Swallowing And Speech
Parkinson’s disease is a neuro-degenerative disorder of the central nervous system (Miller, Noble, Jones & Burn, 2006). It is a progressive disorder that affects muscle control and movement.
It occurs as a result of insufficient levels of the chemical Dopamine produced from the substantia nigra, located in the midbrain portion of the brain (Miller et al., 2006). This occurs due to the death of Dopamine generating cells.
The cause of this cell death is unknown. Parkinson’s disease is often referred to as idiopathic, meaning it has no known cause.
The Role of Dopamine in Parkinson’s Disease
Dopamine is a vital chemical messenger that services communication between the substantia nigra and corpus striatum sections of the brain. When functioning normally, this communication leads to smooth and balanced muscle movement. When not enough Dopamine is produced (i.e. in Parkinson’s disease), communication signals are lost, leading to reduced control of motor movements (Brookes, 2008).
Statistically, Parkinson’s disease is the second most common neurodegenerative condition in Australia (Mehta, Kifley, Wang, Rochtchina, Mitchell & Sue, 2007). It is estimated that approximately one in 350 Australians are diagnosed with Parkinson’s disease. According to Deloitte Access Economics, as of 2011, 64,000 Australians were living with Parkinson’s disease; of which, 20% of people affected were of working age (DAE, 2011). Parkinson’s disease affects both men and women, 52% and 48% respectively. Approximately 80% of people living with Parkinson’s disease are over 65 years of age. The health, lifestyle and financial burdens associated with Parkinson’s disease are significant (DAE, 2011). Access Economics, 2011, estimates that in Australia approximately 50,000 years of healthy life are lost every year due to the effects of Parkinson’s disease. The number of people diagnosed with this condition has grown by 17% in the last six years (DAE, 2011). Overall health costs have also increased by over 48%. It is estimated that a person with Parkinson’s disease will spend about $12,000 per year on healthcare out of their own pockets (DAE, 2011).
Parkinson’s Disease Symptoms
The signs and symptoms of Parkinson’s disease are varied. The key motor symptoms consist of four motor presentations, specifically: tremor, rigidity, bradykinesia (slowness of movement) and postural instability (Poewe, 2009).
Tremor is the most common symptom, usually observed when a person is at rest. It involves oscillations or twitching of one or more body parts (i.e. arm, hand or leg). It becomes more apparent as the disease progresses (Xia & Mao, 2012).
Rigidity is tautness and inflexible resistance to upper and lower limb movement caused by increased muscle tone. One of the initial signs of Parkinson’s disease is joint pain associated with stiffness of the muscles (Xia & Mao, 2012).
Bradykinesia, or slowness of movement, is associated with difficulties planning, initiating and executing muscle movement. Bradykinesia can directly affect participation in everyday tasks involving fine motor control (i.e. dialling a phone number, getting dressed and writing) (Xia & Mao, 2012).
Postural Instability tends to occur in the later stages of disease progression. This can lead to impaired balance and falls. Parkinson’s disease is also characterised by other motor symptoms, including festination (rapid shuffling steps) and changes to gait (Poewe, 2009).
In addition to the motor changes involved with Parkinson’s disease, this condition can affect neuropsychiatric functions. This includes disorders of speech, behaviour, mood, thought and cognition (William-Gray, Foltynie, Lewis & Barker, 2006). Cognitive deficits usually manifest as difficulties with executive function such as, planning activities, memory, abstract thinking, flexibility of thought and self regulation (William-Gray et al., 2006).
89% of people with Parkinson’s disease have difficulties with voice and speech (Ramig, Fox & Sapir, 2008). Motor speech disorders occur as a result of neurological injury to the motor speech system. Dysarthria is a motor speech disorder characterised by changes to the subsystems of speech affecting respiration, resonance, prosody, phonation and articulation (Colton & Caspar, 1996). Dysarthria results in abnormalities in strength, speed, range, tone or accuracy of speech movements (Duffy, 2005).
Hypokinetic dysarthria is a form of dysarthria commonly seen in people with Parkinson’s disease (Duffy, 2005). Hypokinetic dysarthria is associated with neurodegenerative changes resulting from basal ganglia control circuit dysfunction (Duffy, 2005). Speech is characterised by slow individual movements, reduced pitch and loudness, as well as reduced force and excessive tone (Duffy, 2005). Paradoxically, speech can also become fast, accelerated and repetitive. Vocal qualities can be affected by changes to respiration, phonation and prosody. Specifically, patients with Parkinson’s disease often present with voice changes characterised by reduced loudness and stress, monopitch, monoloudness and breathiness (Ramig, Fox & Sapir, 2008).
Eating and swallowing are complex neuromuscular activities consisting essentially of three phases: an oral, pharyngeal and oesophageal phase. Each phase is controlled by a different neurological mechanism. The oral phase is voluntary (i.e. biting and chewing). The pharyngeal phase of the swallow is initiated after the oral phase and is coordinated by the swallowing centre of the brain (located in the medulla oblongata and pons) (Miller et al., 2006). The swallow reflex is controlled by the autonomic nervous system during the pharyngeal and oesophageal phase (Miller et al., 2006).
Successful swallowing results in the transference of food from the mouth to the stomach, whilst protecting the airway. Any difficulties or disruption in the sequence of the swallow can lead to adverse consequences. The term ‘Dysphagia’ means difficulty swallowing (Logemann, 1997). Dysphagia can refer to difficulties at any stage of the swallowing process. This includes chewing, control of food in the mouth, initiating and controlling the pharyngeal phase of the swallow.
Research regarding the specific swallowing changes associated with Parkinson’s disease indicates deficits at both the oral and pharyngeal phases of the swallow (Miller et al., 2006). Oral phase difficulties include disturbed lingual motility resulting in prolonged oral transit time, difficulty with bolus formation and poor anterior to posterior transfer of bolus (El Sharkawi, Ramig, Logemann, Pauloski, Rademaker, Smith, Pawlas, Baum & Werner, 2002). Significant difficulties with dry mouth may also occur due to the side effects of PD related medications (e.g. L-DOPA – Levadopa) (Brooks, 2008).
Oropharyngeal bradykinesia and rigidity, incomplete cricopharyngeal relaxation, reduced cricopharyngeal opening and delayed initiation of the swallow reflex have been suggested as possible features of dysphagia in patients with Parkinson’s disease (Baijens and Speyer, 2009).
Difficulties swallowing can begin in the early stages of Parkinson’s disease and can lead to adverse medical and psychosocial outcomes (Baijens & Speyer, 2009).
Aspiration is a term that refers to foreign particles entering the trachea (windpipe). In healthy individuals, aspiration symptoms may occur (e.g. coughing after drink) – usually without negative health outcomes. In persons with Dysphagia, the risk is heightened due the consistency of difficulties associated with the swallow function. Depending on the nature and severity of the dysphagia, a person may have difficulty swallowing foods and/or fluids (Baijens & Speyer, 2009).
Dysphagia has been linked to the development of dehydration, malnutrition, chest infection and pneumonia (Baijens & Speyer, 2009). Aspiration pneumonia is a pulmonary infection that can develop as a result of foreign particles in the bronchial tree (i.e. a result of aspiration). The nature of particles aspirated can heighten the risk of developing aspiration pneumonia (e.g. chemical or bacteria). The development of infection depends on the nature of the aspirant, the overall health of the individual and the function of the airway defence mechanism (Logemann, 1997).
Research indicates that the psychosocial consequences of swallow dysfunction secondary to dysphagia are significant for people with Parkinson’s disease (Miller et al., 2006). Studies show that dysphagia leads to alteration of eating habits, loss of mealtime enjoyment due to slowness, changed diet, feelings of stigma and sadness and the need for social adjustment (Miller et al., 2006). Research identifies that further concerns are linked to the impact on those caring for a person with Parkinson’s disease (Miller et al., 2006); specifically, the drain on time and energy with preparing meals, the disruption of family life, reduced social interaction (e.g. not having people over for dinner), separate food preparation (i.e. texture modified diets) and the extended time required to complete meals (Miller et al., 2006).
Parkinsons Disease Treatment
Lee Silverman Voice Treatment (LSVT)
The Lee Silverman Voice Treatment (LSVT) is a specific intervention program designed to meet the communication needs of individuals with Parkinson’s disease (Fox, Morrison, Ramig & Sapir, 2002). This approach is also used across other areas of adult rehabilitation including physical and occupational therapy. Research indicates that this intensive management approach to treatment leads to positive patient outcomes (El Sharkawi, Ramig, Logemann, Pauloski, Rademaker, Smith, Pawlas, Baum & Werner, 2002). The purpose of this therapy program is to encourage people to concentrate on loudness as a means to facilitate communication. LSVT specifically focuses on speaking louder through optimal breath support, posture and pitch in order to optimise speech intelligibility (Trail, Fox, Ramig, Sapir, Howard & Lai, 2005). LSVT is also aimed at enhancing vocal and motor speech output in order to integrate loudness into functional communication (Ramig, Fox & Sapir, 2008).
A key feature of the LSVT program is the intensive nature of intervention in which the patient is treated over a course of four weeks during 16 one-hour sessions. Additionally, the program includes home practise tasks that are incorporated into daily carryover exercises. It utilises high intensive speech exercises to integrate into functional daily activities (Fox, Ramig, Ciucci, Sapir, McFarland & Farley, 2006).
Dysphagia may require ongoing management as the disease progresses. Assessing dysphagia usually consists of a Speech Pathologist taking a full medical history; discussing with family members or other staff members regarding current eating patterns or difficulties; assessing the nerves and muscles required for swallowing; observing the person eating and drinking a range of different textured food and fluids; and, where deemed necessary, referring the person for a scan of the swallow – known as a Modified Barium Swallow (Logemann, 1997).
Treatment strategies are personalised to meet the needs of each individual (Logemann, 1997).
Treatment options may include:
- Modifying the thickness of drinks to increase control of fluids
- Mincing or softening food textures
- Reducing the size of mouthfuls
- Adjusting seating and utensils for eating (in conjunction with occupational therapy and physiotherapy recommendations)
- Allowing extra time for meals
- Specific rehabilitation exercises for swallowing as specified by the treating Speech Pathologist
If the type of dysphagia is considered to be severe, a Speech Pathologist may recommend that a person stop eating and drinking (termed ‘Nil by Mouth’). This should be a team decision in the best interest of a person’s health (Logemann, 1997). If it is deemed to be a longer term management option, alternative methods of feeding are considered and implemented to maintain nutrition and hydration (i.e. Nasogastric or PEG feeding).
Management should include education for the person with dysphagia and their family and friends to ensure the whole team is equipped to support optimal management.
If you or a family member need assistance and treatment for Parkinson’s disease contact your local doctor, who will arrange for you to see a speech pathologist. We‘ll provide you with a straightforward, efficient and very effective treatment plan targeted to your concerns.
Written by Jenna Butterworth and Eugene Pillay (June 2013)
ENT Wellbeing Sydney
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