Cognition and metacognition in functional motor symptoms and functional seizures: a case-control study

Cognitive symptoms are common in functional neurological disorder (FND), yet evidence of impaired neurocognitive test performance is variable. We aimed to assess self-reported cognitive symptoms, neurocognitive test performance, and metacognitive confidence in patients with functional seizures (FS) and functional motor symptoms (FMS).

Participants with FS (n = 50) and FMS (n = 50) were compared to age- and gender-matched healthy controls (HC, n = 50), and clinical controls with depression and/or anxiety disorders (CC, n = 50). The Cambridge Neuropsychological Test Automated Battery was used to examine response speed, working memory, executive functions, and social-emotional processing, with subjective confidence rated for each test. Intellectual functioning, performance validity, and self-reported cognitive symptoms were also assessed.

The FND groups reported elevated cognitive symptoms compared to HC and CC (p-values<0.001). Impaired performance was demonstrated in both FND groups on tests of sustained attention (p-values = 0.03- < 0.001) and set-shifting (p-values = 0.01-0.001). Performance validity was comparable between groups (p = 0.64). The FND groups reported reduced post-diction confidence for sustained attention (p < 0.001). Executive performance deficits correlated with reduced test-specific confidence in FS/FMS (p-values = 0.02- < 0.001). In FMS, post-diction confidence for sustained attention performance correlated negatively with cognitive symptoms (p = 0.002). Cognitive symptoms were associated with psychological/physical symptom load, quality-of-life, and/or general functioning in FND and CC groups (p-values = 0.04- < 0.001).

Patients with FS and FMS displayed localized deficits on tests of executive functioning, with reduced domain-specific metacognitive confidence, alongside significant cognitive symptoms. These neurocognitive features were associated with poorer clinical status, warranting interventions targeting cognitive control and/or cognitive symptoms in everyday life.