Pathophysiology of Multiple Sclerosis

Pathophysiology Of Multiple Sclerosis

Multiple sclerosis is a condition in which the CNS of a person present a special kind of distributed lesions (sclerosis) whose pathophysiology is complex and still under investigation. It is considered a pathological entity by some authors and a clinical entity by some others.

Damage occurs in two phases. First some MRI-abnormal areas with hidden damage appear in the brain and spine (NAWM, NAGM, DAWM), followed later by leaks in the blood–brain barrier where immune cells infiltrate causing the known demyelination.

MS is mainly a white matter disease, and lesions appear mainly in a peri-ventricular distribution (lesions clustered around the ventricles of the brain), but apart from the usually known white matter demyelination, also the cortex and deep gray matter (GM) nuclei are affected, together with diffuse injury of the normal-appearing white matter. MS is active even during remission periods. GM atrophy is independent of the MS lesions and is associated with physical disability, fatigue, and cognitive impairment in MS

At least five characteristics are present in CNS tissues of MS patients: Inflammation beyond classical white matter lesions, intrathecal Ig production with oligoclonal bands, an environment fostering immune cell persistence, Follicle-like aggregates in the meninges and a disruption of the blood–brain barrier also outside of active lesions.