Myelopathy / Tropical Spastic Paralysis – Causes, Symptoms and Treatment

Tropical spastic paraparesis (HTLV) (HTLV) HAM / TSP is a chronic progressive demyelinating disease whose essence is a slowly progressive spastic paraparesis resulting from damage to the thoracic spinal tract of the spinal cord. Initially, myelopathy and tropical spastic paralysis were regarded as various diseases of unknown etiology occurring in other geographic regions.

Incidence of myelopathy / tropical spastic paralysis

Myelopathy occurs in regions endemic to HTLV-1 infection, that is:

1. in Japan,
2. in the Caribbean Islands,
3. in Equatorial and South Africa,
4. Central and South America.

About 1% of HTLV-1 infected individuals develop HAM / TSP, more often in women (2: 1). Adults are ill, on average in the fourth decade of life, very rarely children. The incubation period of tropical spastic paralysis is shorter than that of ATLL, especially when HTLV infection has occurred during blood transfusion (up to several months).

Myelopathy / tropical spastic paralysis – causes

The cause of tropical spastic paralysis is the human T-cell lymphotropic virus type 1 (HTLV-1). HAM / TSP-like syndromes following HTLV-2 infection have also been described.

Mechanism of tropical spastic paralysis and myelopathy

In the pathogenesis of myelopathy, an important role is played by perivascular lymphocytic infiltrates and foci of demyelination, mainly in the thoracic spinal cord, less frequently found in the brain. One of the postulated mechanisms of nerve tissue damage is direct infection of glial cells by HTLV-1, which triggers a cytotoxic reaction against glial cells and thus demyelination.

Clinical symptoms of myelopathy / tropical spastic paralysis

The onset of tropical spastic paralysis is slow, rarely sudden. Patients report bilateral weakness and stiffness of the lower limbs, more intense in the proximal sections. Disturbances in the function of the urinary bladder and sphincters as well as disorders of superficial and deep sensation join early. Moreover, positive Babinski’s symptom and excessive tendon reflexes are found.

Course of illness

The myelopathy is progressive. After 10 years, 30% of patients are unable to move at all and 45% require help.

Tropical spastic paralysis / myelopathy – diagnosis

The cerebrospinal fluid of patients with myelopathy / tropical spastic paralysis contains an excessive number of lymphocytic predominant cells (usually 50-100 / mm3) and an increased concentration of protein. Characteristic atypical lymphocytes with a lobular nucleus are detected in the blood and cerebrospinal fluid. Detecting the presence of anti-HTLV-1 antibodies or viral antigens or viral particles in the blood or in the cerebrospinal fluid is also helpful in the diagnosis of HAM / TSP.

It is also possible to determine the HTLV-1 provirus in the brain and spinal cord by PCR. MRI scans reveal demyelinating foci similar to those found in multiple sclerosis.

In the diagnosis of the disease, it is also important to differentiate it from other ailments: Clinically, HAM / TSP may resemble Multiple Sclerosis (MS), with the characteristic of MS paralysis of cranial nerves and no course of exacerbation and remission.

Treatment of myelopathy / tropical spastic paralysis

As with ATLL, effective methods of treating HAM / TSP do not exist, but it is possible to extend the life of patients. Symptomatic treatment is aimed at maintaining normal muscle function as long as possible and reducing spasticity. Approximately 50% of patients benefit from using it glucokortykosteroidów (mainly at the initial stage of the disease).

There is some hope for feeding his wife alone or in combination with interferon alfa. In women with urinary incontinence, it turned out to be effective danazol. Methods of preventing HTLV infection are described above.

What’s the prognosis?

The median survival time for patients with myelopathy / tropical spastic paralysis is 10 years from the onset of symptoms. The main causes of death are infections and cancer.

Source: J. Cianciara, J. Juszczyk, Infectious and parasitic diseases; Czelej Publishing House