Alexithymia is associated with cognitive impairment in patients with Parkinson's disease

Cognitive dysfunction (CD) is a common non-motor symptom of Parkinson's disease (PD). Alexithy-mia is a still poorly understood neuropsychiatric feature of PD. Cognitive impairment (especially visuospatial dysfunction and executive dysfunction) and alexithymia share com-mon pathology of neuroanatomical structures. We hypo-thesized that there must be a correlation between CD and alexithymia levels considering this relationship of neuroanatomy. Objective - The aim of this study was to evaluate the association between alexithymia and neurocognitive function in patients with PD.

Thirty-five patients with PD were included in this study. The Toronto Alexithymia Scale-20 (TAS-20), Geriatric Depression Inventory (GDI) and a detailed neuropsychological evaluation were performed.

Higher TAS-20 scores were negatively correlated with Wechsler Adult Intelligence Scale (WAIS) similarities test score (r =-0.71, p value 0.02), clock drawing test (CDT) scores (r=-0.72, p=0.02) and verbal fluency (VF) (r=-0.77, p<0.01). Difficulty identifying feelings subscale score was negatively correlated with CDT scores (r=-0.74, p=0.02), VF scores (r=-0.66, p=0.04), visual memory immediate recall (r=-0.74, p=0.01). VF scores were also correlated with difficulty describing feelings (DDF) scores (r=-0.66, p=0.04). There was a reverse relationship bet-ween WAIS similarities and DDF scores (r=-0.70, p=0.02), and externally oriented-thinking (r=-0.77,p<0.01). Executive function Z score was correlated with the mean TAS-20 score (r=-62, p=0.03) and DDF subscale score (r=-0.70, p=0.01).

Alexithymia was found to be associated with poorer performance on visuospatial and executive function test results. We also found that alexithymia was significantly correlated with depressive symptoms. Presence of alexithymia should therefore warn the clinicians for co-existing CD.