To describe a case of  HTLV-1 with amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder of upper and lower motor neuron resulting in progressive muscle weakness. HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) is characterized by slowly progressive lower limb weakness and spasticity along with hyperreflexia and pain. It is also associated with neurological manifestations including urinary symptoms with neurogenic bladder along with sensory symptoms with paraesthesia and loss of vibration sense.

We describe a 39-year-old male with no significant past medical history who presented with progressive bilateral lower extremity weakness. The weakness started in his bilateral lower extremity and gradually progressed to his left arm then to right arm. This was associated with increased urinary urgency and incontinence. Patient had mood lability along with pseudobulbar effect.

Motor examination revealed decreased strength in bilateral lower extremities, finger extensors, and flexors. Increased tone and diffuse hyperreflexia were present in both upper and lower extremities. Tongue fasciculations were present. Laboratory workup revealed normal routine blood counts and normal cerebrospinal fluid studies without pleocytosis. On electromyography studies, fasciculation potentials were found in upper and lower extremity muscles. Magnetic resonance imaging of the brain and spine were unremarkable. Further serology workup was unrevealing except for Anti-HTLV-I antibody titers, which was confirmed to be positive with repeat serum testing. TDP43 has been sent. The patient was managed for presumed ALS. He was started on Riluzole, Baclofen. 

We here describe a case of HTLV-1 with ALS presenting with onset of lower limb weakness and urinary symptoms. ALS rarely presents with urinary manifestation as initial complaint and this should warrant further testing including HTLV. The management of ALS in presence of HAM/TSP can be challenging especially given limited data regarding the use of steroids and other immunosuppressive therapies including anti-retroviral medications in such patients.