Year: 2017
Type: article
Abstract: Consistent reductions in cerebral glucose metabolism measured with PET and [F]-2-deoxy-2-fluoro-D-glucose ([F]FDG) have been found in heteromodal association cortices in patients with AD and MCI compared to controls (Smith et al, 1992, Drzezga et al, 2003). Further, cerebral glucose metabolism is a sensitive marker for disease progression in AD that can predict decline in cognition (Landau et al 2010). In a multisite, double-blind study (ADvance) of the effects of deep brain stimulation of the fornix (DBS-f) in mild AD, cerebral glucose metabolism, as well as cognitive outcomes (ADAS-Cog, CDR, and CVLT), were included as outcome measures. The objective of the current analysis is to determine the sensitivity of glucose metabolism to predicting changes in cognition associated with DBS-f. Forty-two mild AD patients were randomized one month after electrode implantation, to continuous stimulation or sham groups, and were monitored for 24 months. The effect of DBS-f on glucose metabolism was measured using logistic regression and cognitive test scores at 6 months and 12 months were predicted by change in glucose metabolism at these same timepoints using lagged analysis. The regions of interest included regions increased with DBS-f that comprise regions spared (pre- and post-central gyrus, cuneus and cerebellum,) and regions affected (temporal and parietal association cortex and hippocampus) in AD. Regression analysis showed that treatment predicted increased hippocampal glucose metabolism after 6-months of DBS in AD patients 65 years and older (b = 0.566, p = 0.040). The lagged analysis revealed that increases in glucose metabolism in the hippocampus, post-central gyrus (b = 0.156, p = 0.025), and the cerebellum (b = 0.162, p = 0.019) at 6-months predicted an increase in CVLT at 12 months, not the other measures. Mild AD patients treated with DBS show increased hippocampal glucose metabolism. Our findings confirm and extend the association between DBS and glucose metabolism in the hippocampus found in the main ADvance outcome paper (Lozano et al, 2016). Further, glucose metabolism at 6-months predicted increases in verbal memory at 12-months. Future analyses will evaluate whether the predictive effect at 6 months continues beyond 12 months. Grant# 4R01AG042165–05.
Source: Alzheimer s & Dementia
Authors: Sarah N. Forrester, Jeannie‐Marie S. Leoutsakos, Andres M. Lozano, Lisa Fosdick, Steven Targum, Constantine Lyketsos, Gwenn S. Smith, The ADvance Study Group
Institution: Johns Hopkins University
Language: English
Subfield: Neurology
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W4252626884