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2021 Alzheimer's Association Research Grant (AARG)

Preoperative Sleep Spindles and Delirium in Alzheimer's Disease

How could sleep disruption after surgery impact one’s risk for developing Alzheimer’s?

Maria Jose Bruzzone Giraldez, M.D.
University of Florida
Gainesville, FL - United States


As people age, they are more likely to undergo various surgeries. Preparation for surgeries especially in older adults, could involve certain health risks including dehydration, delirium (that disrupts mental abilities) among others. 
Recent studies reveal that sleep disruption may impact the risk for developing Alzheimer’s and other brain diseases. Using the technique of electroencephalography or EEG (used to measure electrical signals in the brain) studies have shown changes in sleep structure in individuals with dementia or mild cognitive impairment (a state of subtle memory loss that may precede dementia). Researchers have observed similar changes in sleep structure in people immediately after surgery. 

Sleep “spindles” or bursts of brain activity is thought to mediate many sleep-related functions such as memory consolidation to brain development. Studies show that both in individuals who wake up immediate after surgery and in individuals with cognitive impairment, there may be a reduction in sleep “spindles” that may hinder memory formation and cognition. 

Research Plan

Dr. Maria Jose Bruzzone Giraldez and colleagues will study the impact of sleep spindle activity on delirium and the risk of developing dementia. Dr. Giraldez’s team will leverage the existing infrastructure associated with the University of Florida Perioperative Cognitive Anesthesia Network program. From this program, the researchers will recruit older adult participants with cognitive impairment who show reduced spindle activity on EEG tests and who have elected to undergo surgery with anesthesia. 

The researchers will then monitor the participants for delirium immediately after surgery and for potential losses in memory and other cognitive functions that may develop six weeks and three months later.  Dr. Giraldez believes that these studies may help understand the impact of spindle activity on delirium and cognition in the participants.


The results of this effort could help identify sleep spindles as a biomarker that could predict the risk of developing dementia in older adults undergoing surgery.

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