Chronic Pain Accelerates Dementia

By Dr. Lynn Webster, PNN Columnist

In 2017, JAMA Internal Medicine published a study that found older people with chronic pain experience faster declines in memory and are more likely to develop dementia.  While prior research had shown a link between chronic pain and brain damage, this was one of the first studies to specifically suggest that chronic pain can cause dementia.

The authors reported that people aged 60 and over with persistent pain experienced a 9.2% more rapid decline in memory score when compared to people of the same age without chronic pain. This means that people with chronic pain may experience more difficulty in managing their finances, medications and social connections.

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Dementia is a chronic condition of the brain that involves memory, personality and judgment. It is not a disease; it is a symptom of one or more diseases.

There are many types of dementia. Alzheimer’s disease is considered to be the most common.

Dementia usually worsens over time if the underlying disease remains static or progresses, as is the case with many chronic pain conditions.

There are an estimated 20 million Americans with high impact (the most severe) chronic pain who may be experiencing accelerated decline in cognition due to their pain. The amount of dementia appears to be associated with the severity and duration of chronic pain. Undertreated or untreated chronic pain may accelerate dementia.

Chronic pain affects an even larger percentage of elderly adults (one in three) than the general population. Since the prevalence of chronic pain increases with age, the probability of experiencing dementia increases as well. However, the reasons for that go beyond aging itself.

Seniors are more likely to take multiple medications that can contribute to mental confusion. On average, elderly people take five or more prescriptions. They may also use over-the-counter medications, which adds to potential drug-associated mental compromise.

Opioids, in particular, have been implicated in cognitive impairment. However, a study published in 2016 suggests there is no difference in cognitive decline between people on opioids and those on nonsteroidal anti-inflammatory drugs. The study's implication is that pain, not opioids, leads to cognitive impairment.

Brain Fog

Chronic pain appears to affect the function and structure of the hippocampus. This is the region of the brain that involves learning, memory, and emotional processing.

One explanation for the mental decline associated with chronic pain is that various areas of the brain compete for attention. Attentional impairment compromises memory by diverting attention to the areas of the brain processing pain. In effect, the brain is multi-tasking and favoring the processing of pain over cognition. This may, in part, explain the clinical phrase “brain fog.”

The Australian Broadcasting Company's "All in the Mind" website explains that pain damages the brain in several ways, including a change in the size of the thalamus and a decrease in the amount of a neurotransmitter (gamma-aminobutyric acid) the brain produces. In other words, chronic pain changes the brain structurally and functionally.

The prefrontal cortex is the part of the brain responsible for executive functions, such as cognition, social behavior, personality, and decision-making. It is also the part of the brain that modulates pain.

According to "All in the Mind," some researchers believe that chronic pain decreases the volume of the prefrontal cortex. Over time, brains damaged by pain lose the ability to handle pain — along with some of the personality attributes that make us who we are.

Brain Damage Can Be Reversed

The good news is that the brain damage caused by chronic pain can be reversed, at least to some extent. Unfortunately, the elderly are less likely to recover from dementia caused by chronic pain as compared with younger patients.

If pain is adequately treated, the brain may be able to regain its ability to function normally. A 2009 study of patients with chronic pain due to hip osteoarthritis showed reversal of brain changes when their pain was adequately treated. 

People who don’t have their acute pain managed are more likely to develop chronic pain. It is postulated that the changes in the brain that occur with chronic pain begin with the onset of acute pain. There is also some evidence that an individual’s genes may influence who is at greatest risk for developing brain damage from chronic pain and who is least likely to recover from it. 

Many people have criticized the concept of assessing pain as the 5th vital sign, and have called it a contributing factor for the opioid crisis. As I have said, pain may not be a vital sign, but it is vital that we assess it. Asking patients about their pain is critical to providing interventions that can mitigate the consequences of undertreated pain, including dementia. 

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Lynn R. Webster, MD, is a vice president of scientific affairs for PRA Health Sciences and consults with the pharmaceutical industry. He is author of the award-winning book, The Painful Truth,” and co-producer of the documentary,It Hurts Until You Die.” You can find him on Twitter: @LynnRWebsterMD. 

The information in this column is for informational purposes only and represents the author’s opinions alone. It does not inherently express or reflect the views, opinions and/or positions of Pain News Network.

Chronic Pain Causes Brains to Age More Rapidly

By Pat Anson, PNN Editor

Poorly treated or untreated chronic pain can lead to a number of other health problems, from high blood pressure and insomnia to depression and anxiety.

Now there is evidence that chronic pain also causes brains to age more rapidly, raising the risk of developing Alzheimer’s disease and other neurological problems associated with aging.

“Our findings highlight the need to address chronic pain, not just in older individuals but in potentially everyone, as pain may have unintended consequences in the brain that we don’t yet fully understand,” said lead author Yenisel Cruz-Almeida, PhD, a researcher at the University of Florida Institute on Aging.

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Over a three-year period, Cruz-Almeida and her colleagues used magnetic resonance imaging (MRI) to measure the volume of gray and white matter in the brains of 47 older adults, ages 60 to 83.  The volunteers were free of neurological disorders and in generally good health, although 33 of them had some type of chronic pain.

Volunteers who did not have chronic pain had brains that appeared four years younger than their actual age.

Chronic pain sufferers had brains that appeared an average of two years older. They were also more likely to have greater pain intensity, have a “less agreeable personality” and be less emotionally stable, according to researchers.

The University of Florida produced this video on the study, which was recently published online in the journal Pain.

“Not everybody ages the same way,” said Cruz-Almeida. “I don’t want people to think, ‘Oh, I have chronic pain. I’m doomed.’ This is not the case. That is not the message we want to get out. There is more nuance than that.”

Interestingly, the volunteers who reported getting pain treatment in the last three months had younger-appearing brains compared to those that did not, suggesting that pain relief slows brain aging. Pain sufferers who had a happier outlook on life and were generally more upbeat also had younger-appearing brains.

“The pain experience is not just in your brain,” said Cruz-Almeida. “There appear to be avenues or things that could be done to change brain age.

“Our findings also suggest that both pain treatments and psychological traits may significantly mitigate the effect of pain on the aging brain and could further decrease the risk of age-related deterioration and death.”

Cruz-Almeida is planning additional research with a larger sample of older adults that will look at ways to alleviate accelerated brain aging.

Benzos May Increase Dementia Risk

By Pat Anson, Editor

Anti-anxiety drugs often prescribed to chronic pain patients increase the risk of dementia and Alzheimer's disease when used long term, according to clinicians with the American College of Osteopathic Neurologists and Psychiatrists.

Benzodiazepines --  also known as benzos -- include brand name prescription drugs such as Valium, Ativan, Klonopin and Xanax. They were approved by the U.S. Food and Drug Administration to treat psychiatric conditions, but are also prescribed "off label" to treat bipolar disorder, insomnia, post traumatic stress disorder, and chronic pain.

A Canadian study of 9,000 patients found those who had taken a benzodiazepine for three months or less had about the same dementia risk as those who had never taken one.

But taking benzos for three to six months raised the risk of developing Alzheimer's by 32 percent, and taking them for more than six months boosted the risk by 84 percent.

Similar results were found by French researchers studying more than 1,000 elderly patients.

"Current research is extremely clear and physicians need to partner with their patients to move them into therapies, like anti-depressants, that are proven to be safer and more effective," saidHelene Alphonso, DO, Director of Osteopathic Medical Education at North Texas University Health Science Center in Fort Worth.

The case for limiting the use of benzodiazepines is particularly strong for patients 65 and older, who are more susceptible to falls, injuries, accidental overdose and death when taking the drugs. The American Geriatric Society in 2012 labeled the drugs "inappropriate" for treating insomnia, agitation or delirium because of those risks.

"It's imperative to transition older patients because we're seeing a very strong correlation between use of benzodiazepines and development of Alzheimer's disease and other dementias. While correlation certainly isn't causation, there's ample reason to avoid this class of drugs as a first-line therapy," said Alphonso.

In its draft guidelines for the prescribing of opioid pain medication, the Centers for Disease Control and Prevention (CDC) recommends that opioids and benzodiazepines not be prescribed concurrently whenever possible. A CDC study found that about 80% of unintentional overdose deaths associated with opioids also involved benzodiazepines. Nearly 6,500 people died from overdoses involving benzodiazepines in 2010.

Opioids, benzodiazepines and muscle relaxants are all central nervous system depressants. Mixing the drugs is potentially dangerous because their interaction can slow breathing and raise the risk of an overdose death.

In a study of over 35,000 patient visits for acute and chronic pain, recently published in the journal Pharmacoepidemiology and Drug Safety,  researchers found that the prescribing of benzodiazepines was three to four times more likely when opioids were also prescribed.

Over a third of the patients prescribed opioids for chronic musculoskeletal pain were given a sedative. And patients with a history of psychiatric and substance abuse disorders were even more likely to be co-prescribed opioids and sedatives.

"Multi drug use is the trailing edge of the opioid epidemic," said Mark Sullivan, MD, a professor of psychiatry and behavioral sciences at the University of Washington School of Medicine. "We are making progress on decreasing opioid prescribing, but co-prescribing of opioids and sedatives has not decreased.

"Patients who are on long-term combined opioid and benzodiazepine therapy are often on a treadmill. They feel relief when they take their medications and withdrawal when they stop, so they continue this combined therapy, even though many function poorly and some will die as a result."

Over 50,000 visits to emergency rooms in 2011 involved a combination of benzodiazepines and opioids, according to the Substance Abuse and Mental Health Services Administration (SAMHSA)