Parkinson’s disease

Parkinson's disease is a neurodegenerative disorder that primarily affects the motor system. The symptoms generally develop slowly over time. The most obvious early symptoms are tremor, rigidity, bradykinesia (slowness of movement), and postural instability. Later, cognitive and behavioral problems may arise, with dementia commonly occurring in the advanced stages of the disease. Depression and anxiety are also common, occurring in more than a third of people with Parkinson's disease.

Signs and Symptoms

The main motor symptoms are collectively called "parkinsonism" or a "parkinsonian syndrome". These include:

• Tremor: Shaking, which usually begins in a limb, often the hand or fingers.
• Rigidity: Muscle stiffness that can occur in any part of the body.
• Bradykinesia: Slowness of movement, making simple tasks difficult and time-consuming.
• Postural instability: Impaired balance and coordination, leading to falls.

Non-motor symptoms can include:

• Sleep disturbances
• Sensory symptoms
• Autonomic dysfunction
• Neuropsychiatric problems

Causes

The exact cause of Parkinson's disease is unknown, but it is believed to involve both genetic and environmental factors. The most significant risk factor is age, with most cases occurring after the age of 60. A small percentage of cases are directly inherited and are associated with specific genetic mutations.

Pathophysiology

Parkinson's disease is characterized by the death of dopaminergic neurons in the substantia nigra, a region of the midbrain. This leads to a reduction in dopamine levels in the brain, which is crucial for regulating movement and coordination.

Diagnosis

Diagnosis is based on medical history and a neurological examination. Imaging tests such as MRI or CT scan can help rule out other conditions. The Unified Parkinson's Disease Rating Scale (UPDRS) is often used to assess the severity of the disease.

Treatment

There is no cure for Parkinson's disease, but medications, surgical treatment, and other therapies can help manage symptoms. Common treatments include:

• Levodopa: The most effective medication for controlling motor symptoms.
• Dopamine agonists: Mimic dopamine effects in the brain.
• MAO-B inhibitors: Help prevent the breakdown of brain dopamine.
• Deep brain stimulation: A surgical procedure that involves implanting electrodes in the brain.

Prognosis

The progression of Parkinson's disease varies among individuals. While it is a chronic and progressive disease, many people with Parkinson's disease live long, productive lives. The rate of progression and the severity of symptoms can be managed with appropriate treatment.

Related Pages

• Neurodegenerative disorders
• Dopamine
• Substantia nigra
• Levodopa
• Deep brain stimulation
• Unified Parkinson's Disease Rating Scale