Chi-Ying Lin, MD, MPH, is researching how movement and non-movement symptoms intersect for people with Parkinson’s disease (PD) and Alzheimer’s disease. Through studying these symptoms in people with movement disorders and cognitive disorders, he hopes to learn more about what parts of the brain produce specific symptoms, which could lead to new treatments for people with Parkinson’s.

Following his Parkinson’s Foundation fellowship at Columbia University Irving Medical Center, Dr. Lin is now an assistant professor of neurology at Baylor College of Medicine with dual appointments in the Alzheimer’s Disease and Memory Disorders Center and the Parkinson’s Disease Center and Movement Disorders Clinic, which is a Parkinson’s Foundation Center of Excellence. We spoke to Dr. Lin to learn more about his work and what he finds most promising in current Parkinson’s research.

What led you to Parkinson’s research?

I was very interested in the personalization of Parkinson’s evaluation and treatment plans, and in learning more about how movement and cognitive symptoms intersect.

I came to the United States after my residency in Taiwan because I was interested in neuropathology at Columbia University. When I arrived, I had a chance to hear Dr. Stanley Fahn speak about movement disorders and it blew me away. I decided I wanted additional training in movement disorders. Because of the excellent clinical training and mentorship opportunities in the U.S., I decided to restart my career here, which led me to my residency at Mount Sinai and my fellowship at Columbia University Irving Medical Center, which was supported by the Parkinson’s Foundation.

Why research the intersection of movement disorders and cognitive disorders?

In my first exposure to cognitive disorders in Taiwan, I was not entirely aware that people with movement disorders actually have a lot of cognitive issues. At Columbia University, I learned through the Parkinson’s Foundation that around 50% of people with PD could have either mild cognitive impairment or dementia. I felt it was important to study this intersection, which is a relatively new field.

There is a brain region called the cerebellum that sits right behind the brainstem and above the neck. It used to be thought of as a pure motor organ and was often studied to understand movement. However, in the past 10 years, there has been an increased understanding that the cerebellum controls non-movement symptoms as well.

Can you tell us about your impulse control study?

In my fellowship, I conducted studies, and one primarily focused on the intersection of movement and cognitive disorders, especially for impulsivity and compulsivity, which are commonly seen in people with Parkinson’s. This study compared impulsivity in people with Parkinson’s to people with a different cognitive condition, Cerebellar Ataxia, which can include impulsive behavioral symptoms as well.

Our findings determined that impulsivity was different between the two conditions, and with Parkinson’s disease, it can be more widespread to include several impulsive behaviors that are both movement and non-movement related, including gambling, eating, hypersexuality, spending and compulsively taking medication. This suggests that that cerebellum and basal ganglia, a different part of the brain that is affected by PD, can produce different kinds of impulsive behaviors, furthering our understanding of how the cerebellum functions.

What are you currently researching?

The goal of my current study is to better understand the genetic and environmental factors that lead to Alzheimer’s or Parkinson’s in each participant.

I am on dual appointment in the Parkinson’s Center and Alzheimer’s Center. I’m also part of Baylor’s Precision Medicine Core, where I comprehensively study people with and without cognitive disorders and use clinical history, comprehensive assessments, neuroimaging and genome sequencing to characterize early cognitive impairments and determine the risk a person has for a cognitive disorder. Houston, TX, where Baylor is located, is the most racially and ethnically diverse city in the country, which makes it a great place for this study.

Furthering the work I did during my fellowship; I’m also conducting a functional neuroimaging project to identify the role of the cerebellum in both Alzheimer’s and Parkinson’s. Once we understand the role, we can consider treatments like deep brain stimulation to address impulsivity and compulsivity.

What gives you hope for the future of Parkinson’s research?

My overarching goal is to be part of the experts in the world that find the modifying therapy or, to be ambitious, the corrective therapy for Parkinson’s. Practically, I want to address the symptoms of Parkinson’s, which is why I’m focusing on the cerebellum and its impulsivity power to see if we can better address that symptom for people with Parkinson’s.

What do you see as the most promising recent discoveries in Parkinson’s research?

The Parkinson’s Foundation genetics study, PD GENEration, Mapping the Future of Parkinson’s Disease, is something that my patients and their families benefit from immensely because it not only includes genetic testing, but genetic counseling as well at no cost to participants. I’ve enrolled many patients into the study, and I think overall it will be a very fruitful study for Parkinson’s research.

I also believe the Parkinson’s Foundation study about alpha synuclein detection in stool is very interesting and could lead to earlier Parkinson’s disease detection. It interests me because it is noninvasive and could allow for early-stage study recruitment.

How has support from the Parkinson’s Foundation impacted your career?

My fellowship taught me that Parkinson’s does not look the same in every person, and care must be individualized. I’m so appreciative of the support I’ve received from the Parkinson’s Foundation.

There are not enough movement disorders specialists, especially in rural areas, and the Foundation’s support of expanding care for people with Parkinson’s is so important.

Because of the Parkinson’s Foundation, I was able to learn from well-respected movement disorders leaders and build upon my foundation as a movement disorders neurologist. I was lucky to be in the last fellowship class trained by Dr. Fahn before his retirement. He taught me how to be a very compassionate movement disorders neurologist who actively works with patients and their families to find the best treatment options.

For more information on our research grants, visit Parkinson.org/Grants.

Regularly seeing a neurologist can improve the lives of thousands of people with Parkinson’s disease (PD) each year. However, access to expert Parkinson’s care is not always easily available. A new Parkinson’s Foundation-funded study found that only 9% of Medicare beneficiaries with PD received care from a movement disorders specialist (expertly trained neurologists who can recognize PD’s distinct nuances and tailor treatments to each patient), while 50% saw a general neurologist.

The study identifies critical gaps in care for people with Parkinson’s in the U.S. Those with the greatest disparities in care are women, people of color (those who identify as Asian, Black, Hispanic and Native American) and residents of rural areas. Published in the official, peer-reviewed journal of the Parkinson’s Foundation, npj Parkinson’s Disease, the study analyzed 2019 U.S. Medicare data.

“By utilizing Medicare data from 2019 that represents 90% of people living with Parkinson’s in the U.S., this research provides not only the timeliest but the most comprehensive study of people with PD yet conducted,” said James Beck, PhD, senior author of the study and Parkinson’s Foundation chief scientific officer. “Our findings underscore that Parkinson’s specialists are not the main care providers for people with PD — it is the general neurologists and other clinicians. These professionals, and their patients, could greatly benefit from additional training in PD care.”

Study Findings

• 50% of people with PD receive care for the disease from general neurologists.

• 29% receive PD care from primary care providers.

• Care access disparities persist for women, people of color, and residents of rural areas — each most likely facing additional challenges in receiving a diagnosis and treatment.
• Although depression affects 53% of people with PD receiving Medicare, only 2% receive treatment from a mental health professional.
• Medicare recipients with PD are not likely to access supplemental therapies — physical and occupational therapy, speech-language therapy and mental health services — with only 20% of individuals seeing a physical therapist, for example.

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What do these findings mean for people with Parkinson’s?

There are only 660 movement disorders specialists who practice in the U.S., with a total of six in rural areas. There are one million people in the U.S. living with Parkinson’s.

Forty-one percent of people with PD on Medicare do not see a neurologist or movement disorders specialist. Prior research has shown that receiving care from a PD specialist leads to a better quality of life. These doctors know how to help people manage PD symptoms, screen for crucial symptoms like depression and anxiety, and can help personalize medication and treatment plans.

The Parkinson’s Foundation conducted this study to better identify how it can improve access to specialized PD care. As a result of this study, the Foundation is now expanding disease-specific training to general neurologists and other healthcare providers, and pursuing strategies that improve access to care across all demographic and population groups. The findings from the study will also support policy development and future research that dives deeply into access issues.

The vision of the Parkinson’s Foundation is for all people to have access to quality PD care. The Foundation oversees multiple initiatives aimed at better understanding and improving care, providing professional education opportunities and working to remove care barriers for people with PD. Learn more about how we are increasing access to care through our care programs.

The Urgency of Connecting People to Expert Care

Every year, 90,000 people in the U.S. are newly diagnosed with PD. Unfortunately, many navigate the disease alone for years. Receiving an accurate PD diagnosis can be half the battle, while the other half is finding quality PD care. Those who engage with healthcare professionals trained in PD in the early stages of the disease report better outcomes and quality of life.

The economic burden of Parkinson’s disease to individuals, families and the U.S. government reached $82.2 billion in 2024. Not only is expert care critical to living better with Parkinson’s, receiving care early on can reduce the economic burden of Parkinson’s drastically both on a personal and nation-wide basis.

The number of people with PD will continue to increase substantially in the next 20 years due to the aging population. That is why we are determined to educate healthcare professionals so that people with Parkinson’s will receive a diagnosis earlier, treatment sooner and better care. Our goal is for people with Parkinson’s actively avoid unnecessary complications, such as prolonged hospital stays, and live better with this disease.

How can I find expert care?

If you are living with or caring for someone with Parkinson’s, find PD care near you with these resources:

1. Use our In Your Area feature or call our Helpline at 1-800-4PD-INFO (1-800-473-4636).
2. Learn more about our Global Care Network, designated centers that provide PD care.
3. Talk to your PD doctor about building your care team to address your most troublesome symptoms. Learn more about building your care team.
4. Download the Hospital Safety Kit, designed to help you navigate a hospital stay — planned and unplanned.
5. For healthcare professionals: learn more about PD-tailored care at Professional Education.

Ready to learn more?

• Read more about Finding Care and Treatments.

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