Early diagnostics of Alzheimer‘s dementia – the overview of clinical, laboratory, morphological and functional tests

Gabija Visockytė1, Renata Komiagienė 1,2 

1 Vilniaus universiteto Medicinos fakultetas

2 Vilniaus universiteto ligoninė Santaros klinikos, Radiologijos ir branduolinės medicinos centras

Abstract

According to World Health Organisation (WHO) Alzheimer’s dementia is described as progressive decline of cognitive functions. It mostly affects memory, language and learning abilities. Alzheimer’s dementia begins with mild symptoms, that worsen over time and inevitably results in severe brain damage. With average life expectancy increasing, more and more people are diagnosed with dementia each year and it is estimated, that by year 2050 the prevalence of dementia will reach 152 million people in the world. Alzheimer’s disease diagnostic guidelines recognize that disease progresses with three stages – an early preclinical stage, where no symptoms can be found; a middle stage of mild cognitive impairment; and a final stage – dementia with symptoms so severe, that they affect everyday life and impair the ability for the patients to take care of themselves. In modern medicine, when pathogeneses of various dementias are widely researched, new diagnostic methods are aimed not only at identifying the disease in early stages, but also at accurate differentiation between different types of dementia. Although cognitive and neuropsychological tests remain the first step of assessment for patients with suspected dementia, modern radiological technologies also become more and more important. Magnetic resonance imaging evaluates structural brain changes and helps to exclude organic causes of dementia syndrome (eg. brain tumours, neuroinfections, vascular pathologies) as well as identifies specific atrophic changes, that can be seen in different dementias. Modern positron emission tomography technologies, that use molecular radiotracers, evaluate changes of glucose metabolism in the brain and assesses amyloid deposition – these changes can be seen even in the preclinical stage of the disease. There also are specific laboratory tests, that can evaluate biomarkers in cerebrospinal fluid and help to confirm the diagnosis. Early and specific diagnosis is of crucial importance since it enables administration of treatment, which slows down the progression of Alzheimer’s disease and improves the quality of life for the patients as well as their caregivers.

Keywords: Alzheimer’s dementia, early diagnostics, positron emission tomography