Hereditary spastic paraplegia 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 medications to relieve spasticity.
(See also Overview of Spinal Cord Disorders.)
The genetic basis of hereditary spastic paraplegia 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. Hereditary spastic paraplegia affects both sexes.
Symptoms and Signs of Hereditary Spastic Paraplegia
Symptoms and signs of hereditary spastic paraplegia 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).
Diagnosis of Hereditary Spastic Paraplegia
Clinical evaluation
Sometimes genetic testing
Hereditary spastic paraplegia is suggested by a family history and any signs of spastic paraplegia.
Diagnosis of hereditary spastic paraplegia is by exclusion of other causes and sometimes (eg, if the cause is unclear) by genetic testing. Consultation with a genetic counselor is recommended.
Treatment of Hereditary Spastic Paraplegia
Symptomatic, including medications to relieve spasticity
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.
Key Points
In all forms of hereditary spastic paraplegia, the descending corticospinal tracts and, to a lesser extent, the dorsal columns and spinocerebellar tracts degenerate.
Patients have spastic leg paresis, with progressive gait difficulty, hyperreflexia, clonus, and extensor plantar responses; some forms cause extraspinal neurologic deficits.
Suspect hereditary spastic paraplegia in patients with a family history and signs of spastic paraplegia; exclude other causes and if the diagnosis is unclear, consider genetic testing.
