The diagnosis of PD is based on clinical history and examination as there is no objective test that offers acceptable sensitivity and specificity in early disease. The cardinal features of PD include rest tremor, rigidity, bradykinesia and postural instability^1,2,3. Proposed criteria for diagnosis require the presence of at least tremor or bradykinesia.  Motor symptoms in PD typically begin unilaterally and progress slowly over time.  Asymmetric findings at onset could be the unilateral presence of rigidity noted when the examiner moves the arm or leg, tremor on one side of body (arm or leg), or decreased arm swing while walking.

Clinical pearl: This asymmetry in onset is very helpful to differentiate mild symptoms of slowness and stiffness from that of aging as significant asymmetry is not expected to be present in aging alone.

Tremor is the most easily recognized symptom and is present in 70-80% of PD patients.  In the majority of patients this is a slow, 3- 5 hertz tremor at rest that improves with movement of the body part. It is often asymmetric and initially is present in the arm, leg or chin.  This is in direct contrast to essential tremor for which PD tremor is often misdiagnosed.  Essential tremor (ET) is a higher frequency, 7-14 Hz,  tremor noted with action or holding a posture⁴. On examination or observation, ET will worsen with eating and writing and not be noted with the patient quietly sitting in the chair.  Parkinsonian tremor on the other hand is noted at rest (while a patient is holding or resting arms quietly on their lap or by their side) and is reduced with movement such as daily activities of eating, writing and holding the newspaper. As noted above, other distinguishing features of parkinsonian tremor include unilateral onset, tremor in the leg while sitting and tremor in the chin or lower face. Distribution of tremor differs for essential tremor in that it tends to begin more symmetrically and is noted predominantly in the hands or arms, head or voice.  It is unusual to find essential tremor in the legs.

Clinical pearl: Stress exacerbates motor symptoms of Parkinson's including tremor.  Examine the patient for tremor while sitting quietly in a chair and performing a challenging task such as serial 7 calculations.

Additional features of PD include bradykinesia or akinesia defined as slowness of movement and slowness or difficulty initiating movement, respectively.  Rigidity is defined as a velocity independent increase in tone (unlike spasticity which is velocity dependent meaning it worsens with faster movements) and can be associated with cog-wheeling or a ratchety feel to movement when examining the limbs. In addition to tremor, bradykinesia and rigidity, findings at initial evaluation can include loss of smell, decreased arm swing while walking, difficulty getting out of a chair, micrographia or small handwriting, and masked like facial expression. Characteristic gait problems include flexed posture, and shortened stride length especially on the side affected most by PD. Only mild gait problems should be noted early in disease, however, since significant gait difficulties do not occur at onset but emerge as the disease advances.  In fact, the presence of early postural instability, gait problems and falls suggest an alternative diagnosis.  Additional features that suggest an alternative diagnosis include rapid progression, early autonomic (orthostatic hypotension, sexual dysfunction or neurogenic bladder) or cognitive dysfunction, symmetry of onset, and lack of tremor.

Clinical pearl: Other early symptoms of PD include micrographia or small handwriting, masked like face observed as a loss of spontaneous facial expression and reduced sense of smell. Balance problems in early Parkinson's disease suggest an alternative diagnosis or search for other cause of imbalance such as peripheral neuropathy or musculoskeletal difficulties.

Less common alternative forms of  parkinsonism seen in the primary care setting  include drug induced parkinsonism, Multisystem Atrophy, Progressive Supranuclear Palsy, vascular parkinsonism and normal pressure hydrocephalus. The differential diagnosis of atypical parkinsonism is well outlined in the literature and the reader is referred to reviews by Adler and Christine et. al as well as The American Academy of Neurology Practice Parameter: Diagnosis and prognosis of new onset Parkinson disease for more information^3,5,6 . Of all the forms of atypical or secondary parkinsonism, drug induced parkinsonism is of greatest interest to nursing professionals.  Drug induced parkinsonism is most commonly caused by dopamine blocking agents such as antipsychotics and antiemetics^7.8. These medications are commonly used in the acute care and nursing home setting and should be avoided in PD as they can worsen motor symptoms. It is important to note that although typical antipsychotics are most commonly associated with drug induced parkinsonism, the newer atypical agents can cause parkinsonism especially at higher dose.

"I can't pick up my feet when I walk."

As a nurse you are often called upon to fill in clinical care gaps, providing important education, awareness and advocacy for your patients.  Parkinson's disease is a progressive disorder that changes over time. Be proactive and prevent problems before they occur. In this article we will review disease progression to better understand how motor symptoms change and identify a problem or risk before it occurs.

Motor symptoms progress slowly over many years^2,3.   As noted above symptoms typically begin on one side of the body but do eventually 'spread' to the other side.  Tremor, rigidity and bradykinesia are initially present in the arms and legs, progress from one side of the body to the other and finally- over time- involve axial muscles such as  head, neck and trunk musculature.  Axial involvement is observed as an increase in neck and upper body flexion and rigidity of neck and trunk muscles.  Associated with this change is an increase in generalized slowness, emerging gait, speech and swallowing problems. 

Clinical pearl: Asymmetric shuffling of steps can be 'heard'. Listen for evidence of worsening foot drag on one side and correlate with decreased arm swing on that same side.

 Gait changes include shorter steps or stride length and reduced foot clearance noted as shuffling.  Asymmetry of symptoms often continues and can also be noted in gait with the observation that decreased arm swing and shuffling steps are worse on one side of body.  Imbalance or postural instability is an inability to incorporate normal postural righting reflexes in response to perturbations of center of gravity.  One example of postural instability is retropulsion or the tendency to fall backwards often without warning.  Motor initiation problems termed "freezing" include an abrupt halt in all movement and most frequently occurs with initiating movement such as initiating gait, change in direction such as turns and in small crowded spaces (i.e. door thresholds).  Patients describe freezing as a tendency for 'feet to be glued to the floor, stuck to the floor or frozen'. Freezing is a significant cause of falls.  Physical therapy should be initiated with any gait change, imbalance or freezing. 

Clinical pearl: Freezing of gait worsens in crowds, small areas, and during times of anxiety.  Reduce freezing by removing visual and physical clutter from a room by removing objects, opening up floor spaces and eliminating complex visual patterns to upholstery or flooring.  Other techniques such as placing tape on the floor a strides length apart in high risk areas (threshold, closets) and marching in place when initiating gait can help someone 'overcome a freeze'.  Seek the help of physical therapy to find the best strategies for your patient.

Speech and swallowing problems are noted with signs of axial involvement.  Speech is softer, slowed, irregular and slurred. Swallowing can be affected first for pills, then for liquids, dry foods and other solids.  A speech and swallowing therapist can help with these problems and should be considered at the first signs of difficulty.

 Imbalance, falls, speech and swallowing problems contribute to disability and morbidity in later stage. An overall increase mortality risk of 2.7 is noted in non-demented PD individuals compared to age adjusted non-demented individuals in the same community⁹.    Motor symptoms that contribute significantly to disability include motor fluctuations, dyskinesia, postural instability, motor initiation problems, speech and swallowing problems.  Motor fluctuations and dyskinesia are complications associated with pharmacological treatment and are defined below. 

 Clinical pearl: Parkinson's disease changes slowly. An abrupt decline or exacerbation of symptoms warrants an alternative explanation for change.  Any patient stressor can worsen symptoms acutely including psychological, physical and emotional stress.  Look for clues of a systemic illness such as bladder infection, respiratory infection, new cardiopulmonary disease, or dehydration.