Physical Examination - To understand proper naming, it is important to note that nystagmus has a fast and slow phase whereby the eye jerks quickly in one direction then moves slowly back in the other direction. The naming of nystagmus is based on the fast phase alone. Have the patient follow your finger with their eyes only. Hold the chin in your other hand to prevent movement. Nystagmus is most easily observed on extreme lateral gaze. Have the patient slowly follow your finger in one direction with both eyes then swing the finger quickly to the other side to observe for nystagmus upon the patient tracking the finger. Note the type of movement (horizontal, vertigo, rotary) and whether it is fatiguable (stops after certain number of beats) or non-fatiguable.
Clinical Significance – Nystagmus can be seen in a variety of conditions, including benign positional vertigo, stroke, Wernicke-Korsakoff Syndrome, multiple sclerosis, brain tumors, alcohol, and certain drugs.
Patients with horizontal nystagmus on exam should be further evaluated with a Dix-Hallpike maneuver to assess for benign positional vertigo.
Dix-Hallpike Maneuver – Once horizontal nystagmus found on physical exam or if vertigo is suspected, a Dix-Hallpike maneuver can be done to assess for benign positional vertigo (BPV).
Epley Maneuver – Once BPV is identified through the Dix-Hallpike maneuver, the Epley maneuver can be done to change the location of particles in the semicircular canal and thus possibly alleviate the symptoms of vertigo.
*Figure to left taken from the Journal of American Osteopathic Association