Hereditary spastic paraparesis in adults associated with inborn errors of metabolism: a diagnostic approach.

Spastic paraparesis is a general term describing progressive stiffness and weakness in the lower limbs caused by pyramidal tract lesions. This clinical situation is frequently encountered in adult neurology. The diagnostic survey is usually limited to searching for acquired causes (spinal cord compression, inflammatory, metabolic, infectious diseases) and the so-called 'hereditary spastic paraparesis'. Although poorly recognized by neurologists, spastic paraparesis is also one of the multiple presentations of inborn errors of metabolism (IEMs) in children and adults. Pyramidal signs are usually included in a diffuse neurological or systemic clinical picture; however, in some cases spastic paraparesis remains the only symptom for years. Since these metabolic causes are often treatable, it is essential to include them in the general diagnostic approach to spastic paraparesis. Here we review IEMs causing paraparesis in adults.