A 47–year–old lady was sent to our institution by her PMD for evaluation of ataxia, gradually worsening bilateral leg weakness and numbness for 3 years. She also reported low back pain, paraesthesia of legs, progressive urinary incontinence and constipation. The patient had no history of trauma, fever, headache, seizure or other neurological symptoms. Review of other systems was negative. The patient had no significant family history, sick contacts or any drug abuse. Her back pain was only partially relieved with analgesics. Her vitals were stable. Neurological exam was significant for decreased power in both lower extremities (3/5) with spasticity, hyper reflexia and non sustained ankle clonus. Gait was unsteady. Anal sphincter tone was normal. Rest of the neurological exam was normal. Further workup was pursued to rule out demyelination, infectious, inflammatory or autoimmune etiology. Investigations revealed normal hemogram, serum chemistry, vitamin B12, folate level, HbA1c and urinalysis. ESR was 8mm/h; rheumatoid factor, RPR, anti nuclear antibody, ACE levels, lyme titer and antiphospholipid antibody were negative. CSF analysis was normal. MRI brain, cervical, thoracic and lumbosacral spine was unremarkable for myelopathy or demyelination. On further inquiry, patient revealed that she was originally from Ecuador and had settled in USA for many years. Serum Human T cell lymphotropic virus type 1 (HTLV1) serology was also sent which came back positive. Patient was offered an HIV test which she declined. Based on the clinical picture and serology, diagnosis of tropical spastic paralysis (TSP) or HTLV1 associated myelopathy (HAM) was made. The patient was started on a short course of high dose intravenous steroids followed by oral prednisone taper. The patient was then referred for in–house rehabilitation with which she made gradual progress over a course of months.
There are various pathologies that affect the spinal cord including traumatic, vascular, autoimmune, neoplastic or infectious etiologies. Human T–cell lymphotropic virus type I (HTLV1) is known to cause adult T cell leukemia/lymphoma and slowly progressive neurological disease called HTLV1 associated myelopathy (HAM) or Tropical Spastic Paralysis (TSP) comprising of spastic paraparesis and urinary disturbance. It is characterized by inflammation of spinocerebellar, corticospinal and spinothalmic tracts with relative sparing of the posterior columns. HAM/TSP is endemic in Japan, Caribbean, South America, Middle East, but comparatively rare in USA. There is no definite treatment recommended for this disease, however steroids with their anti inflammatory effects are thought to be useful.
While trauma, vascular, neoplastic entities are common causes of back pain with bowel and bladder malfunction, Tropical Spastic Paralysis (TSP) should be considered a differential diagnosis in immigrants from South America, Japan and other tropical areas.