Authors: Raquel Carolina De Souza da Silva, Ludmila Souza da Cunha, Marcilene Maria de Almeida Fonseca
Published: 2020-12-07
DOI: 10.1002/alz.037509
Source: Full article
AbstractBackgroundAlzheimer's disease (AD) is by definition a functional cognitive decline that causes gradual memory loss, compromising areas of the brain responsible for cognition, function and behavior. AD is responsible for 60‐70% of dementias, affecting about 25 million people worldwide. Therefore, the early diagnosis allows therapeutic intervention with reduction of treatment costs, prolongation of autonomy and delay in the onset of the dementia process.MethodThe bibliographic research was performed in digital platforms, using articles published in the last 11 years in Spanish, English and Portuguese. Its aspects of early clinical diagnosis were analyzed and compared with the results observed in clinical and imaging examinations.ResultIn DSM‐5, AD was separated into three stages: preclinical, mild cognitive impairment (MCI) and dementia. Studies indicate that subtle changes can be detected years / decades before the first clinical symptoms that characterize MCI through biomarkers. Today, there is no obligation for memory loss to precede other symptoms, sensory and motor changes may be present 5‐15 years earlier in the early stages. Clinically, the patient needs to have cognitive and behavioral symptoms that affect daily activities, showing a reduction in their performance that cannot be attributed to other neurocognitive disorders, evidenced in anamnesis taken from the patient and a family member who is aware of the condition and conducting neuropsychological tests or cognitive assessment such as the Mini‐Mental. It is important to remember that tests such as computed tomography or magnetic resonance imaging of the skull should be performed to rule out differential diagnoses, since CSF examination may help to identify infectious dementia of the central nervous system.ConclusionThe percentage of clinically identified cases decreases as the stages of AD are earlier. However, tests with biomarkers are at the same time more sensitive and specific to the diagnosis of AD and may expose the disease even before the onset of symptoms due to the marking of the dementia triggering gene.