Atrophy and dysfunction of parahippocampal white matter in mild Alzheimer%26apos;s disease

作者：Wang Changsheng^*; Stebbins Glenn T; Medina David A; Shah Raj C; Bammer Roland; Moseley Michael E; deToledo Morrell Leyla

来源：Neurobiology of Aging, 2012, 33(1): 43-52.

DOI：10.1016/j.neurobiolaging.2010.01.020

• ApoE
• Diffusion tensor imaging
• Entorhinal cortex
• Perforant path
• Temporal lobe

In addition to atrophy of mesial temporal lobe structures critical for memory function, white matter projections to the hippocampus may be compromised in individuals with mild Alzheimer%26apos;s disease (AD), thereby compounding the memory difficulty. In the present study, high-resolution structural imaging and diffusion tensor imaging techniques were used to examine microstructural alterations in the parahippocampal white matter (PWM) region that includes the perforant path. Results demonstrated white matter volume loss bilaterally in the PWM in patients with mild AD. In addition, the remaining white matter had significantly lower fractional anisotropy and higher mean diffusivity values. Both increased mean diffusivity and volume reduction in the PWM were associated with memory performance and ApoE epsilon 4 allele status. These findings indicate that, in addition to partial disconnection of the hippocampus from incoming sensory information due to volume loss in PWM, microstructural alterations in remaining fibers may further degrade impulse transmission to the hippocampus and accentuate memory dysfunction. The results reported here also suggest that ApoE epsilon 4 may exacerbate PWM changes.

• 出版日期2012-1