Understanding Young-Onset Parkinson's Disease, Symptoms, Causes & Risks

According to the Michael J. Fox Foundation, approximately 10-20% of people with Parkinson’s disease experience symptoms before age 50. This is known as early- or young-onset Parkinson’s disease. There are distinct genetic and clinical differences between young-onset and idiopathic (late-onset) Parkinson’s disease. It’s important for healthcare providers to be aware of and understand these differences, as this will help reduce the number of misdiagnosed or undiagnosed cases of young-onset Parkinson’s disease.

In this article, we will provide an overview of young-onset Parkinson’s disease, highlight the key differences between young-onset and idiopathic Parkinson’s, and discuss the importance of receiving an early, accurate young-onset Parkinson’s disease diagnosis.

Young-Onset Parkinson’s Disease: Symptoms, Diagnosis, and Treatment

People living with young-onset Parkinson’s disease experience similar symptoms as those living with idiopathic Parkinson’s disease. This includes motor-related symptoms, such as:

• Resting tremor: A tremor, or slight shaking, in the hand, arms, legs, jaw, or face while at rest is a common symptom of Parkinson’s disease. In young-onset Parkinson’s disease, tremors may appear slightly different and faster than those seen in idiopathic Parkinson’s disease.
• Bradykinesia (slowed movement): As the disease progresses, movement can become slow. This can include a reduction in automatic movements (such as swinging the arms when walking or blinking), a general slowness in physical actions, or a mask-like facial expression (decreased expression on the face).
• Rigidity: Stiffness or rigidity in the muscles of the limbs and trunk is common in both young-onset and idiopathic Parkinson’s disease.
• Changes in posture, balance, or gait: Changes in posture, balance and coordination, and gait are common and can cause difficulty walking. When walking, steps can become small, the person’s feet may drag, or they may walk with a shuffle. 

People living with young-onset Parkinson’s disease may also experience non-motor-related symptoms, such as:

• Changes in cognitive function: Changes in cognitive functions, such as memory and thinking, can occur in Parkinson’s disease. However, in people living with young-onset Parkinson’s disease, cognitive function is often preserved for a longer period of time.
• Anxiety and depression: Mood disturbances, such as depression and anxiety, are common in Parkinson’s disease, particularly in the early stages.
• Loss of automatic functions: Parkinson’s disease can affect automatic/involuntary functions performed by the body which may cause constipation, urination problems, excessive sweating, low blood pressure, and sexual problems.
• Sleeping troubles: Sleeping issues are common in Parkinson’s disease and other neurodegenerative diseases and often occur early in the disease course. People may have difficulty falling asleep or staying asleep, thrash around while sleeping, experience daytime sleepiness, or have very vivid dreams.

Like idiopathic Parkinson’s disease, young-onset Parkinson’s is diagnosed “clinically”, meaning diagnosis is dependent on medical history, answers to certain questions, physical examination, and the presence of specific physical symptoms. Because Parkinson’s disease is less common in young adults, the path to diagnosis is often lengthy. Treatment of young-onset Parkison’s disease is similar to that of idiopathic Parkinson’s disease.

Key Differences Between Young-Onset and Idiopathic Parkinson’s Disease

Experts currently believe that young-onset Parkinson’s disease manifests itself differently than idiopathic Parkinson’s disease. Young-onset Parkinson’s disease is associated with different symptom characteristics and different rates of disease progression. Additionally, the development of young-onset Parkinson’s disease is believed to be more likely to be related to genetics compared to idiopathic Parkinson’s disease. Certain genetic mutations, such as in the SNCA, PRKN, PARK7, and PINK1 genes, have been linked to an increased risk of young-onset Parkinson’s disease.

The symptoms and rate of disease progression are often different in young-onset Parkinson’s disease. In general, the disease continuum for young-onset Parkison’s disease spans a longer period of time. People living with young-onset Parkinson’s disease usually remain cognitively and functionally intact for a longer period of time. Additionally, they may experience more side effects from dopaminergic, or dopamine-producing, medications, such as more frequent dyskinesias (involuntary movements).

The Importance of an Early and Accurate Diagnosis

In people living with young-onset Parkinson’s disease, the onset of symptoms typically occurs between 21 and 40 years of age—yet only 2% of people diagnosed with Parkinson’s disease are diagnosed before age 40. Misdiagnosis, or lack of diagnosis, of young-onset Parkinson’s disease is common. Because young-onset Parkinson’s disease manifests itself differently and may require slightly different treatment and management approaches, receiving an early and accurate diagnosis of young-onset Parkinson’s is essential for receiving precise, personalized treatment and care. Additionally, younger individuals with Parkinson’s disease are often better candidates for certain surgical and medical interventions.

Parkinson’s disease, while a chronic condition, can be well managed—but this is often dependent on receiving an early and accurate diagnosis. This is particularly important for people living with young-onset Parkinson’s disease, as, at this stage in their life, they may be raising children, working on advancing their careers, or even starting a new chapter of their lives.