Parkinson’s disease

Tremor slowed movement and rigid muscles are the main symptoms

About 10 million people around the world are estimated to be living with Parkinson’s disease. A person with Parkinson’s has abnormally low dopamine levels. Dopamine-generating cells, known as dopaminergic neurons in the substantia nigra part of the brain have died. Experts do not know why these cells die. When dopamine levels are too low, people find it harder to get things done, to control their movements. Dopamine levels progressively drop in patients with the disease, so their symptoms gradually become more severe. Dopamine is involved in the sending of messages to the part of the brain that controls coordination and movement.

Although Parkinson’s disease is not a direct cause of death, it is a progressive chronic disease, and symptoms get worse over time. Parkinson’s disease symptoms and signs may vary from person to person. Early signs may be mild and may go unnoticed. Symptoms often begin on one side of your body and usually remain worse on that side, even after symptoms begin to affect both sides. Parkinson’s signs and symptoms may include tremor, slowed movement, rigid muscles, impaired posture and balance, loss of automatic movements, speech and writing changes. Parkinson’s disease can’t be cured, but medications can help control your symptoms, often dramatically. In some later cases, surgery may be advised.

Many doctors who diagnose this brain disorder rely on the Hoehn and Yahr rating scale to classify the severity of symptoms. The scale is broken into five stages based on disease progression. The five stages help doctors evaluate how far the disease has advanced.

1. Stage one: During this initial phase of the disease that lasts around 3 years, a patient usually experiences mild symptoms.
2. Stage two: In the second stage of Parkinson’s disease that lasts around 6 years, the patients’ symptoms are bilateral, affecting both limbs and both sides of the body.
3. Stage three: Stage three symptoms of Parkinson’s disease last around 7 years and can be rather severe and include the inability to walk straight or to stand. There is a noticeable slowing of physical movements in stage three.
4. Stage four: This stage of the disease is accompanied by severe symptoms of Parkinson’s. Walking may still occur, but it is often limited and rigidity and bradykinesia are often visible. During this stage that lasts around 9 years, most patients are unable to complete daily tasks and usually cannot live on their own.

Stage five: The final stage of Parkinson’s disease lasts around 14 years and it usually takes over the patients physical movements. The patient is usually unable to take care of himself and may not be able to stand or walk during this stage. A patient at stage five usually requires constant one-on-one nursing care.

Symptoms

Parkinson’s disease symptoms and signs may vary from person to person. Early signs may be mild and may go unnoticed. Symptoms often begin on one side of your body and usually remain worse on that side, even after symptoms begin to affect both sides.

Parkinson’s signs and symptoms may include:

• Tremor: A tremor, or shaking, usually begins in a limb, often your hand or fingers.
• Slowed movement (bradykinesia): Over time, Parkinson’s disease may reduce your ability to move and slow your movement, making simple tasks difficult and time-consuming. Your steps may become shorter when you walk, or you may find it difficult to get out of a chair. Also, you may drag your feet as you try to walk, making it difficult to move.
• Rigid muscles: Muscle stiffness may occur in any part of your body. The stiff muscles can limit your range of motion and cause you pain.
• Impaired posture and balance: Your posture may become stooped, or you may have balance problems as a result of Parkinson’s disease.
• Loss of automatic movements: In Parkinson’s disease, you may have a decreased ability to perform unconscious movements, including blinking, smiling or swinging your arms when you walk.
• Speech changes: You may have speech problems as a result of Parkinson’s disease. You may speak softly, quickly, slur or hesitate before talking. Your speech may be more of a monotone rather than with the usual inflections.
• Writing changes: It may become hard to write, and your writing may appear small.
• Therapies in development

Parkinson’s disease can’t be cured, but medications can help control your symptoms, often dramatically. In some later cases, surgery may be advised. Your doctor may also recommend lifestyle changes, especially ongoing aerobic exercise.

In some cases, physical therapy that focuses on balance and stretching also is important. A speech-language pathologist may help improve your speech problems. Medications may help you manage problems with walking, movement, and tremor. These medications increase or substitute for dopamine, a specific signaling chemical (neurotransmitter) in your brain. You may have significant improvement in your symptoms after beginning Parkinson’s disease treatment. Over time, however, the benefits of drugs frequently diminish or become less consistent, although symptoms usually can continue to be fairly well-controlled.

Scientists at the University of Dundee have identified the structure of a key enzyme that protects the brain against Parkinson’s disease. The result of a decade of work, the research team said that solving the 3D structure and inner workings of the PINK1 enzyme represented a major breakthrough.

The PINK1 gene was identified as a key player by Parkinson’s UK-funded researchers back in 2004. Drugs that can switch the PINK1/parkin pathway back on may be able to slow, stop or even reverse nerve cell death, not only in people who have these rare inherited forms of the condition, but also those with non-inherited Parkinson’s. Previous work had indicated that the main role of the PINK1 enzyme is to sense damage to the energy centers of cells known as mitochondria and then switch on a protective pathway involving the targeting of two key proteins, ubiquitin, and Parkin, to reduce the damage. But how this occurred was unknown.

In the new research, the team of Dundee scientists reveals that PINK1 has unique control elements not found in other enzymes of this class that explain how it targets ubiquitin and Parkin to exert its protective role in Parkinson’s.