Symptoms typically worsen over days to weeks, and then improve over 1 to 2 months. Onset of MS after the age of 40 is more likely to follow a progressive course with gait impairment. The rate of production of immunoglobulin within the CSF is useful diagnos tic measure, estimated by comparing the ratios of CSF IgG and albumin to those in the serum. Prolongation of evoked responses in visual, auditory, and somatosensory modalities can identify clinically silent or prior lesions of central pathways. MR imaging of the brain and spinal cord remains the most sensitive and specific test in MS and is useful to document clinically silent lesions and to quantitate the burden of disease accumulated over time Lesions seen on MR imaging, however, may resemble those seen in cerebrovascular disease, normal aging, and other CNS inflammatory diseases such as neurosyphilis or sarcoidosis.
Gadolinium enhancement helps identify active lesions.
Presently, MR imaging is not approved for use during pregnancy, althoug h it should be obtained if clinically indicated because there are no evident harmful effects. Current therapy favors pulse corticosteroids, which accelerate recovery from acute relapses, but are not believed to alter the long-term course. Immunosuppressants are sometimes tried in progressive MS with equivocal results, but are teratogenic and carcinogenic. Symptomatic treatments are available for spasticity, depression, pain, sphincter disturbance, tremor, and fatigue. Careful attention to bowel and bladder function, with prevention of urinary tract infections, is important.