BLOG: Rule out pathology before treating eye movement disorders
Click Here to Manage Email Alerts
When a patient presents with abnormal eye movements and complaints of dizziness, vision therapy might be the answer, but jumping to that conclusion right away would be a mistake.
Just as an optometrist needs to rule out lens or retinal pathology in making a diagnosis of refractive error, it is really important to investigate what pathology might be causing the patient’s nystagmus and vertigo. Not everyone can be an expert in all the potential causes, but eye movement patterns often hold the key to determining whether the cause is most likely cerebellar or peripheral vestibular in nature — and this can help direct the patient to effective treatment more quickly.
The peripheral vestibular system consists of structures in the ear that receive information about the position and movement of the head, as well as acceleration and gravity. Damage to any of these inner-ear structures can lead to dizziness and nystagmus.
The cerebellum is an integrator, rather than a receptor. This small structure, located at the base of the brain just behind the brain stem, packs a big punch: About 50% of the brain’s neurons are found in the cerebellum. It coordinates motor functions by integrating information from the spinal cord, sensory systems (including the eyes and ears) and other parts of the brain. Because it plays such an integral role in balance and movement, cerebellar problems are easily mistaken for vestibular ones, but they may actually be caused by medication or heavy metal toxicity, trauma, alcoholism, a stroke, infection or autoimmune disorders.
Fortunately, with a few specific questions and exam elements, clinicians can learn to recognize common eye movement patterns that facilitate a differential diagnosis between cerebellar and peripheral vestibular conditions. For example, end-gaze nystagmus in both directions (in contrast to nystagmus in one direction) is an indicator of cerebellar disease.
After differentiating between cerebellar and vestibular problems, the next step is to determine whether vision therapy is an appropriate treatment to restore lost function. In many cases, it is an essential part of re-training the brain. But in other situations, it might not help and could even be harmful if the pathology is due to an infectious or inflammatory condition or alcohol-associated thiamine deficiency.
For more information:
Brandon Brock, DNP, DC, NP-C, APRN, DACNB, works as a clinician at Foundation Physicians Group and is owner and operator of Brock Integrative Medicine in Dallas.
Brock will be a presenting a talk on the differential diagnosis of cerebellar and peripheral vestibular disorders at the NORA virtual annual conference, Sept. 12-13, 2020. For more information on the conference, please visit: www.nora2020.com.
Disclaimer: The views and opinions expressed in this blog are those of the authors and do not necessarily reflect the official policy or position of the Neuro-Optometric Rehabilitation Association unless otherwise noted. This blog is for informational purposes only and is not a substitute for the professional medical advice of a physician. NORA does not recommend or endorse any specific tests, physicians, products or procedures. For more on our website and online content, click here.
Collapse