Christina Applegate is finally out of the hospital after a months-long medical stay. According to initial reporting by TMZ, the discharge follows a lengthy period of care related to her ongoing battle with multiple sclerosis (MS). News of the hospitalization first surfaced shortly after her new memoir, You With the Sad Eyes, hit shelves in March. What Is Multiple Sclerosis (MS)? According to the National Multiple Sclerosis Society, MS is “an unpredictable disease of the central nervous system” (this includes the optic nerves, spinal cord, and brain).