en اعصاب و روان Neurology مروری Review <div style="text-align: justify;"><strong>Background & Objectives:</strong> The Human T-cell lymphotropic virus type 1 (HTLV-1) retrovirus is prevalent in some regions, such as Iran. This comprehensive literature review explores the symptoms and risk factors associated with HTLV-1 infection Middle East Region and Iran.</div> <div style="text-align: justify;">Materials & Methods: This narrative review used PubMed, Scopus, Embase, ScienceDirect, and Google Scholar as searching engines using terms HTLV-1, neurological disorders, pathogenesis, transmission, diagnosis, treatment, and epidemiology for articles published between 2000 and 2023. In total, 137 articles were eligible.</div> <div style="text-align: justify;"><strong>Results: </strong>Breastfeeding, unsafe sexual contact, and contaminated blood products are main HTLV-1 transmission routes. Brazil, Ecuador, and the Dominican Republic are countries with a high percentage of HTLV-1 infection, with estimates ranging from 1% to 13.9% in Brazil, up to 57% in Ecuador, and 1% to 5% in the Dominican Republic and it is endemic in Iran, Japan, the Caribbean, South America, and Africa. While numerous patients are asymptomatic, the virus can cause HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and peripheral neuropathy. Tax viral proteins cause nervous system inflammation and HAM/TSP. MRI (magnetic resonance imaging) may decipher spinal cord shrinkage and white matter lesions in affected patients. Immunodeficiency conditions, blood transfusion, and risky sexual behavior increase infection rate. The neurological symptoms are initiated with sensory-motor impairments. The main symptoms are limb weakness, bladder/bowel dysfunction, and cognitive impairment.</div> <div style="text-align: justify;"><strong>Conclusion:</strong> HTLV-1 infection is highly prevalent in Japan, Africa, the Caribbean, Central and South America, and Iran (especially in northeastern regions like Neyshabur). By understanding the pathogenesis and epidemiology of HTLV-1, proper strategies and targeted treatments can be developed for a</div> <div style="text-align: justify;">ssociated disorders like HAM/TSP. International collaboration is essential in addressing health concerns related to HTLV-1 infection.</div> <div><br> &nbsp;</div> Nervous System, HTLV Viruses, HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) 77 93 http://jabs.fums.ac.ir/browse.php?a_code=A-10-3292-1&slc_lang=en&sid=1 Ali Rajabpour Sanati علی رجب پور صنعتی ali.poursanati@gmail.com 100319475328460028832 100319475328460028832 Yes Faculty of Medicine, Birjand University of Medical Sciences, Birjand, Iran دانشکده پزشکی، دانشگاه علوم پزشکی بیرجند، بیرجند، ایران Shahriar Irankhah شهریار ایرانخواه shahriar.irankhah@gmail.com 100319475328460028833 100319475328460028833 No Faculty of Medicine, Birjand University of Medical Sciences, Birjand, Iran دانشکده پزشکی، دانشگاه علوم پزشکی بیرجند، بیرجند، ایران Laadan Rahmani لادن رحمانی Laadanrahmani@gmail.com 100319475328460028834 0009-0005-6416-3874 No Faculty of Medicine, Birjand University of Medical Sciences, Birjand, Iran دانشکده پزشکی، دانشگاه علوم پزشکی بیرجند، بیرجند، ایران Hamidreza Riasi حمیدرضا ریاسی riasi.h@yahoo.com 100319475328460028835 100319475328460028835 No Faculty of Medicine, Birjand University of Medical Sciences, Birjand, Iran دانشکده پزشکی، دانشگاه علوم پزشکی بیرجند، بیرجند، ایران