Early diagnosis and treatment would allow the disease to be suppressed so effectively that severe symptoms might not occur. There is a lot to fight for, because the final stages of Alzheimer's disease are very distressing for the patient and those around them. From being a mentally fit person, one changes into a patient with severe cognitive impairment, not recognising loved ones, with memory lapses (e.g. after going to the shop, he forgets the way back home), losing basic skills (such as brushing his teeth, dressing, eating). He is, alternately, irritable and apathetic, refusing to accept care. The latest reports from US researchers may be groundbreaking.

Researchers from American centres (Columbia University, State Psychiatric Institute, New York Presbyterian) have announced their discovery: odour identification tests may be useful in diagnosing Alzheimer's disease at a stage when symptoms are still imperceptible to the patient's surroundings.

They base their discovery on a study in which they gave each of 397 people (average age 80) without dementia the UPIST (University of Pennsylvania Smell Identification Test) and an MRI to measure the thickness of the intraparietal cortex - the first centre in the brain to be affected by Alzheimer's disease.

After four years, the researchers re-examined this group of patients. 12.6 per cent showed signs of dementia and 20 per cent of them showed, cognitive impairment. The researchers then revisited the UPIST test and found that those patients who had developed dementia and cognitive impairment also scored lower on odour identification tests. This led to the thesis that odour identification tests could become standard methods for predicting the development of Alzheimer's disease.

Researchers at Columbia University conducted another study in which they compared the predictive ability of existing methods to help diagnose Alzheimer's disease with the UPIST method. They tested the effectiveness in predicting how a patient will develop memory impairment. Existing methods detect the disease with a high degree of sensitivity, but, unfortunately, they do not allow the disease to be diagnosed before it has developed in the brain enough to give clear symptoms.

Odour identification tests are therefore a novel method that can replace existing tests. In medicine, all so-called screening tests are valuable. They are carried out at a point in time before a person develops a disease. On a large scale, they help in the treatment of cancers (colorectal, breast). So maybe the UPIST test will become a screening test in the future, detecting Alzheimer's disease at an early stage? This would be a huge achievement and help many people around the world, as earlier diagnosis of the disease means earlier treatment is possible. This is the first research, but after such results, further reports can be expected.