There are a large number of hereditary neurological disorders in which stiff and malfunctioning muscles in the limbs impact mobility. Several of these including this one also have associated eye signs with vision difficulties due to degeneration of the retina.
This condition usually has its onset in late childhood or adolescence although it may first cause symptoms in adulthood. It is a progressive disease and most patients are unable to walk 10 years after the onset. Obesity is present in some patients. The muscles in the arms and legs are stiff and reflexes are hyperactive. Unsteadiness (ataxia) is common. Speech is often slurred and the bladder sphincter often is weak. Swallowing difficulties are common. There may be wasting (atrophy) of the small muscles of the hands. There may be disturbances of sensation as well.
The retina degenerates with visible pigmentation changes and vision loss is common. The eyes often have to-and-fro movements (nystagmus) and seem unable to fixate on targets.
Children have learning difficulties and with time there is cognitive decline to the point where some patients are considered to be mentally retarded. Brain imagining may show a number of abnormalities including a thinning of a special structure called the corpus callosum and loss of brain tissue.
This is an autosomal recessive condition that requires changes (mutations) of both members of a specific pair of genes. Parents who have a change in a single member of the pair apparently clinically normal but each of the offspring of two such parents each have a 25% chance of developing this disorder.
This is a neurological disorder that is most likely diagnosed by neurologists. Ophthalmological evaluation can reveal the abnormal eye movements and the retinal degeneration.
Adults are usually confined to a wheelchair and require assistance with daily living tasks. Special education and physical therapy may provide some benefits but there is no treatment for this condition.