Which of the following causes tropical spastic paresis?

Ans. c. HTLV (Ref: Ananthanaravan 9/e p567: Harrison 19/e p697)HTLV causes tropical spastic paresis."HTLV-1 is also the cause of tropical spastic paraparesis--a neurologic disorder that occurs somewhat more frequently than lymphoma and with shorter latency and usually from transfusion-transmitted virus. "--Harrison 19/e p697"HTLV-1 has been established as the causative agent of adult T-cell Leukemia-Lymphomas (ATL) as well as nervous system degenerative disorder called tropical spastic paraparesis."Tropical Spastic ParaparesisCaused by HTLVQAffects females disproportionatelyPathology:Spinal cord: Symmetric degeneration of the lateral columns, including the corticospinal tracts; some cases involve the posterior columns as well.Spinal meninges & cord parenchyma: Inflammatory infiltrate with myelin destruction.Clinical Features:Onset is insidious; weakness or stiffness in one or both legs, back pain & urinary incontinenceQ.The disease generally takes the form of slow ly progressive & unremitting thoracic myelopathyQPatients display spastic paraparesis or paraplegia with hyperreflexia, ankle clonus & extensor plantar responses.Cognitive function is usually spared; cranial nerve abnormalities are unusual.Diagnosis:MRI: Lesions in both the white matter & paraventricular regions of the brain & spinal cordQ.