Body-First or Brain-First? New Study May Predict Parkinson’s Type Early On

For years, doctors have known that Parkinson’s disease (PD) doesn’t look the same for everyone. Some people experience gut problems or sleep disturbances long before any tremor shows up. Others seem to go straight into classic movement symptoms—shuffling, slowness, or rigidity—without any warning signs. Now, a major long-term study has confirmed something important: Parkinson’s might not just look different from person to person—it might actually begin in different places. Researchers followed over 2,000 people for up to 12 years as part of the Parkinson's Progression Marker Initiative (PPMI), a massive international effort to better understand the disease. What they found is that Parkinson’s tends to start along two different pathways: body-first and brain-first. What’s the Difference? In body-first Parkinson’s, the earliest symptoms tend to show up in the parts of the nervous system outside the brain. These people often experience REM sleep behaviour disorder (RBD), where they act out their dreams. They might also have problems with digestion, blood pressure regulation, or bladder control—signs that the "autonomic" nervous system is affected. In contrast, people with brain-first Parkinson’s don’t usually have those early non-motor issues. Their symptoms start in the brain, particularly the parts involved in movement, and progress outward. These patterns were already visible before diagnosis in people considered at high risk of PD. By using simple sleep questionnaires, motor assessments, and brain scans, researchers could begin to group people based on how their disease seemed to be starting—even before it fully developed. Why This Is Big News This two-pathway model isn’t just interesting science—it could completely change how Parkinson’s is diagnosed, treated, and studied. For starters, it explains why some people’s PD progresses faster, feels more unpredictable, or responds differently to treatment. If doctors can identify whether someone is on the body-first or brain-first pathway early on, they may be able to offer better, more personalised support from the beginning. So… Is One Type "Better"? That’s the big question. And the honest answer is: it depends. People with body-first Parkinson’s might notice symptoms earlier—like sleep issues or digestive trouble—which could lead to an earlier diagnosis. In some cases, this may allow for earlier intervention and support. However, this group also tends to have more widespread symptoms over time, since the disease seems to move from the body into the brain, affecting multiple systems. People with brain-first Parkinson’s may start with fewer warning signs but often experience faster motor progression once symptoms begin. Since they don’t always have early non-motor issues, their diagnosis may come later. Neither path is necessarily "worse," but they do appear to lead to different experiences, and that matters for treatment planning and emotional preparation. How Could This Help People Living With PD? This research opens up the possibility of: Earlier and more accurate diagnosis, using simple tools like sleep and autonomic questionnaires Better personalised care, based on how someone’s disease started and how it’s likely to progress More effective research trials, by grouping people more precisely, so new treatments can be tested more accurately Empowerment through understanding—knowing your “Parkinson’s type” could help you and your healthcare team make more informed decisions