OBJECTIVE: To study the epidemiology of multiple sclerosis in Hong Kong Chinese. DESIGN: Cross-sectional questionnaire survey. SETTING: Neurology and paediatric neurology departments in Hong Kong from January through June 1999. PARTICIPANTS: All confirmed multiple sclerosis patients. MAIN OUTCOME MEASURES: Demographic data, investigation results, Kurtzke's Expanded Disability Status Scale during the last follow-up visit, number of relapses between 1997 and 1998, and treatments used/currently in use. RESULTS: Fifty-three Chinese multiple sclerosis patients were identified. The prevalence was thus estimated to be 0.77 per 100,000 population. This low prevalence was also noted in other multiple sclerosis studies from South-East Asia (range, 0.8-4 per 100,000 population). The female to male ratio among the Chinese multiple sclerosis sufferers was 9.6:1, a figure somewhat higher than that reported in the other studies from South-East Asia (range, 3.2-6.6:1). The Chinese multiple sclerosis patients in this study also had a high spinal cord involvement (66%) and a low presence of cerebrospinal fluid oligoclonal banding (40%). These findings were different from those in Caucasian multiple sclerosis patients. CONCLUSION: Multiple sclerosis in Hong Kong Chinese has a low prevalence, a high female to male ratio, and a low cerebrospinal fluid oligoclonal banding presence.published_or_final_versio

Chan, YW

Lau, KK

Li, HL

Li, LSW

Wong, LKS

Wong, V

Hong Kong Medical Journal

HKU Scholars Hub

Title Epidemiological study of multiple sclerosis in Hong KongChinese: questionnaire surveyAuthor(s) Lau, KK; Wong, LKS; Li, LSW; Chan, YW; Li, HL; Wong, VCitation Hong Kong Medical Journal, 2002, v. 8 n. 2, p. 77-80Issued Date 2002URL http://hdl.handle.net/10722/45233Rights Creative Commons: Attribution 3.0 Hong Kong LicenseHKMJ Vol 8 No 2 April 2002      77ORIGINAL ARTICLEKey words:Epidemiology;Hong Kong;Multiple sclerosis ! !"  !"Epidemiological study of multiplesclerosis in Hong Kong Chinese:questionnaire surveyObjective. To study the epidemiology of multiple sclerosis in Hong KongChinese.Design. Cross-sectional questionnaire survey.Setting. Neurology and paediatric neurology departments in Hong Kong fromJanuary through June 1999.Participants. All confirmed multiple sclerosis patients.Main outcome measures. Demographic data, investigation results, Kurtzke’sExpanded Disability Status Scale during the last follow-up visit, number ofrelapses between 1997 and 1998, and treatments used/currently in use.Results. Fifty-three Chinese multiple sclerosis patients were identified. Theprevalence was thus estimated to be 0.77 per 100 000 population. This lowprevalence was also noted in other multiple sclerosis studies from South-EastAsia (range, 0.8-4 per 100 000 population). The female to male ratio among theChinese multiple sclerosis sufferers was 9.6:1, a figure somewhat higher thanthat reported in the other studies from South-East Asia (range, 3.2-6.6:1). TheChinese multiple sclerosis patients in this study also had a high spinal cordinvolvement (66%) and a low presence of cerebrospinal fluid oligoclonalbanding (40%). These findings were different from those in Caucasian multiplesclerosis patients.Conclusion. Multiple sclerosis in Hong Kong Chinese has a low prevalence, ahigh female to male ratio, and a low cerebrospinal fluid oligoclonal bandingpresence.  !"#$%&'()*+,-./  !"#$ 199916 !"#$%&'()*+,-./01234567 !" #$% ! !"#$%&'()*+ !"#$ !"#$%&'#()*+%,-./0Kurtzke ! !"#19971998 !"#$%&'()"*+,-.'("/01  ! 53 !"#$%&'()*+,-./012 10 0.77 !"#$%&'()*+,-./01#2345( ! 100.8-4) !"#$%&'()*#+,#-./09.6:1 !"#$% !"#$%&'( 3.2-6.6:1) !"#$%&'()*+,-./ !(66%) !"#$%&'()*+,-.%(40%) !"#$%& !"#$%&'()*+&,  !"#$%&'()*+,-.%/0% $1/+23-4567 !"#$%&'()*!+○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○KK Lau  LKS Wong  LSW Li  YW Chan  HL Li  V Wong  HKMJ 2002;8:77-80 !"#$%&'()*+,-./0123Department of Medicine and Geriatrics,Princess Margaret Hospital, 2-10 PrincessMargaret Hospital Road, Hong KongKK Lau, MRCP, FHKAM (Medicine)HL Li, MB, ChB, FHKAM (Medicine)Department of Medicine and Therapeutics,Prince of Wales Hospital, Shatin, HongKongLKS Wong, MD, FRCPDepartment of Medicine, Tung WahHospital, Po Yan Street, Sheung Wan, HongKongLSW Li, FRCP, FHKAM (Medicine)Room 1902, Capitol Centre, 5-19 JardineBazaar, Causeway Bay, Hong KongYW Chan, FRCP, FHKAM (Medicine)Department of Paediatrics, Queen MaryHospital, 102 Pokfulam Road, Hong KongV Wong, MD, FRCPCorrespondence to: Dr KK LauIntroductionMultiple sclerosis (MS) is a particularly devastating disease of the central nervoussystem (CNS), as it strikes predominantly young adults during their mostproductive years. Even when patients are asymptomatic, they cannot predict whentheir condition will relapse again. The use of interferon and other immunomodu-lating therapies has been shown to be effective in the treatment of MS. For78      HKMJ Vol 8 No 2 April 2002Lau et alexample, studies have clearly shown that patients on inter-feron treatment have significantly longer mean symptom-free periods, shorter hospitalisation stays, and less burdenof disease according to magnetic resonance imaging (MRI)brain scans.1-4 However, these trials involved Caucasian MSsufferers, and to date there have been no controlled trials ofinterferon treatment in Chinese MS sufferers. Although it istempting to assume that Chinese MS patients will respondto interferon treatment in the same way as their Caucasiancounterparts, a study in Japan has shown that not only doAsians have a lower prevalence of the disease, but also adifferent pattern, suggesting heterogeneity in the immuno-genetic background.5 Accordingly, this survey was designedto study the prevalence of MS in Hong Kong Chinese andto characterise the clinical features of the disease.MethodsBetween January and June 1999, a territory-wide, cross-sectional survey of MS patients in Hong Kong was carriedout among all neurologists and some paediatric neurologistswho look after paediatric MS patients. Questionnairesconcerning patients’ demographic and clinical characteristicswere compiled. Investigation results including computedtomography (CT), MRI, evoked potential studies, and lum-bar puncture studies (cerebrospinal fluid [CSF] oligoclonalbanding) were also documented. Patients’ clinical status, iedegree of neurological impairment, were assessed usingKurtzke’s Expanded Disability Status Scale (EDSS).6The number of relapses patients experienced over a 2-yearperiod (1997-1998) were recorded, as were their past andpresent treatment.In some hospitals where there was no neurologist, thequestionnaires were sent to physicians with an interest inneurology. To ensure that they were fully completed, thequestionnaires were followed-up by telephone. Hospitalvisits and reviews of case notes were carried out on demandto confirm the diagnosis and current status of MS sufferers.Patients remained anonymous throughout the datacollection process, thereby protecting their privacy, and onlythose who had been followed-up in the 2 years prior to thestudy (ie 1997-1998) were included in the survey.ResultsFifty-three Chinese MS patients were identified, of whom 48were women and five were men. Fifty-one patients alreadyhad their diagnoses established by neurologists, while thetwo remaining MS sufferers had their diagnoses confirmedafter neurologists had the opportunity to review theirhospital records. Two non-Chinese (Caucasian) MS patientswere also identified, but were not recruited to this survey.The patients’ demographic and clinical characteristics(Tables 1 and 2), evoked potential and CSF oligoclonalbanding results (Table 3), and use of immunomodulatingtherapies (Table 4), are summarised. Two patients had afamily history of the disease. For each patient, the clinicalcourse of the disease was classified according to thecriteria suggested by Poser et al7: relapsing-remitting type;secondary progressive type; primary progressive type; orprogressive relapsing type.InvestigationsFifty-two of the 53 patients had MRI and/or CT scans ofthe brain/spinal cord. Of these, 46 (ie 88% of the totalnumber of patients and 87% of the number with scans) hadTable 1. Demographic characteristics of Chinese multiplesclerosis patients in Hong KongDemographic characteristicFemale:male 9.6:1Age of onset of symptoms (years) 29.4 (range, 11-60)Age of diagnosis (years) 32.8 (range, 13-64)Table 2. Clinical characteristics of Chinese multiple sclerosispatients in Hong KongPatients, n=53No. (%)Clinical courseRelapsing-remitting 38 (72)Secondary progressive 9 (17)Primary progressive 4 (8)Progressive relapsing 2 (4)Signs and symptoms At onset During the courseLimb weakness 34 (64) 36 (68)Paraesthesia 35 (66) 36 (68)Blurring of vision/ 24 (45) 27 (51)  blindness/scotomaVertigo 1 (2) 2 (4)Dysphasia 1 (2) 1 (2)Sphincter dysfunction 5 (9) 19 (36)Ataxia 3 (6) 6 (11)Facial palsy 1 (2) 2 (4)Partial transverse myelitis 22 (42) 35 (66)Cerebellar lesion 12 (23) 13 (25)EDSS* On diagnosis During last visit0-3.0 34 (64) 29 (55)3.5-5.0 11 (21) 9 (17)5.5-6.0 4 (8) 3 (6)6.5-7.0 2 (4) 3 (6)7.5-8.0 2 (4) 8 (15)8.5-9.0 0 (0) 1 (2)>9.0 0 (0) 0 (0)* EDSS Kurtzke’s Expanded Disability Status ScaleTable 3. Investigations in multiple sclerosisAbnormal Total No.No. (%)Evoked potential studiesVisual evoked potential 26 (67) 39Brainstem auditory evoked potential 11 (32) 34Somato-sensory evoked potential 18 (62) 29Cerebrospinal fluid oligoclonal banding 10 (40) 25Table 4. Use of immunomodulating therapyImmunomodulating agents Used Currently usedInterferon-beta 13 8Azathioprine 13 3Cyclosporin 1 -Copolymer I 1 -Intravenous immunoglobulin 1 -Adrenocorticotrophic hormone 1 -HKMJ Vol 8 No 2 April 2002      79Multiple sclerosis in Hong Kong Chineseabnormalities that were compatible with the diagnosis ofMS. These patients belonged to the clinically definitediagnostic group that had laboratory-supported evidence.The remaining seven patients belonged to the clinicallypossible diagnostic group, because some investigations,such as MRI, were not performed. Thirty-five patients hadparaesthesia at the onset of their disease indicating spinalcord involvement. Nineteen (36%) patients had selectiveinvolvement of their optic nerves and spinal cords. Ofthese, four (7.5%) had normal MRI brain scans, and wereincluded because they satisfied the diagnostic criteria.The questionnaire revealed that only 25 (47%) of the53 patients had their CSF sent for oligoclonal banding, atest that helps confirm the diagnosis of MS. Of these, 10(40%) had banding present, namely: four (40%) out of 10patients who presented during a relapsing phase of theirdisease; and six (40%) out of 15 patients who presentedduring a non-relapsing phase of their disease.Clinical statusThe mean EDSS was 3.0 (range, 0-8.0) at the time of diagno-sis, increasing to 3.6 (range, 0-8.5) by the last follow-up visit.In other words, these MS patients, who on average startedwith moderate disability were more disabled after 2 years,although they still remained ambulatory. The mean numberof relapses within the 2-year period (1997-1998) was 1.1.DiscussionHong Kong has a population of 6.8 million people, of whommore than 99.7% are of southern Chinese origin. This studythus shows that the prevalence of Chinese MS sufferers isat least 0.77 per 100 000 population. There are 42 hospitalsin Hong Kong, of which 11 are general hospitals receivingreferrals. For complicated diseases, such as MS, patientswill most likely be referred to these hospitals. Hence, wetargeted all the neurologists at these 11 referral hospitalsand followed-up our questionnaires by telephone.In the event, the neurologists and their hospital notesprovided a comprehensive catchment for all MS patients inHong Kong. At the time the survey was conducted (1999),there were 35 neurologists in Hong Kong. This groupformed a small scientific community characterised by frequentacademic and social meetings. Moreover, they had a trackrecord of frequent, successful collaborative studies fordiseases, such as epilepsy, stroke, tuberculous meningitis,and Creuztfeldt-Jacob disease. Added to this, all relevantrecords in public hospitals had been computerised and codedusing the International Classification of Disease codingsystem. When MS patients were at an advanced stage oftheir disease, ie with high EDSS step and much debilitation,they were cared for by the out-reach medical staff ofpublic hospitals, the Community Geriatric Ambulatory Team.It is possible that information from one neurologist wholooked after another two MS patients was overlooked.When we cross-checked our data with the only MS patientsupport group in our locality, the number of participants wassmall, and all were under the care of (known) neurologists.The Chinese MS patient population is a very specificand highly selected group. Because of its small size, wetried to identify every individual through stringent diagnosticcriteria, and then only to count those who were beingactively followed-up, as this would provide maximumpatient information. Those MS sufferers who did not attendany follow-up, or who were being followed-up under thecare of private practitioners, would thus have been beyondthe reach of our survey. However, we believed this number tobe very small, as the treatment provided by public hospitalswas relatively inexpensive and also of a high standard.A study reported by Yu et al8 in 1989 found thatthe prevalence of MS in Hong Kong Chinese was 0.88 per100 000 population. Hence, the local prevalence of MS inChinese appears to have remained persistently low overthe intervening 10-year period. Our study also showed ahigh female to male ratio of MS sufferers (9.6:1). In 1999,the female to male ratio among the general populationof Hong Kong was 49.7:50.3. This combination of a lowprevalence of MS and a high female to male ratio has alsobeen observed in several other South-East Asian cities/countries (Table 5).5,8-12  In each case, the female to maleratio is much higher than in western MS, where it is about1.5:1. We thus conclude that low prevalence and highfemale to male ratio are two characteristics of MS in Asians.The prevalence of MS in the West varies from 5-25/100 000in Italy to 59-103/100 000 in Sardinia.13 Comparatively,Asian MS has a much lower prevalence.Notably, less than half of the patients had their CSF sentfor oligoclonal banding, which was present in 40%, regard-less of whether they were in a relapsing or non-relapsingphase of their disease. This figure is much lower than thatreported for western MS, in which about 80% to 90% ofpatients show positive banding. However, positive bandingin the CSF is not a pathognomonic feature for MS, and now-adays many patients will be investigated with MRI insteadof a lumbar puncture.Most (72%) patients in this study had relapse-remitting–type MS, of whom a further majority (71%) had EDSS stepsbetween 0 and 5.0, meaning that they remained ambulatory.Caucasian MS patients with these disease characteristicsTable 5. Demographic characteristics of multiple sclerosis inAsiaCity/country Prevalence Female:male(per 100 000 population)Hong Kong 0.77*-0.888 9.6:1*Malaysia9 2 6.6:1Thailand10 2 4:1Japan11 4 2.1:15Taiwan12 0.8 3.2:1* Data from this study80      HKMJ Vol 8 No 2 April 2002Lau et alare generally expected to benefit from receiving immuno-modulating therapy. Whether this is also true for theirChinese counterparts depends, of course, on the degree ofsimilarity between the two disease types.ConclusionsThis study has shown that the prevalence of MS in HongKong Chinese was at least 0.77 per 100 000 population.Taken together with the observed high female to maleratio of sufferers and low CSF oligoclonal banding pres-ence compared to that observed in western MS, thesefindings may imply heterogeneity in the immunogeneticbackground of the disease. Accordingly, the response ofChinese MS patients to interferon treatment will be import-ant to note.5 Given the small number of patients identified,a randomised, placebo-controlled trial to test the efficacyof interferon among Chinese MS sufferers in Hong Kong isnot feasible.14 Collaboration with other areas and countriesis necessary.AcknowledgementsWe would like to thank Dr YL Yu, Dr ATT Lee, Dr RTFCheung, Dr CM Chang, Dr TH Tsoi, Dr KF Ko, Dr CK Mok,Dr KK Mo, Dr HK Lin, Dr KK Ng, Dr CK Wong, Dr KYChan, Dr MC Kwan, and Dr KY Mok for their contributions.References1. The IFNB Multiple Sclerosis Study Group. Interferon beta-1b iseffective in relapsing-remitting multiple sclerosis. I. Clinical resultsof a multicenter, randomized, double-blind, placebo-controlled trial.Neurology 1993;43:655-61.2. Paty DW, Li DK. Interferon beta-1b is effective in relapsing-remittingmultiple sclerosis. II. MRI analysis results of a multicenter,randomized, double-blind, placebo-controlled trial. Neurology 1993;43:662-7.3. The IFNB Multiple Sclerosis Study Group and The University ofBritish Columbia MS/MRI Analysis Group. Interferon beta-1b in thetreatment of multiple sclerosis: final outcome of the randomizedcontrolled trial. Neurology 1995;45:1277-85.4. PRISMS (Prevention of Relapses and Disability by Interferon beta-1aSubcutaneously in Multiple Sclerosis) Randomised double-blindplacebo-controlled study of interferon beta-1a in relapsing/remittingmultiple sclerosis. Lancet 1998;352:1498-504.5. Kira J, Kanai T, Nishimura Y, et al. Western versus Asian types ofmultiple sclerosis: immunogenetically and clinically distinct disorders.Ann Neurol 1996;40:569-74.6. Kurtzke JF. Rating neurological impairment in multiple sclerosis:an expanded disability status scale (EDSS). Neurology 1983;33:1444-52.7. Poser CM, Paty DW, Scheinberg L, et al. New diagnostic criteria formultiple sclerosis: guidelines for research protocols. Ann Neurol 1983;13:227-31.8. Yu YL, Woo E, Hawkins BR, Ho HC, Huang CY. Multiple sclerosisamongst Chinese in Hong Kong. Brain 1989;112:1445-67.9. Tan CT. Multiple sclerosis in Malaysia. Neurol J Southeast Asia 1997;2:1-5.10. Vejjajiva A. Multiple sclerosis in Thailand. Neurol J Southeast Asia1997;2:7-10.11. Kuroiwa Y, Hung TP, Landsborough D, Park CS, Singhal BS. Multiplesclerosis in Asia. Neurology 1977;27:188-92.12. Hung TP, Landsborough D, Hsi MS. Multiple sclerosis amongstChinese in Taiwan. J Neurol Sci 1976;27:459-84.13. Rosati G. Descriptive epidemiology of multiple sclerosis in Europein the 1980s: a critical review. Ann Neurol 1994;36(Suppl 2):164S-74S.14. Lau KK, Lee PO, Chan KY, Chan YW, Chin KF. Interferon treatmentfor multiple sclerosis patients in Hong Kong. HKMJ 2000;6:221-3.

香港華人多發性硬化症的流行病學研究：問卷調查

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香港華人多發性硬化症的流行病學研究：問卷調查

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