Diffusion tensor imaging patterns differ in bulbar and limb onset amyotrophic lateral sclerosis.

Area of Science:

• Neuroimaging
• Neurology
• Biophysics

Background:

• Amyotrophic lateral sclerosis (ALS) presents with significant clinical variability in onset and progression.
• Diffusion tensor imaging (DTI) can detect white matter microstructural changes by measuring proton diffusivity (ADC) and directedness (FA).

Purpose of the Study:

• To investigate if different amyotrophic lateral sclerosis (ALS) onset types correlate with distinct patterns in brain diffusion tensor imaging (DTI).

Main Methods:

• Seventeen ALS patients (6 bulbar onset, 11 limb onset) and 17 age-matched controls underwent 1.5T DTI scans.
• Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were analyzed using statistical parametric mapping.

Main Results:

• ALS patients exhibited increased white matter diffusivity below the precentral gyrus and along the corticospinal tract (CST).
• Decreased FA was observed in the posterior limb of the internal capsule and precentral gyrus subcortical white matter.
• Bulbar onset ALS showed increased diffusivity in the CST, while limb onset ALS displayed increased diffusivity in frontal subcortical areas.

Conclusions:

• Diffusion tensor imaging (DTI) reveals prominent changes in the white matter of ALS patients.
• Distinct DTI brain patterns can differentiate between bulbar and limb onset types in amyotrophic lateral sclerosis (ALS).