This heritable condition results from a gene mutation that leads to progressive degeneration of specific areas of the brain controlling balance, gait and eye movements.
By age 40 years most individuals have difficulty sitting still and walking. These symptoms worsen slowly and some need walking assistance by the age of 50. Slurred speech (dysarthria) is often noted about the same time. Nearly all patients have the to-and-fro motion of ‘dancing eyes’ (nystagmus) but nothing is known about vision. A few complain of sensory changes such as alterations in touch and muscle weakness has been noted in several individuals as well.
This is an autosomal dominant condition passed directly from parent to child with a 50% probability.
The diagnosis is most likely to be made by a neurologist. No treatment is available but patients may benefit from physical therapy and devices for mobility assistance. Longevity does not seem to be impacted.