Hippocampal atrophy but not white-matter changes predicts the long-term cognitive response to cholinesterase inhibitors in Alzheimer's disease.

Introduction: This study aimed to investigate the feasibility of predicting the long-term effects of cholinesterase inhibitors (ChEI) with common clinical neuroimaging parameters of Alzheimer's disease, including medial temporal lobe atrophy (MTA) and white matter hyperintensity (WMH).

Method: A cohort of 353 patients with very mild to moderate Alzheimer's disease received cholinesterase inhibitors and were followed for a median of 46.6 months. Baseline clinical data, including age, educational level, Clinical Dementia Rating (CDR), Taiwanese Mental State Examination (TMSE), and visual scoring for MTA and WMH were tested as possible predictive factors that influence the survival from a TMSE decline of at least 3 points.

Results: During the follow-up period, 162(46%) patients had a significant TMSE decline. Patients with age-adjusted prominent MTA had a significantly shorter TMSE-decline free interval than those without (43.4 ± 4.5 months vs. 68.2 ± 9.5 months, log rank test p-value =0.001). However, the severity of WMH does not significantly influence cognitive outcomes. Cox regression analysis identified that younger age at the time of starting ChEI (p < 0.0005) and higher total MTA scores (p = 0.002) predict a more rapid TMSE decline under ChEI therapy.

Conclusions: Younger age at the time of starting ChEI and higher visual scoring of MTA may imply a more advanced Alzheimer's pathology. WMH load is not a prognostic indicator of treatment response to ChEI.