What Is Parkinson’s Disease? 

What are the typical symptoms of Parkinson’s Disease? 

Parkinson’s is a degenerative brain disease. It primarily affects one’s ability to control movements¹. The three most significant motor symptoms are: 

Tremor: A constant, rhythmic trembling, often in limbs, lips or jaw that occurs at rest and stops with voluntary movements. 

Rigidity: Painful Muscle stiffness that makes motion difficult. People with Parkinson’s commonly experience stiffness in the shoulders, arms and legs. 

Bradykinesia: General slowness of actions, especially when performing sequential tasks—like cooking or dressing. 

These three symptoms typically appear early in the disease. Usually, patients develop a light tremor on one side of their body or a stiffness in the shoulder before all three symptoms take hold.

Parkinson’s is not purely a movement disorder. It is a neurodegenerative disease. Neurodegenerative diseases occur when the nerve cells, also known as neurones, in the brain, die. When useful neurons die, it makes once simple actions difficult for your brain to complete.

As the condition progresses, patients may suffer from additional symptoms¹, including among others: 

• Difficulty to maintain balance
• Changes in posture
• Inability to start movements like walking or reaching
• Loss of smell
• Constipation 
• Vivid, scary, shocking dreams 
• Hallucinations 

What happens in the brains of Parkinson’s patients? 

A large part of our brain is concerned with movement. Many specialized areas signal to each other in a perfectly timed sequence to orchestrate our movements. We usually don’t think about how difficult walking on two feet actually is. Try thinking about walking down a flight of stairs as you do it. Suddenly coordinating the movements is very difficult.

Even simple tasks, for eample, holding a glass, require coordination of a lot of neurons in many different parts of the brain. You could think of it as like a relay race. A message is transmitted from one part to the next. Each area passing on the baton to the next one, until a muscle contracts or relaxes. Every step adds one component of movement, much like passing the baton. While some batons signal that a movement should be started, some signal that a movement should stop. Movement always needs a certain balance of activation and inhibition. 

The movement problems in Parkinson’s become apparent when a specific brain region, known as substantia nigra, has lost a significant number of neurons. This region uses the signal molecule dopamine to signal other areas that a movement should be started. In Parkinson’s a protein called alpha-synuclein fails to fold into the right shape. Instead, it clumps together with other alpha-synuclein proteins to form aggregates. These clumps become larger and larger like a big pile of garbage inside the neuron. Eventually the nerve cell cannot function anymore and dies. When between 50 and 70% of neurons in the substantia nigra have died, the first symptoms of Parkinson’s start to appear. 

Without the dopamine signal from the substantia nigra, other areas of the brain don’t work well together. When Parkinson’s patients fail to get out of a chair, it is because the substantia nigra does not pass on its baton. As a result, the next steps in the relay are slightly off in timing. This means the muscles don’t receive a signal to move at the right time, or with the right strength. Patients want to move, but their body can’t execute the movement. 

Who is at risk of developing Parkinson’s? 

Parkinson’s typically occurs at an older age. Your genes can have a say whether you get the disease or not. Around 5–10% of patients have a mutation in one or more genes that put them at high risk to get the disease². However, lifestyle factors do play a significant role, too. Exposure to toxic chemicals, for example, some used in agriculture, or traumatic head injuries can increase your risk for Parkinson’s². On the other hand, there are some changes you can make too your lifestyle that can reduce your risk. These include regular exercise, a healthy diet high in fruits, vegetables and grains but low in dairy products, with coffee and tea (in moderation).

How is Parkinson’s diagnosed? 

Accurately diagnosing Parkinson’s—especially in the early stages—is challenging¹. The age of onset, the type and extent of symptoms and its progression vary considerably among patients. Moreover, some symptoms of Parkinson’s disease are common to other conditions. For example, you can have a tremor but not have Parkinson’s. Doctors will look at a patient from many angles to make sure their diagnosis is correct¹: 

• Medical history 
• Medical examination with multiple motor and non-motor assessments
• Genetic testing 
• Brain scans 
• Biomarkers taken from blood or other bodily fluids 

How do we treat Parkinson’s? 

Sadly, we do not yet have a cure for Parkinson’s disease, but modern medicine offers some effective treatments to relieve the symptoms. 

Drug based therapy 

Most Parkinson’s drugs aim to increase the amount of dopamine in the brain. As explained earlier, the motor symptoms occur because the nerve cells in the substantia nigra, which release dopamine, die. As a result, other parts of the brain don’t receive a strong enough dopamine signal to start planning and executing movements. L-Dopa (also known as Levodopa) comes in pill form. It’s absorbed through your digestive system and travels to your brain where it is converted to dopamine³. Since its first use in 1961 to this day, L-Dopa remains the single best medical therapy for Parkinson’s⁴⁵. L-Dopa can be transformative for patients. Patients regain the ability to even jump and run after having difficulties just walking from the kitchen to the bedroom. 

In many cases L-Dopa is administered together with other drugs that enhance its effect. They increase the amount of Dopamine that reaches the brain or extend the duration it stays there. Every individual living with Parkinson’s has a unique response to dopamine therapy. Physicians will tailor the exact dose and combination of drugs for each patient.
L-Dopa does have some unfortunate long-term side effects. Some patients experience sudden involuntary movements. Moreover, patients can have periods throughout a day in which L-Dopa stops working and the Parkinson’s symptoms come back. These fluctuations can limit patients in their daily lives. People with Parkinson’s disease will still need help and support for day-to-day activities. Uncertainty about how bad their symptoms will be throughout the day can make activities they would usually enjoy a cause of anxiety. For example, attending a concert or going grocery shopping might feel beyond their abilities. If medication stops working, more advanced therapies exist, for example, Deep Brain Stimulation. 

Invasive therapy

In Deep Brain Stimulation, electrodes are permanently implanted into deep parts of the brain. The electrodes then stimulate the nerve cells in areas that initiate of movement. Seventy-five percent of patients report that Deep Brain Stimulation markedly improved their motor symptoms. As many as 95% of patients would recommend the treatment⁶. Thanks to advances in medical device manufacturing, brain imaging techniques and surgical procedures, Deep Brain Stimulation has become an effective treatment for Parkinson’s. 

Supportive actions 

Lifestyle factors do not only play a role in the development of Parkinson’s but also in its progression. Maintaining a healthy lifestyle with a balanced diet, daily physical activity and a positive outlook on life can be highly beneficial. 

Additionally, physiotherapy programs can help patients to manage their symptoms. Some find that they lose the ability to walk or move if they have to concentrate on something else at the same time. Getting stuck when somebody asks a question can make life very difficult. Dual-Task Training asks patients to practise performing a cognitive task like counting backwards, while walking. The idea is to retrain the brain to adapt to using other neural pathways when one fails. Regular practice of Dual Task Training can improve gait and overall balance.

Outlook 

Looking at the medical progress since the pioneering work of James Parkinson inspires confidence and hope. Although Parkinson’s patients are confronted with significant challenges, excellent treatment options have transformed a once debilitating disease into a manageable condition. Through a combination of medical interventions, supportive care, and a positive outlook, individuals with Parkinson’s can navigate their journey with resilience and dignity. Through new advances like gene therapy or regenerative medicine, we inch closer towards the goal of not only treating but ultimately curing Parkinson’s. 

References: 

1. Tolosa E, Garrido A, Scholz SW, Poewe W. Challenges in the diagnosis of Parkinson ’ s disease. Lancet Neurol. 2021;20(5):385–397. doi:10.1016/S1474-4422(21)00030-2.Challenges ↩︎
2. Simon DK, Tanner CM, Brundin P. Parkinson Disease Epidemiology, Pathology, Genetics and Pathophysiology. Clin Geriatr Med. 2020;36(1):1–12. doi:10.1016/j.cger.2019.08.002.Parkinson ↩︎
3. Muthuraman M, Koirala N, Ciolac D, et al. Deep brain stimulation and L-DOPA therapy: Concepts of action and clinical applications in parkinson’s disease. Front Neurol. 2018;9(AUG). doi:10.3389/fneur.2018.00711 ↩︎
4. Elsworth JD. Parkinson’s disease treatment: past, present, and future. J Neural Transm. 2020;127(5):785–791. doi:10.1007/s00702-020-02167-1 ↩︎
5. Goetz, Christopher G. The History of Parkinson’s Disease: Early Clinical Descriptions and Neurological Therapies. Cold Spring Harb Perspect Med. 2011;1(a008862). ↩︎
6. Hitti FL, Ramayya AG, McShane BJ, Yang AI, Vaughan KA, Baltuch GH. Long-Term outcomes following deep brain stimulation for Parkinson’s disease. J Neurosurg. 2020;132(1):205–210. doi:10.3171/2018.8.JNS182081 ↩︎