Prof Barbara Sahakian warned that intelligent people could pass the test despite being in the early stages of the disease.
The NHS drugs rationing body has proposed changing its guidance to allow three drugs previously limited to those in the moderate and severe stages of Alzheimer’s to be given to those in the mild or early stages.
While welcoming the reform, Prof Sahakian warned that the test currently used to detect early Alzheimer’s is so poor the new guidance may make little practical difference.
The “mini mental state examination” is used to screen for early Alzheimer’s but includes questions such as who is Prime Minister, what is the date today and remember three things you did yesterday.
As well as missing high functioning people with early Alzheimer’s disease, the test is language based so people who cannot speak good English are at a disadvantage and may fail the test even though they are healthy, she added.
“The MMSE is not fit for purpose in detecting early dementia. It is far too easy and not sensitive enough.
“The trouble is that it is not going to detect mild people, especially bright people, so what is the point in changing the drugs guidance?”
She said other tests are available which examine a person’s ability to remember newly acquired learning as this is the first sign of deterioration.
One test produces six patterns in boxes on a screen and patients then have to remember where they were once they are hidden again.
Healthy elderly people tend to do very well on the test while those who are in the early stages of the disease are detected easily and cheaply.
Prof Sahakian said: “It is so frustrating. After all those people had to suffer because the drugs were withheld and now they have finally reversed that decision they are going to continue with a poor test that will not detect those early cases who can now benefit from treatment.”
Telegraph UK