Hereditary Spastic Paraparesis
Hereditary spastic paraparesis is a group of rare hereditary disorders characterized by progressive, spinal, nonsegmental, spastic leg paresis, sometimes with intellectual disability, seizures, and other extraspinal deficits. Diagnosis is clinical and sometimes by genetic testing. Treatment is symptomatic, including drugs to relieve spasticity.
(See also Overview of Spinal Cord Disorders.)
The genetic basis of hereditary spastic paraparesis varies and, for many forms, is unknown. In all forms, the descending corticospinal tracts and, to a lesser extent, the dorsal columns and spinocerebellar tracts degenerate, sometimes with loss of anterior horn cells.
Onset can be at any age, from the first year of life to old age, depending on the specific genetic form.
Symptoms and signs of hereditary spastic paraparesis include spastic leg paresis, with progressive gait difficulty, hyperreflexia, clonus, and extensor plantar responses. Sensation and sphincter function are usually spared. The arms may also be affected. Deficits are not localized to a spinal cord segment.
In some forms, patients also have extraspinal neurologic deficits (eg, spinocerebellar and ocular symptoms, extrapyramidal symptoms, optic atrophy, retinal degeneration, intellectual disability, dementia, polyneuropathy).
Treatment for all forms of hereditary spastic paraparesis is symptomatic. Baclofen 10 mg po bid, increased as needed up to 40 mg po bid, is given for spasticity. Alternatives include diazepam, clonazepam, dantrolene, botulinum toxin (botulinum toxin type A or botulinum toxin type B), and tizanidine.
Physical therapy and exercise can help maintain mobility and muscle strength, improve range of motion and endurance, reduce fatigue, and prevent spasms. Some patients benefit from using splints, a cane, or crutches.