Cell-mediated autoimmune condition characterised by repeated episodes of inflammation of the nervous tissue in the brain and spinal cord, causing loss of the insulating myelin sheath

Aetiology

• Greater incidence in females (3:1)
• Presentation is typically between 20 and 40 years of age
• Much more common in white populations and with increasing distance from the equator
• Causes of MS are not completely understood but the autoimmune process appears to be caused both by genetic and environmental factors
  • At least 60 genes have been implicated in the development of MS, with the majority of these relating to immune system function and regulation, including HLA and MHC polymorphisms
  • Environmental factors which have been implicated include viral infections (e.g. EBV), and vitamin D deficiency
• Factors associated with worse prognosis include: older, male, motor signs at onset, early relapses, many MRI lesions and axonal loss

Pathophysiology

• T-cell-mediated autoimmune disease that causes an inflammatory process mainly within the white matter of the brain and spinal cord
• Plaques of demyelination occur anywhere in CNS white matter but have a predilection for certain sites including the optic nerves, the brainstem and its cerebellar connections and the cervical cord (corticospinal tracts and posterior columns)
• Peripheral myelinated nerves are not directly affected in MS

Pathophysiology of lower urinary tract dysfunction

• Increased tone at bladder neck
• Detruser hypersensitivity
• Detruser sphincteric dysenergia

Patterns of MS

• Relapsing-remitting MS (RRMS) (85-90%) - symptoms occur in attacks (relapses) with a characteristic time course: onset over days and typically recovery, either partial or complete, over weeks
• Secondary progressive MS - this late stage of MS consists of gradually worsening disability progressing slowly over years; some 75% of patients with relapsing-remitting MS will eventually evolve into a secondary progressive phase by 35 years after onset
• Primary progressive MS (PPMS) (10-15%) - characterized by gradually worsening disability without relapses or remissions