A Comparison of Clinical Presentation and MRI Findings in Neuromyelitis Optica Spectrum Disorder and Spinal Cord Infarct in Complex Patients With Multiple Co-morbidities

Background: Neuromyelitis optica spectrum disorder (NMOSD) can be difficult to differentiate from other causes of longitudinally extensive transverse myelitis (LETM), such as spinal cord infarct (SCI), especially when patients are complex and have multiple co-morbidities.

Objectives: It is therefore of utility to compare the MRI findings in such cases in order to distill the key characteristics associated with each condition and improve diagnostic accuracy while predicting variability.

Methods: This case comparison examines two patients with acute LETM that were  followed by a single provider. Each patient’s clinical history, cervical and thoracic MRI, CSF studies, AQP4-Ab serology and comorbidities are compared, ultimately leading to the final diagnosis of NMOSD and SCI in each patient respectively.

Results: In these patients, clinical history differed in time to nadir and precipitating factor of hypotension. Etiology specific features on MRI, such as the “owl’s eye sign” for SCI and “bright spotty lesions” for NMOSD, were found to be unreliable, but subtle associated features helped to synthesize the clinical picture.

Conclusions: These difficult cases underscore the need for neurologists to be familiar with the differential diagnosis of LETM and to judiciously use key distinguishing findings on MRI to help differentiate NMOSD from other diseases such as SCI.