When we think about Parkinson’s disease, most of us picture shaking hands, slow movement, stiffness, or difficulty walking. These are the symptoms families notice and the symptoms that often lead someone to a doctor. But Parkinson’s disease may begin much earlier.
Years before the first tremor appears, some people experience constipation, sleep problems, loss of smell, or subtle changes in mood and movement. These symptoms are common and can happen for many reasons, so they are easy to ignore. Yet researchers are increasingly asking whether, in some people, these quieter changes may offer clues about what is happening in the nervous system. For Nepal, this raises an important question: can we recognize Parkinson’s disease earlier, before visible symptoms begin to change a person’s daily life?
The conversation between the gut and brain
We often think of the brain and digestive system as separate. In reality, they are constantly communicating. Anyone who has felt butterflies in the stomach before an examination has experienced this connection.
One major link is the vagus nerve, which extends from the brainstem to several organs, including parts of the digestive system. Parkinson’s researchers have become increasingly interested in this pathway because of a protein called alpha synuclein. This protein is normally present in nerve cells, but abnormal forms can accumulate in Parkinson’s disease. Abnormal alpha synuclein has also been identified in parts of the digestive nervous system in some people with Parkinson’s.
These findings have led scientists to explore whether, in some patients, disease related changes may begin outside the brain and later involve the brain through connected nerve pathways. Animal studies provide important ways to investigate this possibility. But the idea should not be overstated. Scientists have not shown that every case of Parkinson’s begins in the gut. Parkinson’s is complex, and different people may develop the disease through different biological pathways.
Looking before the tremor
One of the biggest challenges is that people usually seek neurological care after visible movement problems appear. A hand begins shaking. Walking becomes slower. Muscles become stiff. Handwriting gets smaller. Yet the biological process may have been developing quietly for years.
Current medications can improve symptoms and quality of life, but they do not cure Parkinson’s disease or reliably stop its progression. That is why identifying earlier stages has become an important research goal.
Constipation has received particular attention because digestive problems can occur before movement symptoms in some patients. But constipation alone does not mean someone has Parkinson’s disease. It is extremely common and can result from diet, dehydration, medication, inactivity, and many other conditions. Most people with constipation will never develop Parkinson’s.
The more useful question may be what happens when several persistent changes occur together. Digestive problems accompanied by loss of smell, unusual movements during sleep, increasing stiffness, or gradually slowing movement may deserve further medical attention. No single symptom provides a diagnosis, but patterns may eventually help clinicians identify people who need neurological evaluation.
What we are studying
As a Nepali neuroscientist working in the United States, I study Parkinson’s disease using experimental models to understand how changes in digestion, movement, and different parts of the nervous system develop over time.
In our laboratory, we measure how long it takes material to move through the digestive system and compare those changes with changes in movement. The question is simple: what changes first? If digestive dysfunction appears before measurable movement problems, understanding why could provide another clue about the early stages of disease.
My research also examines a familiar feature of Parkinson’s: it often does not affect both sides of the body equally. One person may first notice shaking or stiffness in the right hand while the left appears normal; another may experience the opposite. We investigate whether limb dominance and biological differences between the two sides of the nervous system might influence this unequal vulnerability, and whether pathways connecting the gut and brain could contribute.
Animal studies cannot explain everything about human Parkinson’s disease, but they allow us to ask biological questions that would otherwise be difficult to investigate. The larger goal is to understand not only what happens after Parkinson’s becomes visible, but what may happen before.
Why this matters for Nepal
In many Nepali families, shaking hands and slow walking remain the defining signs of Parkinson’s disease. Other symptoms may receive less attention. Constipation is treated as a stomach problem. Loss of smell may be ignored. Sleep disturbances may be accepted as normal. When an older person begins moving slowly, families may simply consider it part of aging.
Again, none of these symptoms alone is a reason to assume Parkinson’s. But greater awareness can help people recognize when several persistent changes deserve medical attention.
Access is another challenge. For someone living outside a major city, seeing a neurologist may require hours of travel and expenses for transportation, accommodation, tests, and repeated visits. Nepal therefore cannot build neurological care only around specialist hospitals in a few cities. Primary care doctors and other healthcare workers can help recognize concerning patterns and refer patients when needed.
Nepal also needs better information about its Parkinson’s burden. How many Nepalis are living with the disease? At what age are they diagnosed? Do rural patients reach specialists later? What nonmovement symptoms are common? Without reliable data, planning services is difficult. A national Parkinson’s registry could gradually collect standardized information about diagnosis, symptoms, treatment, and outcomes.
Nepal does not need to build an expensive research infrastructure overnight. We can begin with awareness, stronger referral systems, better clinical data, and closer collaboration between hospitals and universities. Nepali doctors and scientists working abroad can also contribute through research partnerships, mentorship, training, data analysis, and international networks. Knowledge can travel even when people cannot.
Beyond the first tremor
Modern Parkinson’s research is teaching us to look beyond the hand that shakes and even beyond the brain itself. The gut, sleep, smell, movement, and different parts of the nervous system may each hold pieces of a larger puzzle.
We should not frighten people by suggesting that ordinary constipation or sleep problems mean Parkinson’s disease. Usually they do not. But we should not ignore what science is beginning to reveal: for some people, the body may be changing long before the first visible tremor appears.
For Nepal, the first step is not a revolutionary test. It is awareness, better training, stronger neurological services, better national data, and more research. For years, we have recognized Parkinson’s when the hand begins to shake. The future is asking whether we can recognize the disease before that moment arrives.
Perhaps one day, the earliest clue will not come from the hand at all. It may come from a quieter part of the body that we have not been paying enough attention to.
