What are the symptoms? There are three main features of FSP: the legs become stiff (spasticity) and there is a variable amount of weakness (paraplegia), and muscle cramps and spasms can also be present. The complicated form of FSP can also be associated with other symptoms, such as ataxia, dementia, visual dysfunction or epilepsy, though the presence and severity of additional symptoms varies from person to person. What are the causes? FSP is caused by degeneration of the upper motor neurons (which help to carry signals from the brain to the muscles) within the brain and spinal cord. How is it diagnosed? A combination of factors are taken into account when making a diagnosis of FSP: family history, the presence/absence of additional signs and the exclusion of other non-genetic causes of spasticity, which is particularly important in cases caused by a sporadic mutation. Cerebral and spinal magnetic resonance images (MRIs) are used to exclude other conditions. Along with the age at onset, these clinical and genetic data allow clinicians to decide whether to do genetic testing for FSP. How is it treated? A multidisciplinary treatment regime is used to manage symptoms. There are three main treatment types: physiotherapy/exercise, electrical muscle stimulation and prescription medication. Physiotherapy in the form of regular exercises to keep muscles stretched helps in reducing stiffness and pain. Functional electrical stimulation (FES) delivers electrical impulses directly to certain muscle groups, producing contractions in muscles normally paralysed due to FSP. Prescription medication may include baclofen (a voluntary muscle relaxant to relax muscles and reduce tone), tizanidine (to treat intermittent spasms) and diazepam or clonazepam (to decrease intensity of spasms). Botulinum toxin (botox) may also be administered to treat spasticity. Botox can reduce spasticity one to two weeks post-injection, with an effect lasting around three to four months. Inheritance patterns and prenatal diagnosis Inheritance patternsThe chromosomal locations (loci) of many spastic paraplegia genes are now known, although several of the actual genes and mutations causing FSP remain to be identified. All modes of inheritance (autosomal dominant, autosomal recessive and X-linked) have been described. The most common form of inheritance is autosomal dominant, with the commonest being a pure FSP caused by mutations in the SPG4/SPAST gene on chromosome 2, encoding spastin. Prenatal diagnosisPrenatal testing is only available for pregnancies at increased risk if the disease-causing mutation has already been identified in the family. Is there support? HSP Support Group (UK) Helpline: 01702 218184Email: via websiteWebsite: hspgroup.org The Group is a Registered Charity in England and Wales No. 1109398. It provides information and support for people diagnosed with Hereditary Spastic Paraplegia and their families. It offers grants to members for wheelchairs or scooters. Group details last updated October 2015.