Mood, cognition issues tied to deficit recognizing, describing emotions
Study: Better assessments, rehabilitation efforts needed to address condition
Having difficulty recognizing and describing emotions may be associated with cognitive issues and with mood disorders such as depression, apathy, and impulse control problems in people with Parkinson’s disease, a review study suggests.
As a result, the condition, called alexithymia, or emotional blindness, may reduce patients’ health-related quality of life.
Specific interventions to ease alexithymia are lacking, meaning “further research is required to establish the best rehabilitation approaches for enhancing patient well-being,” the researchers wrote.
The study, “Possible Implications of Managing Alexithymia on Quality of Life in Parkinson’s Disease: A Systematic Review,” was published in Parkinson’s Disease.
Parkinson’s disease is caused by the progressive loss of dopaminergic neurons, nerve cells responsible for producing dopamine, a chemical messenger involved in motor control. This leads to brain signaling issues and a characteristic set of motor symptoms that include muscle rigidity, slowed movements, and resting tremors.
Prevalence of alexithymia in Parkinson’s
A nonmotor symptom of Parkinson’s, alexithymia has been reported to be more prevalent in people with the disease than in the general population. To better understand it, researchers in Italy reviewed available literature published between 2013 and 2023. Twelve studies with up to 119 patients were included in the analysis and the prevalence of alexithymia among people with Parkinson’s varied considerably between studies, the maximum being 56%. Men were more frequently affected than women.
While some studies indicated that those with alexithymia had more advanced Parkinson’s disease, based on the Hoehn and Yahr scale, this wasn’t seen consistenly across all the analyses.
One study indicated that in treated patients with early-stage Parkinson’s, alexithymia was associated with both motor and nonmotor symptoms. No detailed information was provided on specific treatments that could influence alexithymia, however. There was also lack of information on patients with moderate disease or those having symptom fluctuations.
Alexithymia wasn’t significantly affected in patients who underwent deep brain stimulation (DBS), a surgical procedure used to treat Parkinson’s motor symptoms by stimulating brain regions with electrical impulses.
“This suggests that alexithymic symptoms may persist in advanced [Parkinson’s disease] stages, irrespective of surgical interventions, pointing to the need for additional therapeutic strategies,” the researchers wrote.
One study identified alexithymia as a significant predictor of cognitive decline in Parkinson’s, a finding backed by another study that showed a link between alexithymia and nonverbal cognitive tasks. The condition was associated with poorer performance in tests of visuospatial and executive function, and with symptoms of depression. Visuospatial function requires perceiving and manipulating visual information, while executive function refers to a set of skills required to plan ahead and meet goals.
Alexithymia also was linked with difficulty recognizing, representing, and regulating emotions, with particular issues interpreting facial expressions and social cues. It was also associated with lower health-related quality of life, primarily related to difficulty identifying and describing feelings. It also meant a higher burden for caregivers.
Among the studies, only one used the Bermond-Vorst Alexithymia Questionnaire, a tool that covers both cognitive and affective aspects of alexithymia. To assess the condition, most studies used the 20-item Toronto Alexithymia Scale (TAS-20), a self-reported questionnaire, which according to the scientists may have limitations given the cognitive issues associated with Parkinson’s.
Rehabilitation strategies are scarce and their effectiveness is not established. One study reported benefits of DBS by targeting the subthalamic nucleus, a brain region involved in motor control, at easing alexithymia symptoms. Another study reported minimal effects, however.
Going forward, “research should focus on developing comprehensive assessments and rehabilitation strategies for emotional processing, considering its significant impact on the quality of life of both patients and caregivers,” the researchers wrote.
About the Author
