Those patients who progressed most rapidly expressed significantly more dendritic transcripts than patients who progressed more slowly chronic encephalitis confined to one hemisphere and contralateral cerebellar hemi-atrophy.
In the active phase, neuronophagia, activated microglial cells (rod cells), microglial nodules, and perivascular lymphocytic infiltrates, are present.
This was followed by two consecutively smaller epidemics with respective peaks each about 12 years later, and there is now a new epidemic IV on these islands.
Explanations for changing incidence of MS over time should bring us closer to solving the etiology of this disease.
In western societies, MS is second only to trauma as a cause of neurologic disability in early to middle adulthood.
In the Faroe Islands, MS was absent before 1943 when a major point-source epidemic began, reaching an incidence rate of 10 per 100,000 population in 1945.Migration studies indicate MS is already acquired by age 15 in high-risk endemic areas and that low-to-high migrants increase their risk from age 11 years.Therefore MS is an environmental disease ordinarily acquired in adolescence with a long incubation before symptom onset. The site of attack is organ- or tissue-specific or more systemic : as the self-antigen(s) is usually expressed in more than one cell type, from an anatomical point of view autoimmune diseases should more properly be enclosed among the multi-organ failures (MOF). Streptococcus pneumoniae, Haemophilus influenzae) as after splenectomy, gram positive bacteria (Staphylococcus aureus), rotavirus and parvovirus (due to decreased Ig A on mucosal surfaces) They are caused by autoimmune reactions and affect ~ 3-5% of the population with 2/3 of the patients being women.Some patients can have fleeting attacks lasting several minutes, and still others have attacks lasting a week or longer and may take months to regain normal equilibrium.