Cognitive Tests Are Good. The Way Trump Talks About Them Is Bad.
The MoCA is a starting point—it bundles together mini-tests on several different areas of cognition, and if a patient has a lower score in certain areas, a provider might order more in-depth assessments on, for example, language or memory. But it’s dangerous to take it as a definitive diagnostic. While some patients may have test results that indicate clear loss of cognition, most of the time the test only shows the need for more testing. Sometimes, the additional testing reveals there are no issues after all; the test was designed not to miss anyone, so there’s a risk of people without cognitive impairments accidentally testing too low. That happens about 13 percent of the time, Nasreddine said. Patients might be distracted or tired or stressed that day; certain medications, like Benadryl, can also cause cognitive issues.
“If there’s a problem on the test, it doesn’t automatically mean that you have Alzheimer’s or a neurological condition,” Nasreddine said. That’s why it’s important for an experienced health care provider to administer the test and not overinterpret it, he said. Cognition also isn’t the same as ability, Karlawish said, so before concluding that a patient shouldn’t be driving or living alone, for example, providers would want to investigate further, just as they would before making any other diagnosis. “The echocardiogram tells you a lot about the heart, but it doesn’t alone diagnose heart failure,” he said.
At the same time, sometimes the tests don’t pick up people in the early stages of cognitive impairment, Karlawish said. “It’s not at all uncommon to have someone who has a score on the MoCA which is ‘normal,’ doesn’t indicate impairment, and yet when you test in greater detail on the various cognition measures, you pick up impairment,” he said. To return to the analogy of heart disease: A test might not pick up issues if the patient is walking across the room, but more testing might find they have trouble climbing the stairs.
