Semiquantitative Scale for Assessing Brain MRI Abnormalities in Wilson Disease: A Validation Study

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Magnetic Resonance Imaging (MRI) is crucial for detecting brain abnormalities in Wilson disease, including T2 hyperintensities, T2 hypointensities, and atrophy.
• A validated scoring system for quantifying radiological severity in Wilson disease is currently lacking.
• This study aimed to address this gap by developing and validating a brain MRI visual rating scale specifically for Wilson disease.

Purpose of the Study:

• To develop and validate a brain MRI visual rating scale for assessing radiological severity in Wilson disease.
• To differentiate between reversible (acute toxicity) and non-reversible (chronic damage) MRI findings.
• To correlate MRI findings with clinical severity using the Unified Wilson Disease Rating Scale.

Main Methods:

• A novel Wilson disease brain MRI severity scale was created, incorporating subscores for acute toxicity (T2 hyperintensities) and chronic damage (T2 hypointensities and atrophy).
• The scale was validated using 1.5T MRI scans from 39 Wilson disease patients at baseline and after 24 months of anticopper treatment.
• Interrater and intrarater reliability were assessed, along with the temporal evolution of the MRI score and its association with clinical scores.

Main Results:

• The developed MRI severity scale demonstrated good intrarater and interrater agreement.
• In patients with neurologic Wilson disease, the total MRI severity score improved over two years, primarily due to reduced acute toxicity.
• The chronic damage score showed deterioration over the study period, and both total and chronic scores correlated positively with clinical severity.

Conclusions:

• The Wilson disease brain MRI severity scale is a simple, reliable, and valid tool for semiquantitative assessment of radiological Wilson disease.
• The scale allows for tracking treatment response and disease progression through distinct measures of acute and chronic brain changes.
• This validated scale can aid in standardizing the evaluation of brain involvement in Wilson disease and monitoring therapeutic interventions.