What is Parkinson’s disease (PD)?

Parkinson’s disease (PD) is a chronic, progressive neurological disease that affects nerve cells (neurons) in an area of the brain called the substantia nigra. These cells normally produce dopamine, a chemical (neurotransmitter) that transmits signals between areas in the brain. These signals, when working normally, coordinate smooth and balanced muscle movement. PD, however, causes neurons in the substantia nigra cells to die, leading to a lack of dopamine in the brain. This lack of dopamine occurs especially in the part of the brain known as the basal ganglia. The basal ganglia are responsible for organizing movement commands from other parts of the brain. The loss of dopamine causes PD symptoms.

Who gets Parkinson’s disease (PD)?

Incidence of PD has reported higher in men than woman, especially after the age of 60. The average age at the onset of symptoms is 61. However, 10% of patients are diagnosed before age 40. There is increasing evidence that PD may be inherited.

What are the symptoms of Parkinson’s disease (PD)?

Common symptoms of PD include tremor, or a shaking that begins on one side of the body. In some cases, this tremor is confined to only one body part, such as the hand or foot. However, it may spread as the disease progresses and it can worsen with stress. Tremor rarely disables a patient and often disappears during sleep and when the arm or leg is being moved.

Bradykinesia, another common symptom, is a generalized slowness of movement. Common activities, such as getting dressed or bathing, may take a patient several hours to complete.

Most patients with PD develop some degree of rigidity, or stiffness of limbs. This rigidity is caused by uncontrolled tensing of muscles and results in the patient being unable to move about freely. Also, patients may experience aches or pains from affected muscles.

Balance and coordination problems are additional symptoms of advancing PD. Patients typically develop a forward or backward lean that makes them more likely to fall when bumped. Additionally, a posture is often developed in which the head is bowed and shoulders are slumped (stooped posture).

Other less common symptoms include:

It is important to note that the symptoms of PD can be very different between patients, sometimes making it hard to diagnose. In fact, as many as 25% of cases are misdiagnosed.

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