شیوع و ویژگی های آلکسیتیمیا در بیماری پارکینسون

Background Alexithymia, a reduction in the tendency to think about emotions, together with a difficulty in identifying and describing feelings, has been characterized as a personality trait, but may be secondary to other pathological conditions. Objective The authors aimed at investigating alexithymia in Parkinson's disease (PD). Method Seventy PD patients and 70 control subjects were administered the 20-item Toronto Alexithymia Scale. Results The authors found that 21.4% of PD patients and 10.0% of controls could be classified as alexithymic. PD patients and controls significantly differed on global levels of alexithymia. However, univariate analyses showed that PD patients differed significantly only on the subscale investigating difficulty describing and communicating feelings. Conclusion These results indicate that some facets of alexithymia are a relevant feature of PD, possibly in relation to the neuropathological changes that characterize the disease.

Alexithymia is a cognitive-affective disturbance mainly characterized by a relevant reduction in the tendency to think about emotions together with a difficulty in identifying and describing feelings and distinguishing feelings from bodily sensations of emotional arousal.1 According to some authors,2 alexithymia could be a personality trait that contributes to the development and severity of somatic and psychopathological disorders.3., 4. and 5. Results from other studies suggest, instead, that alexithymia may be secondary to other pathological conditions.6., 7. and 8. There are few reports in the literature on alexithymia in individuals with Parkinson's disease (PD). Nevertheless, some studies indicate that an impairment in the processing of emotional experience may be present in PD patients.9., 10., 11., 12., 13. and 14. (However, Adolphs et al.15 present a partially discrepant view.) In particular, Jacobs et al.11 showed impaired performance in PD patients on a task assessing emotional facial imagery and on tasks probing emotional expression and the perception of emotion in faces. Recently, Dujardin et al.16 described impaired decoding of facial emotions in PD patients at an earlier stage of the disease. Moreover, Simons et al.17 reported PD patients’ specific difficulty, as compared with healthy-control subjects, in creating emotional facial expressions. Results consistent with PD patients’ deficit in communicating and decoding emotions were obtained in studies on the ability to recognize and express affective verbal expression.9., 10. and 11. In a previous study, we found that alexithymia occurred in about 21% of a cohort of 58 PD patients and that it was strongly associated with severity of depression.18 We speculated that a dysregulation of the dopaminergic mesocorticolimbic system, which occurs in PD and is reported to be more severe in PD patients with depression,19 could be related to the described alexithymic expression. However, in that study, the lack of a control sample without PD prevented us from drawing firm conclusions about the prevalence of alexithymia in PD and whether the association between alexithymia and depression is particularly strong in PD or simply reflects an overlap of the depressive and alexithymic symptoms widely documented in persons without PD.20 The present study was aimed at investigating the prevalence and characteristics of alexithymia in hospitalized PD patients without dementia, as compared with a group of hospitalized control subjects suffering from orthopedic and peripheral nervous system pathologies. We also investigated the relationship between alexithymia and depressive and anxious symptoms in PD versus brain damage-free control groups.