From the paper, it looks like the area involved is the medial pre-frontal cortex (mPFC). Give mPFC's role in memory, my initial suspicion is that the brain rhythms are a symptom, and not a cause, of memory loss. That means that fixing the brain rhythms might not fix the underlying memory problems.

It's also worthy to note that moderate exercise can improve connectivity of the mPFC, so that is at least one way to avoid these troubles.