Parkinson's disease is a brain disorder. It occurs when certain nerve cells (neurons) in a part of the brain called the substantia nigra, closely associated with the motor system controlling movement, die or become impaired.
Normally, these cells produce a vital chemical known as dopamine. Dopamine allows smooth, coordinated function of the body's muscles and movement. When approximately 80 percent of the dopamine-producing cells are damaged, the symptoms of Parkinson's disease appear.
Parkinson’s disease usually affects people over the age of 50. It is a movement disorder that is chronic and progressive, meaning that symptoms continue and worsen over time. Nearly one million people in the United States are living with Parkinson's disease. The cause is unknown, and although there is presently no cure, there are treatment options such as medication and surgery to manage its symptoms.
Related disorders (Parkinson plus disorders) include multiple system atrophy, progressive supranuclear palsy and corticobasal degeneration.
Symptoms of Parkinson's disease vary from patient to patient and can involve many body systems from muscles to skin. They may also appear slowly and in no particular order. Many years may pass before early symptoms progress to the point where they interfere with normal activities. It is also important to note that a patient may not necessarily have all of these symptoms.
The four hallmark symptoms of Parkinson's disease are:
- Rigidity: Stiffness when the arm, leg or neck is moved back and forth.
- Resting tremor: Tremor when a body part is relaxed, such as in the hand, foot or chin. A “pill rolling” movement of thumb and fingers at rest is common.
- Bradykinesia: Slowness in initiating or maintaining movement.
- Loss of postural reflexes: Patients have poor balance and may fall.
Other, more subtle symptoms of Parkinson's disease may include:
- Small cramped hand-writing
- Decreased arm-swing or scuffing of foot on the affected side when walking
- Decreased facial expression
- Lowered voice volume
- Feelings of depression or anxiety
- Episodes of feeling “stuck in place” when initiating a step
- Increase in dandruff or oily skin
- Less frequent blinking or swallowing
- Vivid or active dreaming
The process of making a Parkinson's disease (PD) diagnosis is based on the hallmark symptoms and how the symptoms came about; as well as what is seen on a thorough examination. There is no X-ray or blood test that can confirm Parkinson's disease. Blood tests and brain scans known as magnetic resonance imaging (MRI) may be performed to rule out other conditions that have similar symptoms.
People suspected of having Parkinson's disease should consider seeking the care of a neurologist
who specializes in Parkinson's disease.
Much more is known about Parkinson’s disease now than in the past. There are several medications available to treat some of the symptoms. Additionally, it is known that many other therapies in combination with medication, can significantly improve the symptoms of Parkinson’s disease. Proper medical management and a multidisciplinary approach can help restore lost functions and protect against secondary symptoms that could otherwise develop.
Current medicines work primarily as dopamine replacement, since many of the movement symptoms are caused by lack of dopamine. The medicines most commonly used will attempt to either replace or mimic dopamine, which can improve tremor, rigidity and slowness associated with Parkinson's disease. Many new medicines are being studied that may work in different ways to treat symptoms and slow the progression. Non-medication treatments include physical and speech therapies designed specifically to target the problem areas of PD.
Deep brain stimulation is currently, the most commonly used surgical treatment of PD. This procedure is performed by a neurosurgeon experienced in this type of Functional Neurosurgery. During this surgery, electrodes are place in the specific areas of the brain known as the Subthalamic Nucleus (STN) or Globus Pallidus Internus (GPI). Using a pacemaker-like device (implanted in the chest), a mild electric impulse occurs that stimulates the brain and block the signals that cause some of the symptoms of PD. Not every patient with PD is a good candidate for this procedure. That can be determined by thorough pre-surgical evaluation with a Parkinson’s disease expert or a Movement Disorders Neurosurgeon. The pre-surgical evaluation is quite extensive to make certain the patient that undergoes this surgery will have the best results possible. Deep brain stimulation surgery was approved by the FDA for treatment of PD in 2002.
Several new surgical treatments for Parkinson’s disease are also currently being researched.