Positive Clinical Signs of Functional Neurological Disorders Are Found in Patients With Functional Cognitive Disorders.

INTRODUCTION: The proposition of diagnostic criteria of functional cognitive impairment (FCD) is relatively recent, includes different subtypes of heterogenous aetiologies, and likely involves underlying mechanisms similar to those found in functional neurological disorders (FNDs). The present study aims at describing clinical features in a group of patients with FCD in order to identify positive signs of FCD and the overlap with FND. MATERIALS AND METHODS: We prospectively included patients with FCD and patients with FND with disabling cognitive complaints seen in the Neurology department of Avicenne Hospital (Bobigny, France), which houses a memory clinic and a multidisciplinary FND unit. RESULTS: We included 39 patients between April 2023 and December 2024, 19 having isolated FCD, and 20 FND with cognitive features (FND + FCD). In the systematic symptom checklist, memory impairment was the most frequent cognitive complaint, reported by all patients. Among patients classified as having FND + FCD, 95% presented at least one positive sign of FND on neurological examination, while 42.1% of those classified as having FCD alone showed at least one of the positive signs. CONCLUSION: This study highlights the potential utility of screening for positive clinical signs in patients presenting with FCD and the overlap between FND and FCD.