Spinocerebellar ataxia type 3

Spinocerebellar ataxia type 3 (SCA3) is a condition characterized by progressive problems with movement. People with this condition initially experience problems with coordination and balance (ataxia). Other early signs and symptoms of SCA3 include speech difficulties, uncontrolled muscle tensing (dystonia), muscle stiffness (spasticity), rigidity, tremors, bulging eyes, and double vision. People with this condition may experience sleep disorders such as restless leg syndrome or REM sleep behavior disorder. Restless leg syndrome is a condition characterized by numbness or tingling in the legs accompanied by an urge to move the legs to stop the sensations. REM sleep behavior disorder is a condition in which the muscles are active during the dream (REM) stage of sleep, so an affected person often acts out his or her dreams. These sleep disorders tend to leave affected individuals feeling tired during the day.

Over time, individuals with SCA3 may develop loss of sensation and weakness in the limbs (peripheral neuropathy), muscle cramps, muscle twitches (fasciculations), and swallowing difficulties. Individuals with SCA3 may have problems with memory, planning, and problem solving.

Signs and symptoms of the disorder typically begin in mid-adulthood but can appear anytime from childhood to late adulthood. People with SCA3 eventually require wheelchair assistance. They usually survive 10 to 20 years after symptoms first appear.