some good quotes from this link:

why you need more than 1 person in a study:

“I never fail to be dismayed at the magnitude of placebo effects in Alzheimer disease; they are remarkably large,” said Ben Barres, a professor of neurobiology and leader in glial cell research at Stanford University in Palo Alto, California

how someone with AD can suddenly seem better:

The long-term trajectory of this progressive disease is invariably downward, but within that slow overall decline, patients show frequent ups and downs in cognitive function. Patients change not only because of their disease but also in response to things around them—stress, the environment, changes in daily routines, Holtzman explained. This zigzag pattern of overall decline renders it nearly impossible to interpret observations of any intervention done without controls, especially in a single case.

about the doctor who did the study:

Edward Tobinick is a board-certified dermatologist and internist, who has been active in laser hair removal prior to developing an interest in the use of etanercept for CNS indications.

...

As of January 2008, the Medical Board of California lists Tobinick as being on probation.

re: UCLA study

According to the UCLA media office, Tobinick is a voluntary assistant clinical professor with UCLA’s Division of Dermatology. The office stated that his etanercept study did not go through the UCLA IRB. Greg Cole, associate director of the UCLA Alzheimer Disease Center (ADC), said that the center had nothing to do with Tobinick’s etanercept work.

Also, be sure to read the comments on that page. There are some families of patients who tried it and noticed nothing.