White matter integrity and processing speed in sickle cell anemia.

Area of Science:

• Neurology
• Hematology
• Neuroimaging

Background:

• Sickle cell anemia (SCA) is a genetic blood disorder.
• Cognitive impairment, particularly slower processing speed, is a known complication of SCA.
• The underlying neurobiological mechanisms, especially concerning white matter integrity, require further investigation.

Purpose of the Study:

• To investigate the relationship between white matter integrity and processing speed in individuals with SCA.
• To determine if neuroimaging parameters correlate with cognitive deficits in SCA patients.

Main Methods:

• Retrospective cross-sectional study involving 37 SCA patients with silent cerebral infarction, 46 SCA patients with normal MRI, and 32 sibling controls.
• Cognitive assessment using Wechsler scales.
• 3-tesla MRI with diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) for white matter analysis.

Main Results:

• Patients with SCA demonstrated significantly lower processing speed index (PSI) compared to controls.
• PSI deficits were observed in SCA patients regardless of silent cerebral infarction presence.
• Reduced processing speed correlated with microstructural white matter changes detected by DTI and NODDI parameters.

Conclusions:

• Processing speed is a vulnerable cognitive domain in SCA, potentially affecting other cognitive functions.
• Deficits in processing speed are associated with alterations in normal-appearing white matter integrity.
• Findings highlight the importance of assessing and understanding white matter changes in managing cognitive health in SCA.