Diagnostic Approach for Multiple Sclerosis

Imaging Studies

Brain MRI is the most important paraclinical tool for MS diagnosis due to its high sensitivity in detecting demyelinating plaques 2
A standardized brain MRI protocol should include axial T1-weighted sequences, axial T2-weighted and proton-density sequences, and sagittal 2D or isotropic 3D T2-FLAIR sequences 1, 2
Spinal cord MRI is recommended even in patients without spinal symptoms, as asymptomatic cord lesions are found in 30-40% of patients with clinically isolated syndrome 1
The standardized spinal cord MRI protocol should include sagittal dual-echo, sagittal STIR, and contrast-enhanced T1-weighted spin-echo sequences 1

CSF examination is primarily used to rule out other causes of neurological symptoms, with key findings including albumino-cytological dissociation, oligoclonal bands, and elevated IgG index 4, 5
Blood tests, including complete blood count and blood chemistry, help exclude other causes of neurological symptoms 5

The 2017 McDonald Criteria require demonstration of inflammatory-demyelinating injury disseminated in both time and space, with diagnosis based on clinical evidence of lesions and dissemination in space and time 4
Diagnosis requires two or more attacks with objective clinical evidence of two or more lesions, or one attack with objective clinical evidence of one lesion plus dissemination in space and time 4

Important differential diagnoses include neuromyelitis optica spectrum disorders, characterized by aquaporin-4 antibodies and longitudinally extensive transverse myelitis 6
Other differential diagnoses include vascular disorders, infectious diseases, and metabolic disorders 4, 5

Relying solely on MRI findings without clinical correlation can lead to misdiagnosis, and non-standardized MRI examinations may yield inaccurate results 2
Diagnosing MS based on radiologically isolated syndrome findings alone is not recommended, as at least one clinical event consistent with acute demyelination remains essential for MS diagnosis 6