Tola R

Motor neuron disease in the province of Ferrara, Italy, in 1964–1982

We carried out an intensive incidence, prevalence, and mortality survey of motor neuron disease (MND) in the province of Ferrara, northern Italy. Based on 72 patients, the mean incidence per year for the period 1964 through 1982 was 0.98 cases per 100,000. On December 31, 1981, the prevalence rate was 3.95 per 100,000. In the 19-year period the average mortality rate was 0.83 per 100,000 per year. The disease was more common in men, in individuals aged 50 to 70 years, and in residents in rural areas engaged in agricultural work. A retrospective case-control study, confirming a significantly higher frequency of MND in farmers and persons living in rural areas, revealed that the disease was more common in the lower social classes to which most unskilled and heavy laborers belong. In addition, a significantly increased risk for MND was found in patients with previous histories of trauma, but confounding variables may account for this association.

The risk of Parkinson disease in Mediterranean people

On the basis of previous epidemiologic studies, Parkinson disease was thought to be evenly distributed throughout the world. These studies, however, were conducted only on North European populations. The position with regard to the Mediterranean peoples was still unknown, and we therefore studied the frequency of Parkinson disease on the island of Sardinia, where some ethnic groups of the Mediterranean stock are represented. Based on 967 accepted cases, the prevalence per 100,000 population on January 1, 1972, was 65.6; the average annual incidence for the period 1961 through 1971 was 4.9. These figures are one-half of the figures established for North Europeans. Our findings suggest racial differences in predisposition to Parkinson disease. Some Negroid features are present in Sardinians. If, as seems likely, Africans prove to be relatively unsusceptible to the disease, the risk for Sardinians and other Mediterranean ethnic groups might be intermediate between North Europeans and Africans.

The frequency of multiple sclerosis in Mediterranean Europe: an incidence and prevalence study in Barbagia, Sardinia, insular Italy

Recent investigations on multiple sclerosis (MS) distribution in Italy, based on relatively small population groups, contradict the current thesis, derived from studies undertaken in populations exceeding 300,000, of a lower spreading of the disease in Mediterranean Europe. Intensive surveys on small populations strengthen the suggestion that Italy is a high‐risk area, although MS studies based on prevalence rather than incidence could also be biased by geographic variables making prevalence unsuitable for comparing MS prevalence rates found in different years and/or zones. We report a further epidemiologic study in Barbagia, Sardinia, insular Italy, undertaken both to establish the MS incidence in the last 20 years, and to estimate a new prevalence rate. Based on 31 probable incident cases, the mean incidence per year for the years 1961‐1980 was 2.9 per 100,000 (3.2 if age‐ and sex‐standardized to the Italian population). On October 24, 1981, the prevalence per 100,000 was 65.3 (77.9 if standardized to the Italian population). These results confirm that in Barbagia, MS occurs more frequently than expected in a Mediterranean area, and give further support to the idea that MS frequency in Italy is similar to that established for most central and northern European countries.

Multiple sclerosis in southern Europe. A prevalence study in the sociosanitary district of Copparo, northern Italy.

The prevalence of multiple sclerosis (MS) in the Italian studies presently available is reported to be between 3.3 and 19.5 per 100,000. All these studies, however, have been undertaken in populations exceeding 300,000 and probably offer underestimates of MS frequency. Current sanitary organization in Italy is inadequate for epidemiological search and many patients with MS may be overlooked when large populations are studied. So, accurate estimates of MS frequency are possible only as a result of intensive surveys in small population groups. Prevalence figures of 53 and 32 per 100,000 have been recently reported by Dean et al. who studied the frequency of MS in small population groups in Sicily. The present study reports the results of a similar survey in the district of Copparo (population 45,153) in northern Italy. The prevalence of probable MS found in Copparo was 31 per 100,000. This result confirms the findings of Dean et al. in southern Italy and supports Deans opinion that the true frequency of MS in Italy as a whole is higher than that indicated by the Italian studies.

The geographical distribution of multiple sclerosis, rheumatoid arthritis, rheumatic heart disease and poststreptococcal nephritis in Sardinia: Climatic and socioeconomic factors

SummaryThe comparative geography of multiple sclerosis (MS) and non-neurological diseases considered to be autoimmune is of great interest. But there are few appropriate investigations. Some have found an increase in the frequency of MS, rheumatoid arthritis and rheumatic heart disease depending on the geographic latitude. Nevertheless, the significance of the latitude effect as an indicator of a possible etiological relationship between MS and these conditions has been questioned. In this paper, the frequency of MS, rheumatoid arthritis, rheumatic heart disease and poststreptococcal nephritis is reported from Sardinia where appreciable differences in climatic and socioeconomic conditions exist. There was a positive correlation of the distribution of MS with the distribution of rheumatic heart disease and poststreptococcal nephritis. On the other hand, no correlation was found with the distribution of rheumatoid arthritis.ZusammenfassungDie Ähnlichkeit zwischen Multipler Sklerose (MS) und nicht neurologischen autoimmunen Erkrankungen veranlassen zur Annahme, daß einige gemeinsame ätiologische Mechanismen im Spiele sein könnten. Das Problem der vergleichenden geographischen Verteilung von Multipler Sklerose und autoimmuner Krankheit ist wenig untersucht. Einige Forscher fanden eine ähnliche Zunahme der Häufigkeit der MS, rheumatoider Arthritis und rheumatischer Herzkrankheiten bei zunehmenden Breitengraden. Es besteht allerdings Zweifel, ob tatsächlich dieser „latitude effect“ als ein wirklicher Indikator von ätiologischen Gemeinsamkeiten zwischen den genannten Krankheiten anzusehen ist. Wir berichten in der vorliegenden Arbeit über die Häufigkeit von MS, rheumatoider Arthritis und rheumatischen Herzkrankheiten sowie Nephritis nach Streptokokkeninfektionen in Sardinien, wo nennenswerte Unterschiede in Bezug auf klimatische und sozioökonomische Gegebenheiten bestehen. Die Verteilung der MS zeigte eine positive Korrelation mit der Verteilung rheumatischer Herzkrankheiten und von Nephritis nach Streptokokkeninfektion. Andererseits wurde keine Korrelation mit der Verteilung der Polyarthritis rheumatica festgestellt.

Epidemiology of multiple sclerosis in Italy. A further descriptive study in Barbagia, Sardinia

Italy is currently regarded as a medium-frequency area for MS. This opinion is based on the results of 30 prevalence studies undertaken on large populations exceeding 300000. Recently, however, it has been stated that the surveys of large populations in Italy do not provide reliable figures comparable to those found in northern-central Europe. In fact, current public health organization in Italy is inadequate for epidemiologic search, and accurate estimates of MS frequency are possible only as a result of intensive surveys of small populations. To date, eight studies of this sort are available, which suggest that Italy also falls into the high-risk zone. However, more accurate investigations of this kind are needed. For this reason, we carried out a second survey of MS in Barbagia, Sardinia, an appropriate area for descriptive investigation. On prevalence day, October 24, 1981, 32 subjects (18 women and 14 men) living in the study area were found to be suffering from probable MS. The patients were classified according to the diagnostic criteria of Allison and Millar. As the total population was 49022, the crude prevalence rate was 65.3 per 100000 (95% CI:44–93). The rate, age- and sex-adjusted to the Italian population, was 78. These results, higher than those found in a previous study in the same area, give further support to the possibility that the risk for MS in Italy is similar to that in northern-central Europe, and, therefore, cast doubt on the widely accepted opinion that MS prevalence is a function of geographic latitude.