by Melina Walling, AZ Cental
Dementia often initially shows symptoms shared by many other conditions, including anxiety and depression, both of which have been on the rise in recent years.
Dr. Jordan Karp, professor and chair for the department of psychiatry at University of Arizona, knows this from his clinical experience. Karp described one patient, an academic, whom he had diagnosed with and was treating for anxiety but who didn’t seem to be getting much better. He initially showed a newfound fear of driving, but was so high functioning that he was still going to work and scored well on basic cognitive screens.
Karp said things didn't click for him until he met the patient's wife, who described more of the changes she was seeing at home. Eventually, he realized the patient had likely become scared of driving because of changes to his visuospatial perception and had been going to work but had not been accomplishing much there.
"Often we see behavioral and psychiatric symptoms as the presenting reason why people are brought to the doctor and they seek medical care," Karp said. "Their brains are changing and behavior comes from the brain. It's what is first brought to attention."
But if the patient behaves the same, a doctor might not spot the changes. That's a problem called diagnostic overshadowing, and it's commonly seen in individuals with intellectual and developmental disabilities, said Liz Carr, a clinical director who has worked with those with intellectual and developmental disabilities for many years and also trains other caregivers in the field.
Diagnosis is like playing 20 questions, she said, except there are hundreds of possible answers and nobody playing knows the answers.
For older adults with and without disabilities, she said, there are other conditions common to aging that mimic the signs of dementia: dehydration and malnutrition; metabolic disorders; urinary tract infections; vitamin deficiencies; and sensory impairments, among others.
So how do doctors actually diagnose dementia? Cognitive tests are a start, but doctors often need a brain scan or a spinal tap to confirm the presence of amyloid plaques, the clumps of proteins that build up between nerve cells and are a hallmark of Alzheimer's disease and some other dementias.
Those tests are expensive right now and out of reach for most patients, said James Fitzpatrick, a director of advocacy with the Alzheimer's Association. PET scans, for instance, cost thousands of dollars and are usually not covered by insurance. Spinal taps are costly and invasive, which discourages their use in most cases. And specialized tests and clinicians are also especially hard to access for those who don't live in major cities.
All of that means several clinical, technical, geographical and financial hurdles are working against early and accurate diagnosis of dementia.