As Parkinson’s progresses, some symptoms increase in intensity, others may appear for the first time. In this feature, we ask clinicians and researchers to comment on a few of these.
Swallowing problems are common in Parkinson’s and may occur with varying degrees of severity early in the disease, not just as Parkinson’s advances.
Signs of swallowing problems include:
- difficulty with manipulating and forming a food bolus (ball)
- sensation that food is stuck in throat
- difficulty swallowing solids
- coughing when eating or drinking
- wet or gurgly voice
- eating takes longer
- recurrent chest infections
- weight loss
Swallowing difficulties may also exist with no overt signs. People are often not aware of their swallowing problems because of the sensory and other deficits associated with Parkinson’s. “One of the insidious things about Parkinson’s is silent aspiration where food or liquid enters the airways and goes into the lungs without any signs or symptoms. There’s no coughing.” says Dr. David McFarland, a professor in the School of Speech Therapy and Audiology at the University of Montreal and a speech-language pathologist.
“The possibility of this developing into aspiration pneumonia depends on such factors as the overall health of the person, the degree of oral care and the presence of food or liquid in the lungs.” Poor oral hygiene, associated with the difficulty people have brushing their teeth, often means that bacteria in the mouth gets swallowed and ends up in the throat, airway and lungs. Aspiration pneumonia is a major cause of death in Parkinson’s.
Swallowing problems can have major impacts on quality of life. When eating is no longer easily enjoyable, people begin to eat less or not at all, leading to poor nutrition and weight loss. People may also severely limit their socializing as it relates to meals.
If people with Parkinson’s or family members suspect a swallowing disorder, the first step is to see the family physician for a referral to a speech-language pathologist for an evaluation.
The speech-language pathologist will do a clinical assessment of swallowing and may conduct the modified barium swallow study (MBSS), which is the gold standard test for evaluating problems with swallowing. The test X-rays swallowing as the person eats and drinks. “We look at such things as the timing of the swallowing, airway protection – whether food or liquid is entering the airway, and how much food is left behind in the mouth and throat after swallowing.” says Angela South, speech-language pathologist at the University of Western Ontario, London, Ontario. “That’s important to know because people may not report any changes or manifest any symptoms but when we X-ray them, we find these problems hiding underneath the surface.”
An alternative test of swallowing, the fibre endoscopic evaluation of swallowing (FEES), uses an endoscope to see what happens to food and liquid as the person swallows.
Since Parkinson’s medications do not appear to alleviate swallowing problems and deep brain stimulation surgery may worsen swallowing for some people, the classic approach to managing swallowing problems is to work with changes in posture and behaviour in order to make it easier to swallow and reduce the risk of aspiration. Diet modification – for example, changing food textures, thickening liquids, softening food – may eventually be necessary if swallowing worsens. The speech-language pathologist will develop a customized program to make swallowing as safe as possible, to reduce the risk of infection and complication, and to maximize quality of life.
Efforts are also being made to improve the underlying impaired physiology of swallowing through behavioural interventions such as:
- Tongue exercises: However, not all researchers agree that lingual strength is affected in Parkinson’s.
- Expiratory muscle strength training: Strengthening the muscles used in coughing. A small 2009 study by Dr. Christine Sapienza, professor and chair of the Department of Communication Sciences and Disorders at the University of Florida showed that cough improved.
- LSVT (LOUD): A voice treatment that was developed to improve communication for people with Parkinson’s and has been shown, in a small study, to improve swallowing. “It targets some of the underlying problems that are present for both voice and speech,” says McFarland who is also vice-president and co-founder of LSVT Global Inc. The intervention needs to be intensive, targeted and functionally relevant.
- Gum chewing: Recent research from the NPF Centre of Excellence at London Health Sciences Centre found that when people with Parkinson’s chewed gum they were able to control their saliva better, so they reduced drooling, had an easier time talking because there wasn’t saliva pooled in their mouth, and reduced the number of choking and coughing episodes they had with their saliva. Angela South, who was a researcher on the original project is now taking it a step further to see what impact gum chewing has on the swallowing mechanism. “We will X-ray the swallowing while people are chewing gum, have them rest for a few minutes and then measure it again to see if there is any carryover effect.”
Proper management of swallowing problems requires a multidisciplinary approach and usually requires the services of a registered dietitian for balanced nutrition and suggestions on ways to make modified diet foods appealing. Also required is an occupational therapist for recommendations on ways to improve the eating environment. A social worker may be able to assist people with making social adjustments to their changing dietary needs and habits.
Psychosis is abnormal thoughts and perceptions. In Parkinson’s, the most common symptom is hallucinations – usually visual, but sometimes auditory, olfactory (smell) or tactile. It can sometimes progress to the point that people become paranoid and delusional, for example, thinking that a spouse is having an affair or that there’s someone in the house trying to steal things.
“On average, 50% of Parkinson’s patients may experience psychosis at some time in their lives. It is more common as the disease advances,” says Dr. Susan Fox, associate professor of neurology at the University of Toronto and a neurologist at the Movement Disorders Clinic at Toronto Western Hospital.
Dr. Fox says a large proportion of the 50% may have mild, benign or minor visual hallucinations. “On going to sleep or waking, they may see a person or an animal in their bedroom and it doesn’t distress them. Those patients may not need treatment specifically. However, for a smaller number of people, the psychosis will be disabling, particularly if it includes delusion or paranoia, and will require more care. The prevalence of disabling psychosis has been linked to hospitalization and nursing home admission.”
Risk factors for psychosis include cognitive impairment, including dementia, and REM sleep behaviour disorder, a condition where people shout, move around, hit and physically act out their dreams at night. People with Parkinson’s who get urinary or respiratory infection are also more at risk of getting delirium with these infections.
Dr. Fox notes that, because psychosis tends to occur when people are on medication, it was previously thought to be just due to drug side-effects. Now, it is considered to be part of the disease process. “It’s the disease itself that primes the brain to be sensitive to medications which can trigger the symptoms.”
If individuals or family members become aware of psychosis symptoms, the first step is to tell the family doctor. The doctor can determine if there is an infection or other underlying medical problem that needs to be addressed first and then decide if the symptoms require treatment or not. “There is evidence that sometimes if you treat these symptoms early, they may not progress as much,” says Dr. Fox. “Once hallucinations start, there is the risk that they may go dormant but be triggered in the future.”
If there has been a recent increase in dosage or change in medication that seems to correlate with the onset of the psychosis, the doctor may recommend reducing the dose or stopping the drug. This could bring improvement in the psychosis symptoms but at the expense of worsening some of the motor symptoms.
There are currently two lines of treatment for psychosis in Parkinson’s: The first class of drugs is the atypical anti-psychotics. The most common one is quetiapine. If quetiapine doesn’t help, then clozapine is prescribed. However because it has a slight risk of causing a low white blood cell count, the patient’s blood has to be monitored weekly. The second group of drugs is the cholinesterase inhibitors. They are used in both people with Parkinson’s with dementia and people without dementia who have visual hallucinations. Researchers are working on developing new drugs to address psychosis in Parkinson’s without worsening the motor symptoms.
Dementia and Mild Cognitive Impairment in Parkinson’s
Dementia is a general term used to describe a variety of changes in cognitive functioning. Because different brain structures are affected by different types of pathology, Parkinson’s disease dementia tends to differ from Alzheimer’s-type dementia both in progression and overall pattern, particularly early in the dementia. “For example, severe language impairment, comprehension difficulties and rapid forgetting are less likely to occur early on in Parkinson’s disease,” says Dr. Alex Tröster, a professor in neurology at the University of North Carolina and co-director of the National Parkinson Foundation Center of Excellence in Chapel Hill, North Carolina.
Dementia in Parkinson’s disease is linked to advancing age, lower education, postural instability and gait impairment, among other factors. Nearly 30% of people with Parkinson’s will develop dementia.
Dementia with Lewy bodies is related to Parkinson’s dementia. Both are considered to be Lewy body dementias and synucleinopathies (diseases caused by the deposition of alpha-synuclein protein in nerve cells). “They seem to share a similar pathology but possibly different parts of the brain are affected at different times,” says Dr. Tröster.
The clinical difference between Parkinson’s disease and dementia with Lewy bodies is that:
- The diagnosis is Parkinson’s disease dementia when the Parkinson’s is diagnosed first and at least 12 months have elapsed before the dementia emerges.
- The diagnosis is dementia with Lewy bodies, if the cognitive and behavioural changes either precede or accompany the first year of parkinsonian symptoms.
“People with Lewy body dementia seem to experience hallucinations and fluctuations in attention earlier in the disease,” says Dr. Tröster. Risk factors for Lewy body dementia include sensitivity to hallucinations and REM sleep behaviour disorder.
Dr. Tröster recommends that, “When the person with Parkinson’s is having a lot of arguments with family members about whether there is a serious cognitive problem or not, then you need a referee. Be aware of the changes, don’t deny them. Seek an assessment. Neuropsychological evaluation can be helpful.”
Researchers are investigating whether medications like memantine and cholinesterase inhibitors are effective in Parkinson’s disease dementia. In Canada, cholinesterase inhibitors are currently used. Another area of research is developing assessment tools so clinicians can more accurately distinguish Parkinson’s dementia from other dementias.
Mild cognitive impairment
Some people with Parkinson’s may experience milder cognitive changes that can remain relatively stable for a long time. Studies looking at cognitive impairment early in Parkinson’s disease are finding that when neuropsychological testing is done at the time of diagnosis, it is possible to detect very subtle or mild changes that may or may not be obvious to the person with Parkinson’s or the caregiver.
Recent research is also attempting to classify mild cognitive impairment in Parkinson’s. Dr. Tröster notes that the few published studies, to date, agree on two things:
- People with Parkinson’s with mild cognitive impairment more commonly have cognitive impairment in a single area of functioning rather than multiple areas; and
- Non-memory impairment – especially difficulty with attention and abstract thinking – is more common than memory impairment.