2026 American Academy of Neurology Autoimmune Abstract Website

Objective:

To describe a case of an atypical motor manifestation (dystonia) of AQP4-positive Neuromyelitis Optica Spectrum Disorder (NMOSD).

Background:

Neuromyelitis Optica spectrum disorder (NMOSD) is a rare autoimmune inflammatory disease that affects the optic nerves and spinal cord, causing acute myelitis. Although motor complications are well known, secondary dystonia resulting from myelin lesions remains an underreported manifestation that can significantly affect the patient's quality of life.

Design/Methods:

N/A.

Results:

A 64-year-old Ecuadorian woman with a history of optic neuritis and transverse myelitis developed progressive right hemiparesis and sensory loss over a period of three months. MRI revealed an extensive longitudinal spinal cord lesion from the medulla oblonglata to C6-C7. Serum AQP4-IgG was positive, confirming NMOSD. During follow-up, the patient developed generalized right dystonia, characterized by adductive-extensor shoulder posture with forearm supination, wrist flexion and knee extension. Management included high-dose intravenous methylprednisolone, maintenance immunotherapy with rituximab, and repeated injections of botulinum toxin A targeting the dystonic muscles (pectoralis major, trapezius, quadriceps, among others), with partial symptomatic improvement.

Conclusions:

Dystonia secondary to extensive myelitis is a rare manifestation of NMOSD. It is important to emphasize that these disorders can develop months after the onset of the disease. The treatment of choice for NMOSD is immunotherapy, which in this case was combined with botulinum toxin A, demonstrating that comprehensive management significantly improves relapse rates.