April 14, 2021

Parkinson’s Disease Symptoms – 4 Cardinal Signs

The article Parkinson’s disease early symptoms described a variety of signs that might be indicative of oncoming or early Parkinson’s. Given that many of the signs could be due to a variety of completely unrelated conditions, a more structured and formal classification is required to differentiate Parkinson’s from other diseases. This can be achieved by grouping the symptoms into primary motor related symptoms (4 Cardinal Signs), associated symptoms and neuropsychiatric dysfunction.

This article explains the 4 primary/major motor symptoms for Parkinson’s disease diagnosis, which includes:


  • Caused by impaired conduction of signals/impulses from the brain to the muscles.
  • Affect about 70% of patients at start of disease. Not everyone will experience tremors although most go on to develop them at the later stages.
  • Typically starts on 1 side (unilateral) i.e. asymmetric, and progresses to both sides (bilateral) after several years.
  • Can possibly affect eyelids, jaw, tongue, lips, chin, arm, forearm, hand, fingers, leg, feet and some people experience a sensation as though their internals are ‘trembling’. However, people who experience head/torso or voice tremors tend not to have Parkinson’s (any apparent tremor is usually caused by the upper extremities shaking violently). Head tremor is a typical feature of the condition Essential Tremor (ET).
  • A useful diagnostic tool:
    Parkinson’s disease tremors: Resting tremors – Increase when the person is resting and decrease when the person begins to move.
    Non-Parkinson’s tremors: Active tremors – Increase when trying to use or move the part of the body and decrease on resting.
  • Characteristic ‘Pill Rolling’ action between the thumb and 1st finger.


Muscle Rigidity

  • Caused by increased and excessive muscle contractions and muscle tone.
  • Stiffness, lack of movement and associated pain in certain parts of body including face, neck, arms can be an early sign of the disease.
  • Abnormal muscle tone resulting in muscular spasm /cramps and abnormal posture (Dystonia) is associated with a lack of normal movement and rigidity.
  • 2 types of muscle rigidity that can attack at random:
    ‘Cogwheel Rigidity’: Non-uniform and ratchety.
    ‘Leadpipe Rigidity’: Uniform.
  • Unable to swing arms when walking. One side is usually more affected during early stages i.e. asymmetric.


Slow Movement (Bradykinesia)

  • Caused by impaired conduction of signals/impulses from the brain to the muscles.
  • Brady=Slow Kinesia= Movement
  • Freezing Episodes : Problem initiating voluntary movement. This can progress to freezing mid-action e.g. whilst walking (later stages of disease).
  • Walking characterized by small steps or shuffling action.
  • Issues of safety arise e.g. crossing a road becomes increasingly problematic.
  • Difficulty in rolling over in bed or standing up and getting out of a chair.
  • Associated with clinical evidence of asymmetry.


Postural Instability/Balance Disturbances

  • Caused by loss of reflexes.
  • Becomes more noticeable as the disease progresses and usually present at later stages. If it occurs early in the disease, it is normally an atypical Parkinson’s syndrome.
  • Stooped posture and gait disturbance.
  • Problem turning around and navigating stairways.
  • Issues of safety arise e.g.
    40% of patients have experienced a fall.
    10% of patients experience weekly falls.


Next, we will consider  Parkinson’s disease symptoms – Associated Symptoms

Parkinson’s Disease Early Symptoms

Parkinson’s disease early symptoms may be subtle, go unnoticed and develop gradually over a number of years. A person will often feel ‘out of sorts’ and unable to pinpoint what exactly is wrong with them. It is not uncommon at this stage, for a patient to visit their practitioner and be told that they probably have a virus, are run down or suffering from stress.

Parkinson’s disease early symptoms may include:

  • Feeling ‘off-color’ or overly tired and worn out despite resting and sleeping.
  • Fatigue lasts more than 2 weeks.
  • Reduced sense of smell.
  • Irritable or depressed for no apparent reason.
  • Stiffness.
  • Aching.
  • Unsteady.
  • Executive dysfunction: easily distracted and difficulty with making decisions.
  • Losing track of a thought or word.
  • Significant weight gain/midlife obesity when a person was in their 40’s and 50’s.

Should any of the above signs persist longer than one would reasonably expect e.g. fatigue and feeling unwell due to a virus, most practitioners would begin to investigate the situation in order to determine if there was a significant underlying cause.

The type, severity and rate that Parkinson’s disease symptoms develop varies significantly between individuals e.g. although tremor or shaking is a classic Parkinson’s symptom, some people never experience it or only at the later stages of the disease. Therefore, aside from the general signs noted above, Parkinson’s disease symptoms can be categorized as follows:

  • 4 Cardinal signs: refers to the 4 major motor symptoms for diagnosis, namely:
    • Tremor.
    • Slow Movements (Bradykinesia).
    • Muscle Rigidity.
    • Postural Instability/balance disturbances (usually later stages).


The following points should be borne in mind regarding Parkinson’s disease symptoms:

  • Although most people will have a number of signs, a person does not need to exhibit all of the symptoms to be diagnosed with Parkinson’s disease.
  • Parkinson’s is usually unilateral (1 side) at the early stages progressing to bilateral (2 sides) as the condition worsens.
  • Given that Parkinson’s symptoms are highly individual, a patient will need regular medical assessment and medication will need to be tailored to the individuals needs.

Finally, it must be remembered that various non-Parkinson’s conditions can present themselves as having similar symptoms to Parkinson’s disease. Therefore, if a person is concerned that they may have Parkinson’s disease early symptoms, they should always consult a qualified practitioner for a professional diagnosis.