Familial Spastic Paraparesis (FSP) is also known as Hereditary Spastic Paraparesis (HSP). It is a specific cause of paraparesis. IMPORTANT: spastic paraparesis is a clinical sign that has many potential causes. FSP/HSP is a diagnosis of exclusion - the other potential causes must be excluded through diagnostic evaluation. The patients have spasticity of the lower extremities.
Spastic paraparesis has many potential causes, including: MS (multiple sclerosis), spinal cord tumors (neoplasms), herniated intervertebral disks (usually thoracic), spinal vascular malformations (AVM's), infection (Tropical SP due to HTLV-1, primary lateral sclerosis, spinocerebellar ataxia, familial ALS (amyotrophic lateral sclerosis), vitamin deficiencies (B12 and E), and DOPA-responsive dystonias. In my case, the doctors performed a dye trace in my spine to exclude tumors, spinal vascular malformations and disk herniation. They never did narrow it down to a specific cause.