The role of Neuropsychological assessment in the Differential Diagnoses of Late-Onset Depression, Dementia, and Mild Cognitive Impairment

Abstract

Objective: The present study aimed to compare the neuropsychological test parameters of dementia, depression, and MCI patients and determine the disease-specific test characteristics and their relationship with electroencephalography. Methods: Ninety-one patients who were admitted to the neurology outpatient clinic with forgetfulness complaints between October 2019 and March 2022 and whose neuropsychological tests were performed were included in the study. The files of these 91 patients were reviewed retrospectively and their sociodemographic data were recorded. Furthermore, the EEG results which were taken during the patients' evaluation period due to forgetfulness were evaluated. Neuropsychological tests were compared between patients with dementia, MCI and depression. It was also investigated whether there was a relationship between NPT test parameters and EEG in patients with EEG results. Results: The study was completed with 87 patients. Of these 87 patients, 54 were female and 33 were male. Twenty-four patients had depression, 16 MCI, and 47 dementia. All of the dementia patients had Alzheimer's type dementia. When dementia, depression, and MCI groups were compared, the age difference was statistically significant (p=0.001). The mean age of the depression group was 66.5, the MCI group was 73.5, and the dementia group was 77. WMS-I, WMS-II, WMS-III, WMS-IV, similarities test, clock drawing test, trail making test, shape copying, language, and mood evaluation tests were statistically significantly different between the groups.  There was no statistically significant difference between the groups regarding gender, education level, dominant hand, and occupation. EEG background activity frequencies were also examined between the groups, and there was no statistically significant difference. Conclusion: In conclusion, when evaluating patients who present with the complaint of forgetfulness, a detailed neuropsychological evaluation must be performed in addition to other diagnostic tests. Sensitive tests should be included to confirm the diagnosis, especially in cases where being in between for the differential diagnosis. Thus, further studies are needed on this subject.