Dr. Nathan Keiser
DC, DACNB, FABBIR
Board Certified Chiropractic Neurologist
The Keiser Clinic · Chelsea, Michigan
Background
Dr. Nathan Keiser is a board-certified chiropractic neurologist specializing in POTS, dysautonomia, post-concussion syndrome, traumatic brain injury, and cerebral blood flow regulation. He was certified as a diplomate in chiropractic neurology by the American Board of Chiropractic Neurology (ACNB) in 2010 and is a Fellow of the American Board of Brain Injury and Rehabilitation (FABBIR).
He has treated patients from 48 US states and 17 countries at The Keiser Clinic in Chelsea, Michigan. His clinical approach is mechanism-first: identifying the specific neurological, vascular, and structural failures driving each patient's symptoms rather than managing symptoms with medication.
Academic & Teaching
Dr. Keiser serves as Assistant Professor of Clinical Neurology at the Carrick Institute, which provides post-graduate instruction for doctors of all disciplines in clinical and functional neurology. He is actively involved in ongoing research and presents regularly across North America and Europe.
Clinical Focus
- POTS (Postural Orthostatic Tachycardia Syndrome)
- Dysautonomia and autonomic dysfunction
- Cerebral blood flow regulation and orthostatic cerebral hypoperfusion
- Post-concussion syndrome and traumatic brain injury
- Vestibular disorders
- ME/CFS (Myalgic Encephalomyelitis / Chronic Fatigue Syndrome)
- Long COVID neurological symptoms
Diagnostic Approach
Dr. Keiser's clinic uses transcranial Doppler ultrasonography to measure cerebral blood flow velocity during tilt testing, capnography to monitor CO2 dynamics, video-oculography for eye movement assessment, and comprehensive autonomic stress testing. These tools allow identification of mechanisms that standard autonomic testing cannot detect, including orthostatic cerebral hypoperfusion syndrome (OCHOs) and hypocapnic cerebral hypoperfusion (HYCH).
Credentials
- DC — Doctor of Chiropractic
- DACNB — Diplomate, American Chiropractic Neurology Board (certified 2010)
- FABBIR — Fellow, American Board of Brain Injury and Rehabilitation
- Assistant Professor, Clinical Neurology, Carrick Institute