Speech language pathologists (SLPs) are often important members of the care team for patients with Parkinson’s disease (PD). SLPs treat a wide variety of communication and swallowing problems, including those faced by people with PD. It is estimated that nearly one million are living with PD in the U.S., which is more than the combined number of people diagnosed with multiple sclerosis, muscular dystrophy, and Lou Gehrig’s disease (or Amyotrophic Lateral Sclerosis; Parkinson’s Foundation, 2019). Many of these individuals with PD come from culturally and linguistically diverse (CLD) backgrounds. SLPs must be aware of how CLD factors may impact these patients and the disease itself so that they can provide evidence-based, culturally sensitive care to each patient. SLPs must also educate themselves about potential cultural biases that can affect assessment and treatment of PD.

What is Parkinson’s Disease?

Parkinson’s disease (PD) is a neurodegenerative disorder that affects the neurons involved in the production of dopamine. Dopamine is a neurotransmitter that is responsible for controlling movement, emotional responses, and the ability to feel pleasure and pain. These affected neurons are primarily located in the substantia nigra, a part of the basal ganglia in the midbrain (Parkinson’s Foundation, 2019).

What are the Symptoms of PD?

Early symptoms

While each person with Parkinson’s has a unique disease progression, early symptoms of PD may include tremorsanosmia (loss of smell), trouble sleeping, and trouble moving or walking

Speech, language, and swallowing

People with PD often have speech, language, and swallowing problems, in addition to movement and non-movement symptoms.

Speech problems may include hypophonia (soft or low voice), problems with articulation, and decreased speech intelligibility (Ma et al., 2010; Moya-Galé et al., 2018)

Language may also be impacted by PD, with patients demonstrating simpler syntax (e.g. sentence formation) and action-verb deficits. Action-verb deficits may be an early or pre-clinical marker of PD (Calvo et al., 2018; Johansson et al., 2019).

Dysphagia (difficulty swallowing) is another common problem in PD. About ¾ of patients have festinations of the tongue, or “lingual pumping”. Lingual pumping is a repetitive, involuntary, anteroposterior (front to back) movement of the tongue on the soft palate. Lingual pumping typically occurs before the food is moved from the oral cavity (mouth) to the pharynx (throat) and may be associated with aspiration (Argolo et al., 2015).

Other problems related to swallowing and feeding that may be found in patients with PD include sialorrhea (drooling), anosmia, loss of taste, and early satiety (feeling full after eating only a small amount; Parkinson’s Foundation, 2019). When making treatment recommendations for patients with PD who have dysphagia, it is important for culturally competent clinicians to consider the social and cultural significance of meals and eating.

Cognitive symptoms

Cognition and memory may also be affected in patients with Parkinson’s. About 70% of people with PD eventually develop symptoms of dementia as the disease progresses. Executive function, which encompasses attention, planninginhibition, and shifting, may be affected (Dirnberger & Jahanshahi, 2013), as well as communicative participation (Miller & Cronin-Golomb, 2010).

Movement & non-movement symptoms

There are three main motor symptoms in Parkinson’s disease. These are:

  1. Bradykinesia
  2. Tremor
  3. Rigidity

Bradykinesia is an abnormal slowness of movements that is often present in PD. Resting tremors (limb shakes while at rest) and/or “pill-rolling” tremors are also common in patients with PD. Pill-rolling tremors appear as if the patient were rolling a pill or small object between their thumb and forefinger. Rigidity is stiffness or inflexibility of muscles. This may include “cogwheel rigidity” with a stop-and-go effect during a range of motion maneuver (e.g. moving an arm from bent to outstretched).

Facial masking, sometimes called hypomimia, is also common in patients with PD (Tickle-Degnen, et al., 2011), as are dystonia (muscle cramping), problems with balance and gait (walking), and dyskinesia (involuntary and erratic writhing movements; Parkinson’s Foundation, 2019). Patients with PD may also have problems with fatigue, anxiety and depression as their disease progresses (Scott et al., 2000).

CLD Factors that May Impact Parkinson’s Disease

Linguistic background

Lee Silverman Voice Therapy (LSVT) LOUD®is an evidence-based treatment for patients with Parkinson’s disease. However, the research on the efficacy of LSVT for non-English speakers is still being developed. Different languages have differing syntax (e.g. word order), semantics (e.g. meaning), and prosody (e.g. intonation, tone, stress, and rhythm). Because of this, it is important for clinicians to know how these features may be influenced by PD in assessment and treatment. Although research has demonstrated improvements from LSVT in Cantonese, French, and Portuguese speakers, conversational speech intelligibility was not measured. A recent study of Spanish speakers found that speech intelligibility and functional communication improved significantly with LSVT treatment (Moya-Galé et al., 2018).

Prosody is affected by PD similarly in Cantonese speakers as in English speakers with monopitch, harsh voice, and monoloudness being most severely affected. Voice quality and degree of reduction in articulation may help differentiate between mild and moderate dysarthria from PD (Ma et al., 2009).

The development of cross-cultural adaptations of outcome measures such as the Dysarthria Impact Profile (DIP) may help clinicians measure the psychosocial impact of slight-to-moderate dysarthria in people with PD who are not native English speakers (Cardoso et al., 2018).

Sex differences

Men are diagnosed with Parkinson’s disease about 1.6 times as often compared with women (Lubomski et al., 2014). There are sex-related differences in symptom profile, clinical characteristics, and long-term outcomes. Men with PD tend to have more motor impairment and rigidity, as well as a correspondingly greater need for assistance from caregivers (Miller & Cronin-Golomb, 2010). Men may have greater difficulties with activities of daily living (ADLs), cognition, and communication, despite higher doses of Parkinson’s medication, which have a negative impact quality of life (Lubomski et al., 2014). Verbal fluency and recognition of facial emotions are more often affected in men, whereas visuospatial cognition is more often affected in women.

Women also tend to have more problems with dyskinesia and depression compared to men. There is some evidence that estrogen may have an effect on dopaminergic neurons and pathways in the brain (Miller & Cronin-Golomb, 2010). Overall, PD has been found to have a greater impact on health and well-being in men (Lubomski et al., 2014). Women tend to have a later symptom onset and significantly less motor impairment despite comparable disease duration (Lubomski et al., 2014). Understanding sex differences in PD is important when developing treatment plans for managing PD.

Cultural Bias in the Assessment of Parkinson’s Disease

When evaluating patients with Parkinson’s, it is important to consider that cultural and linguistic factors may affect assessment results.

Cultural bias in smell ID tests

Because Parkinson’s can impact sense of smell, smell identification tests are sometimes used as screeners for PD. However, people from different cultural backgrounds may be less sensitive to certain smells, creating an inherent bias in smell identification tests that may prevent them from being diagnostically valuable. Although culturally specific tests with multiple language formats have been developed, such as those in Spain, Germany, Japan, the United States, and Latin America, no culturally universal olfactory function test has been developed (Rodríguez-Violante et al., 2014). The cultural specificity of smells may preclude the possibility of a single universal smell identification test.

Cultural bias in language testing

When assessing the language abilities of patients with Parkinson’s, SLPs need to be mindful that language testing can prone to cultural and linguistic bias. A New Zealand study examined the potential cultural bias of the Boston Naming Test (BNT) and possible adaptations to reduce this bias (Barker-Collo, 2001). For instance, some “common” items are not familiar to Korean individuals, while some of the “most difficult” items are easily identified by this population. In New Zealand, “pretzel” is a commonly missed item, because this is not a common food there, while “beaver” was often mistaken for “platypus” or “possum,” which are more common to that geographical area (Barker-Collo, 2001). Clinicians should be aware of the potential for high levels of cultural and linguistic bias in standardized language assessments and norms for these assessments should not be used outside of the US or with CLD populations.

Cultural bias associated with facial masking

Hypomimia or “facial masking,” is a common symptom of Parkinson’s disease. Facial masking is the reduction of automatic and controlled expressive movement of facial musculature, creating an appearance of apathy, social disengagement or compromised cognitive status. Ethnic and gender stereotypes and cultural values can influence practitioners’ impressions of patients with facial masking (Tickle-Degnen et al., 2011).

A study of Taiwanese and American healthcare practitioners and patients with Parkinson’s found that practitioners tend to perceive patients with more facial masking to be more depressed, less sociable, less socially supportive, and less cognitively competent (Tickle-Degnen et al., 2011). Masking had a stronger effect on perceived sociability of American patients, but a stronger effect on perceived cognitive competence and social supportiveness of Taiwanese patients. Judgments of sociability, and judgments of cognitive competence and social supportiveness, were more strongly biased by masking in American and Taiwanese practitioners, respectively. Masking had a stronger effect on judgments of women than men, particularly in American patients (Tickle-Degnen et al., 2011). The existing biasing effects of facial masking may be intensified by these interacting patient and practitioner factors. Practitioner cultural and gender biases could negatively impact the therapeutic alliance (SLP-patient relationship) and lead to health care disparities.

Effects of PD on CLD Factors

Effect of PD on patients’ religious cognition

Religious cognition may also be affected in patients with PD as their disease progresses. A pilot study found that patients with Parkinson’s had lower levels of religiosity compared to age-matched controls with non-neurological diseases (e.g. chronic back pain; Butler et al., 2011). Compared to controls, patients with Parkinson’s participated significantly less in private spiritual practices, had less sense of divine forgiveness and ability to forgive, and had fewer positive and negative spiritual experiences. While there was no difference in the amount of positive socioemotional spiritual support these patients received from their religious communities, the community members placed significantly fewer demands on patients with PD compared with controls.

There was also an interacting effect of gender on patients’ religiosity. Men with PD had fewer positive spiritual experiences, lower sense of forgiveness, and lower positive congregational support compared to women with PD (Butler et al., 2011). These findings suggest that regions of the brain necessary for religious experiences are affected by PD. Specifically, the loss of right brain functions involving dopamine may contribute to an overall decrease in religiosity in patients with Parkinson’s.

Family Member Perspective

I am a graduate student at UMD studying to become a speech-language pathologist. Last fall, my father-in-law was diagnosed with Parkinson’s disease at the age of 68. Receiving a diagnosis of Parkinson’s is difficult and scary, not just for the affected individual, but for their family and community as well. My father-in-law, mother-in-law, husband, and I are still learning what it means to live with Parkinson’s disease and the uncertainty that it creates in our lives, even though the initial shock of the diagnosis has mostly worn off. 

Putting together his care team was crucial to managing his Parkinson’s disease. He was surprised that this process was not better organized and found referrals from other patients with PD to be more valuable than resources his physicians were able to provide. Finding a movement disorders specialist, SLP, physical therapist, and the right combination and dosage of medications has been very beneficial. Through intensive speech therapy (LSVT LOUD®), physical therapy (LSVT BIG®), a medication regimen, and the Rock Steady Boxing program through Maryland Association for Parkinson’s Support (MAPS), my father-in-law feels like he is in better shape than before he had symptoms of Parkinson’s. He has seen significant improvements in his speech, functional abilities, and quality of life.

Not every patient with Parkinson’s is so fortunate as to have access to speech-language therapy and other treatments. Even when CLD patients are able to assemble a care team and participate in speech therapy, there may still be added burdens of a language barrier between patient and clinician, coming from a different cultural background, or dealing with cultural and linguistic biases that SLPs may or may not be aware of during assessment and treatment. CLD clients may also come from a culture with a large power distance, therefore the SLP’s position of power as a healthcare provider could create an added barrier for patients and their families. The already challenging experience of living with or having a family member with PD may be made significantly harder if SLPs are not culturally competent. By educating ourselves about the cultural and linguistic factors that influence patients’ experience living with PD, we can become advocates and allies for our CLD patients.

Becoming Culturally Competent SLPs

When treating CLD patients with Parkinson’s disease, SLPs should be aware of how cultural, linguistic, religious and gender differences may impact assessment, treatment, and the therapeutic alliance. Clinical outcomes and the therapeutic alliance will ultimately benefit from increased understanding of these differences. SLPs need to educate themselves about these factors and make appropriate adjustments in assessment and treatment.            

By understanding and considering the factors that make patients with PD diverse, clinicians can provide culturally sensitive care to these patients and their families. Use of ethnographic interviewing techniques, dynamic assessments, and bias-free language assessments will benefit CLD patients with Parkinson’s during assessment. Understanding the sex differences and linguistic variations among patients with Parkinson’s and the potential for clinician cultural or gender bias will enable SLPs to provide culturally responsive treatment. Culturally competent SLPs will also be able to educate patients and their families about the variations in PD progression based on patient-specific CLD factors. Developing cultural competence in treating CLD patients with PD will ultimately help to provide these patients with the best possible care.

Amber Doctrow is part of the the Cultural and Linguistic Diversity program for Speech-Language Pathology students at the University of Maryland. The program aims to broaden students’ understanding of culture and language in order to minimize disparities in service delivery to culturally and linguistically diverse populations. Her clinical interests include early speech and language development and the effects of neurological disorders on speech and swallowing.