While Parkinson’s disease is mainly associated with motor deficits, recent research shows that patients suffering this devastating disease are also plagued by difficulties in to communicate clearly. In an extensive review, Thomas Holtgraves and Chelsea Cadle from Ball State University in Indiana tease out which areas of communication might be affected in Parkinson’s patients, giving practical advice to people in their surroundings on how to ease and improve communication.
The review, “Communication impairment in patients with Parkinson’s disease: challenges and solutions,” was published in the Journal of Parkinsonism and Restless Legs Syndrome.
Cognitive deficits have long been acknowledged as an integral part of Parkinson’s, but the interest for language processing and communication in Parkinson’s has lately contributed to a wealth of research, advancing the understanding of which particular domains are affected, and how deficits impact communication in patients.
A better understanding and awareness of communication difficulties can benefit both patients and their families, caretakers, and treating physicians — maintaining and evolving fruitful relationships.
Comprehension is the most well-studied domain of communications in Parkinson’s, and research shows that patients have difficulties with a variety of aspects of understanding.
Syntactic comprehension allows people to extract meaning from sentences by combining words in a particular order and rejecting unlikely word arrangements. Much research shows that this kind of language processing is not functional in Parkinson’s patients, reducing the overall understanding of a conversation. This is particularly true when presented with complex sentences.
This difficulty is linked to cognitive impairments in working memory and set-shifting — the ability to change behavior with a changing relevance of a stimuli. This leads to difficulties in managing nonroutine tasks requiring complex processing, and can be noted by the use of unusual language. Since research has shown that this problem is most severe when patients need to use internal cues, as opposed to external, activities such as planning might be notably problematic.
Emotion recognition is an essential part of both verbal and nonverbal communication, allowing the listener to interpret the true meaning of a statement. Studies exploring this area in Parkinson’s are not entirely in agreement, but plenty of data suggests that patients might have difficulties in emotion recognition using facial expressions or speech prosody — the emotional context of language.
Some studies have suggested that Parkinson’s patients who did not suffer dementia but were all medicated had a global deficit in face processing. Face recognition skills are usually divided into the ability to match unfamiliar faces by their identity, discriminate faces by sex or emotional expression, and discriminate faces based on speech sound.
Other studies, however, only found problems with the emotional part of facial recognition, and some indicated that recognition of emotions differed between various emotional states, and that patients more often failed to recognize disgust over other feelings.
Luckily, such impairments might be lessened by dopamine replacement therapy. The emotional content of language is also affected in Parkinson’s, where patients often have difficulty in identifying and discriminating between emotions expressed through language.
Other studies, however, found only problems with the emotional part of facial recognition, and some indicated that recognition of emotions differed between various emotional states, noting that patients more often failed to recognize disgust compared to other feelings. Luckily, such impairments might be lessened by dopamine replacement therapy. Also the emotional content of language is affected in Parkinson’s, where patients often have difficulty in identifying and discriminating between emotions expressed through language.
The disrupted emotional processing, including both recognition of emotions in facial expressions and in language, is not linked to either motor skills or level of depression, but is instead influenced by difficulties in working memory processing.
Understanding of nonliteral language, such as metaphors, sarcasm, and irony, employs a kind of language processing known as pragmatic meaning comprehension — understanding the meaning behind the words. Because studies show this area of the understanding of language is also affected in Parkinson’s, it is crucial for people interacting with patients to identify the degree of impairment in pragmatic language processing and keep in mind that minimizing the use of nonliteral language has a big chance to improve understanding.
Pragmatic meaning comprehension also involves “speech acts,” or what a speakers wish to achieve when they talk — for example, begging. Among Parkinson’s patients, deficits in correctly identifying action verbs in speech seem to be linked to symptom severity.
Spoken and unspoken words
The production of language has also been studied in Parkinson’s, but such studies are hampered by the difficulty to know if a problem in language production depends on processes inherent to production, or fail because of an incorrect understanding in the first place.
Studies, however, show that Parkinson’s patients use language with simpler syntax and lower information content than healthy individuals. Such difficulties seem to arise at later disease stages since non-demented and mildly impaired patients do not show these features.
An aspect of speech production that might take its social toll is the tendency of Parkinson’s patients to make pauses that are prolonged and often inappropriately timed. Since a pause often signals that it is another person’s turn to speak in a conversation, patients might find that others often interrupt their speech. The use of incorrect verbs is also frequent among Parkinson’s patients, and verbal fluency is often impaired.
This fluency more often affects semantic content, rather than phonetic, indicating that working memory involving meaning is more affected than memory involving phonetics. There is evidence that these problems in language are linked to each other, and more importantly, to the level of cognitive deficits, and tend to worsen as the disease progresses.
An aspect not commonly linked to language production, that might nevertheless contribute to impairments, is the motor capacity of the respiratory, throat, and vocal tracts. The tendency of patients to produce shorter sentences has been linked to decreased respiratory function.
Patients at times have difficulties adjusting speech volume to adjust to a situation, such as a noisy environment. However, there was, however no problem in adjusting volume when asked to do so.
All these speech production deficits may lead to the perception that Parkinson’s patients are less friendly, happy, involved, and interested. Studies where people get to listen to interviews also showed that people interpreted Parkinson’s patients as more hostile, unhappy, tense, and anxious.
But the content of speech by patients was perceived as more coherent, comprehensible, interesting, and interesting. Knowledge of a person’s diagnosis and its impact on speech might help in reducing negative impressions.
Finally, pragmatic language production has also been investigated in Parkinson’s. Such skills include verbal features such as topic selection, topic maintenance, turn-taking, and variations of word use, as well as paralinguistic features such as emotional expression and vocal quality, and nonverbal features such as gaze and gestures.
Studies show that patients have deficits in some of these aspects, particularly the nonverbal ones. Adding to the complexity of the deficit is the frequent inability of patients to recognize it.
Approaching Parkinson’s communication
Based on the findings explored here, the review authors crafted a number of recommendations aimed at people interacting with individuals suffering from Parkinson’s. They point out that these suggestions need to be used judiciously so that the speaker is not perceived as condescending, and the advice needs to be adapted to each patient’s specific types of impairment.
When speaking, it might be necessary to avoid complex syntax. Try to reduce the load on working memory by chunking information into smaller bits, and wait for acknowledgement before processing. It is also advisable to clearly delineate topics, and when shifting topics, announce the change by a verbal acknowledgement, such as “Returning to what we were talking about earlier …”
Avoiding reliance on emotional expressions and nonliteral meaning might also improve understanding, as could the use of performance verbs when describing actions. Reducing distractions might also improve communications, and the authors suggest that speaking at a slightly higher octave at a reduced rate might ease understanding.
To improve communications, speakers should also simplifying information content and questions, and encourage patients to give feedback on interpretations to reduce the risk of misunderstanding.
Similarly, the authors recommend that when listening to people with Parkinson’s, it is crucial not to judge, particularly since some patients are not aware of their deficits. Giving conversations enough time, taking into account the tendency of patients to make long and seemingly misplaced pauses, is likely to improve communications.
Finally, an understanding and encouraging atmosphere can reduce stress and improve communications, and there might be times when asking a person to speak up will make a conversation flow with less effort.