Epidemiology of multiple sclerosis in Croatia Eris Materljan a, *, Juraj Sepcic b a Teaching Unit for Primary Care, Health Center Labin, School of Medicine, 20a Aldo Negri, 52220 Labin, Croatia b Department of Neurology, School of Medicine, University of Rijeka, Rijeka, Croatia Keywords: Epidermology; Croatian; Precalence; Incidence; Migrants ‘‘Not all that counts can be counted; not all that can be counted, counts’’. Bruce C. Schoenberg. 1. Introduction In 1897 Franjo Gutschy reported two cases of multi- ple sclerosis (MS) in the Liecnicki Viestnik [1]. This was the first official report of pathologically verified MS in Croats [2]. Radoslav Lopasic noted that ‘MS is present particularly in a restricted area in the western parts of Croatia’ [3]. In 1969 one of us (JS) carried out the first systematic epidemiological survey of MS in that region [4]. The present paper is a compilation of the results of an analysis of the Croatian national medical bibliogra- phy from 1887 to December 2000. Its aim is to provide an exhaustive review of epidemiological descriptive, analytic and genetic observations on MS in Croatia [5  /9]. From 1897 to 1945, the few papers dealing with MS discussed the symptoms, signs and differential diagnosis of the disease, most of them focusing on the relation between MS and pregnancy [5,6] (Fig. 1). From 1946 to 2000, MS research intensified, covering mostly its laboratory aspects, immunology and epidemiology [7  / 9]. The major contributions to MS research in Croatia were made in the analysis of cerebrospinal fluid by the Zagreb neurobiochemistry group [10,11], in the role of T- and B-lymphocytes, and of natural killer cells, by the Zagreb and Rijeka immunology groups, [12  /15] and epidemiological research by the Croatian Reference Center for Demyelinating Diseases in Rijeka [16 /22] (Fig. 2). Neuroepidemiological and clinical studies of MS in Croatia reveal a high percentage of erroneous diagnoses. This suggests that physicians in general, as well as some neurologists, are not well acquainted with its differential diagnosis, that uniform diagnostic criteria and algo- rithms for the disease are lacking, that complementary examinations frequently are incomplete and that the diagnosis of MS seems to be made irresponsibly in order for the patient to obtain disability assistance (Table 1) [23] (L. Radolovic-Prenc, unpublished data, 2001). 2. Descriptive epidemiology The prevalence data of MS in Croatia from 1969 to date are presented in Table 2, and from 1991 to date in Fig. 3. The rates indicate that Croatia is a zone of moderate to high risk for MS although it is certain that the data are incomplete. The distribution of MS in Croatia is not homogeneous: in Gorski Kotar, a mountainous region in western Croatia, there is a spatial cluster of MS that has remained stable for many years. In the neighboring areas of Slovenia, to the north of Gorski Kotar, in the Kocevje region, the prevalence of MS is also very high. Together, ignoring political and administrative borders, Gorski Kotar and the Kocevje region represent an area of high risk for MS in central Europe. The epidemiological studies of MS in Croatia have confirmed the observations of other European researchers that MS in central and southeastern Europe, especially along the Adriatic coast, was underestimated in the past [4,16,18,19,22,24  /33] (I. Radosevic-Jelic, unpublished data, 2001). The mean incidence rates of MS in Croatia are shown in Table 3. The incidence rates in Gorski Kotar are the highest [18]. In the areas ravaged by the war of 1991  /1995, the county of Osijek and Baranja, for unknown reasons, the incidence of MS has increased 2-fold in the last 10 years [29]. The MS mortality rates ranged from 0.5 in Istria in 1981, to 2.9 per 100 000 inhabitants in Gorski Kotar in 1993 (Table 4)[18]. * Corresponding author. Fax:  /385-52-856-177 E-mail address: eris.materljan@pu.tel.hr (E. Materljan). Clinical Neurology and Neurosurgery 104 (2002) 192  /198 www.elsevier.com/locate/clineuro 0303-8467/02/$ - see front matter # 2002 Published by Elsevier Science B.V. PII:S0303-8467(02)00037-9