GSS and Us Gradually worsening inbalance while walking or standing and poor cordination Unable to walk a straight line without swaggering rigid muscle tone and strange reflexes Visual disturbances (sometimes blindness) and deafness involuntary movements of the eyes Impaired ability to swallow Personality changes (irritable, intolerant, yet often unexplainably cheerful) Progressive decrease in intelligence and memory loss Eventually full blown and progressive dementia, caused by deposits of gray matter in the cerebral cortex