Intravesical injection of onabotulinumtoxinA in neurogenic overactive bladder patients with human T‐cell leukemia virus type 1‐associated myelopathy: A single‐institution case series

Introduction Neurogenic overactive bladder is a main feature of human T‐cell leukemia virus type 1‐associated myelopathy/tropical spastic paraparesis. We successfully performed intravesical onabotulinumtoxinA therapy for refractory neurogenic overactive bladder due to human T‐cell leukemia virus type 1‐associated myelopathy/tropical spastic paraparesis. Case presentation We retrospectively reviewed four neurogenic overactive bladder patients with human T‐cell leukemia virus type 1‐associated myelopathy/tropical spastic paraparesis who underwent bladder wall injections of onabotulinumtoxinA from April to October 2020. All patients were female. Their median age was 66 (range, 63–71) years. They were previously treated with β3‐adrenergic receptor agonists or anticholinergic drugs alone or in combination for ≥12 weeks. However, insufficient results were obtained. After 4 weeks of intravesical onabotulinumtoxinA therapy, overactive bladder symptoms improved and maximum cystometric capacity increased in all cases. Conclusion Intravesical onabotulinumtoxinA therapy may be useful for treating refractory overactive bladder due to human T‐cell leukemia virus type 1‐associated myelopathy/tropical spastic paraparesis.