Parkinson’s & Movement Disorder Institute

The Parkinson's & Movement Disorder Institute

Mission Patient Care:

Foremost, the physicians, research scientists and staff at the Parkinson's and Movement Disorders Institute all share the common goal of providing superior care to our patients in the treatment of neurological disorders affecting movement. It is our belief that people who must cope with symptoms or illness have enhanced quality of life when they understand their diagnosis and treatment plan, and when they are informed and active participants in their own health care.

We also know that we learn and improve as physicians from our experiences with all of our patients. In our clinical practice we encourage a relationship of open communication between patient and physician.


To ensure that we are providing care with the most current knowledge and therapies available, and to further knowledge of the causes and treatment of neurological disorders, we are committed to active participation in basic and clinical scientific research.


The physicians and scientists of the Institute strive to further their own understanding of movement disorders, and also contribute to general awareness and education, through participation in support organizations, public speaking, and training of students in our laboratory.

Dr. Truong - Botox Injections for Voice DisordersFounded by Dr. Daniel D. Truong, a recognized expert in research and treatment of Parkinson's disease, dystonia and other movement disorders, the Institute was first established at the University of California, Irvine as the Parkinson's and Movement Disorder Program.

Today, the Institute is comprised of eight specialists dedicated to a full spectrum of patient care and research in the areas of Parkinson's disease and movement disorders, from medical treatment to surgical approaches. In addition to Dr. Daniel Truong, the Institute's specialists are Dr. Victor Passy, an expert in the treatment of spasmodic dysphonia; Dr. Mayank Pathak, who specializes in spasticity; Dr. Karen Frei, who is a neurgeneticist with special interest in Movement Disorders.

We joined together with the common goals of investigating and treating neurological disorders that impair movement. These efforts are accomplished, of course, through the efforts of many people within the organization, including clinical and research staff.

What our patients say about PMDI

TestimonialDr. Truong gave me a normal life back!
He is kind, caring and one in a million! I was unable to speak due to dysphonia and through his wonderfully simple vocal injections I am now able to again take control of my life. I have been going to Dr. Truong for over 20 years and I'm sure that my professional and personal life would not have turned out the same without him!

Other patients tell the same story. Patty Johnson, a Dana Point resident and personnel assistant for the Capistrano Unified School District, went to Truong after her lips uncontrollably puckered, frozen in the shape of a carp's mouth. Today, after botox treatments, Johnson says she believes she is cured.

Barbara Rood, a receptionist at a local college, described regaining her voice after two years "like emerging from a dark pit. I imagine it's like a blind person seeing again."

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About UsOur Physicians

The Parkinson's & Movement Disorder Institute is made up of the following members:


Daniel D. Truong, M.D.

Mayank Pathak, M.D.

Thong Nguyen, M.D.

Christina Nguyen, M.D.

Kong Truong, M.D.

About UsOur Locations

The central office for the Medical Group is located in the campus of Orange Coast Memorial Medical Center in Orange County.

This office is our main location for patient care and clinical research.9940 Talbert Ave., Suite 100, Fountain Valley, CA 92708

A second office in Laguna Hills, Orange County, is a location for patient care.

A third office is in a medical office building across the street from Long Beach Memorial Medical Center view details