Block: Eyes & Brain
Length: Half Day
Abstract: Causes of dizziness include benign inner ear conditions as well as more severe and dangerous brain disorders such as stroke. In patients affected with acute dizziness and vertigo, eye movement examination outperforms neuroimaging for diagnosing stroke. For this reason, eye movements are routinely examined and recorded in neurology and neuro-otology clinics around the world. The use of eye movements is widespread in many fields of clinical research, including neurology, psychology and psychiatry. However, in many occasions, eye movement recordings have remained restricted as research tools and have not made their way to the clinic. Here, instead, we will focus on use cases where eye movements directly provide information that can be diagnostic, either on their own or in combination with a few other pieces of data such as patient’s history. In some cases, clinician’s examination is just qualitative and consists in looking directly at the patient’s eyes. In other cases, eye movements are recorded, typically with video infrared goggles, and become part of the clinical record of the patient. This tutorial will describe the tests that are regularly performed in the clinic to aid physicians in the diagnosis of patients with dizziness, oscillopsia, or double vision. These tests include the head impulse test, the test of skew, Dix-Hallpike maneuver, interpretation of nystagmus, etc. To properly understand the rationale of these tests we will first cover the basic concepts of eye movement control together with the relevant anatomy and physiology.
Scope: The tutorial will review behavioral properties and the neural substrate for the fundamental types of eye movements: vestibular-optokinetic reflex, saccades, smooth pursuit, gaze holding and fixation, and vergence. Then, it will review the clinical tests most used in neurology, otolaryngology, and ophthalmology clinics to diagnose patients affected with dizziness, oscillopsia, and double vision. Interpretation of these tests allows the clinicians to identify the disease and, in some cases, localize the lesion with more accuracy than neuroimaging.
Audience: The tutorial audience will be anybody interested on basic properties of eye movements and the neural circuits responsible for their control as well as researchers interested in clinical applications of eye movement recordings.
Teachers: Jorge Otero-Millan is a postdoctoral fellow in the Department of Neurology at Johns Hopkins University currently working in the laboratory of David S. Zee, author of the book “The Neurology of Eye Movements”. In July 2020 Jorge will join the faculty of the University of California at Berkeley as an Assistant Professor in the School of Optometry. With a background in engineering, during his PhD and Postdoctoral training, Jorge has collaborated with Neurologists, Ophthalmologists, and Otolaryngologists analyzing eye movements of patients suffering from disorders affecting the brain, the eyes, or the inner ear.