What Is Young-Onset Parkinson's Disease?

Parkinson’s disease (PD) is most commonly diagnosed in people over the age of 60, with an average age of 62 at diagnosis. However, some people develop the disease at younger ages. Some doctors consider anyone diagnosed with PD under the age of 50 to have young-onset Parkinson’s disease, while other doctors refer to people diagnosed under the age of 40 to have young-onset Parkinson’s disease.^1,2

Between 2 percent and 10 percent of the 1 million people living with Parkinson’s have young-onset PD.¹

Causes of young-onset Parkinson’s disease

The exact cause of PD is not known, although scientists believe it results from a combination of genetic and environmental factors. The genetic factors play a larger role in young-onset PD, and researchers have found certain genetic mutations that are linked to a higher risk of developing young-onset PD, including:

• PRKN
• SNCA
• Parkin (Park2)
• PINK1 (Park6)
• LRRK2

While genetic testing is available, not everyone who has these genetic mutations develops PD, and the presence of these genetic mutations does not impact treatment decisions. Researchers continue to study the impact of genetic and external factors in the development of PD.^1-3

Unique characteristics of young-onset Parkinson’s disease

Although Parkinson's is similar among people of all ages, those with young-onset PD generally have slower disease progression. They also tend to experience more side effects from dopaminergic medications and are more likely to have dyskinesias in response to the drug levodopa. Dyskinesias are abnormal, involuntary movements. They appear like a “dance” with wiggling movements of arms, legs, body or face.  

Other problems associated with PD, such as memory loss, confusion, and problems with balance tend to occur less often in people with young-onset Parkinson's. However, as with PD in older patients, the disease severity and symptoms vary from person to person.^1,2

Symptoms of young-onset Parkinson’s disease

The same symptoms that are seen in older patients with PD are seen in young-onset PD, including:

• Tremor of the hands, arms, legs, or face
• Rigidity of the limbs and trunk
• Slowness of movement
• Gradual loss of spontaneous movement (bradykinesia)
• Impaired balance
• Lack of coordination
• Depression
• Sleep disturbances
• Impaired memory or thinking
• Difficulties with urination or constipation¹

In general, people with young-onset PD less frequently have memory loss, confusion, and balance difficulties. They tend to experience more cramping and abnormal postures, such as the arching of the foot, and depression. ^1,2,4

Challenges of young-onset Parkinson’s disease

PD is known as a disease that affects older people, and while this is generally true, this perception can make a diagnosis of PD in a younger person difficult. The diagnosis process may take longer in a younger person, as doctors may overlook the symptoms or mistake them for something else. In addition, the diagnosis can be especially challenging for a young person to accept, as they may also consider PD to be a disease that affects older people.²

Treatment for young-onset Parkinson’s disease

Most people with PD are prescribed carbidopa/levodopa (Sinemet) to manage their motor symptoms; however, people with young-onset PD have a higher likelihood of side effects from this medication, such as dyskinesia. Physicians often use other medications for people with young-onset PD, including monoamine oxidase B (MAO-B) inhibitors and dopamine agonists.^1,3

Deep brain stimulation may also be an option for motor symptoms of Parkinson's. Deep brain stimulation is a surgical technique in which electrodes are inserted into specific areas of the brain and an impulse generator (similar to a pacemaker) is inserted under the collarbone or the abdomen. This stimulator restores the balance of neuronal firing in a brain area called the basal ganglia. This brain area is responsible for controlled movements.^1,5

Young-onset PD patients also respond well to physical therapy, occupational therapy, speech therapy, and exercise to alleviate motor symptoms.⁶