we detailed the historical aspects of the use of TPE in neurological disorders in Malaysia over the last four decades and discussed the challenges behind the establishment of the first in-house neurology-driven TPE service in the country. Local TPE database from a national neurology centre in Kuala Lumpur over the past 20 years was analyzed. We observed a remarkable three folds increase in the use of TPE at our center over the past 10 years (total 131 TPE treatments) compared to a decade prior, with expanding clinical indications predominantly for central nervous system demyelinating disorders. Besides using membrane filtration method, centrifugal technique was adopted, providing new opportunities for other clinical beneficiaries such as a neurologist driven "in-house TPE unit". However, there were real world challenges, especially having to provide services with limited funding, human resources, and space. In addition, much has to be done to improve accessibility, availability, and sustainability of TPE services at our center and nationwide. Nevertheless, even with limited resources and support, it is possible with concerted efforts to work within the confines of these limitations to establish a safe, successful, and sustainable TPE service.
  9. Schee JP, Viswanathan S
    Mult Scler, 2019 07;25(8):1189-1195.
    PMID: 29771191 DOI: 10.1177/1352458518775912
    We identified five female patients retrospectively with relapsing short-segment partial myelitis whose clinical and paraclinical features were suggestive of cord involvement of multiple sclerosis (MS)-type albeit not rigidly fulfilling the 2017 McDonald criteria. Notably, these patients had not developed any typical MS-like brain lesions despite repeated neuroimaging assessments over years. Comprehensive work-up for differential diagnoses of MS and other causes of transverse myelitis particularly neuromyelitis optica spectrum disorders had been consistently negative on longitudinal follow-up. Thus, we postulate a possible entity of pure spinal MS which may represent a novel forme fruste within the MS disease spectrum.
  10. Viswanathan S, Appiwatanakul M, Nayak A, Islam B, Khatri B, Pangeran D, et al.
    Ther Apher Dial, 2019 Jun;23(3):289-297.
    PMID: 30927331 DOI: 10.1111/1744-9987.12806
    In conjunction with the third regional Southeast Asian (SEA) therapeutic plasma exchange (TPE) conference in Kuala Lumpur, Malaysia, 25 clinicians and researchers from SEA and South Asian countries attended the inaugural strategy meeting for the establishment of a regional TPE consortium for neurological disorders. The primary objective was to establish regional collaboration to improve delivery of TPE services in SEA. A pre-meeting survey was conducted to gather insights on disease spectrum, contextual practice challenges, and the need for a regional TPE consensus. Challenges identified include limited healthcare funding in support of diagnostic workup, TPE therapy, as well as development of clinical infrastructure and expertise capacity building. There was favorable interest in developing a working plan contextualized to this region. Strategies to overcome challenges were discussed. This included the need for a comprehensive referral system and network of regional TPE centers suited to local needs, supported by innovative TPE delivery programs.
  11. Yan Hung SK, Hiew FL, Viswanathan S
    Ann Indian Acad Neurol, 2019 1 30;22(1):102-103.
    PMID: 30692769 DOI: 10.4103/aian.AIAN_232_18
    Multiple co-infections can predispose a patient to autoimmune encephalitis. Out of thirty cases of N-methyl-D-aspartate receptor (NMDAR) encephalitis seen at a single tertiary referral center, only two cases of co-infection with NMDAR encephalitis were identified. One of these cases was highly interesting due to the presence of more than one co-infections along with the presence of cortical dysfunction, seizures, and orofacial dyskinesias at the onset in a male in the absence of tumors, which was refractory to initial treatment.
  12. Viswanathan S, Hung SKY, Goyal V, Apiwattanakul M, Thirugnanam UN, Abdullah S, et al.
    J Clin Apher, 2018 Oct;33(5):559-568.
    PMID: 29626354 DOI: 10.1002/jca.21630
    In December 2017, 79 delegates attended the 2nd regional plasmapheresis conference and workshop for Southeast Asia (SEA) on the immunomodulatory role of plasma exchange in central and peripheral nervous system disorders in Kuala Lumpur, Malaysia. This meeting featured 6 plenary lectures, interactive sessions dedicated for experience sharing, case presentations, and a practical session for paramedics. Clinical experts and researchers from 7 SEA countries and India shared experience and challenges in treating autoimmune neurological disorders. While the spectrum of diseases and neurology practice remained largely similar, there was great disparities in accessibility of therapeutic plasma exchange (TPE) within SEA countries and between urban or rural settings. Costs, human resources, and healthcare policies are common challenges in providing sustainable TPE services. Novel techniques and innovative ideas in performing TPE were explored. A working consortium comprising of key opinion leaders was proposed to improve standards of TPE and enhance future research.
  13. Viswanathan S, Rose N, Arip M, Chai CH, Law WC, Sim R, et al.
    Mult Scler Relat Disord, 2018 Oct;25:300-308.
    PMID: 30172173 DOI: 10.1016/j.msard.2018.07.003
    We performed a retrospective observational analytical study looking at the frequencies and characteristics of multiple sclerosis(MS) and neuromyelitis optica spectrum disorders(NMOSD) in consecutive patients with idiopathic inflammatory demyelinating disease (IIDDs) attending three centers (2009-2017). Of 523 patients with IIDDs, there were 173 patients with NMOSD and 230 patients with MS. The percentage of NMOSD: IIDDs was 33%. The percentage of NMOSD:Total MS and NMOSD cohort was 43%. Of 141 seropositive NMOSD patients, 134(95%) were from the three main ethnic groups. The percentage of seropositive NMOSD to IIDDs and to combined MS and NMOSD was 26.9% and 35% respectively. Ratios of MS to NMOSD were nearly equal at 1.3 to 1.0, reinforcing the high ratio of NMOSD to MS in Asia. Nearly half of the Chinese cohort were seropositive ie; 71/141 (50%) with the remainder being Malays; 56/141 (39.7%) and Indians; 7/141 (5%). Amongst the other indigenous groups seropositivity was seen in 2 each of Iban, Bajau, Kadazan descent as well as one of Bidayuh origin. Comparatively, seropositivity in NMOSD is commoner amongst the Chinese compared to the Malays (p ≤ 0.005) and Indians, p ≤ 0.05 with ratios as high as 10:1. In the MS group of 230 subjects, 123(53.5%) were Malays (ratio of MS:NMOSD of 2:1), 41(17.8%) were Chinese, (ratio of MS:NMOSD of 0.5:1.0) and 54 (23.5%)were Indians (ratios of MS:NMOSD of 5:1 amongst the Indians). The remainder from East Malaysia were made up of 2 each of Kadazans, Ibans and Bajaus including 3 each of Bidayuh and Eurasian descent. Comparatively, in the NMOSD and MS cohorts a female preponderance was noted more so amongst Chinese NMOSD patients, with rare familial occurrence in both but more in Malay MS/NMOSD patients. This study also highlighted some of the inter-ethnic differences in presentation of MS and NMOSD amongst the 3 main ethnic races in Malaysia and confirms indigenous races having MS/NMOSD which needs further research. It also reviewed current literature on similar inter-ethnic differences world wide. To conclude, MS and NMOSD are the commonest demyelinating diseases seen in Malaysia with interesting inter-ethnic differences and similarities.
  14. Hung SKY, Hiew FL, Viswanathan S, Puvanarajah S
    J Peripher Nerv Syst, 2018 Sep;23(3):183-189.
    PMID: 30027593 DOI: 10.1111/jns.12282
    Intravenous immunoglobulin (IVIG), corticosteroids and therapeutic plasma exchange (TPE) are evidence-based conventional treatments for chronic inflammatory demyelinating polyneuropathy (CIDP). In many centres, unconventional treatments are frequently used as alternatives. We evaluated the outcome of conventional and unconventional therapies in 31 CIDP patients. Overall response rate with conventional first-line immunotherapies was 77% (20/26), comparable between IVIG and corticosteroids (80% vs 70%). Use of TPE was limited. Treatment response among typical and atypical CIDP were comparable (76 vs 80%). Non-responders were patients with progressive form of typical CIDP and DADS. Majority (21/26, 81%) of patients with persistent neurological deficits received maintenance therapy. Two subgroups of patients frequently treated with maintenance immunosuppressants were those with improving or stable disease following first-line treatment (12, 57%) and those with progressive form of CIDP (2, 10%). Primary indications for immunosuppressant use were corticosteroids-sparing and additional immunosuppression effects. Nine (64%) patients with improving or stable disease given azathioprine were taken off corticosteroids after a median duration of 14 months (range 12-108). Two (14%) eventually achieved cure or clinical remission without treatment. Maintenance IVIg was given to 6 (29%) relapsing CIDP patients; none of achieved cure or remission after similar median duration of treatment. Less potent immunosuppressant drugs (azathioprine, mycophenolate mofetil, and methotrexate) were frequently used, with moderate adverse effect profiles. In resource limited setting, unconventional treatments were commonly used among CIDP patients with different clinical course of progression. In most cases, careful risk-benefit re-assessment is required to justify its further use.
  15. Hiew FL, Ong JJ, Viswanathan S, Puvanarajah S
    J Clin Neurosci, 2018 Apr;50:203-207.
    PMID: 29398193 DOI: 10.1016/j.jocn.2018.01.018
    Long-term outcome in Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) is very limited, especially from Asian countries. We aimed to determine the outcome of our cohort of CIDP patients and to define the relevant clinical, electrophysiological and laboratory determinants of disease activity, progression and treatment response. We retrospectively reviewed records of 23 CIDP patients attending our Neurology service at Kuala Lumpur Hospital, Malaysia between January 2000 and December 2016. We analysed data on neurological deficits, electrophysiological and laboratory parameters to determine diagnostic characteristics, correlation with disease activity and clinical outcomes following treatment. Included were 15 (65%) males and 8 (35%) females with a mean age of 42.7 years (SD 14.4). Mean duration of follow-up visit was 66 months (range 6-134 months). The cohort consists of 19 classical (sensory-motor) CIDP and 4 MADSAM. Large majority of patients (66%) had either stable active disease (CDAS 3, 44%) or were in remission (CDAS class 2, 22%) following treatment with standard immunotherapies (Intravenous Immunoglobulins, steroids or immunosuppressants). The proportion of CIDP patients in each CDAS class was comparable to published cohorts from North America and Europe. Medical Research Council (MRC) sum score was the only clinical score that differed across CDAS classes (p = .010) with significant inverse correlation (Spearman's rho -0.664, p = .001). In conclusion, treatment outcomes of our CIDP cohort was comparable to those of published series. Further studies with larger cohort of patients from other parts of Asia are important to determine the long-term outcome of this heterogenous disease in this region.
  16. Chee KY, Ong KY, Mak CY, Yacob S, Yeo SC, Thrichelam N, et al.
    Asia Pac Psychiatry, 2017 Dec;9(4).
    PMID: 28326670 DOI: 10.1111/appy.12278
    INTRODUCTION: The objective of this study was to establish the psychometric properties of the AD8 Dementia Screening Interview in patients with Parkinson disease (PD) with or without cognitive impairment using the Montreal Cognitive Assessment Tool (MoCA) for comparison.

    METHODS: The AD8 was translated into Malay for Malay-speaking participants. A correlation analysis and a receiver operator characteristic curve were generated to establish the psychometric properties of the AD8 in relation to the MoCA.

    RESULTS: One hundred fifty patients and their caretakers completed the AD8 and MoCA. Using a cutoff score of 1/8, the AD8 had 81% sensitivity and 59% specificity for the detection of cognitive impairment in PD. With a cutoff score of 2/8, the AD8 had 83% specificity and 64% sensitivity. The area under the receiver operator characteristic curve was 80%, indicating good-to-excellent discriminative ability.

    DISCUSSION: These findings suggest that the AD8 can reliably differentiate between cognitively impaired and cognitively normal patients with PD and is a useful caregiver screening tool for PD.

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