Tropical spastic paraparesis (TSP), is a medical condition that causes weakness,

muscle spasms A spasm is a sudden involuntary contraction of a muscle, a group of muscles, or a hollow organ, such as the bladder. A spasmodic muscle contraction may be caused by many medical conditions, including dystonia. Most commonly, it is a musc ...

, and sensory disturbance by

human T-lymphotropic virus The primate T-lymphotropic viruses (PTLVs) are a group of retroviruses that infect primates, using their lymphocytes to reproduce. The ones that infect humans are known as human T-lymphotropic virus (HTLV), and the ones that infect Old World monk ...

resulting in paraparesis, weakness of the legs. As the name suggests, it is most common in

tropical regions The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

, including the

Caribbean The Caribbean ( , ; ; ; ) is a region in the middle of the Americas centered around the Caribbean Sea in the Atlantic Ocean, North Atlantic Ocean, mostly overlapping with the West Indies. Bordered by North America to the north, Central America ...

Blood transfusion Blood transfusion is the process of transferring blood products into a person's Circulatory system, circulation intravenously. Transfusions are used for various medical conditions to replace lost components of the blood. Early transfusions used ...

products are screened for

human T-lymphotropic virus 1 Human T-cell lymphotropic virus type 1 or human T-lymphotropic virus (HTLV-I), also called the adult T-cell lymphoma virus type 1, is a retrovirus of the human T-lymphotropic virus (HTLV) family. Most people with HTLV-1 infection do not appear t ...

(HTLV-1) antibodies, as a preventive measure.

Signs and symptoms

Some of the signs of Tropical spastic paraparesis are: Polymyositis HE

:::::::*Leg instability :::::::*Urinary dysfunction. :::::::*Bowel dysfunction :::::::*Back pain :::::::* Erectile problems :::::::*

Psoriasis Psoriasis is a long-lasting, noncontagious autoimmune disease characterized by patches of abnormal skin. These areas are red, pink, or purple, dry, itchy, and scaly. Psoriasis varies in severity from small localized patches to complete b ...

Individuals with TSP may also exhibit

uveitis Uveitis () is inflammation of the uvea, the pigmented layer of the eye between the inner retina and the outer fibrous layer composed of the sclera and cornea. The uvea consists of the middle layer of pigmented vascular structures of the eye and ...

(inflammation of the uveal tract of the eye),

arthritis Arthritis is a general medical term used to describe a disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, Joint effusion, swelling, and decreased range of motion of ...

(inflammation of one or more joints), pulmonary lymphocytic alveolitis (inflammation of the lung tissues),

polymyositis Polymyositis (PM) is a type of chronic inflammation of the muscles ( inflammatory myopathy) related to dermatomyositis and inclusion body myositis. Its name is derived . The inflammation of polymyositis is mainly found in the endomysial layer ...

(an inflammatory muscle disease),

keratoconjunctivitis sicca Dry eye syndrome, also known as keratoconjunctivitis sicca, is the condition of having dry eyes. Symptoms include dryness in the eye, irritation, redness, discharge, blurred vision, and easily fatigued eyes. Symptoms range from mild and occas ...

(persistent dryness of the cornea and conjunctiva), and infectious dermatitis (inflammation of the skin). HTLV-1 can be transmitted via breastfeeding (mother to child), sexual contact, via blood contact (transfusion or

needle sharing Needle sharing is the practice of intravenous drug-users by which a needle or syringe is shared by multiple individuals to administer intravenous drugs such as heroin, steroids, and hormones. This is a primary vector for blood-borne diseases whi ...

Pathogenesis

In tropical spastic paraparesis, HTLV-1 shows elevated cellular acquired immune response as well as high production of

proinflammatory cytokine An inflammatory cytokine or proinflammatory cytokine is a type of signaling molecule (a cytokine) that is secreted from immune cells like helper T cells (Th) and macrophages, and certain other cell types that promote inflammation. They include int ...

Interferon Interferons (IFNs, ) are a group of signaling proteins made and released by host cells in response to the presence of several viruses. In a typical scenario, a virus-infected cell will release interferons causing nearby cells to heighten ...

overexpression has been demonstrated as well. Also the number of

NK cell Natural killer cells, also known as NK cells, are a type of cytotoxic lymphocyte critical to the innate immune system. They are a kind of large granular lymphocytes (LGL), and belong to the rapidly expanding family of known innate lymphoid cells ...

s (

CD56 Neural cell adhesion molecule (NCAM), also called CD56, is a homophilic binding glycoprotein expressed on the surface of neurons, glia and skeletal muscle. Although CD56 is often considered a marker of neural lineage commitment due to its discover ...

+ and

CD16 CD16, also known as FcγRIII, is a cluster of differentiation molecule found on the surface of natural killer cells, neutrophils, monocytes, macrophages, and certain T cells. CD16 has been identified as Fc receptors FcγRIIIa (CD16a) and FcγR ...

+) is diminished.

Diagnosis

Among the methods of diagnosing tropical spastic paraparesis are

MRI Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and rad ...

(magnetic resonance imaging) and lumbar puncture (which may show lymphocytosis). Often, the diagnosis process is based on symptoms and one's risk of exposure to the virus. A spinal tap or lumbar puncture may be used to obtain blood and CSF samples which can then be tested for parts of the virus or antibodies produced to combat the virus. MRI may be performed on the brain and spinal cord to check for abnormalities such as spinal cord degeneration and other potential causes of symptoms.

Treatment

Treatment of TSP involves

corticosteroid Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are invo ...

s to help with inflammation. However, any success with corticosteroids is short-lived, with symptoms worsening as the dosage is reduced. A synthetic derivative, 17-alpha-ethinyltestosterone, can be used to treat tropical spastic paraparesis, improvement in motor and bladder function was reported but not sustainable.

Mogamulizumab Mogamulizumab, sold under the brand name Poteligeo, is a humanized, afucosylated monoclonal antibody targeting CC chemokine receptor type 4 (CCR4). It is given by injection into a vein. The most common side effects include rash, infusion-rel ...

, an anti-CCR4 IgG1 monoclonal antibody, is also being researched as a possible treatment for tropical spastic paraparesis. The antibody reduces HTLV-1 proviral load and production of proinflammatory

cytokine Cytokines () are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are produced by a broad range of cells, including immune cells like macrophages, B cell, B lymphocytes, T cell, T lymphocytes ...

Valproic acid Valproate (valproic acid, VPA, sodium valproate, and valproate semisodium forms) are medications primarily used to treat epilepsy and bipolar disorder and prevent migraine headaches. They are useful for the prevention of seizures in those with ...

has also succeeded in reducing the proviral load of HTLV-1 (though clinical benefits were minimal or none). A further combination of valproic acid and

zidovudine Zidovudine (ZDV), also known as azidothymidine (AZT), was the first antiretroviral medication used to prevent and treat HIV/AIDS. It is generally recommended for use in combination with other antiretrovirals. It may be used to prevent mothe ...

has demonstrated a decrease in proviral loads (in animals).

Prognosis

The prognosis for tropical spastic paraparesis indicates some improvement in a percentage of cases due to immunosuppressive treatment. A higher percentage will eventually lose the ability to walk within a ten-year interval.

History

For several decades, the term ''tropical spastic paraparesis'' was used to describe a chronic and progressive clinical syndrome that affected adults living in equatorial areas of the world. This condition was initially thought to be associated with infectious agents (such as '' Treponema pertenue'' and ''

Treponema pallidum ''Treponema pallidum'', formerly known as ''Spirochaeta pallida'', is a Microaerophile, microaerophilic, Gram-negative bacteria, gram-negative, spirochaete bacterium with subspecies that cause the diseases syphilis, bejel (also known as endemic ...

'', which cause inflammation of the

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity o ...

) and with chronic nutritional deficiencies (such as

avitaminosis Vitamin deficiency is the condition of a long-term lack of a vitamin. When caused by not enough vitamin intake it is classified as a ''primary deficiency'', whereas when due to an underlying disorder such as malabsorption it is called a ''seconda ...

) or exposure to potentially toxic foods (such as bitter

cassava ''Manihot esculenta'', common name, commonly called cassava, manioc, or yuca (among numerous regional names), is a woody shrub of the spurge family, Euphorbiaceae, native to South America, from Brazil, Paraguay and parts of the Andes. Although ...

). Tropical myeloneuropathies are classified as two separate syndromes: tropical ataxic neuropathy (TAN) and tropical spastic paraparesis (TSP). They are placed together because they are found in tropical countries, although tropical spastic paraparesis has occurred in temperate countries (e.g., Japan).

References

External links

{{DEFAULTSORT:Tropical Spastic Paraparesis Viral diseases