Spinal Cord Atrophy Predicts Progressive Disease in Relapsing Multiple Sclerosis

Area of Science:

• Neurology
• Neuroimaging
• Multiple Sclerosis Research

Background:

• Understanding silent progression and secondary progressive multiple sclerosis (SPMS) remains a challenge.
• Novel methods are needed to analyze spinal cord atrophy from legacy MRI scans.
• Cervical cord atrophy plays a crucial role in disease progression.

Purpose of the Study:

• To investigate the role of spinal cord and brain atrophy in silent progression and conversion to SPMS.
• To utilize a novel method for accurate upper cervical cord area measurement from existing brain MRI scans.
• To assess the predictive value of spinal cord and brain measures for disease progression.

Main Methods:

• Single-center observational study including relapsing-remitting MS (RRMS), SPMS patients, and controls.
• Analysis of RRMS patient subsets who converted to SPMS or experienced silent progression over 12 years.
• Assessment of brain and spinal cord measures from MRI to predict silent progression and SPMS conversion.

Main Results:

• Patients converting to SPMS exhibited significantly faster cord atrophy rates ( -2.19%/yr) up to 4 years prior to conversion compared to RRMS matches (-0.88%/yr).
• Spinal cord atrophy rates decelerated post-conversion, aligning with rates observed in SPMS patients at study entry.
• Each 1% increase in spinal cord atrophy rate correlated with a 69% shorter time to silent progression and a 53% shorter time to SPMS conversion.

Conclusions:

• Cervical cord atrophy is the primary driver of silent progression and conversion to SPMS.
• Spinal cord atrophy is evident from early disease stages and predicts disease progression speed.
• The diagnosis of SPMS represents a late acknowledgment of an ongoing neurodegenerative process rather than a distinct disease phase.