A groundbreaking discovery has led researchers to rethink Parkinson’s disease, suggesting the possibility of two separate types of the condition. This new understanding could pave the way for more targeted and effective treatments.
Mounting evidence suggests that there might be two separate types of the world’s fastest-growing neurological condition. This fresh understanding could lead to much-needed new treatments.
Researchers have been studying Parkinson’s disease, a condition characterized by nerve cell loss in the brain. However, it also affects neurons in the heart that manage autonomic functions such as ‘heart rate and blood pressure.’ A team of neuroscientists, led by Per Borghammer, has made a groundbreaking discovery that challenges our current understanding of the disease.
Parkinson's disease is a neurodegenerative disorder characterized by the loss of dopamine-producing neurons in the brain.
It affects movement, balance, and coordination, leading to symptoms such as tremors, stiffness, and slowed movement.
The exact cause is unknown, but genetics and environmental factors contribute to its development.
Parkinson's disease primarily affects older adults, with most cases diagnosed after age 60.
As of 2022, there is no cure, but medications can manage symptoms.
The Heart’s Role in Parkinson’s
Borghammer’s team was examining whether REM sleep behaviour disorder (RBD), a condition that causes people to act out their dreams and is often found in people who later develop Parkinson’s disease, could be an early form of the neurological condition. Instead of starting with the brain, they looked for nerve cell loss in the heart. This approach led them to a surprising finding: neurons in the heart were depleted, which was not visible on scans using radioactive tracers.

Two Types of Parkinson’s
There are several types of Parkinson's disease, each with distinct characteristics.
The most common type is Idiopathic Parkinson's, accounting for about 70-80% of cases.
This type has no known cause and typically affects individuals over the age of 60.
Other types include Familial Parkinson's, which is inherited, and Secondary Parkinson's, caused by medications or toxins.
Vascular Parkinson's is related to reduced blood flow in the brain, while Neurodegenerative Parkinson's involves the degeneration of dopamine-producing neurons.
What struck Borghammer was that Parkinson’s didn’t seem to follow the same trajectory in everyone it affected. RBD strongly predicts Parkinson’s, but not everyone with Parkinson’s experiences RBD. This realization led him to conclude that Parkinson’s must be at least two types: one where neuron loss starts outside the brain, eventually working its way in, and another where neuron loss is largely restricted to the brain from the beginning.
Parkinson's disease is primarily classified into two main types: idiopathic and secondary.
Idiopathic Parkinson's accounts for approximately 80-90% of cases, where the exact cause remains unknown.
Secondary Parkinson's, on the other hand, is caused by external factors such as toxins, infections, or brain injuries.
Additionally, there are several subtypes, including juvenile-onset Parkinsonism and Parkinson's disease dementia.
Research suggests that genetic mutations play a significant role in some cases, while environmental factors contribute to others.
This new understanding of Parkinson’s has significant implications for treatment. By identifying these two distinct forms of the disease, researchers may be able to develop more targeted and effective therapies. The discovery also highlights the importance of considering the heart as a potential site for Parkinson’s research, rather than just focusing on the brain.
- newscientist.com | A dramatic rethink of Parkinson’s offers new hope for treatment