Parkinson’s Disease (PD) is a progressive neurodegenerative movement disorder caused by degeneration of dopaminergic neurons in the substantia nigra pars compacta, which results in reduced production of a neurotransmitter named striatal dopamine, and overproduction of alpha-synuclein, resulting in the formation of Lewy bodies.
PD affects 1-2 per 1000 of the population at any time, and its prevalence increases with growing age, inflicting one percent of the population above the age of sixty. The most common form, Idiopathic PD, can be divided into motor and non-motor symptoms. The most common motor symptoms of PD are resting tremors, rigidity, bradykinesia, and stooped posture in the form of postural disturbance. Cognitive dysfunction is prevalent in PD, which is the most common non- motor symptoms, along with insomnia, constipation, anxiety, depression, and fatigue. Presence of α-synuclein has been associated with motor symptoms, while decrease in β-amyloid and tau patholgy has been reported with non-motor symptoms. Patients with PD are mainly divided into two phenotypes based on motor symptoms, i.e. Tremor-dominant (TD) and Postural Instability Gait Difficulty (PIGD).
This figure illustrates the current scenario of a patient’s consultation with a physical therapist. In the above figure, x-axis connotes time, while y-axis denotes amount of dopamine in the body. When the dopamine starts depleting from the body, patients exhibit initial symptoms of stiffness and musculoskeletal pain around the body. The patient then consults an orthopedician, and is prescribed some NSAIDs and muscle relaxant that subside the initial symptoms. This is the neuroprotection stage.
Depletion of dopamine continues, and when it crosses the dopamine threshold line, early signs of PD are noticed. These are soft monotone voice, masked face, slower and smaller movements, mild postural changes, and tremor (50 – 60 %). At this stage, they then consult a neurologist and are diagnosed with PD, where the prescribed medicine will result in complete reversal of the signs and symptoms (the honeymoon effect). This is referred to as neurorestoration stage.
As the honeymoon effect recedes (reappearance of the signs and symptoms), late signs of PD emerge. This include articulation disorders, swallowing difficulties, rigidity, freezing, balance difficulties, postural changes, and difficulties in gait. The patient is then referred to a physical therapist with these signs and symptoms. This is referred to as the compensatory stage.
Early detection of the disease, along with physiotherapeutic intervention during the neuroprotection stage, results in a better prognosis of the disease and complete reversal of signs and symptoms than in the compensatory stage, where the prognosis of the disease is sluggish. Hence, early detection of the symptoms and rehabilitation are essential for the rapid recovery of patients.
Neural Plasticity: The Foundation of Eurorehabilitation
Neural plasticity (NP) is the ability of the brain to repair and reorganize itself. In the past, many scientists believed that the central nervous system (brain and spinal cord) was a permanent tissue. It is hardwired, and cannot change from birth till the time we age. Any injury or damage to the brain was considered permanent. 1990-1999 was named as “the decade of the brain”, during which mammoth amount of research was done on the nervous system. During this period, they recognized the adaptive capacity of the brain and the capability of the nervous system to change its activity in response to intrinsic and extrinsic stimuli by reorganizing its structure, functions, and connections. They found that the basic property of a neuron is to modify the strength and efficacy of a synaptic transmission through a diverse number of activity-dependent mechanisms, typically referred to as synaptic plasticity, or activity-dependent neural plasticity.
Exercise is Medicine
The importance of exercise is now becoming more evident, and people are more inclined towards achieving good health through exercise and physical fitness than by taking medicines. For example, in the case of hyperlipidimia, people opt for exercise to reduce the lipid deposition in the body instead of consuming medicine.
Exercise acts directly on molecular machinery via neurotropic factor expression, neurogenesis, synaptogenesis, pre- and post-synaptic modulation, angiogenesis, suppression of oxidative stress, stabilization of calcium homeostatis, and reduction of inflammation. Exercise produces happy hormones like endorphins and serotonin, which help in the healing of tissues. Exercise results in an increase in neurotropin, named Glial cell line-derived neurotrophic factor (GDNF) in striatum, which initiates a cascade of cellular events responsible for protecting vulnerable neurons, however, not the neurons that perish (Zigmond et al 2009). Repetitive activity will increase synaptic strength and synapses number of map reorganization for better behavioral outcomes (Adkins et al., 2009).
Rehabilitation Implications in case of Parkinsonism
The primary motor characteristics in PD are rigidity, tremors, bradykinesia, hypokinesia, and postural instability. Among these symptoms, bradykinesia (reduced ampiltude of movement), hypokinesia (slowness of movement), and kinesthetic awareness (sensory deficits) are the most important basis for Lee Silverman Voice Treatment BIG (LSVT BIG). In case of PD, the internal generated movements are impaired, hence, the patients will not be able to formulate the movement themselves until and unless the external cues are provided. Deficits are normalized when attention is focused on cues related to planning the amplitude of movement (external or attention). This indicates that the neural substrate required for normal movement exists in patients with PD (Morris et al., 1994).
With PD patients, various signals become weak, i.e.
- a) GET Ready signal is too weak
– Inadequate preparation / anticipation for movement
– Clinical: bradykinesia / hypokinesia
- b) GO signal is too weak
– Inadequate selection/initiation of a movement
– Clinical: freezing/start hesitation
- c) NO GO signal is too weak
– Inadequate completion of a movement
– Clinical: festination and
sequential movements are more difficult/run together
(Nambu et al., 2002)
External cues have been shown to be effective in triggering sequential movements and improving movement characteristics in individuals with mild to moderate PD. External cues appear to facilitate movement by utilizing different brain areas. The premotor cortex is active in the generation of movement in response to visual or auditory stimuli. Normally, the supplementary motor area (SMA), with inputs from the basal ganglia (BG), is involved in the initiation of self-generated movements and the performance of well-learned, repetitive movement sequences. PD patients have a disruption of internal cues or trigger for movements and do not self-initiate the movement due to under activation of SMA. External cues heighten the patient’s attention through a common mode of action, that is, to bypass the diminished internal cueing of the BG.
PD patients cannot self-monitor and self-correct their under-scaled movements because of the sensory integration deficits, which interfere with the movement plan, body orientation, and error detection capabilities (Vaugoyeau et al., 2007).
Factors interfering with normal movements in PD
- a) Sensory motor deficits
– Reduced activation for
internally generated movement
– Sensory proprioceptive processing problems
– Perceptual sensory-motor mismatch
- b) Cognitive-executive function and attentional deficits
– Inadequate preparation for movement
– Divided attention/ adapting to environmental conditions
- c) Emotional-motivational deficits
– Reduced vigor, implicitly choose small/slow
movements, loss of self- efficacy, default to low energy, despite greater capacity.
All these above factors can be addressed properly via LSVT BIG treatment protocols.
Lee Silverman Voice Treatment BIG (LSVT BIG)
Recent advances in neuroscience have suggested that exercise-based behavioral treatments may improve function, and possibly slow progression of motor symptoms in individuals with PD. The LSVT program for individuals with PD has been developed and researched over the past 20 years, beginning with a focus on the speech motor system (LSVT LOUD), and more recently has been extended to address limb motor systems (LSVT BIG).
LSVT BIG is an intensive amplitude-based program for the limb motor system. It helps in re-education of the sensori-motor system by recalibrating the sensory perception. It is administered in an intensive manner to challenge the impaired motor system. It is performed as a high intensity exercise of 8/10 RPE in Borg’s Scale. LSVT BIG provides the rationale for early intervention that promotes intensive and continuous exercise (Inactivity is pro-degenerative).
LSVT is a unique program that includes a combination of:
- a) An exclusive target on increasing amplitude (loudness in the speech motor system; bigger movements in the limb motor system),
- b) A focus on sensory recalibration to help patients recognize that movements with increased amplitude are within normal limits, even if they feel “too loud” or “too big,” and
- c) Training self-cueing and attention to action to facilitate long-term maintenance of treatment outcomes.
LSVT BIG focuses on the strategies of:
- Neuroprotection: It is the ability to prevent degeneration of neurons during progression of disease. Potentially, this strategy could also restore lost function.
- Disease modification: It includes improvement in rate of progression of disability, and independent of impact on survival of dopaminergic neurons.
LSVT BIG is a thorough standardized protocol that targets large amplitude whole body movement. The protocol includes treatment for four consecutive days per week for four weeks (i.e. 16 sessions in a month) with a treatment period of 60 minutes per session. Daily carryover assignments and homework are given every day for 30 days. LSVT BIG adheres to the principal of neuroplasticity, where intensity within the exercise should be of high effort, large amplitude, repetitive, complex, and salient.
- Maximal Daily Exercise
- Floor to ceiling – 8 reps
- Side to side – 8 each side
- Forward step – 8 each side
- Sideways step – 8 each side
- Backward step – 8 each side
- Forward rock and reach – 10 each side (working up to 20)
- Sideways rock and reach – 10 each side (working up to 20)
- Functional Component Tasks:
- a) Five Everyday Tasks –5 reps of each
– Sit to stand
– Pulling the keys out of pocket
– Opening cabinet door
- b) Walking BIG
– Distance /time may vary
- c) Hierarchy tasks
- Patient identified tasks
– Getting out of bed
– Playing golf
– In and out of car
- Build complexity across four weeks of treatments towards long-term goals
Parkinson Wellness Recovery! Moves (PWR!Moves)
Recent advances in basic and clinical science research suggest that exercise and learning approaches may protect, repair, and optimize function in persons with PD. PWR!Moves are building blocks for everyday movement and involve the performance of whole body large amplitude, “big” movements in multiple postures (e.g. prone, supine, all 4’s, sitting, standing). The basic four PWR!Moves are PWR! Up, PWR! Rock, PWR! Twist, and PWR! Step, that are taught as essential functional exercises that target the primary symptoms of PD, i.e. bradykinesia, rigidity, and incoordination. They provide the repetition and specificity of training for people with PD and can be scaled up or down as per the severity of the disease, integrated into function/ADL/lifestyles, implemented across disciplines (occupational therapist/physical therapist/speech language and pathologist) and settings (therapy and community), and reinforced in other exercise programming (e.g. treadmill, cycling, pole walking, yoga, boxing, dance, Tai Chi etc.)
Exercise4BrainChange (E4BC) helps to guide the clinicians to implement essential principles of learning and neuroplasticity identified in the literature to real world practice. Techniques are described to advocate forced use, progressive difficulty, reinforcement, active engagement, empowerment, attention to action, sensory awareness training, and neural readiness (e.g. aerobic conditioning, mental imagery). Each of these principles is rooted in research in exercise, science, motor control, and motor learning.
E4BC framework applied to PWR!Moves allow for a comprehensive PD specific approach that can target the multiple motor, sensory, cognitive, and emotional symptoms of PD. PWR!Moves are building blocks of function that underlie all meaningful activities, including sports and recreation. Any movements that require lifting the whole body (trunk and limbs) against gravity counteract the stooped posture of PD. They actively stretch the flexor muscles on the front of the body and strengthen the extensor muscles on the back of the body. Better alignment improves your ability to be ready to get movement started on the first attempt and to recover your balance. Returning to this position (reset) between actions improves the speed and accuracy of your everyday movements. Adding PWR!Arms and PWR!Hands (PWR!Reach) further enhances posture of head and shoulders, interacts with trunk motion for dynamic balance, and improves ability to manipulate tools or objects while doing chores or hobbies. The body follows the arms, so PWR!Reach to go and PWR!Reach to hold yourself up.
PWR!Moves is more than just exercising, it is a philosophy to live your life better in presence of PD. PWR!Moves exercises specifically targets four skills shown by research to interfere with mobility in people with PD (anti-gravity extension, weight shifting, axial mobility, and transitional movements).