Tropical myeloneuropathies initially identified in tropical regions are categorized into two main clinical syndromes with some overlapping characteristics, namely, TSP (tropical spastic paraparesis) and TAN (tropical ataxic neuropathy). Although TSP and TAN are different conditions, they are often grouped together because of their prevalence in tropical areas. TSP is found in temperate areas like southern Japan, where it is known as HAM (HTLV-1-associated myelopathy). HAM/TSP and TAN have different causes and clinical symptoms. TAN is primarily sensory neuropathy. TSP/ HAM mainly affects the spinal cord, which can lead to an upper motor neuron syndrome.
Epidemiology
To estimate the prevalence rate of HAM/TSP and HTLV-1 is difficult because of their gradual onset. Sporadic cases have been found with a lifetime risk of about 1.7 % and 7% in the U.S. HAM/TSP and TAN are common seen in common areas with endemic HTLV-1 like Seychelles, South America, Caribbean, Southern Japan, and equatorial Africa. About 10 to 20 million people are HTLV-1 carriers in the world. TSP has been seen with a lifetime risk of about 0.25% in India.
Research on mortality and morbidity of TAN is limited. As per one study, Nigeria has high mortality rates of TAN patients compared to general population. The incubation period from HTLV infection to the symptoms of myelopathy may vary from months to decades with an older age of 50 years and older. High HTLV proviral load linked with rapid progression to severe disability.
TAN is prevalent in Africa and affects individuals from lower socio-economic areas. Most TSP/HAM patients are from socio-economic areas and are black or mixed descent. Both TAN and HAM/TSP are common in women than men. The women-to-men ratio is about 3:1. This disease can present at any age but is mostly seen in the 3rd or 4th decade of life.
Anatomy
Pathophysiology
TAN is a sensory neuropathy. It affects different malnourished populations specifically to those who consume a high cassava. It is a drought resistant plant crop which contains high levels of cyanogenic glycosides. Their proportions elevate in dry conditions. This condition can be reduced by proper methods like soaking and grating. A deficiency of vitamin B group was the cause of TAN earlier. Treatment to those deficiency of vitamin B group has less chance. TAN was earlier linked with vitamin deficiency or tropical malabsorption in prisoners of war.
HTLV-1 linked with TSP/HAM is an upper motor neuron syndrome. It affects mainly the lower extremities. It is an infection with HTLV-1. It is a type C retrovirus related to other retroviruses. It includes the bovine leukemia virus. HTLV-1 is transmitted by intimate or sexual contact. The particular pathogenesis of TSP/HAM is not clear, and it is unknown how the disease progressed from an asymptomatic carrier state to a clinical state of HTLV-1 infection. Elevated HTLV-1 proviral load in the peripheral blood and CSF related to severity of symptoms in TSP/HAM.
Etiology
TAN (tropical ataxic neuropathy)
This condition is linked with excessive consumption of cassava. It is known as tapioca or mandioca. It is an important calorie source for many tropical areas. About 300 million people depend on cassava for sustenance, specifically in tropical areas of America and Africa. Cassava contains cyanide in the form of a cyanogenic glycoside. It is called linamarin. It releases cyanide by linamarinase or hydrolysis. Chronic cyanide intoxication is identified as the cause of TAN in areas like Nigeria and Tanzania.
Treatment with high dosages of vitamins is ineffective. It indicated that vitamin deficiencies are not the factor of the disease. Cassava consumption is linked with other neurological diseases, konzo. It affects children and young women.
While processing the cassava to flour, cyanide is removed, drought disease lead to neglected or short processing procedures. This can lead to high levels of cyanide, specifically when cassava is consumed raw or sun-dried. It can lead to an elevated rate of several cyanide poisoning.
Historically, TAN in prisoners of war was attributed to tropical malabsorption and vitamin deficiencies. Many affected individuals were found to be deficient in B-group vitamins with some studies suggesting a strong correlation between TAN and chronic thiamine deficiency.
TAN and HAM/TSP currently do not have standardized treatments. Management of this disease focuses on the relief of symptoms. Medications like benzodiazepines, baclofen, and tizanidine are used along with physical treatment.
Patients who have Tan or HAM/TSP may have neuropathic pain. It can be managed by tricyclic antidepressants, baclofen, and antiepileptics. These medications are not approved by the FDA for this disease. Controlled trials to evaluate the antiviral agents for TSP/HAM are still in process.
by Stage
by Modality
Chemotherapy
Radiation Therapy
Surgical Interventions
Hormone Therapy
Immunotherapy
Hyperthermia
Photodynamic Therapy
Stem Cell Transplant
Targeted Therapy
Palliative Care
modification-of-the-environment
Dietary modification:
Multivitamin supplementation is suggested. In areas like cassava flour is a dietary supplement, it is important to set a standard for cassava processing methods to reduce the risk.
Prevention:
To prevent HTLV-1 infection, it is important to manage TSP. The virus can be transmitted by different ways, like intimate or sexual contact, sharing needles among the drug users, breastfeeding, intrauterine transfer, blood transfusion, and neonatal transmission. As per one study, about 60% of the people with HTLV-1 antibody positive for blood transfusion have seroconversion. Breastfeeding is a contraindication for HTLV-1 carriers.
Administration of pharmaceutical agents with drugs Use of interferons
Specialty: Neurology
Interferon beta-1a: It is used to treat multiple sclerosis. Interferons activate the Stat/Jak pathway, triggering the stimulation of interferon-responsive genes. The expression of B7-1 on the surface of immune cells may be reduced along with increasing the levels of TGF-beta can be carried by interferon beta in patients with M.S.
Peginterferon alfa-2a: It consists of IFN alfa-2a linked to the PEG molecule, which is 40-kd branched. Immunological and clinical improvements are seen with the use of this medication.
Use of agents that reduce blood viscosity
Pentoxifylline: The drug may change the rheology of RBCs, which in turn reduces the viscosity of blood
Use of corticosteroids
Prednisolone: This drug is known to inhibit the inflammatory reactions related to the disease via suppression of the key components of immune system.
Use of deacetylase inhibitors
Valproic acid: An inhibitor of histone deacetylase, sodium valproate has positive effects on decreasing the PVL (proviral load) and enhances recognition of infected cells by immune system.
Use of CCR4 inhibitors
Mogamulizumab: It is an anti-CCR4 antibody which targets selectively and thus decreases the number of infected HTLV-1 cells.
Tropical myeloneuropathies are diseases which can impact the spinal cord and peripheral nerves. It is seen in tropical areas because of infection and nutritional factors. To manage these diseases includes many phases:
Diagnosis and assessment:
This is the starting phase, which includes a complete clinical evaluation, diagnostic tests, and neurophysiological studies to properly identify the condition.
Acute management:
This phase includes how to treat the disease, manage the symptoms, and provide supportive care. It includes rehabilitation by physical therapy, occupational therapy and use of assistive devices.
Long-term management:
This phase includes monitor the progress, implementation of preventive measure and give psychosocial support to manage long term effects of the condition.
Education and prevention:
This phase includes the education of patients about the disease and increase the awareness to prevent recurrence and manage the risk factor.
Tropical myeloneuropathies initially identified in tropical regions are categorized into two main clinical syndromes with some overlapping characteristics, namely, TSP (tropical spastic paraparesis) and TAN (tropical ataxic neuropathy). Although TSP and TAN are different conditions, they are often grouped together because of their prevalence in tropical areas. TSP is found in temperate areas like southern Japan, where it is known as HAM (HTLV-1-associated myelopathy). HAM/TSP and TAN have different causes and clinical symptoms. TAN is primarily sensory neuropathy. TSP/ HAM mainly affects the spinal cord, which can lead to an upper motor neuron syndrome.
To estimate the prevalence rate of HAM/TSP and HTLV-1 is difficult because of their gradual onset. Sporadic cases have been found with a lifetime risk of about 1.7 % and 7% in the U.S. HAM/TSP and TAN are common seen in common areas with endemic HTLV-1 like Seychelles, South America, Caribbean, Southern Japan, and equatorial Africa. About 10 to 20 million people are HTLV-1 carriers in the world. TSP has been seen with a lifetime risk of about 0.25% in India.
Research on mortality and morbidity of TAN is limited. As per one study, Nigeria has high mortality rates of TAN patients compared to general population. The incubation period from HTLV infection to the symptoms of myelopathy may vary from months to decades with an older age of 50 years and older. High HTLV proviral load linked with rapid progression to severe disability.
TAN is prevalent in Africa and affects individuals from lower socio-economic areas. Most TSP/HAM patients are from socio-economic areas and are black or mixed descent. Both TAN and HAM/TSP are common in women than men. The women-to-men ratio is about 3:1. This disease can present at any age but is mostly seen in the 3rd or 4th decade of life.
TAN is a sensory neuropathy. It affects different malnourished populations specifically to those who consume a high cassava. It is a drought resistant plant crop which contains high levels of cyanogenic glycosides. Their proportions elevate in dry conditions. This condition can be reduced by proper methods like soaking and grating. A deficiency of vitamin B group was the cause of TAN earlier. Treatment to those deficiency of vitamin B group has less chance. TAN was earlier linked with vitamin deficiency or tropical malabsorption in prisoners of war.
HTLV-1 linked with TSP/HAM is an upper motor neuron syndrome. It affects mainly the lower extremities. It is an infection with HTLV-1. It is a type C retrovirus related to other retroviruses. It includes the bovine leukemia virus. HTLV-1 is transmitted by intimate or sexual contact. The particular pathogenesis of TSP/HAM is not clear, and it is unknown how the disease progressed from an asymptomatic carrier state to a clinical state of HTLV-1 infection. Elevated HTLV-1 proviral load in the peripheral blood and CSF related to severity of symptoms in TSP/HAM.
TAN (tropical ataxic neuropathy)
This condition is linked with excessive consumption of cassava. It is known as tapioca or mandioca. It is an important calorie source for many tropical areas. About 300 million people depend on cassava for sustenance, specifically in tropical areas of America and Africa. Cassava contains cyanide in the form of a cyanogenic glycoside. It is called linamarin. It releases cyanide by linamarinase or hydrolysis. Chronic cyanide intoxication is identified as the cause of TAN in areas like Nigeria and Tanzania.
Treatment with high dosages of vitamins is ineffective. It indicated that vitamin deficiencies are not the factor of the disease. Cassava consumption is linked with other neurological diseases, konzo. It affects children and young women.
While processing the cassava to flour, cyanide is removed, drought disease lead to neglected or short processing procedures. This can lead to high levels of cyanide, specifically when cassava is consumed raw or sun-dried. It can lead to an elevated rate of several cyanide poisoning.
Historically, TAN in prisoners of war was attributed to tropical malabsorption and vitamin deficiencies. Many affected individuals were found to be deficient in B-group vitamins with some studies suggesting a strong correlation between TAN and chronic thiamine deficiency.
TAN and HAM/TSP currently do not have standardized treatments. Management of this disease focuses on the relief of symptoms. Medications like benzodiazepines, baclofen, and tizanidine are used along with physical treatment.
Patients who have Tan or HAM/TSP may have neuropathic pain. It can be managed by tricyclic antidepressants, baclofen, and antiepileptics. These medications are not approved by the FDA for this disease. Controlled trials to evaluate the antiviral agents for TSP/HAM are still in process.
Neurology
Dietary modification:
Multivitamin supplementation is suggested. In areas like cassava flour is a dietary supplement, it is important to set a standard for cassava processing methods to reduce the risk.
Prevention:
To prevent HTLV-1 infection, it is important to manage TSP. The virus can be transmitted by different ways, like intimate or sexual contact, sharing needles among the drug users, breastfeeding, intrauterine transfer, blood transfusion, and neonatal transmission. As per one study, about 60% of the people with HTLV-1 antibody positive for blood transfusion have seroconversion. Breastfeeding is a contraindication for HTLV-1 carriers.
Neurology
Specialty: Neurology
Interferon beta-1a: It is used to treat multiple sclerosis. Interferons activate the Stat/Jak pathway, triggering the stimulation of interferon-responsive genes. The expression of B7-1 on the surface of immune cells may be reduced along with increasing the levels of TGF-beta can be carried by interferon beta in patients with M.S.
Peginterferon alfa-2a: It consists of IFN alfa-2a linked to the PEG molecule, which is 40-kd branched. Immunological and clinical improvements are seen with the use of this medication.
Use of agents that reduce blood viscosity
Pentoxifylline: The drug may change the rheology of RBCs, which in turn reduces the viscosity of blood
Neurology
Prednisolone: This drug is known to inhibit the inflammatory reactions related to the disease via suppression of the key components of immune system.
Neurology
Valproic acid: An inhibitor of histone deacetylase, sodium valproate has positive effects on decreasing the PVL (proviral load) and enhances recognition of infected cells by immune system.
Neurology
Mogamulizumab: It is an anti-CCR4 antibody which targets selectively and thus decreases the number of infected HTLV-1 cells.
Neurology
Tropical myeloneuropathies are diseases which can impact the spinal cord and peripheral nerves. It is seen in tropical areas because of infection and nutritional factors. To manage these diseases includes many phases:
Diagnosis and assessment:
This is the starting phase, which includes a complete clinical evaluation, diagnostic tests, and neurophysiological studies to properly identify the condition.
Acute management:
This phase includes how to treat the disease, manage the symptoms, and provide supportive care. It includes rehabilitation by physical therapy, occupational therapy and use of assistive devices.
Long-term management:
This phase includes monitor the progress, implementation of preventive measure and give psychosocial support to manage long term effects of the condition.
Education and prevention:
This phase includes the education of patients about the disease and increase the awareness to prevent recurrence and manage the risk factor.
Tropical myeloneuropathies initially identified in tropical regions are categorized into two main clinical syndromes with some overlapping characteristics, namely, TSP (tropical spastic paraparesis) and TAN (tropical ataxic neuropathy). Although TSP and TAN are different conditions, they are often grouped together because of their prevalence in tropical areas. TSP is found in temperate areas like southern Japan, where it is known as HAM (HTLV-1-associated myelopathy). HAM/TSP and TAN have different causes and clinical symptoms. TAN is primarily sensory neuropathy. TSP/ HAM mainly affects the spinal cord, which can lead to an upper motor neuron syndrome.
To estimate the prevalence rate of HAM/TSP and HTLV-1 is difficult because of their gradual onset. Sporadic cases have been found with a lifetime risk of about 1.7 % and 7% in the U.S. HAM/TSP and TAN are common seen in common areas with endemic HTLV-1 like Seychelles, South America, Caribbean, Southern Japan, and equatorial Africa. About 10 to 20 million people are HTLV-1 carriers in the world. TSP has been seen with a lifetime risk of about 0.25% in India.
Research on mortality and morbidity of TAN is limited. As per one study, Nigeria has high mortality rates of TAN patients compared to general population. The incubation period from HTLV infection to the symptoms of myelopathy may vary from months to decades with an older age of 50 years and older. High HTLV proviral load linked with rapid progression to severe disability.
TAN is prevalent in Africa and affects individuals from lower socio-economic areas. Most TSP/HAM patients are from socio-economic areas and are black or mixed descent. Both TAN and HAM/TSP are common in women than men. The women-to-men ratio is about 3:1. This disease can present at any age but is mostly seen in the 3rd or 4th decade of life.
TAN is a sensory neuropathy. It affects different malnourished populations specifically to those who consume a high cassava. It is a drought resistant plant crop which contains high levels of cyanogenic glycosides. Their proportions elevate in dry conditions. This condition can be reduced by proper methods like soaking and grating. A deficiency of vitamin B group was the cause of TAN earlier. Treatment to those deficiency of vitamin B group has less chance. TAN was earlier linked with vitamin deficiency or tropical malabsorption in prisoners of war.
HTLV-1 linked with TSP/HAM is an upper motor neuron syndrome. It affects mainly the lower extremities. It is an infection with HTLV-1. It is a type C retrovirus related to other retroviruses. It includes the bovine leukemia virus. HTLV-1 is transmitted by intimate or sexual contact. The particular pathogenesis of TSP/HAM is not clear, and it is unknown how the disease progressed from an asymptomatic carrier state to a clinical state of HTLV-1 infection. Elevated HTLV-1 proviral load in the peripheral blood and CSF related to severity of symptoms in TSP/HAM.
TAN (tropical ataxic neuropathy)
This condition is linked with excessive consumption of cassava. It is known as tapioca or mandioca. It is an important calorie source for many tropical areas. About 300 million people depend on cassava for sustenance, specifically in tropical areas of America and Africa. Cassava contains cyanide in the form of a cyanogenic glycoside. It is called linamarin. It releases cyanide by linamarinase or hydrolysis. Chronic cyanide intoxication is identified as the cause of TAN in areas like Nigeria and Tanzania.
Treatment with high dosages of vitamins is ineffective. It indicated that vitamin deficiencies are not the factor of the disease. Cassava consumption is linked with other neurological diseases, konzo. It affects children and young women.
While processing the cassava to flour, cyanide is removed, drought disease lead to neglected or short processing procedures. This can lead to high levels of cyanide, specifically when cassava is consumed raw or sun-dried. It can lead to an elevated rate of several cyanide poisoning.
Historically, TAN in prisoners of war was attributed to tropical malabsorption and vitamin deficiencies. Many affected individuals were found to be deficient in B-group vitamins with some studies suggesting a strong correlation between TAN and chronic thiamine deficiency.
TAN and HAM/TSP currently do not have standardized treatments. Management of this disease focuses on the relief of symptoms. Medications like benzodiazepines, baclofen, and tizanidine are used along with physical treatment.
Patients who have Tan or HAM/TSP may have neuropathic pain. It can be managed by tricyclic antidepressants, baclofen, and antiepileptics. These medications are not approved by the FDA for this disease. Controlled trials to evaluate the antiviral agents for TSP/HAM are still in process.
Neurology
Dietary modification:
Multivitamin supplementation is suggested. In areas like cassava flour is a dietary supplement, it is important to set a standard for cassava processing methods to reduce the risk.
Prevention:
To prevent HTLV-1 infection, it is important to manage TSP. The virus can be transmitted by different ways, like intimate or sexual contact, sharing needles among the drug users, breastfeeding, intrauterine transfer, blood transfusion, and neonatal transmission. As per one study, about 60% of the people with HTLV-1 antibody positive for blood transfusion have seroconversion. Breastfeeding is a contraindication for HTLV-1 carriers.
Neurology
Specialty: Neurology
Interferon beta-1a: It is used to treat multiple sclerosis. Interferons activate the Stat/Jak pathway, triggering the stimulation of interferon-responsive genes. The expression of B7-1 on the surface of immune cells may be reduced along with increasing the levels of TGF-beta can be carried by interferon beta in patients with M.S.
Peginterferon alfa-2a: It consists of IFN alfa-2a linked to the PEG molecule, which is 40-kd branched. Immunological and clinical improvements are seen with the use of this medication.
Use of agents that reduce blood viscosity
Pentoxifylline: The drug may change the rheology of RBCs, which in turn reduces the viscosity of blood
Neurology
Prednisolone: This drug is known to inhibit the inflammatory reactions related to the disease via suppression of the key components of immune system.
Neurology
Valproic acid: An inhibitor of histone deacetylase, sodium valproate has positive effects on decreasing the PVL (proviral load) and enhances recognition of infected cells by immune system.
Neurology
Mogamulizumab: It is an anti-CCR4 antibody which targets selectively and thus decreases the number of infected HTLV-1 cells.
Neurology
Tropical myeloneuropathies are diseases which can impact the spinal cord and peripheral nerves. It is seen in tropical areas because of infection and nutritional factors. To manage these diseases includes many phases:
Diagnosis and assessment:
This is the starting phase, which includes a complete clinical evaluation, diagnostic tests, and neurophysiological studies to properly identify the condition.
Acute management:
This phase includes how to treat the disease, manage the symptoms, and provide supportive care. It includes rehabilitation by physical therapy, occupational therapy and use of assistive devices.
Long-term management:
This phase includes monitor the progress, implementation of preventive measure and give psychosocial support to manage long term effects of the condition.
Education and prevention:
This phase includes the education of patients about the disease and increase the awareness to prevent recurrence and manage the risk factor.
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