[Controversies in neurology: Diagnosis, follow up and therapy of multiple sclerosis with pathomechanismal approach]

Abstract

The clinical boundaries between the relapsing and progressive course of multiple sclerosis are often indistinct. Despite the variable patterns of evolution, there are no biological reasons for discerning different multiple sclerosis phenotypes. Indeed, both primary progressive and secondary forms of the disease share similar pathological features in respect of the extent of inflammatory infiltrates, axonal damage, and cortical demyelination. The data indicating that primary progressive multiple sclerosis is preceded by an asymptomatic relapsing remitting phase. The proposed definition of secondary progressive multiple slcerosis, the attainment of at least EDSS of 4 is required to mark the transition to the progressive phase. Therefore, the clinical progress can be uncovered in the early phase of the disease. Furthermore, a continuous progression independent of relapsing activity is commonly observed during the relapsing remitting phase. A continuous smouldering process underpins the subtle clinical deterioration, which stands out as an important unmet treatment target. Concerning cognitive dysfunction of the patients pro-inflammatory cytokines have been associated with worse cognition in active multiple sclerosis, and this inflammatory milieu could also contribute to altered mentation during relapses. Therefore, long before people with multiple sclerosis become physically disabled, they have usually acquired hidden disabilities related to cognitive impairment. Silent progression appears during the relapsing remitting phase and it associates with brain atrophy. This suggests that the same process that underlies secondary progressive multiple sclerosis likely begins far earlier than is generally recognized. This supports a unitary view of multiple sclerosis biology.

Keywords: atrophy; biomarkers; multiple sclerosis; progression independent of relapses; silent progression.