Microstructural white matter changes underlying cognitive and behavioural impairment in ALS--an in vivo study using...

Area of Science:

• Neuroimaging
• Neuroscience
• Neurology

Background:

• Amyotrophic lateral sclerosis (ALS) frequently presents with frontotemporal cognitive and behavioral disturbances.
• Executive functioning and behavioral control are often impaired.
• Previous structural imaging studies in ALS did not consistently assess cognitive status.

Purpose of the Study:

• To investigate microstructural white matter changes associated with cognitive impairment in ALS patients using diffusion tensor imaging (DTI).
• To correlate DTI findings with neuropsychological and behavioral measures.

Main Methods:

• Assessed 72 non-demented ALS patients and 65 healthy controls with a comprehensive neuropsychological test battery and DTI.
• Compared DTI measures of fiber tract integrity using tract-based spatial statistics across patient and control groups.
• Correlated neuropsychological and behavioral measures with DTI findings.

Main Results:

• ALS patients without cognitive impairment showed white matter changes primarily in motor tracts.
• Approximately 30% of ALS patients exhibited additional white matter alterations in extra-motor, particularly frontal, regions.
• Impaired executive and memory functions correlated with white matter integrity in association tracts.

Conclusions:

• DTI can detect differences in white matter integrity between cognitively unimpaired and impaired ALS patients.
• Microstructural white matter changes in non-demented, cognitively impaired ALS patients are linked to executive and memory dysfunction, involving prefrontal and temporal areas.