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Up & Coming: Vikas Kotagal, MD: Decoding the Motor Subtypes of Parkinson Disease


Vikas Kotagal, MD, a fellow in movement disorders and neurodegenerative diseases in the department of neurology at the University of Michigan, is on a mission to understand the underlying cause of differing motor features in Parkinson disease (PD).

Recently named a 2012 AAN Foundation Clinical Research Training Fellow, Dr. Kotagal hopes this opportunity will allow him to discover the clinical differences behind tremor-predominant manifestations of PD and gait-predominant ones, as well as to identify what these mechanisms might mean for future patient care, he told Neurology Today.

Dr. Kotagal, who earned his medical degree from University of Minnesota at Minneapolis in 2007, and completed his neurology residency at the University of Michigan, has a full plate — pursuing his research and dedicating out of office time to his 5-month-old daughter with his wife in Ann Arbor. Here, Dr. Kotagal discusses his research.


We're investigating motor-heterogeneity or motor subtypes within Parkinson's disease. No two patients with PD have the same motor symptoms or motor features to their disease — not to mention non-motor symptoms like depression and dementia.

Specifically, the four main motor features of PD are rigidity, resting tremor, bradykinesia or slowness of movement, and postural instability. It's known that patients with tremor may have a more benign disease course if that's their predominant symptom and patients with gait problems may have a more difficult disease course if that's their predominant symptom.

What we don't know is why some patients have one and some patients have the other. We're going to look at patients with PD who have tremor-predominant disease and who have gait-predominant disease and go through a series of neuropsychological tests and questionnaires, gait assessments, and neuroimaging tests using PET imaging, to figure out what the underlying differences are between these patients and what determines the disease course in PD.


Every patient we see with PD is different than the patient who came in the hour before. What's particularly notable about that is when I have a clinic appointment where I tell someone that I think that they have PD, the first question that usually comes to mind is: What does this mean for my future? People often will think, “I have a neighbor or father-in-law (or whomever) that has PD and he is in a wheelchair — or has this problem or that problem — is that what I'm going to face?” And the truth is we don't have a lot of good information to be able to counsel patients on “This is what you can expect in the next few years,” and “this is what you can expect 20 years from now,” because every patient is so different.

Understanding the reasons behind these differences, I think, is really important when it comes to being able to clinically advise patients about their disease and what they can expect going forward.


I have many mentors, but the two who have influenced me the most are Nic Bohnen and Roger Albin, who are both neurologists here at the University of Michigan. Nic Bohnen has helped me think about PD in a different fashion than I would have before — in particular about what the relationship is between motor symptoms and non-motor symptoms, and how can we figure out what causes certain patients to have some and other patients to not have any such features.

Roger Albin has taught me a lot about clinical research and he's somebody who I regularly run questions by because he's so knowledgeable about PD and about clinical research in general.

For somebody like me who is early in my career, just working with them both and observing how they see patients, how they conduct research, is a huge benefit because it's rare that you get the chance to work with two people who have been really successful at this.


When I was a medical student, I took care of a lady who was admitted to our hospital who developed visual hallucinations and an odd personality where she would confabulate or say things that were clearly not true. This came on out of the blue for a lady who was otherwise in her 60s, normal, no cognitive problems to speak of, and nobody could quite figure out why.

She had a disorder called PRES [Posterior Reversible Encephalopathy Syndrome] at the time, which is caused by a number of things, but in her case it was due to uncontrolled hypertension. And it was amazing to me to see that once her high blood pressure was treated, that this state of — for lack of a better term — psychosis could resolve, and that this lady who seemed so impaired from a cognitive and psychiatric perspective in the hospital could over a series of days get better and improve. She ultimately went home without significant cognitive impairment.


Movement disorders and PD to me are fascinating because of the complicated nature of the basal ganglia, which at least in PD we think is a chief part of what's going wrong and causing the disease. There's a lot of circuitry and interconnections that I find cool and interesting from that perspective.

The other thing is that Parkinson's is such a huge umbrella term for a lot of different disorders. For example, when someone has Duchenne muscular dystrophy or ALS, they have a well-characterized disorder — one has a very solid idea of either the cause or at least what one can expect and what symptoms transpire from having that disease. But PD is really just this mystery, I think, both in terms of what causes it and the symptoms patients develop after the disease starts. It really varies from patient to patient and I find that mystery and that variety of it to be very interesting.


Listen here as Dr. Vikas Kotagal discusses his research focusing on motor-heterogeneity or motor subtypes within Parkinson's disease:

AAN Clinical Research Training Fellowships are funded by American Academy of Neurology and the American Academy of Neurology Foundation, and provide $55,000 per year for two years, plus $10,000 per year for tuition to support formal education in clinical research methodology at the fellow's institution or elsewhere. Twelve fellowships were awarded for 2012, and more than 80 training fellowships have been awarded through the program since its inception in 1996. For more information about the program, visit