Spatial profiling of the corticospinal tract in amyotrophic lateral sclerosis using diffusion tensor imaging

Area of Science:

• Neuroimaging
• Neuroscience
• Radiology

Background:

• Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease affecting motor neurons.
• The corticospinal tract (CST) is crucial for voluntary movement and is impacted in ALS.
• Noninvasive imaging techniques are needed to understand CST degeneration patterns.

Purpose of the Study:

• To utilize diffusion tensor imaging (DTI) to noninvasively assess CST anatomy.
• To characterize the pattern of CST degeneration in ALS patients.
• To correlate DTI findings with clinical parameters in ALS.

Main Methods:

• DTI scans were performed on 14 ALS patients and 15 healthy controls.
• Diffusion parameters including fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were measured along the intracranial CST.
• Eigenvalues (lambda( parallel) and lambda( perpendicular)) were analyzed to assess diffusion directionality.

Main Results:

• Diffusion parameters showed spatial dependency along the CST in healthy subjects.
• ALS patients exhibited reduced FA in the cerebral peduncle, correlating with upper motor neuron signs.
• Increased lambda( parallel) in the corona radiata and correlations between FA/ADC with symptom duration/spasticity were observed.

Conclusions:

• DTI can detect intracranial CST degeneration in ALS.
• Distinct diffusion changes occur in rostral and caudal regions of the CST in ALS.
• DTI parameters provide insights into CST integrity and its relationship with ALS progression and symptoms.