The Profile of Cognitive Complaints Associated with Neurodegenerative Dementia: A Single Centre Retrospective Analysis in Northern Portugal

Abstract

Introduction: The detection of early phases of neurodegenerative cognitive disorders is challenging. Differentiating these from non-neurodegenerative conditions is increasingly important, especially with the recent approval of disease-modifying treatments for early Alzheimer's in Europe (lceanemba and donanemba). This study aimed to identify the clinical profile of patients presenting for the first time at a general Neurology clinic with cognitive complaints due to neurodegenerative conditions, i.e. Alzheimer's disease and related disorders.

Methods: We conducted a retrospective, single-centre study of patients referred by primary care to a general neurology outpatient clinic for cognitive complaints. Sociodemographic and clinical data were collected from primary care records and the first neurology appointment. Diagnoses of a "neurodegenerative disorder" or "non-degenerative disorder" were established per the judgment of the attending physician according to established guidelines. Patients with overt dementia (moderate/advanced stages) were excluded.

Results: Among 283 patients, 169 (59.7%) had a non-degenerative condition, 108 (38.2%) a neurodegenerative disorder and six (2.1%) were lost to follow-up. Characteristics associated with a diagnosis of a neurodegenerative disorder were: age >76 years (OR 1.05); retirement (OR 3.42); absence of psychiatric pathology (OR 0.54); apathy (OR 3.36); major cognitive complaints (i.e. cognitive impairment likely to cause harm or requiring assistance) (OR 2.27); absence of responsibility demanding tasks (OR 0.50); presence of head turning sign (OR 2.89); cognitive bedside scores below the established cut-off (OR 7.88); focal/asymmetrical atrophy in imaging reports (OR 2.40). After multivariate analysis, failure to recall any words on delayed recall and focal/asymmetrical atrophy on imaging reports remained significant predictors of neurodegeneration. The model achieved 93.4% accuracy, 87.4% sensitivity, and 88% specificity in distinguishing degenerative from non-degenerative cognitive disorders, although these results should be interpreted with caution. Diagnostic changes occurred in older individuals (OR 1.04), those with lower bedside scores (OR 4.17), parkinsonian features (OR 4.05), and apathy (OR 4.40).

Conclusion: Our study provides a profile of patients presenting for the first time to a general neurology clinic who might be on the early stages of a neurodegenerative process (older, major complaints, cognitive bedside testing below established thresholds, focal and/or asymmetrical atrophy in brain imaging, impaired delayed recall tasks, and parkinsonism), and who may benefit from further testing. Prospective validation of these criteria in primary care and other neurology clinics is advised.