Increased periventricular thalamic damage gradient in multiple sclerosis detected by quantitative gradient echo MRI.

Area of Science:

• Neuroimaging
• Neurology
• Biomedical Engineering

Background:

• Multiple sclerosis (MS) involves thalamic tissue damage, often exhibiting a 'surface-in' gradient from the ventricular surface.
• The clinical implications of this thalamic gradient in MS remain incompletely understood.

Purpose of the Study:

• To evaluate the periventricular thalamic gradient of tissue integrity in MS using quantitative gradient-recalled echo (qGRE) MRI.
• To investigate the relationship between this gradient and clinical variables in MS patients.

Main Methods:

• Acquired structural and qGRE MRI scans from MS patients and healthy controls (HC).
• Utilized qGRE-derived R2t* values as a measure of tissue integrity.
• Calculated the periventricular thalamic gradient by analyzing R2t* values in concentric bands radiating from the ventricular surface.

Main Results:

• MS patients exhibited a significantly steeper periventricular thalamic gradient compared to HC (mean slope 0.55 vs. 0.36; p < 0.001).
• The MS thalamic gradient correlated with longer disease duration (p = 0.027) and higher Expanded Disability Status Scale (EDSS) scores (p = 0.019).
• Thalamic involvement was symmetrical in both left and right hemispheres.

Conclusions:

• An increased thalamic gradient in MS was detected in vivo using qGRE MRI.
• This gradient is associated with disease duration and clinical disability, supporting the 'surface-in' pathology hypothesis in MS.
• The symmetric thalamic involvement suggests a potential cerebrospinal fluid (CSF)-mediated pathological process.