Alzheimers research challenges NICE guidelines

5 March 2009

Guidelines issued by the National Institute of Clinical Excellence (NICE) about the prescription of drugs for patients with Alzheimer's disease are inadequate, according to new research by the University of Hull.

According to NICE, only patients with a moderate severity of Alzheimer's disease should be prescribed cholinesterase inhibitor (ChEI) drugs, but the paper entitled, ‘Responders to ChEI Treatment of Alzheimer's Disease Show Restitution of Normal Regional Cortical Activation', published in the April 2009 issue of Current Alzheimer Research (Vol. 6), shows that patients with early stages of the disease may have an excellent response to treatment.

The study was carried out at the Clinical Neuroscience Centre at the University. There were 26 patients in the study, they were selected from the 100 patients who attend the University's Memory Clinic and all had early stage Alzheimer's disease.

The patients were treated over a five-month period and their brain activity was assessed at the beginning of the course of treatment and again at the end. Since the typical early symptoms of the disease are deterioration in linguistic skills and loss of recent and working memory, the group was tested using semantic association and working memory tests. These tests have been devised by Professor Venneri, Dr. Shanks and Dr. McGeown at the University of Hull, and do not normally form part of standard clinical assessment.

The patients' behaviour was monitored by a functional MRI (fMRI) scan before and after treatment. fMRI is a sophisticated form of brain scan which shows considerable detail of brain activity when a patient performs certain tasks.

Professor Annalena Venneri explains, "We tested the patients' semantic association by giving them a word and then a choice of two other words, they had to decide which ones were linked. In order to test their working memory, we showed them letters running across a screen and they had to press a button when the same letter was shown twice. These are simple tests, but they are a good indicator of the early stages of the disease."

Nine out of the 26 patients responded well to treatment and regained normal levels of activity in brain areas used by healthy people when doing these tasks, suggesting that the NICE guidelines may not be the best way to identify those people who have the best chance of response to the treatment.

The main difference between responders and non-responders was their level of impairment on a semantic fluency task at baseline which was more severe in responders. The score on this simple test was able to predict the level of normal brain response during the fMRI tasks after treatment.

Professor Annalena Venneri says, "The research stresses the need to identify responders at the early stages of the disease by accurate assessment of patients' deficits and stabilise their symptoms, giving patients a better quality of life for a longer time. These responders are currently missed in the averaging out of the NICE guidelines, which are based on scoring below a certain level on a basic screening instrument such as the Mini Mental State Examination."

The author Terry Pratchett - like many others at the early stages of the disease - is currently having to pay for their own treatment because their condition is not severe enough to warrant NHS funded treatment.

Britain has an ageing population, there is an estimated 750,000 people in the UK currently suffering from dementia and projections suggest that this will rise to 850,000 in 2010 and 1.8 million in 2050.