[Epidemiologic aspects of multiple sclerosis]. / Epidemiologische Aspekte der multiplen Sklerose.

Epidemiology plays a prominent role in the search for environmental risk factors in multiple sclerosis (MS). The basic pattern with the predilection for temperate zones of the globe, whites, females and medium age groups was confirmed throughout. Whether or not MS is increasing in frequency is highly debated. Although no clear risk factors have been demonstrated so far, a certain association of the MS risk with the factors "low temperatures and precipitation", "consumption of animal proteins/fats or meat", "familiar occurrence of MS" and with a late occurrence of common childhood infections became obvious. Many other putative risk factors were not confirmed in most studies.

[Multiple sclerosis mortality 1973-1987 in Baden-Württemberg in comparison with socio-geographical variables]. / Die Multiple-Sklerose-Mortalität 1973-1987 in Baden-Württemberg im Vergleich mit soziogeographischen Variablen.

Mortality due to MS in the State of Baden-Württemberg (south-west Germany) during the years 1973-1987 was studied in its geographical distribution for a possible association with selected sociogeographic indices for that period. The overall rate for Baden-Württemberg (1.3/100,000) was lower than in the neighbouring state of Hesse (1.5/100,000). A relative excess of cases was found in the highland region of the Swabian Alps. In multivariate analysis, correlations were found with the characteristics "forest area/inhabitant", "oat cultivation" and "concentration of polyaromatic hydrocarbons in the drinking water", whereas climate and height above sea-level were not associated. These findings require replication elsewhere.

Prognostic criteria in an epidemiological group of patients with multiple sclerosis: an exploratory study.

Demographic and clinical features and data on medical history and prior environmental exposure collected during an epidemiological long-term study of multiple sclerosis (MS) were tested for their possible prognostic value. Fifty-two benign MS patients were compared with 29 patients having a malignant course. A primary or secondary progressive course and cerebellar/lower brain-stem symptoms at onset indicated an unfavourable course, whereas no predictive value of sex or of any other type of onset symptomatology was found. Age at onset per se had no influence on prognosis but was associated with more rapid progression only by its relationship with a chronic progressive type of course. Prior illness, surgery, trauma and childhood exposure to defined environmental factors could not be identified as relevant for prognosis.

Epidemiological investigations into multiple sclerosis in Southern Hesse. V. Course and prognosis.

Course and possible prognostic predictors were studied retrospectively in 363 MS patients collected during an epidemiological study. The proportion of patients showing a primarily progressive course was 18%; 19% of patients of more than 10 years duration showed a benign course, and 8% of those of less than 16 years duration, a malignant course. Although benign cases were twice as frequent in females as in males, the difference between both sexes was not significant. A primarily or secondarily progressive course, a high number of functional systems involved and cerebellar signs occurring in the course indicated a poor prognosis whereas symptoms at onset, age at onset as such, and occupation were without predictive value. No predictors of a favourable course were found. Of the patients of 11-15 years duration, 17% were confined to a wheelchair, 40% were restricted to a walking distance of 500 metres or less, 61% were unable to work and 45% had urinary incontinence. The corresponding figures for those of 21-25 years duration were 40%, 71%, 76% and 50%.

Prognostic indicators in multiple sclerosis.

The influence of sex, age at onset, course of the disease and initial symptomatology on the mortality of patients with multiple sclerosis is analysed. A sample of 1926 patients was followed up prospectively over 4.9 years. Both, the mortality ratio (number of observed to expected deaths) and the excess death rate are calculated. Whereas the mortality ratio as a parameter of overall mortality is influenced by a variety of factors, such as age and sex; the excess death rate represents the number of extra deaths per 1000 exposed to risk in an indicated year and is, therefore, a parameter of the mortality which is attributed to MS. The excess death rate was comparable for the sexes, it was slightly higher for patients with a higher age at onset and it was clearly higher for the progressive course. Patients with initial diplopia and sensory signs and symptoms had the lowest excess death rate, whereas patients with pareses, cerebral and sphincter disturbances at onset showed the highest excess death rate.

Epidemiological aspects of multiple sclerosis: a comparative study of four centres in Europe.

Epidemiological data of 931 patients with definite and probable multiple sclerosis in four areas in Europe (Groningen, Göttingen, Darmstadt and Baranya) were collected and compared. The same criteria and scoring methods were used. Clear differences between the areas appeared: a high percentage of severely disabled patients were encountered in the northern part (Groningen) and a high percentage of signs and symptoms related to supraspinal lesions in brainstem, cerebellum and hemispheres were found in the south east (Hungary). In Göttingen, in the central part of the total area, a relatively higher percentage of younger MS patients with minimal disability were found. However, it still has to be determined to which extent these differences are real or caused by information bias.

An evaluation of laboratory investigations in patients with multiple sclerosis.

The contribution of VEP, CT and oligoclonal bands (OB) to the diagnosis of MS was studied in a group of 213 hospitalized patients. Whereas the diagnostic values of VEP and OB were both in the same range, the combination of both methods increased the proportion of cases with "definite MS" from 58 to 75%, whereas CT did not contribute significantly to diagnostic ascertainment. Vitamin B12 absorption was less than 10% in 27% of cases. A slight tendency towards increased serum IgG and IgM levels was found, and the rheumatoid factor was demonstrated in 6% of cases.

Epidemiological investigations into multiple sclerosis in Southern Hesse. III. The possible influence of occupation on the risk of disease.

In order to discover possible exogenous risk factors in the etiology of multiple sclerosis, the pattern of the patients' occupation during adolescence and at disease onset was analysed in an epidemiological group of MS patients in Southern Hesse (West Germany) and compared with that of the German population in the corresponding years. During adolescence, male patients were more frequently occupied in metal processing and electrical trades and female patients more commonly in commerce and administration than expected. At onset, some more female patients than expected were working in commerce and administration whereas male patients did not deviate from the pattern in the general population.

Epidemiological investigations into multiple sclerosis in Southern Hesse. IV. The influence of urban and rural environment on disease risk.

Residence during childhood and at disease onset in urban, semirural and rural communities respectively was investigated in an epidemiological group of MS patients in Southern Hesse (West Germany). Patients originated more frequently from small rural communities and less frequently from provincial towns than expected, whereas residences at onset corresponded to the distribution in the general population. The size of the community of residence did not influence age at onset, the later progression rate or the symptoms at onset.

Epidemiological investigations into multiple sclerosis in southern Hesse. I. Methodological problems and basic epidemiologic characteristics.

An epidemiological field-survey on multiple sclerosis (MS) was carried out in the southern part of the state of Hesse (West Germany). Out of 472 patients primarily ascertained, 75% could finally be accepted as definite or probable MS cases. Cross-checking of the 3 sources for case-finding (practitioners and specialists, neurological hospital, MS society) revealed that case-finding in all and especially that of definite and probable MS cases was rather complete. The overall prevalence rate was 58.3, the annual incidence 2.15 and the mortality rate 2.0 per 100,000. Male patients showed a faster course than females. The prevalence in immigrants who mostly originated from Mediterranean countries, was significantly lower (14.3 per 100,000) than the prevalence in the German population (63.1 per 100,000).

Epidemiological investigations into multiple sclerosis in southern Hesse. II. The distribution of cases in relation to exogenous features.

In order to discover possible exogenous variables associated with a higher multiple sclerosis risk, the distribution of cases with definite and probable multiple sclerosis ascertained in the course of a micro-epidemiologic study in Southern Hesse was evaluated and compared with some environmental factors. The prevalence in 1980, the prevalence of cases with disease-onset within the region according to locality of onset and the rate of native Southern Hesse patients according to childhood residence all showed a similar geographical distribution, with the highest values in the south-eastern, mountainous part of the region. This district has a lower annual mean temperature, more annual snow-days and a higher annual precipitation compared to the remaining area. A statistical comparison revealed no association with industrial or agricultural activities, with a particular type of land use, with cattle, pig- or horse-breeding, or with sanitary or housing standards. On the other hand, a slight association with the soil type could be demonstrated, with higher rates on loam and clay subsoils when compared to predominantly sandy regions. Whether this finding has any significance or not remains to be clarified.