Now accepting Telehealth appointments. Schedule a virtual visit.

eRiver Neurology of NY, LLC

Adult & Pediatric Neurology Specialists located in Poughkeepsie, Fishkill, Hudson, and Rhinebeck, NY
Now offering virtual care & appointments

Welcome to eRiver Neurology of NY

Residents of Poughkeepsie, Fishkill, Hudson, and Rhinebeck, New York, have an outstanding resource in eRiver Neurology of NY, LLC. Under the leadership of neurologist Samuel Koszer, MD, this practice has earned its reputation for excellence in all aspects of neurology care, including the diagnosis and treatment of epilepsy, Parkinson’s disease, multiple sclerosis, and neuromuscular disorders.

Dr. Koszer, the founder and managing partner of eRiver Neurology of NY, LLC, brings more than two decades of experience to his patients.

Board certified in both neurology and clinical neurophysiology, and fellowship trained in epilepsy, Dr. Koszer specializes in the most hard-to-treat manifestations of Parkinson’s disease, multiple sclerosis, and epilepsy, and has helped many patients who have failed to find relief through other treatment avenues.

At eRiver Neurology of NY, LLC, patients have access to comprehensive EEG services that provide insight into brain function. On-site rapid and innovative MRI services reduce waiting times in the current environment of limited access during Covid-19 pandemic. Infusion treatments are also conveniently available in a safe controlled in-office.

Every effort is made to ensure each of the practice’s four locations meets the needs of those in the community. Everyone deserves excellent neurological care in a setting that is well staffed and convenient, and that offers the services needed to refine and implement a customized treatment plan.

From the specialists and medical support staff to the administrative professionals who keep the offices running smoothly, every team member at eRiver Neurology of NY, LLC shares a dedication to personalized care. Patients notice that commitment from the moment they book their initial appointment through treatment and follow-up care.

Available services include management of sleep apnea, narcolepsy, insomnia, Alzheimer’s disease, and muscular diseases. Those who’ve suffered a stroke or experienced severe or recurring headaches can also find relief through advanced neurological care.

Technology is an essential part of eRiver Neurology of NY, LLC. A great deal of time and effort goes into researching the best diagnostic and treatment platforms on the market.

The technology at the practice represents the cutting edge of neurological care. The staff all receive ongoing training to leverage these tools to their greatest advantage.

Booking an appointment at eRiver Neurology of NY, LLC is as simple as a quick phone call. Patients can also schedule online using the easy booking tool, which is available at any time, day or night.

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Samuel Koszer MD
Glenn Castaneda MD
Rose Mathew DO
Kathryn McDonell DNP, FNP
Jillian Jones, NP
David Ryan, EEGT
Joyce Tuller, EEGT
Nancy Matteo, Research, LPN
Kathy Ryan, Office Manager

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Epilepsy Monitoring
Outpatient Infusions
Clinical Trials
In Office MRI

Set Up Office Infusions



We now offer Telehealth, giving you access to high quality medical care -- virtually. The process is easy, efficient, and can be done from the comfort of your home.



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    We provide outpatient infusions of medications for Multiple Sclerosis, Myasthenia Gravis and other Neurologic Diseases. This is done in a pleasant controlled setting minimizing person to person contact. Call for more information.


There are cases where standard treatments and therapies prove to be ineffective. eRiver Neurology has access to a wide variety of experimental clinical trials. When you or your doctor have exhausted all other avenues of treatments, we can offer these options with a careful scientific approach.

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    Our in office portable MRI, first of its kind! Specially designed for claustrophobic, and overweight persons, young children and those with metal non-electronic implants!

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Telehealth: The Advantages of Telemedicine

Struggles to get to the clinic? Trying to reduce your exposure to COVID-19, as well as other contagious illnesses, and still need to see your doctor? Telehealth is safe and easy — receive quality care from anywhere.

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