How UTIs can affect the brain

New research has revealed how the brain and the urinary tract are intertwined in unexpected ways

By Mary Elizabeth Williams

Senior Writer

Published May 4, 2021 5:50AM (EDT)

Dementia bran scan research (Getty Images)
Dementia bran scan research (Getty Images)

This was bad, even for her. Even with middle-stage dementia, even after a recent bout of COVID-19. The change in my mother-in-law had been abrupt and disturbing. When we'd spent Easter together, she'd struggled for the word for "oven" and couldn't answer when I asked if she'd like a glass of milk. But she'd capably said grace, asked my daughter about her school work, and insisted on helping clear the table. By the following week, though, she'd become belligerent and paranoid. She refused to eat, refused to bathe. Her housekeeper said she was frightened of her.

And then she fell. In the emergency department, we learned she had a urinary tract infection, or UTI. We also learned that was likely the reason for the sudden personality change. The brain and the urinary tract, it turns out, are deeply connected.

I already knew how dangerous urinary tract infections can be. Just earlier this year, a beloved friend's father, who'd also had dementia, died when a UTI turned to sepsis. The Sepsis Alliance reports that "more than half the cases of urosepsis among older adults are caused by a UTI." 

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Urinary tract infections are common among people of all ages, and — usually — easily treatable. But the elderly can be uniquely vulnerable to getting them. As was the case with my mother-in-law, they can find keeping up their hygiene more challenging. And, as a 2015 report from Biomed Research International titled why "Lower Urinary Tract Symptoms Are Associated with Increased Risk of Dementia among the Elderly" also notes, "the progressive impairment of global brain function may have a substantial influence on the micturition control." In other words, patients may simply forget to urinate when they need to — another risk factor for UTIs.

And where there are cognitive limitations, the situation often gets worse once an infection sets in. 

"Older patients have suppressed immune systems," explains Dr. Kecia Gaither, Director of Perinatal Services at NYC Health + Hospitals/Lincoln. "Younger patients have stronger immune systems, and unless have underlying renal or mental pathology, are able to articulate pain with urination, frequency, back pain, etc., and seek treatment."

When dementia is present, she says, patients often "are unable to communicate effectively, drink appropriately, practice self-hygiene." An older person with dementia has the deck stacked: they are more susceptible to getting an infection, and then limited in the ability to express what they're feeling and take action to alleviate symptoms, creating a rapidly escalating physical and mental health crisis.

Given her condition, I could understand how my mother-in-law could get a UTI. What I could not at first grasp was why it was making her so angry and confused. "A UTI is generally a bacterial infection," explains neuroanatomist Dr. Jill Bolte Taylor, author of the forthcoming  "Whole Brain Living: The Anatomy of Choice and the Four Characters That Drive Our Life." "Our body recognizes that the bacteria is foreign and does not belong inside of our body, and responds to the invasive bacteria by turning on our immune system, which is how our body defends itself from something that does not belong inside of us," Taylor says. "Our immune response is a full-body response that influences the brain, as well as every other part of the body." 

"The brain," she explains, "is hyper-sensitive to both bacterial infection in the central nervous system of the brain and spinal cord, as well as to the molecular byproducts of bacterial infection anywhere else in the body. We notice problems in the brain because it is easy for us to detect radical changes there in response to minor shifts in the chemistry of our body." And we see brain changes more in older people because, Dr. Taylor says, "The older brain is more sensitive to the changes." The dementia-afflicted brain, even more so. 

"When we're younger the blood brain barrier is much stronger and it's very protective, but as we age it begins to weaken," says Aleece Fosnight, a board-certified physician assistant and Medical Advisor at Aeroflow Urology in North Carolina. "With the barrier in a weakened state, it gets easier for infections to travel to other parts of the body like the brain and cause more serious issues."

But that doesn't mean that UTIs can't do a world of damage, even if you're not eligible for Social Security. A few years ago, my daughter had an underlying one when she was hit with a case of strep throat. The infectious combination nearly killed her.

"Absolutely there are risks of UTIs affecting the cognitive functions of young people as well as the elderly," Fosnight says."While usually the immune system is good at protecting younger people, for those with comorbidities, like high blood pressure, diabetes or an autoimmune disease, it can be weakened and allow these issues to occur. Even for those with a healthy immune system, if treatment is put off for too long it could lead to becoming septic among other serious health issues." Among the symptoms of sepsis from an UTI, regardless of age, are confusion and anxiety. 

For most of us who are not elderly and dealing with dementia, though, a UTI is not usually a life or death emergency. But for our elderly parents and grandparents, the situation gets more complicated.

According to a 2020 report in the Journal of the American College of Emergency Physicians, "Up to 50% of people living with dementia present to the emergency department in a given year," and "nearly one third of people living with dementia who visit the emergency department are diagnosed with a UTI." Yet as the authors point out, hasty diagnoses create their own potentially fatal problems, like "antibiotic‐associated morbidity (eg, such as Clostridium difficile colitis) and multidrug‐resistant bacteria." Going to the hospital creates a whole other set of risks for worsening the problems of the vulnerable patient, even if they do have a UTI.

So what can we do to protect ourselves, and our loved ones? Prevention is challenging, but primary.  While it can be almost impossible to know how often a person with dementia is urinating or how well they're cleaning themselves, it may be possible to gently remind them about those things. More than that, though, it's crucial to recognize the signs, because a UTI may not manifest in them as pelvic pain or pressure. Dr. Taylor recommends that in addition to the usual symptoms, keep an eye for an uptick in for signals like "confusion, delirium, agitation, hostility." 

Two weeks after her trip to the emergency room, my mother-in-law is still weak and still confused. She still has dementia, and that will not change. She is, however, considerably calmer, thanks to the round of antibiotics she received. She experiences her dementia in every part of her body, and every part of her body informs her dementia. Her brain and her bladder are entwined, just like all of ours are. I know now the importance of respecting the connection.

By Mary Elizabeth Williams

Mary Elizabeth Williams is a senior writer for Salon and author of "A Series of Catastrophes & Miracles."

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Alzheimer's Dementia Elderly Health Mental Health Neurology Reporting Uti