Very late onset neuromyelitis optica spectrum disorders

Area of Science:

• Neuroimmunology
• Neurology
• Clinical Medicine

Background:

• Neuromyelitis Optica Spectrum Disorder (NMOSD) typically affects adults but can present insidiously in the elderly.
• Very late onset NMOSD (VLO-NMOSD), defined as onset at age ≥70, is rare, with limited case series data.
• Understanding VLO-NMOSD is crucial due to its potential for aggressive progression in older populations.

Purpose of the Study:

• To investigate the clinical characteristics of VLO-NMOSD.
• To compare VLO-NMOSD with early onset NMOSD (EO-NMOSD) and late onset NMOSD (LO-NMOSD).
• To identify unique features of NMOSD in elderly patients.

Main Methods:

• Retrospective study classifying NMOSD patients into three age groups: EO-NMOSD (≤49 years), LO-NMOSD (50-69 years), and VLO-NMOSD (≥70 years).
• Evaluation of clinical features, MRI findings, laboratory data, and immunotherapies.
• Statistical comparison of characteristics across the three defined age subgroups.

Main Results:

• VLO-NMOSD patients (11%) showed significantly shorter intervals between episodes and diagnosis compared to EO-NMOSD and LO-NMOSD.
• Optic neuritis and MRI brain lesions were less frequent in VLO-NMOSD.
• VLO-NMOSD patients exhibited higher disability scores and significantly longer spinal cord lesions.

Conclusions:

• Very late onset NMOSD (VLO-NMOSD) is characterized by severe myelitis with extensive spinal cord lesions.
• Elderly patients with VLO-NMOSD are less likely to experience optic neuritis.
• These findings suggest distinct clinical phenotypes of NMOSD based on age of onset.