Hereditary Spastic Paraplegia (HSP)

Hereditary spastic paraplegia (HSP) is a group of rare, inherited disorders characterized by progressive weakness and stiffness (spasticity) of the legs.

Causes and Inheritance

HSP is caused by mutations in genes that are responsible for the development and maintenance of the nervous system. The condition is usually inherited in an autosomal dominant pattern, meaning a single copy of the mutated gene is enough to cause the disorder. However, some forms of HSP can be inherited in an autosomal recessive or X-linked pattern.

Types of HSP

There are several types of HSP, including:

• Uncomplicated HSP: characterized by progressive spasticity and weakness of the legs, with minimal other symptoms.
• Complicated HSP: in addition to spasticity and weakness, individuals may experience other symptoms such as cognitive impairment, seizures, and sensory loss.
• Pure HSP: a form of uncomplicated HSP with minimal other symptoms.
• Complex HSP: a form of complicated HSP with significant other symptoms.

Symptoms

The symptoms of HSP can vary depending on the type and severity of the condition. Common symptoms include:

• Progressive weakness and stiffness of the legs
• Difficulty walking or balance problems
• Spasticity (increased muscle tone)
• Clonus (involuntary muscle contractions)
• Bladder control problems
• Bowel control problems
• Cognitive impairment (in some forms of HSP)
• Sensory loss (in some forms of HSP)

Diagnosis

The diagnosis of HSP is based on a combination of clinical evaluation, family history, and genetic testing. A doctor may perform the following tests to diagnose HSP:

• Physical examination
• Medical history
• Family history
• Genetic testing (to identify mutations in genes associated with HSP)
• Imaging studies (such as MRI or CT scans) to rule out other conditions

Treatment and Management

There is no cure for HSP, but various treatments can help manage the symptoms. These may include:

• Physical therapy to maintain mobility and strength
• Occupational therapy to improve daily functioning
• Medications to reduce spasticity and pain
• Orthotics or assistive devices to aid walking and balance
• Surgery to correct deformities or relieve pressure on the spine

Prognosis

The prognosis for individuals with HSP varies depending on the type and severity of the condition. In general, individuals with uncomplicated HSP tend to have a slower progression of symptoms and a better prognosis than those with complicated HSP.

With proper management and treatment, many individuals with HSP can lead active and fulfilling lives. However, the condition can significantly impact daily functioning and quality of life, and may require ongoing medical care and support.

Frequently Asked Questions (FAQs)

What is Hereditary Spastic Paraplegia (HSP)?
A group of rare genetic disorders characterized by progressive weakness and stiffness in the legs.

What are the primary symptoms of HSP?
Spasticity, weakness, and stiffness in the legs, often progressing to difficulty walking.

Is HSP a single disease or multiple diseases?
HSP is a clinically and genetically heterogeneous group of disorders.

How is HSP typically inherited?
Usually inherited in an autosomal dominant or autosomal recessive pattern.

What are the known genetic causes of HSP?
Mutations in over 70 different genes have been associated with HSP, including SPAST, ATL1, and REEP1.

Can HSP be diagnosed pre-symptomatically?
Yes, through genetic testing, but this is typically only possible if a family member has been diagnosed.

Is there a cure for HSP?
No, currently there is no cure, but symptoms can be managed with physical therapy and medication.

How common is HSP?
Estimated to affect approximately 1.3 to 9.6 per 100,000 people worldwide.

Are there different types of HSP?
Yes, classified as pure or complicated, depending on the presence of additional neurological symptoms.

Can HSP affect other parts of the body besides the legs?
In some cases, yes, particularly in the complicated forms, which can involve the arms, hands, and other systems.