May 6, 2017

Are Silent Seizures a Symptom of Alzheimer's Disease?

While I was taking care of my mom, Dotty, I often worried about seizures. Silent Seizures.

Researchers are beginning to suspect that treating these seizures could help manage Alzheimer's or possibly slow it down.

My mother often suffered from severe headaches particularly in the morning. This was an ongoing problem that would come and go. The research below indicates that the silent seizures occurred while patients were sleeping..

I actually received training on what to look for, and the signs and symptoms of seizures.

By Bob DeMarco

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I clearly remember our doctor telling me - if you get worried call 911 immediately. He then said to me, you call me after you get her settled down in the hospital.

I also worried about silent seizures because they can present as a form of confusion. Alzheimer's patients often present signs of confusion.

Researchers are beginning to suspect that treating these seizures could help manage Alzheimer's or possibly slow it down.

Silent seizures recorded in the hippocampus of two patients with Alzheimer's disease

Seizure-like activity in key memory structure may contribute to cognitive symptoms, offering new therapeutic target

  • Massachusetts General Hospital (MGH) investigators have identified silent, seizure-like activity in the hippocampus – a brain structure significantly affected in Alzheimer’s disease.

These alterations in the brain’s electrical activity could not be detected by standard EEG readings taken on the scalp and primarily occurred during sleep, a time when the preceding day’s memories are consolidated.

“While it is not surprising to find dysfunction in brain networks in Alzheimer’s disease, our novel finding that networks involved in memory function can become silently epileptic could lead to opportunities to target that dysfunction with new or existing drugs to reduce symptoms or potentially alter the course of the disease.”
“We now have to study more individuals to validate this finding and understand how prevalent it is in Alzheimer’s patients, whether it occurs in other neurodegenerative disorders and how it responds to treatment.” ~ Andrew Cole, MD, director of the MGH Epilepsy Service and senior author of the Nature Medicine paper.
  • The investigators describe two patients – both women in their 60s – who had developed symptoms suggestive of Alzheimer’s disease, such as confusion and repeatedly asking the same questions
  • Brain imaging studies and cerebrospinal fluid analysis for both patients were consistent with Alzheimer’s disease
  • It is common for patients with Alzheimer’s to experience fluctuations in their symptoms, but in both of these patients, those fluctuations were more exaggerated than typically seen.

While scalp EEG recordings did not reveal seizure-like activity, the investigators suspected that there may be undetected seizures within the hippocampus – a key structure affected by Alzheimer’s disease that is critical for memory consolidation and is a common source of seizures in people with epilepsy. 

They decided to try a more direct way of monitoring electrical activity in the hippocampus and related structures.

Electrodes were placed adjacent to those structures on both sides of the brain through the foramen ovale (FO), naturally occurring openings at the base of the skull. Each patients’ brain activity was monitored simultaneously with both implanted electrodes and with scalp EEG for 24 to 72 hours.

In one patient, the FO electrodes revealed frequent bursts of electrical activity called spikes, often associated with seizures, most which were not detectable by scalp EEG.
  • During a 12-hour period she experienced three seizures, all taking place during sleep but not producing any visible symptoms. 
Treatment with an anti-seizure medication eliminated the seizure-like activity, and in the following year, she experienced only one episode of confusion, which occurred after she missed several doses of her anti-seizure medication.

FO electrode recording in the other patient also revealed frequent spiking during sleep, but anti-seizure treatment had to be discontinued because of adverse effects on her mood.
Our findings confirmed the presence of serious dysfunction of the neuronal networks affected by Alzheimer’s disease and confirmed our hypothesis that epileptic phenomena are an important component of that disturbance,” says Cole, who is a professor of Neurology at Harvard Medical School. “
Additional recordings with FO electrodes in patients with Alzheimer’s disease will help us develop better tools based on computerized analysis of EEG signals and possibly functional neuroimaging studies to ascertain how common silent seizures are in Alzheimer’s disease without the need for the minimally invasive electrodes we used in these patients.”

The report appeared in the online publication in Nature Medicine.

A recent study led by Alice Lam, MD, PhD, also of the MGH Epilepsy Service and lead author of the current study demonstrated a novel tool for detecting hippocampal seizures not detectable by scalp EEGs in patients with epilepsy.

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Cole adds, and his team is working to refine this tool and apply it to Alzheimer’s disease. Since there also is evidence that higher levels of neuronal activity can increase the production and deposition of Alzheimer’s associated proteins such as tau and amyloid-beta, understanding whether seizure-like activity accelerates the progression of Alzheimer’s disease will be a high priority for their team.

Atypical (a-TIP-i-kul) seizure means unusual or not typical. The person will stare (as they would in any absence seizure) but often is somewhat responsive. Eye blinking or slight jerking movements of the lips may occur. ~ Epilepsy Foundation

What Are the Symptoms of an Absence Seizure?

Because absence seizures are usually quite brief, tend to strike during times of inactivity, and closely resemble daydreaming or "being off in one's own world," they may pass unnoticed by others and go undiagnosed for some time.

Absence seizures fall into two categories: typical and atypical.

~ WebMD

Undetected or "silent" seizures may contribute to some symptoms associated with Alzheimer's disease, such as confusion.

The seizures occur in the hippocampus -- a part of the brain involved in the consolidation of memories. Researchers suspect that treating these seizures could help manage Alzheimer's or possibly slow it down.


Additional co-authors of the Nature Medicine paper are Gina Deck, MD, MGH Epilepsy Service; Emad Eskandar, MD, MGH Department of Neurosurgery; and Alicia Goldman, MD, PhD, and Jeffrey Noebels, MD, PhD, Baylor College of Medicine. Support for the study includes National Institute of Neurological Disorders and Stroke grants R25-NS065743, U01-NS090362, and R01-NS029709; and grants from Citizens United for Research in Epilepsy and the Blue Bird Circle Foundation.

Massachusetts General Hospital, founded in 1811, is the original and largest teaching hospital of Harvard Medical School.

Seizures are a sign of brain injury and are caused by sudden disorganized electrical activity in the brain. Seizures can be characterized by spasms or convulsions.

Alzheimer disease (AD) and epilepsy are disorders commonly seen in the elderly. Many studies have shown that patients with AD are at increased risk for developing seizures and epilepsy.

Transient symptoms in Alzheimer disease (AD) are frequent and include seizures, syncope, and episodes of inattention or confusion.

Undetected or "silent" seizures may contribute to some symptoms associated with Alzheimer's disease, such as confusion.

The main underlying cause of memory loss and confusion is the progressive damage to brain cells caused by Alzheimer's disease.