A specific biomarker for amyotrophic lateral sclerosis: Quantitative susceptibility mapping.

Area of Science:

• Neurology
• Radiology
• Biomarkers

Background:

• Accurate amyotrophic lateral sclerosis (ALS) diagnosis is challenging due to a lack of specific biomarkers and overlapping symptoms with mimic conditions.
• Magnetic Resonance Imaging (MRI) quantitative susceptibility mapping (QSM) is explored as a potential tool to aid in differentiating ALS.

Purpose of the Study:

• To investigate the utility of QSM in distinguishing ALS patients from those with mimic diagnoses.
• To compare motor cortex susceptibility in ALS patients versus control groups using QSM.

Main Methods:

• A blinded retrospective study analyzed QSM MRI data from 2015-2018.
• Quantitative susceptibility values in the hand and face homunculi were compared between ALS patients (n=50) and mimic (n=35) or non-motor neuron symptom groups (n=70).
• Statistical analyses included ANOVA, Tukey-Kramer, ROC analysis, and Youden's index.

Main Results:

• ALS patients exhibited significantly higher mean susceptibility values in the hand and face homunculi compared to mimic, leukoaraiosis, and normal groups (p<0.001).
• ROC analysis for differentiating ALS from mimics yielded an area under the curve of 0.71 (hand) and 0.67 (face).
• Youden's index demonstrated 100% specificity and 36% sensitivity for hand homunculus measurements in distinguishing ALS from mimics.

Conclusions:

• Quantitative susceptibility mapping (QSM) demonstrates significant diagnostic potential for suspected ALS cases.
• QSM exhibits high specificity in differentiating amyotrophic lateral sclerosis from mimic diagnoses, aiding clinical assessment.