Cardinal Features

Tremor is present in approximately half of all patients. Patients with resting tremor usually have a more slowly progressive course of illness than those without tremor. Parkinson tremor has regular rate and rhythm. Tremor usually begins on one side in the hand or leg, although sometimes the jaw is affected first. It is most obvious when the affected limb is at rest or when a person is under stress. The tremor usually affects only one side of the body, during the early stages of the disease. A Parkinson tremor is rarely disabling and usually disappears during sleep or is lessened with intentional movement, such as reaching out to shake hands or gripping the steering wheel.

Bradykinesia, profound slowness of movement and loss of spontaneous and automatic movement, is often the most disabling symptom of Parkinson disease. There may be hesitation in starting to move ("freezing"), small steps or a shuffling gait, and a loss of fine motor control affecting manual dexterity. This symptom is particularly frustrating because of its effect on function. Early signs of bradykinesia are lack of arm swing on the affected side, small handwriting (micrographia), masked face, soft speech, and difficulty getting out of a couch or car.

Rigidity refers to increased muscle tone that is felt by the examiner on movement of the arm, leg, and neck. Rigidity will be more pronounced on the more affected side of the body. Rigidity of the trunk may also be present. A major premise of body movement is that all muscles have an opposing muscle. Movement is possible not just because one muscle becomes more active, but because the opposing muscle relaxes. In Parkinson disease, rigidity comes about when, in response to signals from the brain, this delicate balance of opposing muscles is disturbed. Some patients refer to this as "tightness" in their limbs. Unlike arthritis, there is no pain associated with rigidity.

Postural instability, or impaired balance and coordination, causes patients to develop a forward or backward lean and to fall easily. When challenged from the front or when starting to walk, patients with a backward lean have a tendency to fall backwards. This is known as retropulsion. Postural instability can cause patients to have stooped posture, with the head bowed and the shoulders dropped. The body does this to compensate for the postural reflex changes. This is the most serious symptom of Parkinson disease because of the risk of falls.

Secondary Symptoms

Micrographia – small, cramped handwriting may be one of the first signs.

Reduced arm swing and a slight foot drag on the affected side is an early manifestation of Parkinson disease.

Freezing – a term used to describe the phenomenon of being "stuck in place" when attempting to initiate movement. Anxiety causes freezing and is treated with anti-anxiety medication. More anti-Parkinson medication will not improve freezing.

Dysarthia – low voice volume or muffled speech.

Anxiety and depression – generally present in people with Parkinson disease, usually resulting in weight loss and disrupted sleep or early morning awakening.

Decrease in automatic reflexes such as blinking due to slowness of movement.

Seborrhea dermatitis – increase in dandruff and oily skin.

Constipation – due to slowness of movement in the colon. Anti-Parkinson medications are also constipating. Increased fluids, fiber, and exercise are generally indicated for people with Parkinson disease.

Sleep disturbances – talking and acting out dreams are common in people with Parkinson disease.

The symptoms present in Parkinson disease, medications that are helpful, and the rate of progression vary tremendously from one person to another. Some people will need to adapt their lifestyle to accommodate any difficulty the Parkinson disease might present; for instance, it may take longer or require more concentration to accomplish a task once considered "automatic."

Side Effects of Anti-Parkinson Treatment

Dyskinesias – impairment of voluntary movements resulting in fragmented or jerky motions.

Choreic movements – irregular movements induced by medication.

Dystonia – twisting of limb or cramping due to Parkinson disease. May also be side effect of treatment.

Blepharospasm – tight closure of the eyes that may be a side effect of treatment.

Psychiatric side effects of treatment may include hallucinations, delusions, paranoia, hypersexuality, mania and psychosis.