A research group from the Faculty of Psychology and Logopedics at the University of La Laguna has published a study in the journal Archives of Clinical Neuropsychology, indicating the existence of early alterations in the complexity of narrative discourse in individuals with Parkinson's disease. These alterations are observed even before clear signs of mild cognitive impairment manifest.
The research analyzed the linguistic capabilities of 27 Parkinson's patients and compared them with those of 24 healthy individuals, with the collaboration of the Asociación de Parkinson de Tenerife. Parkinson's, the second most frequent neurodegenerative disease after Alzheimer's, is commonly associated with motor symptoms but can also cause cognitive and language impairments that impact quality of life.
The study aimed to identify cognitive changes in the early stages of the disease. It is known that between 30% and 50% of Parkinson's patients develop mild cognitive impairment, and a larger percentage may develop dementia over time. The final sample included 14 patients without mild cognitive impairment and 13 diagnosed with it.
Using linguistic tests, including the well-known "Cookie Theft" picture, narrative capacity was assessed. Results showed that both patients with and without mild cognitive impairment produced more simple sentences and fewer complex structures, indicating a reduced ability to connect ideas and articulate elaborate narratives.
Lower linguistic complexity and reduced verbal production speed were observed in Parkinson's patients, although the total number of words used and the total time spent on the task did not differ significantly from the control group. A key finding is that these narrative alterations appeared to be independent of the patients' general cognitive status or the motor progression of the disease.
Unlike other language tests such as verbal fluency, narrative discourse showed a different behavior. Patients with mild cognitive impairment associated with Parkinson's did show worse results in semantic fluency and word naming tasks, confirming previous research on linguistic difficulties related to more advanced stages of cognitive decline. However, researchers noted that the reduction in narrative complexity appeared even in patients who did not yet exhibit other relevant cognitive signs.
The authors conclude that narrative language could serve as an early marker for cognitive alterations in neurodegenerative diseases and emphasize the need to develop tools that allow for the detection of subtle changes before more evident clinical symptoms emerge.
