J Epidemiol Community Health: first published as 10.1136/jech.41.1.5 on 1 March 1987. Downloaded from Journal of Epidemiology and Community Health, 1987, 41, 5-13 Epidemiology of multiple sclerosis in the north-east (Grampian Region) of Scotland-an update JAYANT G PHADKE AND ALLAN W DOWNIE From the Department of Neurology, Aberdeen Royal Infirmary SUMMARY The north-east of Scotland (Grampian Region) has undergone three incidence and prevalence surveys, including the present one, since 1970. Results from these indicate a true increase in the prevalence ofthe disease in the region. The incidence ofthe disease has remained continuously high and shows a slightly upward trend. Literature on the subject of repeated surveys in different regions ofthe world has been reviewed in detail. The need for a prevalence study from the south ofthe British Isles has been emphasised in order to enable one to judge if the increase in Scotland is in keeping with the pattern in the whole of the British Isles. The familial incidence of the disease was noted to be virtually unchanged between the three surveys. Certain other aspects of aetiological significance have been analysed, viz, clustering of patients at birth or at onset of the disease; ages of occurrence of childhood viral infections such as measles, mumps, chickenpox and rubella; and the role of canine distemper infection. Protected by copyright. The area now known as the Grampian Region has been 7 I previously reported 2 to have the highest prevalence of multiple sclerosis (MS) compared to any other surveyed area of comparable population (471 000). We have carried out a further study ofincidence and prevalence of the disease as at December 1980 to assess the present situation. In addition, historical details of possible aetiological relevance were enquired about, foreudar example, age of occurrence of certain childhood viral MorY Buchan infections, degree of exposure to dogs as domestic pets, and family history of neurological disease or of Go , autoimmune diseases. The clinical features of the berdeen disease, with particular attention to its course and ide ond http://jech.bmj.com/ prognosis, were also studied and will form subjects of later publications. Materials and methods rigFioictritc1Ii1 utstricts7ii.UojnfrnmninnLyramptan megionRoia5nn sinceJiU5l iA07YIy/j Due to administrative reorganisation since 1975, the north-east area has been reformed as Grampian was of the nucleus of those found 1980 series made up on September 28, 2021 by guest. Region. This corresponds closely with the area in the earlier studies who were known not to have died previously surveyed, but minor and appropriate or left the area, and to this were added all the new adjustments had to be made in some boundary areas. patients ascertained from a variety of sources since A breakdown into the 28 areas containing a that time. These sources included hospital diagnostic population of 10 000 or more as carried cwt in the record index, neurology departmental records, previous two surveys' 2 to allow comparisons of including the records of patients referred for visual prevalence in these small sub-units was not possible evoked responses, patients found in long-stay wards, because of the reorganisation, but the new sub- patients found in the local branch of the Multiple division ofthe region into five districts still allowed for Sclerosis Society, and patients under care of the some comparisons between the three surveys. The Community Nursing Services. After preliminary 5 J Epidemiol Community Health: first published as 10.1136/jech.41.1.5 on 1 March 1987. Downloaded from 6 Jayant G Phadke and Allan W Downie screening of case notes of all the patients compiled during the major part of their childhood, and their from the above sources (1200), lists of suspected occupation at the presumed onset. patients known to be cared for by individual general From all these and other clinical and social details practices were prepared. National Health Service from the assembled data, patients were classified into numbers, present address, and name of the general possible and probable MS categories as in the earlier practitioner for each patient were personally obtained series' 2 in which Broman et ars (1965)4 modifications from records of the local Primary Care Department, ofAllison and Millar's (1954)5 classification was used, and this made the tracing ofpatients much easier. The although on this occasion the categories previously list of patients known to be in each general practice labelled probable (group 1) and early probable and was then submitted to the practice with a request, as latent (group 2) were merged, while the category before, that they notify any other cases known to them possible was retained as before. Probable MS but not to us, and remove any patients who were no therefore included patients with a history and physical longer on their lists. Information about current signs of a central nervous system disease disseminated disability status (using McAlpine's Disability Scale3), in time and place, in whom other neurological about the number ofrelapses since the patient was last conditions had been excluded as far as possible. Also seen in the hospital, and also about other possible included in this category were patients at an earlier relevant factors, as mentioned above, was requested. stage of the disease with a relapsing remitting course, The returned questionnaires from the general who had few persisting physical signs of central practitioners added 13 further cases of multiple nervous system lesion, but in whom diagnosis was sclerosis to the number about whom information had supported by paraclinical evidence such as elevated already been available, but six cases had to be removed immunoglobulin G in the CSF, prolonged visual from our preliminary lists as notice oftheir death since evoked response latency or an abnormal CT scan. the previous survey had not been received from other Possible MS included patients with a history and sources. In ten patients identified in the 1973 survey, examination compatible with MS in whom otherProtected by copyright. further events had made the diagnosis ofMS no longer diagnoses had been excluded as far as possible. tenable, and in two of these another diagnosis had Evidence of multiplicity of lesions was sometimes been established at necropsy. lacking in these patients. This group included some The 'balance sheet' showing the change between patients with progressive spastic paraparesis where 1973 and 1980 is shown in table 1. All except five full investigations, including myelography, had patients were examined at least once, and a large excluded other likely causes of such a picture. Patients number had been examined several times by a member with optic neuritis alone were not included. of the Neurological Services in Aberdeen. Finally, because of easy storage, ready access, and After all the available information from the family ability to carry out complete correlations and doctor and from the hospital case notes had been statistical analyses, all the above data were coded and entered on a patient's card, questionnaires were sent to entered on a main line computer. As in the 1973 each patient asking for details ofthe ages at which they study,2 all patients were 'flagged' in the central had suffered from the various infective illnesses Registrar's Office at Edinburgh by sending that office (mumps, measles, chickenpox, rubella, and herpes each patient's full name, age, National Health Service zoster). They were also asked for their address at the number, and address. This has proved to be invaluable http://jech.bmj.com/ presumed onset of their disease, at their birth, and in reliable ascertainment of deaths in the past. Results Table I Analysis and details of 1980 survey In all, 839 patients thought to have the disease were Number ofpatients present in the region on the prevalence day, 1 Source Female Male Total December 1980. Six hundred and eighty-two were in 1973 Survey 402 232 634 the probable and 157 in the possible category. on September 28, 2021 by guest. Deaths between 1973 and 1980 from the 1973 Survey 77 42 119 Left area between 1973 and 1980 24 9 33 DISEASE PREVALENCE Cases rejected from 1973 Survey 8 2 10 Despite stringent and only slightly altered selection Remaining cases from 1973 Survey 293 179 472 criteria, the prevalence figures indicate a marked Migration into Grampian after increase between 1970, 1973, and the present survey onset of disease elsewhere 20 5 25 New cases since 1973 Survey (table 2). (alive on prevalence day I Dec. 1980) 236 106 342 The new administrative districts created in the 549 290 839 reorganisation of 1975 are shown in figure 1. The total Total cases in 1980 survey population rose by 44 000 between the 1971 and 1981 J Epidemiol Community Health: first published as 10.1136/jech.41.1.5 on 1 March 1987. Downloaded from Epidemiology ofmultiple sclerosis in the north-east (Grampian Region) of Scotland-an update 7 Table 2 Prevalence ofmultiple sclerosis in the Granpian Region of Scotland (1970,.1973 and 1980) No ofpatients Prevaknce rate/lOO 000 Year Mak Femaak Total Probabk Possible M.:F ratio Probable All cases 1970 215 342 557 464 95 1:1-59 106 127 1973 232 402 634 517 117 1:1-73 117 144 1980 290 549 839 682 157 1:1-89 145 178 NB. The prevalence rates have been rounded up to the nearest whole number census.6 Figures obtained in the 1973 survey from the noted between any of the districts. No trend was small sub-units were rearranged to allow a noticeable either on arranging the figures for the comparison, and an excess noted in 1973 in the area address at onset in a similar way.