About Parkinson's Disease
WHAT IS PARKINSON DISEASE (PD)
Parkinson disease is a progressive neurodegenerative disease that is categorized as a movement disorder but the disease includes many non-motor symptoms. There is no cure as of today for PD and current treatments help with the PD symptoms but do not prevent or delay the disease.
Over one million Americans and an estimated eight million people worldwide, currently live with PD. PD effects 1 in 100 Americans over the age of 60. It is reported that there are nearly 50,000 new cases are diagnosed each year in the USA and prevalence surveys have found that 35-42% of cases in the general population go undiagnosed. The prevalence of PD will increase substantially in the next 20 years. By 2030, the number of people with PD is expected to double. The average age of onset is approximately 62 years old; however, up to 10% of persons with PD are diagnosed before the age of 40.
There is not a definitive test available today to diagnosis PD; rather, it is diagnosed on the basis of clinical history and findings of a neurological exam. Parkinsonism is the term applied to a group of physical symptoms of resting tremors, slowness of movement (bradykinesia), rigidity of muscles, and instability of posture and walking. The presence of at least two of these cardinal signs is necessary for the definitive diagnosis of PD. The variety and severity of symptoms vary from person to person. Symptoms typically appear insidiously on one body part or side of the body but progress to affect the entire body over time.
CARDINAL PHYSICAL SYMPTOMS
It is important to understand the physical features of PD in order to plan an exercise program specifically designed to aid in decreasing or combating these symptoms. Let’s take each symptom one at a time.
Resting Tremor: Resting tremors are by far the most recognizable of all PD features. Tremors are seen in approximately 75% of PD cases. Tremors are evident at rest and decrease with purposeful movement. Tremors can initiate in one body part such as the fingers, hand, foot, arm, leg, jaw or tongue and are typically asymmetrical. It is not typical to see tremors in the head or neck. Tremors can increase with walking, stress, and anxiety; they usually disappear during sleep.
Rigidity: Rigidity is an involuntary increase in muscle tone that results in continuous resistance to passive movement. It has been described by some patients as internal resistance to movement. I have had other patients compare it to trying to move through mud. Rigidity superimposed with tremors results in a ratchet type of resistance to passive movement described as “cog-wheel” rigidity. It feels like a continuous catch-release when trying to passively move a limb (arm/leg).
Bradykinesia (Slowness of movement)/Freezing: Bradykinesia is a very significant feature of PD that affects all aspect of movement, including walking, crossing the street, dressing, putting on shoes, bed mobility, getting out of a car, food preparation, eating, brushing teeth, etc. There can also be a progression from slow moving to having some difficulty initiating movement. One study suggests that step initiation correlates with sensory information from the basal ganglia. Since this sensory feedback loop is disturbed in PD, you may require external cues to achieve appropriate functional movement. The difficulty with initiating movement comes into play with changing directions with walking or turning corners. Freezing episodes can also occur. The freezing phenomenon is when you are truly frozen and virtually unable to move. Some people describe their freezing episodes as “feeling like my feet are glued to the floor.” Many scenarios can trigger freezing episodes. Some common triggers include crossing thresholds, turning corners, surface changes such as carpet to multicolor or non-uniform tile patterns, as well as entering or exiting elevators and escalators.
Postural Instability: The loss of postural reflexes and the associated inability to make rapid postural corrections can also lead to declining gait and falls. Your reflexes and ability to catch yourself following loss of balance are either absent or too impaired to avoid a fall. If your balance gets offset backwards, you would basically fall like a cut tree. Essentially if your balance is offset, you may not be able to recover, so prevention is the key. Posture plays one of the most significant roles in both risk and prevention of falls. The more that you are able to keep your center of gravity over your base of support (your legs), the less likely you are to fall. For this reason, the suggested exercise programs presented later will be focused on posture and purposeful movements.
NON MOTOR SYMPTOMS
PD is described as a movement disorder; however, people with PD also experience non-motor symptoms such as constipation, loss of taste and smell, sleep disorders, micrographia (small hand writing), microphonia (softness or low tone of voice) and others.
The treatment of PD requires many modalities and a multi-disciplinary approach that includes a neurologist, primary care physician, physical and speech therapy and possibly a neurosurgeon. Exercise and medications are two of the most beneficial strategies to assist in staving off the physical symptoms of PD. Animal studies have shown that physical activity can be neuro-protective. Medications typically work very well in the early stages but as the disease progresses, there are typically drug related complications including on/off motor fluctuations and medication side-effects. Deep Brain Stimulation (DBS)is also a consideration/standard of care. DBS is a FDA approved therapy for PD when medications no longer adequately control motor symptoms including dyskinesias and motor fluctuations. DBS is a sort of pacemaker for the brain that assists in controlling the motor symptoms of PD including reducing or eliminating tremor, akinesia (freezing), bradykinesia, and rigidity. DBS is non-destructive and is reversible.
ADAPTED/REPRODUCED WITH PERMISSION FROM:
MOVE IT! An Exercise and Movement Guide for People with Parkinson’s Disease
By: Kevin Lockette PT
Langdon Street Press