Normal brain imaging accompanies neuroimmunologically justified, autoimmune encephalomyelitis

Area of Science:

• Neuroimmunology
• Neurology
• Radiology

Background:

• Multiple Sclerosis (MS) diagnosis typically relies on characteristic MRI findings.
• Some patients present with MS-like symptoms but lack conventional MRI abnormalities.
• Understanding these atypical cases is crucial for accurate diagnosis and management.

Purpose of the Study:

• To investigate patients with clinical presentations suggestive of MS but normal conventional MRI.
• To characterize the underlying pathology using advanced MRI techniques and immunological markers.
• To propose a novel classification for this distinct neurological condition.

Main Methods:

• Selected patients meeting 2010 McDonald MS criteria but with normal brain/spinal cord MRI.
• Analyzed diffusion tensor MRI for fractional anisotropy (FA) in white matter.
• Assessed peripheral blood B-cell subset frequencies and compared them to healthy controls.

Main Results:

• Eleven functionally disabled patients (9 women, 2 men) were identified.
• Diffusion tensor MRI revealed significant white matter abnormalities (decreased FA).
• Increased plasmablast frequency was observed, similar to Neuromyelitis Optica Spectrum Disorder (NMOSD).

Conclusions:

• Neurologic disability is linked to white matter damage, detectable by advanced MRI.
• Efficacy of plasmapheresis and B-cell abnormalities suggest an autoimmune pathogenesis.
• Proposed term: 'Normal-appearing Imaging-associated, Neuroimmunologically Justified, Autoimmune encephalomyelitis' (NAIJAE).