How To Take Early Action Against Cognitive Decline, From A Neurologist

What if the cognitive glitches you've been brushing off as stress or a busy schedule are actually worth paying attention to, and the window to do something about them is wider than you think?

Isaacson shared the story of his dad's cousin, who started repeating herself back in 2007. At the time, her care team thought this was simply part of normal aging. And, despite Isaacson personally advocating with her primary care doctor, it took years for her to receive an Alzheimer's diagnosis.

This kind of dismissal is exactly what Isaacson wants people to push back against. Seeing a doctor early doesn't mean catastrophizing. It can simply mean getting a basic screen to rule out reversible causes of cognitive decline. According to Isaacson, at least 5% of cognitive decline cases have something potentially reversible at the root, whether that be a vitamin deficiency, a thyroid problem, hormones being off, or an infection. A physical exam, neurological exam, and possibly a brain MRI can help clarify what's actually going on.

Isaacson also makes an important distinction between attention problems and memory problems. "A lot of people aren't able to pay attention or get information overload, and it's mistaken for memory loss or Alzheimer's when they just are overburdened with information," Isaacson said. A 15-minute cognitive screening in a doctor's office will help make this distinction. The tests aren't perfect, but they give you a baseline to work off of for years to come.

Once someone has cognitive symptoms, Isaacson says blood testing becomes relevant as a screening tool to assess whether those changes are related to Alzheimer's pathology. However, he's quick to point out that "there is no one magic test for brain health."

Blood biomarker testing for brain health is promising, but Isaacson is transparent that it currently has a lot of limitations. Variables like whether the sample was shipped on dry ice, how long it sat in transit, whether the person was sick at the time of the draw, and which machine processed the sample can all affect accuracy.

His lab takes specific precautions to mitigate this, including a nasal swab on every patient to rule out active infection, which can cause false positives by elevating brain inflammation markers. "We only let people mail us samples Monday through Wednesday, because if they mail it Thursday and it gets stuck over the weekend, the samples are done," Isaacson said. His also runs certain tests in duplicate to make sure they are accurate, and stores every in a negative 80 degree freezer in perpetuity, knowing the science is still evolving.

Whether or not someone has symptoms of cognitive decline, managing risk factors is something Isaacson says everyone can and should be doing.

He starts with sleep. His research using wearable data found that people getting more than 7 hours and 11 minutes per night performed better cognitively than those getting less. He explains that sleep and REM sleep are particularly important for the brain's glymphatic system (essentially the brain's waste-removal network) to clear out disease-causing cells. "Exercise during the day loosens up amyloid. Amyloid is the sticky protein, the plaque that builds up in the brain of a person with Alzheimer's," Isaacson explained.

Sleep takes the trash out at night, removing the amyloid from the brain. He recommends aiming for at least an hour and 15 to 20 minutes of deep sleep and REM sleep, respectively, to give your brain enough time to do this.

There are also many medical conditions that can contribute to Alzheimer's. High blood pressure, insulin resistance, high cholesterol, and obesity all increase risk. Pre-diabetes can affect memory function and raise Alzheimer's risk well before a formal diabetes diagnosis.

Hearing loss is another often-overlooked factor. According to Isaacson, "8% of dementia cases are attributable to hearing loss," and 45% of those cases of dementia may be preventable if that person takes action to restore their hearing. So while hearing aids may feel like a sign of getting old, they should actually be viewed as a preventative tool.

For women concerned about cognitive decline, Isaacson highlights the perimenopause transition as a critical window. Two out of every three brains affected by Alzheimer's are women's brains, and research on this gap points to the connection between menopause and Alzheimer's risk.

"During the perimenopause transition, that rapid drop of estrogen for women is a critical window of opportunity. That's when a woman has to do something," he said. Isaacson points to hormone replacement therapy as one of the most powerful tools available to women during this time.

If testing and evaluation do point toward a neurodegenerative condition, Isaacson wants people to know there are still options.

On the treatment side, anti-amyloid drugs delivered via infusion have generated both interest and debate. Isaacson says that in the right patient at the right dose, they may be a reasonable option, and he uses them in select patients. While he's careful about the language—he refrains from saying that any treatments can "reverse" Alzheimer's—he has seen patients regain cognitive abilities after a diagnosis.

"Have we improved people? Oh, yeah. Have we normalized their amyloid and tau in their blood? Oh, yeah. Have their brains grown? Oh, yeah," he says.