UCLA team identifies brain rhythms linked to seizures in Alzheimer's

A UCLA Health research team has identified changes in brain rhythms that indicate seizure activity in Alzheimer's patients. 

The findings, published in Brain Communications, build on UCLA neurologist and senior author Dr. Keith Vossel's pioneering work that first linked silent epileptic activity to cognitive decline in Alzheimer's disease. 

Vossel's previous studies showed that silent seizures, detected through overnight electroencephalography (EEG) and one-hour magnetoencephalography (MEG), occur in more than 40% of Alzheimer's patients-beyond the 20% who experience overt seizures. His research has demonstrated that both silent and overt seizures accelerate cognitive decline. 

In this latest study, the team including UCLA postdoctoral fellow Dr. M.C. Vishnu Shandilya, Dr. Richard Staba from the UCLA Epilepsy Center and colleagues at UCSF, analyzed MEG and EEG recordings for high-frequency oscillations (HFOs) - fast bursts of rhythmic activity first discovered by Dr. Anatol Bragin at UCLA as markers of epilepsy.

While HFOs are widely studied in epilepsy, this study is the first time they have been examined in neurodegenerative diseases. The researchers found that HFOs occur at rates two to three times higher in Alzheimer's patients than in cognitively normal individuals. MEG proved more effective than EEG at detecting these signals due to its superior signal-to-noise properties. 

The study also found that HFOs were more asymmetric (appearing more on the right side) in Alzheimer's patients with epileptic activity. Notably, HFOs that coincided with epileptic spikes were suppressed by the antiseizure medication levetiracetam, based on data from Vossel's Phase 2a clinical trial. These findings suggest that HFOs could serve as a critical biomarker for identifying Alzheimer's patients at the highest risk for seizures. 

Encouragingly, MEG screening for HFOs takes just 10 minutes, offering a practical and efficient way to identify Alzheimer's patients at higher risk of epileptic activity."

Dr. Keith Vossel, UCLA neurologist and senior author

Vossel's prior research has shown that low doses of levetiracetam can improve spatial memory and problem-solving abilities in Alzheimer's patients with epileptic activity. A quick MEG exam could therefore provide a valuable tool for early intervention-enhancing patient care while reducing healthcare costs.