Functional Cognitive Disorder: Differential Diagnosis of Common Clinical Presentations

Abstract

Background Cognitive symptoms in the absence of neurological disease are common. Functional cognitive disorder (FCD) has been conceptualized as a cognitive subtype of functional neurological disorder. Although FCD is understood as different from exaggerated or feigned cognitive complaints, previous accounts have provided little practical advice on how FCD can be separated from factitious or malingered cognitive complaints. Also, the distinction of FCD from other medical or mental health disorders that impact on cognition is an area of ongoing study and debate. Diagnostic precision is important to prevent iatrogenesis and for the development of needed treatment protocols. Method We summarize the current literature and present seven anonymized case vignettes to characterize the challenges in this area and develop proposals for solutions. Results/Conclusions Recognizing the limitations of categorical diagnostic systems, we position FCD as distinct from feigning and cognitive symptoms of psychiatric disorders, although with overlapping features. We set out typical clinical features and neuropsychological profiles for each category of cognitive disorder and a statistical method to analyze performance validity tests/effort tests to assist in determining feigned or invalid responding.

Agreement and disagreement in pediatric functional neurological symptom disorders: Comparing patient reported outcome measures (PROMs) and clinician assessments

“…Studies have suggested that subjective reports of cognitive difficulties, including forgetfulness, distractibility, and retrieval problems, are frequent in patients with FNSD [58] . These deficits may be attributed to various factors, such as pain, fatigue, and excessive interoceptive monitoring, common in FNSD, which can negatively impact working memory, attention, and overall cognitive processing speed [59] . Further contributions to these subjective cognitive experiences may be perfectionism and the tendency to overinterpret cognitive impairments, both of which have been reported as clinical characteristics of FNSD [60] .…”

“…Although both conditions may involve subjective reports of cognitive challenges, FNSD encompasses a broader spectrum of neurological symptoms, including learning difficulties. Conversely, FCD presents a specific focus on cognitive problems such as forgetfulness and memory impairments [59] , [69] . However, given the considerable heterogeneity in the literature and methodological shortcomings, further research is warranted before dissociating the nature of cognitive difficulties in FNSD from those in FCD [58] .…”

Primary progressive aphasia: six questions in search of an answer

“…Some symptoms (such as ‘tip-of-the-tongue’ hesitations in lvPPA [ 87 ]) are commonly experienced by normal speakers. Some patients presenting with health anxiety or functional cognitive disorder describe prominent speech and language symptoms: aside from lack of progression (and sometimes, abrupt onset), positive clues to these diagnoses on history include elaborate symptom descriptions and discrepancies between the severity of the subjective complaint and daily life performance [ 88 ]. On examination, hallmarks of a functional speech disorder include stuttering or prosodic changes (‘childlike’ or a ‘foreign accent’) with pronounced variability (severe disruption interspersed with segments of normal speech) and distractibility [ 89 ].…”

A Case of Functional Cognitive Disorder: Psychotherapy and Speech and Language Therapy Insights

“…Given features of internal inconsistency (i.e., report of severe memory trouble yet evidence of intact memories and self-reported daily living activities in interview), we communicated a diagnosis of functional cognitive disorder (FCD), a type of FND, to the patient and her partner. [1][2][3] We discussed that this condition is common and that treatments are available. We also pointed out that there was likely no overt structural damage, and that there was a possibility for improvement.…”