The Tale of Two Parkinson’s: Brain-First vs. Body-First

For years, living with Parkinson’s has felt like navigating a maze without a map. You might wonder why your friend with Parkinson’s struggles with tremors but sleeps soundly, while you might struggle with digestion or dizziness but have only a mild shake. For decades, medicine treated these as variations of the exact same condition. However, a groundbreaking study published in 2025 by Palermo and a team of researchers has confirmed what many experts have long suspected: Parkinson’s is likely not one single disease, but two distinct types that travel through the body in opposite directions. Understanding this distinction is not just academic; it changes how we view your symptoms, your history, and potentially your future care. The New Discovery The study, published in npj Parkinson’s Disease, applied a new technology called "radiomics" to standard brain scans. Radiomics allows computers to look at medical images and see invisible textures and patterns that the human eye simply cannot detect. By analysing these hidden patterns, the researchers were able to separate patients into two clear categories based on where the disease originated. The researchers found that Parkinson’s seems to attack the body in one of two ways: "Body-First" or "Brain-First." The "Body-First" Traveler In this version of the condition, the biological changes do not start in the brain. Instead, they begin in the complex network of nerves in the body, most likely the gut or the nose. From there, the condition travels slowly up the nervous system, eventually reaching the brainstem. If you are a "Body-First" person, you likely dealt with frustrating, unexplained health issues years before you ever noticed a tremor. You might have had chronic constipation, issues with blood pressure dropping when you stood up, or a specific sleep issue called REM Sleep Behavior Disorder, where you act out vivid dreams by kicking or shouting. In this type, the disease spends a long time damaging the body’s automatic systems before it ever touches the movement centers in the brain. The "Brain-First" Traveler In the second type, the process is the opposite. The changes begin inside the brain itself, specifically in the areas that control emotion and smell, before spreading to the movement centers and then eventually down into the body. If you are a "Brain-First" person, your story likely started with the classic motor symptoms. You might have noticed a tremor in one hand or stiffness on one side of your body as your very first sign. Unlike the Body-First group, you likely did not suffer from the years of sleep shouting or severe digestion issues before your diagnosis. Your autonomic system—the part that controls blood pressure and digestion—often stays healthier for longer in this version of the disease. What This Means for You Right Now If you have already been diagnosed, you might wonder if this science actually changes anything for you today. The answer is yes, because knowing which path your Parkinson’s took can give you a much clearer owner’s manual for your own body. First, it offers profound validation. If you have spent years battling fatigue, dizziness, or gut health issues, this study confirms that these were not just random annoyances or side effects of aging. They were likely the core early symptoms of Body-First Parkinson’s. It proves that your experience is real and biologically distinct from someone who mainly just has a tremor. Second, it helps you prioritise what to watch out for. For those who fit the Body-First profile, the risk of falls often comes not just from tripping, but from blood pressure drops (orthostatic hypotension). This means that for you, drinking water and managing salt intake is just as important as taking your Levodopa. It suggests that your heart and gut health are central to your neurological wellbeing. For those fitting the Brain-First profile, the focus might be different. Since the disease starts centrally, you might want to be more vigilant about changes in mood, focus, or memory, as these systems are closer to the disease's origin point. The Future of Care Perhaps the most exciting aspect of the Palermo study is that it proves we can tell these two types apart using standard brain scans combined with new AI analysis. In the past, making this distinction required invasive biopsies or rare, expensive heart scans. As this science moves into clinics, we move closer to a world where your treatment is tailored to your type. Instead of a "one size fits all" approach, doctors may soon be able to say, "You have Body-First Parkinson's, so we are going to treat your gut and blood pressure aggressively from day one," or "You have Brain-First Parkinson's, so we will focus on neuro-protection." Ultimately, this research is a message of hope. It signals that the medical community is finally untangling the complexity of Parkinson’s, moving away from guessing and toward a precise understanding of the unique journey you are on.