Chapter 77 - Hereditary Spastic Paraplegia

Abstract

The hereditary spastic paraplegias (HSP) are a large group of disorders that share the primary clinical feature of lower extremity spastic weakness. Lower extremity weakness and spasticity (occurring in varying proportions and to variable degree) may be isolated (“uncomplicated” HSP); or associated with additional neurologic abnormalities (“complicated HSP”), such as cognitive impairment, peripheral neuropathy, amyotrophy, or ataxia. Symptoms beginning in infancy may be nonprogressive. Later-onset symptoms typically worsen insidiously over many years. Postmortem studies in uncomplicated HSP have shown axon degeneration particularly involving the distal ends of corticospinal tract and dorsal column fibers. There are more than 70 genetic types of HSP. Genetic testing can confirm the diagnosis of HSP for the majority of subjects. The differential diagnosis includes treatable disorders (e.g., B12 deficiency, cervical spondylosis, dopa-responsive dystonia, multiple sclerosis) as well as disorders whose prognosis is quite different than HSP (e.g., amyotrophic lateral sclerosis and multiple sclerosis). Treatment for HSP is symptomatic.