HTLV-1 associated myelopathy/tropical spastic paraparesis

Alternate names

HAM/TSP; Human T-cell leukemia virus type 1 associated myelopathy/tropical spastic paraparesis; Tropical spastic paraparesis (formerly)

Definition

HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a progressive disease of the nervous system that affects less than 2% of people with HTLV-1 infection.

Cause

• The cause of TSP was obscure until the mid-1980s, when an important association was established between the human retrovirus — human T-cell lymphotrophic virus type 1 (also known as HTLV-1) — and TSP.
• TSP is now called HTLV-1 associated myelopathy/ tropical spastic paraparesis or HAM/TSP.
• The HTLV-1 retrovirus is thought to cause at least 80 percent of the cases of HAM/TSP by impairing the immune system.

Signs and symptoms

Signs and symptoms of HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) vary but may include:

• Slowly progressive weakness and spasticity of one or both legs
• Exaggerated reflexes (hyperreflexia)
• Stiff muscles
• Muscle contractions in the ankle (ankle clonus)
• Lower back pain
• A 'weak' bladder and/or urinary incontinence
• Minor sensory changes, especially burning or prickling sensations and loss of vibration sense

Diagnosis

Tropical spastic paraparesis can be diagnosed by using MRI (magnetic resonance imaging) and lumbar puncture (which may show lymphocytosis).

Treatment

• Treatment generally aims to control the specific symptoms, as there is no standard treatment available.
• Interferon alpha may be beneficial over short periods, and some aspects of the disease may be improved with interferon beta.
• Stiff and spastic muscles may be treated with lioresal or tizanidine, and urinary dysfunction may be treated with oxybutynin.
• Corticosteroids were reported to slow progression in one case series and reduce neurologic disability in another.
• However, others have reported no such benefit with corticosteroids and there have been no randomized clinical trials.

NIH genetic and rare disease info

• NIH info on HTLV-1 associated myelopathy/tropical spastic paraparesis

HTLV-1 associated myelopathy/tropical spastic paraparesis is a rare disease.