Cognitive functions and white matter tract damage in amyotrophic lateral sclerosis: a diffusion tensor tractography...

Area of Science:

• Neuroimaging
• Neurology
• Cognitive Neuroscience

Background:

• Amyotrophic lateral sclerosis (ALS) primarily affects motor neurons but also presents with cognitive and behavioral symptoms.
• Diffusion tensor (DT) magnetic resonance imaging (MR) is sensitive to microstructural changes in white matter (WM) tracts in ALS patients.

Purpose of the Study:

• To investigate the association between cognitive functions and extramotor white matter (WM) tract abnormalities in patients with ALS.
• To explore the utility of DT MR imaging in understanding cognitive impairment in ALS.

Main Methods:

• DT MR imaging was performed on 16 non-demented ALS patients and 15 healthy controls.
• Neuropsychological and behavioral evaluations were conducted.
• Diffusion tensor (DT) tractography assessed the integrity of the corticospinal tract (CST), corpus callosum, and major long-range association tracts.

Main Results:

• 69% of ALS patients scored below the fifth percentile in at least one cognitive test.
• Cognitive functions, including attention and executive functions, correlated with DT MR imaging metrics of the corpus callosum, CST, and bilateral long association WM tracts.
• Verbal learning, memory, and visual-spatial abilities were associated with specific WM tract integrity (fornix and left uncinate fasciculus).

Conclusions:

• White matter (WM) tract degeneration is significantly associated with neuropsychological deficits in ALS patients.
• DT tractography shows potential for elucidating the role of WM network abnormalities in cognitive impairment development in ALS.