Differentiating Functional Cognitive Disorder from Early Neurodegeneration: A Clinic-Based Study

Area of Science:

• Cognitive Neurology
• Neuropsychology
• Clinical Psychiatry

Background:

• Functional cognitive disorder (FCD) presents with cognitive symptoms inconsistent with objective functioning.
• Differentiating FCD from early neurodegenerative conditions like Mild Cognitive Impairment (MCI) is clinically challenging.
• Neuropsychometric assessment is crucial for characterizing FCD and distinguishing it from neurodegeneration.

Purpose of the Study:

• To enhance the clinical characterization of FCD.
• To differentiate FCD from neurodegenerative Mild Cognitive Impairment (nMCI) using a comprehensive assessment battery.
• To identify specific neuropsychometric markers for FCD.

Main Methods:

• Recruited two patient cohorts: FCD (n=21) and nMCI (n=17), plus healthy controls (n=25).
• Administered the Hopkins Verbal Learning Test-Revised (HVLT-R), Trail Making Test Part B (TMT-B), DASS, and MMPI-2RF.
• Compared performance across groups, focusing on cognitive, mood, personality, and performance validity measures.

Main Results:

• FCD and nMCI groups showed similar impairments in TMT-B, immediate recall, recognition, mood symptoms, personality measures, and performance validity tests compared to controls.
• FCD participants significantly outperformed nMCI participants on HVLT-R delayed free recall and retention (p=0.01).
• FCD demonstrated preserved delayed recall and retention, contrasting with impaired immediate recall and recognition, a pattern distinct from prodromal neurodegeneration.

Conclusions:

• Mood, personality, and certain cognitive functions are similarly altered in both FCD and nMCI.
• Preserved delayed recall and retention in FCD, despite deficits in immediate recall and recognition, serves as a key differentiator from nMCI.
• Identifying these neuropsychometric features is vital for the emerging field of cognitive neurology and clinical practice.