Season of birth in multiple sclerosis

The monthly distribution of births of people who were later diagnosed with multiple sclerosis (MS) did not differ significantly from that of the general population in British Columbia, Canada. This is in contrast to a recent report on the Danish population.     

Risk of multiple sclerosis inversely associated with birth order position

The aim of this study was to ascertain whether there is an association between risk of multiple sclerosis (MS) and birth order position. Our reference population was 198,000 persons born in the period 1930–50 and recorded in the register of school health records from the school health service of the Copenhagen council. We compared 46 persons from the register who had developed MS with matched controls from the register, three for each case. An inverse association between risk of MS and birth order position was found. Early birth orders tend to delay exposure to an infectious agent from early childhood to a later age. Therefore, our finding supports the hypothesis that MS is causally related to an infection that is inapparent when it occurs in early childhood, while infection later in life may result in severe disease.     

Birth order and multiple sclerosis

A correlation has been reported between the development of MS and sibling birth order. We have re-examined the question in 2 groups of MS families. The first group consisted of 175 MS patients from single affected families. The second consisted of 36 families in which 2 or more sibs in the family had MS. Our results show no association between birth order and MS in single-affected sibships. In multiplex sibships, affected individuals appear to be randomly ordered.     

Birth order and risk of multiple sclerosis: Are they associated and how?

By analyzing birth order distribution in 107 patients with multiple sclerosis, a positive association is found between birth order and risk of multiple sclerosis. Conditionally to the number of siblings in the 107 families, patients' mean birth order is significantly greater than expected. The number of patients whose birth order is equal to one is significantly smaller than the corresponding expected value. The present finding is in contrast to recent results observed by Isager et al. (1980) and this potential association deserves to be further investigated.     

Is sporadic MS caused by an infection of adolescence and early adulthood? A case-control study of birth order position

Birth order position was examined in 164 cases with sporadic multiple sclerosis (MS), i.e. no other family members with MS, and spousal controls, matched for sibship size, socioeconomic status and opposite sex. The results did not find an association between birth order position and the subsequent development of MS and thus do not support the concept of an infectious cause for MS where "early exposure" is protective and exposure to the infection is a single event of short duration.     

Birth order and multiple sclerosis

No significant difference in birth order and risk of multiple sclerosis (MS) was found in a large-scale investigation employing 2 different study methods: case-control and comparison of birth order with expected distribution. This finding is at variance with conflicting results of 2 recently published investigations. Our findings suggest that birth order cannot be used as a surrogate for age-of-infection, but must be measured directly in further studying the role of delayed childhood infection in the pathopoiesis of MS.     

Season of birth and multiple sclerosis in Sweden

Objective –  To estimate the risk of multiple sclerosis (MS) by month of birth in Sweden.
Materials and Methods –  Cases ( n  = 9361) were obtained from the Swedish MS Registry. All births in Sweden 1900–2007 served as controls ( n  = 12,116,853). The risk of MS was analyzed for each month of birth separately compared with birth during the other 11 months.
Results –  More (11%) cases with MS than expected were born in June. Fewer (8% and 10%) cases with MS than expected were born in December and January (non-significant after correction for multiple analyses). More (5%) cases with MS than expected were born in February–July as compared with August–January.
Conclusions –  This study supports previous results suggesting an association between the risk of MS and the season of birth. Decreased exposure to sun in the winter leading to low vitamin D levels during pregnancy is a possible explanation that needs further research.     

Planned vaginal births in women with multiple sclerosis: delivery and birth outcome

Objective –  The objective of this study was to investigate the effect of maternal multiple sclerosis (MS) on delivery and birth outcome in births without planned caesarean section.
Methods –  Data were collected from the compulsory Medical Birth Registry of Norway from 1988 to 2002. Intended vaginal births in this time period were 449 births given by MS mothers and 851,060 control births.
Results –  The MS mothers had a higher rate of induction of labour, and there was a strong trend for slower progression of second stage of labour and increased use of forceps. The MS group had lower birth weight and length of the neonates. The frequency of birth defects and the neonatal mortality were not increased in the MS group.
Conclusions –  Maternal MS affects the birth process and the neonate prenatally, even when the births with planned caesarean section are excluded. MS-related neuronal dysfunction linked to the uterus, is postulated as the most likely mechanism.     

Pregnancy,delivery and birth outcome in different stages of maternal multiple sclerosis

To investigate the influence of maternal multiple sclerosis (MS) on pregnancy, we compared pregnancy, delivery and birth outcome in births prior to onset of MS (pre MS), between MS onset and diagnosis (early MS), and after diagnosis of MS (manifest MS). Mothers with MS were identified through linkage of the Norwegian MS Registry and the Medical Birth Registry of Norway (1967-2002). All pre MS births (n = 1910), early MS births (n = 555), and manifest MS births (n = 308) were compared.There was a significantly lower mean birth weight in term births (adjusted for gestation in weeks, mother's age, time period and caesarean section) in the manifest MS compared to the pre MS group (P = 0.046). The rate of birth complications and interventions did not differ between the three groups.Manifest MS in birth-giving mothers seems to affect birth weight.     

Multiple sclerosis and macrocytosis

Twenty-seven patients with multiple sclerosis had mild but significant macrocytosis when compared with an individually matched neurological control group and the normal laboratory reference range. The cause of the macrocytosis is unknown, but our recent clinical observations implicate a possible disturbance in vitamin B12 metabolism, binding or transport.     

Multiple sclerosis in Chile

So far as we know this series of 68 cases is one of the first clinical accounts of multiple sclerosis in South America. Average age of onset was 30.7 years and female:male ratio was 2:1. The most frequent initial symptom was motor impairment and less frequent was visual loss. Most affected site of involvement in established cases was the optic nerve. There were no familial cases. The severity of the disease in Chile proved to be the same as elsewhere. No characteristic clinical pattern peculiar to the region emerged.     

Multiple sclerosis and parainfluenza 1 virus

Summary 54 cultures were established from brain tissue obtained 2–3 hrs after death from 1 case of multiple sclerosis and 30 cultures from another case. Following fusion with indicator cells in the presence of lysolecithin, a parainfluenza type 1 virus (6/94 virus) was isolated from cultures representing one plaque area in the first case and one plaque area in the second case. A cell line chronically infected with the 6/94 virus has been maintained for more than 100 passagesin vitro. A close relationship to the Sendai Hemagglutinating Virus of Japan (HVJ) is indicated from RNA-RNA hybridization and the patterns of electrophoretic mobilities of viral polypeptides. Conversely, differences in optima for growth-requirement temperatures, hemolytic activity and the capability to fuse mammalian cells, distinguishes 6/94 virus and HVJ as distinct phenotypic entities of a closely related genotype.Supported in part by funds from the National Multiple Sclerosis Society; USPHS Research Grant NS-11036 from the National Institute of Neurological Disease and Stroke and RR 05540 from the Division of Research Resources; by Deutsche Forschungsgemeinschaft AZ, Me270/10, Schwerpunkt Multiple Sklerose und verwandte Erkrankungen.     

Multiple sclerosis and mortality statistics

ABSTRACT – We have previously found a 3-fold increase in prevalence and a corresponding increase in incidence of multiple sclerosis (MS) from 1963 to 1983 in the county of Hordaland, Norway. When studying the official mortality statistics and the deceased patients in our clinical MS-material, no increase in death rate could be observed in the same period.
We also found that official mortality statistics include both over- and underestimates of MS-patients. Of definite MS-patients in the clinical material, 91.7% were registered with MS on the death certificates, either as underlying or contributory cause of death. When studying only underlying cause of death, we found that 59.5% of deceased definite MS patients were registered as MS on the death certificates.
This study shows that official mortality statistics reflect a change in incidence of MS both incompletely and with a delay of several decades.     

Multiple sclerosis and other immunologic diseases

A characteristic feature of immunologic diseases is their association with each other. For multiple sclerosis (MS), several retrospective studies reported increased as well as expected coincidence rates with other immunologic diseases. We conducted a prospective case-control study of MS patients and healthy volunteers and found 13/101 MS patients and 2/97 controls with such diseases (P = 0.009, chi-square test), as well as 47/88 MS patients versus 31/95 controls with a variety of circulating autoantibodies (P = 0.004, chi-square test). These results speak for an increased coincidence of MS with other immunologic diseases and support the idea that MS is also an immunologic disease.     

Multiple sclerosis trait: the premorbid stage of multiple sclerosis. A hypothesis

The unexpectedly low rate of concordance in monozygotic (MZ) twins with multiple sclerosis (MS) suggests that they share a systemic condition called the multiple sclerosis trait. This trait constitutes the premorbid stage of the disease and is quite distinct from asymptomatic MS. It results from the action of an antigenic challenge to the immune system of a genetically susceptible person but is short of producing lesions of the central nervous system parenchyma; in fact, the disease may never develop in people with the trait. An environmental triggering event is required to transform the trait into the disease. The discordance of clinical involvement and magnetic resonance images in MZ twins reflects differences in the effect of environmental influences.     

Multiple sclerosis in Jordan: a clinical and epidemiological study

Objectives To characterize the clinical, demographic and epidemiological features of multiple sclerosis (MS) in Jordan. Methods Data for consecutive Jordanian patients, fulfilling the McDonald criteria for clinically definite and clinically probable MS, during the time period 2004–2005 were collected and analyzed in the three major referral centers for MS in Jordan. Results We identified a total of 224 patients (165 females, 87%; 59 males, 13%). The mean (±SD) age of onset was 29.3 (±9.6) years, and mean (±SD) duration of illness was 3.9 (±9.3) years. The prevalence of MS in the city of Amman was 39/100,000. The prevalence of MS in Irbid, north Jordan, was 38/100,000. The most frequent presentation was weakness (30.8%), followed by optic neuritis (20.1%), sensory impairment (19.6%), and ataxia (14.3%). A relapsing remitting pattern was identified in 90.2% of patients, the rest being primary and secondary progressive, and one patient had a progressive relapsing course. Family history of MS was found in 9.4% of the cases. About 60% of the patients were using interferon beta. The degree of physical disability was determined using the Expanded Disability Status Scale (EDSS). Younger age of onset, shorter duration of illness, a relapsing remitting pattern, and use of interferon were identified as statistically significant predictors of less disability. Conclusion Jordan is a medium-high risk country for MS, with prevalence higher than what has previously been reported, possibly representing an increase in incidence. Clinical and demographic characteristics are similar to most reports worldwide. Received in revised form: 17 December 2005     

Multiple sclerosis in the two northernmost counties of Norway

The prevalence of MS in the two northernmost counties of Norway increased from 20.6 per 100,000 in 1973 to 31.5 per 100,000 in 1983, the increase being most marked in women. The average annual incidence seems to have been stable over the past 20-30 years. None of the patients had a pure Lapp background (having a Lapp mother and father).