PET scans for Alzheimer's

Townsend Letter for Doctors and Patients, Feb-March, 2005 by Jule Klotter

Doctors at UCLA, who recently used Positron Emission Tomography (PET scan) to identify early-stage Alzheimer's in actor Charlton Heston, are trying to convince Medicare to reconsider its earlier decision to deny coverage for the procedure. Without PET, early-stage Alzheimer's can be difficult to distinguish from normal aging, depression, and other types of dementias. People with Alzheimer's show less activity in the cortex (the center for memory, thought, and decision making), according to PET scans. PET is about 90% accurate in identifying early-stage Alzheimer's. Early detection allows people the option of using some of the new medications that have been shown to delay the progress of the disease. It also gives patients and families time to get their personal affairs in order and to make decisions about future care. A PET scan is not the only reliable way to diagnose early-stage Alzheimer's, however. According to an article in The Wall Street Journal (16 October 2003), a good neurologist can diagnose Alzheimer's with 80 to 90% accuracy for about $300, by using a complete physical exam and a two-to-three-hour test of cognitive function. A PET scan costs about $1500.

Medicare refused to add PET scans for Alzheimer's diagnosis to its coverage in April 2003. Instead of paying for scans, Medicare suggested putting all possible Alzheimer's patients on medication like Aricept or Reminyl. The drugs cost patients about $150 to $200 a month and have side effects, usually temporary, that include nausea, vomiting, and diarrhea. Doctors who are pushing for the PET scan worry that the occasional serious side effect connected with these drugs, such as heart trouble, will become more common if larger numbers of people take them.

The agency has agreed to consider the proposal submitted by the UCLA team. The new application for Medicare coverage includes a list of guidelines that prevents PET from being used indiscriminately. With these guidelines in place, only an estimated 10% of the million people suspected to have Alzheimer's each year would be eligible for Medicare reimbursement.

Johannes, Laura. Finding Alzheimer's Early. The Wall Street Journal. 16 October 2003.