Transverse diffusivity of cerebral parenchyma predicts visual tracking performance in relapsing-remitting multiple...

Area of Science:

• Neuroscience
• Medical Imaging
• Neurology

Background:

• Multiple sclerosis (MS) is a demyelinating disease affecting the central nervous system.
• Cognitive decline is a common symptom in MS patients, impacting daily functioning.
• Diffusion Tensor Imaging (DTI) is a neuroimaging technique used to assess white matter integrity.

Purpose of the Study:

• To investigate the relationship between cerebral white matter damage in MS patients and cognitive performance.
• To determine if DTI-derived measures of brain microstructure correlate with cognitive decline.

Main Methods:

• 15 relapsing-remitting MS patients underwent DTI scans to measure fractional anisotropy and diffusivity in the cerebral parenchyma.
• Cognitive function was assessed using the Symbol Digit Modalities Test (SDMT) and the Paced Auditory Serial Addition Test (PASAT).
• Statistical analysis was performed to correlate DTI metrics with cognitive test scores.

Main Results:

• A significant positive correlation was observed between fractional anisotropy in the brain and SDMT performance.
• This correlation was primarily driven by transverse diffusivity, a marker of axonal loss and demyelination.
• No significant association was found between DTI measures and PASAT performance, potentially due to psychometric limitations.

Conclusions:

• Altered white matter microstructure, specifically transverse diffusivity, is associated with impaired information processing speed in MS patients.
• DTI measures, particularly those reflecting non-principal diffusion directions, may serve as sensitive markers for MS-related cognitive deficits.
• The SDMT appears to be a more sensitive cognitive measure than the PASAT for detecting MS-related white matter pathology.