Neuromyelitis optica - a cause for longitudinally extensive transverse myelitis: a rare case report from Nepal and literature review.

Introduction: Neuromyelitis optica is a rare autoimmune condition, which is manifested by inflammation of optic nerve (optic neuritis) and spinal cord (myelitis). Longitudinally extensive transverse myelitis (LETM) is a neurological disorder leading to contiguous inflammatory spinal cord lesion, seen as T2 hyperintensity that extends over three or more vertebral segments on MRI of spine. Here, the author presents a case report on LETM from Western Nepal. Case presentation: The author reports a case of 21-year-female with no known comorbidities who presented to neuro OPD with complaint of progressive bilateral lower limb weakness for 2 weeks, associated with bowel and bladder incontinence for 3 days. There is no significant past or family history. Discussion: A detailed history, clinical examination, radiological findings, and interventions like lumbar puncture, MRI is critical to intervene for the cause of LETM. Treatment of patient depends upon underlying etiologies. In this case, patient is managed by IV methylprednisolone. Regular assessment and evaluation help in determining the prognosis of patient. Conclusion: Neuromyelitis optica spectrum disorder (NMOSD), being more common in middle-aged group (30-45 years); can occur in younger age group as per our case. Specialized AQP4 detection is often constrained in many parts of Nepal which is a big challenge, especially in resource-limited settings. This case highlights that positive AQP4 testing helps in reaching a definitive diagnosis and timely initiation of high-dose steroids and immunosuppressive therapy that brings out substantial recovery at 2 months - consistent with literature showing that early aggressive therapy prompts to better outcomes.