Pain a Problem in Alzheimer's Disease

Sept. 22, 2006 -- Alzheimer's patients feel pain -- but because it's hard for them to tell anyone about it, their pain is undertreated.

That might seem obvious. But there's been an assumption that Alzheimer's patients can't feel pain as sharply as can other agingaging adults. That assumption plays out in practice: Alzheimer's patients receive painkillers less often than their peers do.

Now an Australian study provides powerful evidence that Alzheimer's patients feel pain as powerfully as others -- if not more so.

"Pain perception and processing are not diminished in Alzheimer's diseaseAlzheimer's disease, thereby raising concerns about the current inadequate treatment of pain in this highly dependent and vulnerable patient group," conclude Leonie J. Cole and colleagues at the University of Melbourne and the National Ageing Research Institute, Parkville, Victoria, Australia.

Brains Tell What Patients Can't

Cole and colleagues studied 14 patients with mild-to-moderate Alzheimer's disease and 15 age-matched volunteers without Alzheimer's. All study subjects underwent a test in which a device pressed their thumbs until they felt just noticeable pain, weak pain, and moderate pain.

During this test, the researchers used a real-time brain scan -- functional magnetic resonance imaging (fMRI) -- to look for activity in the brain's major pain channels.

Pain activity in the brain was just as strong in the Alzheimer's patients as in the healthy volunteers. In fact, pain activity lasted longer in the Alzheimer's patients.

This, Cole and colleagues suggest, means that the patients were less able than healthy people to turn their attention away from the pain. Less able to put the pain into the context of their experience, they found the pain more distressing.

And these were patients still able to communicate. Pain may be even more bewildering to more severely affected patients.

"The experience of pain may be more distressing for these patients on account of their impaired ability to accurately appraise the unpleasant sensation and its future implications," Cole and colleagues suggest.

Their study appears in the advance online edition of the journal Brain.

How to Recognize Alzheimer's Pain

The study findings don't surprise pain expert Christopher L. Edwards, PhD, director of the Pain and Palliative Care Center at Duke University in Durham, N.C. Edwards has studied pain in people who are unable to communicate.

"We traditionally assume that individuals without verbal ability don't have the same pain we do. That is not correct," Edwards tells WebMD. "These patients do have the capacity for pain. Their pain is relevant, and it is deserving of evaluation and treatment."

Fortunately, Edwards says, it's possible to tell when a person is experiencing pain -- even if that person isn't able to tell you about it.

Doctors can use a tool called the Pain and Discomfort Scale or PADS. It's a system for evaluating pain based on facial expressions and body movements.