ASSOCIATION BETWEEN APATHY AND CLINICAL FRONTAL-SUBCORTICAL DYSFUNCTION IN A MEXICAN SAMPLE OF ELDERLY PATIENTS WITH NEUROCOGNITIVE DISORDERS

Abstract

Apathy is a common neuropsychiatric symptom (NPS) in neurocognitive disorders (NCDs), associated to frontal-subcortical circuit dysfunction, and easily confused with depression. It's also considered a poor prognosis factor, which affects activities of daily living and increases significantly the caregivers’ burden. However, there is no definite consensus on the definition, concept, clinical role, anatomical structures involved, or “gold standard” diagnostic tool to detect it at beside. The Frontal System Behaviour Scale (FrSBeS) is considered a good clinimetric instrument to identify frontal-subcortical dysfunction before and after NCD's onset, and useful in several neuropsychiatric syndromes. Therefore, we explore the clinical association between apathy and depression with fronto-subcortical dysfunction in a Mexican sample of elderly patients with NCDs. This observational, descriptive, and transversal study includes subjects with NCDs, 60 years or older, with mini-mental (MMSE) >15/30 and that attend to the National Institute of Neurology and Neurosurgery (INNN), in México City. Participants were assessed with the Neuropsychiatric Inventory (NPI) and the FrSBeS from routine evaluations at the INNN's dementia clinic. We evaluate 42 subjects with NCDs, 24(57.1%) with major neurocognitive disorder (MNCD) and 18(42.9%) with mild neurocognitive disorder (mNCD). Age, gender and education did not show significant differences between MNCD and mNCD. Apathy was present in 15(62.5%) of MNCD and in 6(33.3%) of mNCD. FrSBeŚs total score comparisons only demonstrate an increase after the NCDs onset (p<0.05) and in presence of some NPSs, especially apathy (p<0.01). Using sensitivity analyses, we compare FrSBeŚs total scores in patients with NCDs that presented (a)apathy, (b)depression, (c)apathy plus depression and (d)none; we find differences in two post-hoc comparisons: (b) vs. (c) (p=0.07) and (c) vs. (d) (p=0.03).