MY APPROACH to Managing the Dizzy Patient at a Center of Balance
Dizziness is a common complaint by patients seeking medical attention and the second most frequently reported symptom post concussion.1,2 The balance system is controlled by signals to the brain from the eyes (visual system), the inner ear (vestibular system), and the sensory systems of the body, including muscles and joints (somatosensory system). Disruption to any one or more of these coordinating systems can lead to visual symptoms and complaints of dizziness and disequilibrium. Oftentimes, the etiology of dizziness is multifactorial and, thus, requires an interdisciplinary approach.
The Center of Balance at our health center is an interprofessional clinic designed for patients with symptoms of dizziness, imbalance, and disequilibrium. When a referral is made to the clinic, an audiologist, an optometrist specializing in neuro–vision rehabilitation, and a physical therapist specializing in vestibular therapy perform evaluations and develop a comprehensive rehabilitative treatment plan. Some management plans require further referral to cardiology, physiatry, psychology, or behavioral health, while others may include vestibular, physical, or vision rehabilitation. This case demonstrates the value of an interdisciplinary approach to managing the dizzy patient, and, in particular, the important role of the neuro–optometrist as part of the rehabilitation team.
Presenting profile and symptoms
KM, a 45-year-old female, was referred from the ear, nose, and throat (ENT) specialist to our Center of Balance. She reported horizontal diplopia at near after about 20 minutes of reading (most symptomatic when looking up and down from her phone), eyestrain, and nausea when scrolling through her phone or computer screens. She also reported a general sensation of disequilibrium that worsened in crowded environments. These symptoms became noticeable after a motor vehicle accident where she was rear-ended in July 2018.
Of note, KM was previously prescribed Meclizine, an antihistamine medication used to suppress the central emetic center, by her ENT doctor without complete resolution of her symptoms of dizziness. She was no longer taking Meclizine when she presented for her vision evaluation.
Pertinent clinical findings
KM’s best corrected visual acuities were 20/20 OD/OS at distance and near, with low hyperopia (+1.00 DS OD, +1.25 DS OS) and presbyopia (Add: +1.50). KM presented to the vision evaluation wearing progressive addition lenses (PALs), which were prescribed by her primary care optometrist. KM reported no issues when she started wearing the PALs (prior to the motor vehicle accident). However, post accident, she reported the glasses were not as comfortable, especially when looking up and down from her phone.
Her ocular motor control demonstrated stable fixation in both eyes, but jerky movement with few fixation losses on pursuit and few saccadic intrusions in all gazes. Extraocular muscles were full and unrestricted, with no diplopia or pain reported.
KM’s binocular function showed moderate exophoria at near (10 prism diopter [pd] exophoria) with a receded near-point of convergence (NPC) and poor regrasp and recovery (break, 10 cm; recovery, 14 cm). Her fusional reserves were restricted and inadequate for her visual needs (Near BI: x/8/4; BO: x/12/2). On the dynamic visual acuity test,3 KM was able to read the 20/30 line with five rounds of head shaking, but reported that the letters were blurred with momentary doubling. KM was only able to complete eight cycles of the Tannen prism flipper test4 (TFT) with more difficulty with base-in. Peripheral OKN test4 showed increased discomfort in the inferior quadrant with a scale of 4, while the other quadrants were a scale of 1. Free-space testing was performed when possible. Testing was completed through KM’s habitual PALs.
Audiology and vestibular evaluations
Audiology evaluation indicated normal hearing bilaterally. Videonystagmography confirmed abnormal saccades (poor velocity) and abnormal tracking (slow pursuits) with normal positional and caloric tests.
Vestibular therapy evaluation demonstrated that dizziness was exacerbated with head movement and peripheral motion. Standing balance test demonstrated increased sway, loss of balance, dizziness, and nausea with eyes closed; eyes open was within normal limits. Tandem Romberg test showed excessive swaying with eyes closed; eyes open was within normal limits. Dynamic balance walk revealed poor balance during turns with head/eye movement. Finally, the evaluation confirmed vestibulo–ocular reflex impairment and limited cervical mobility, and ruled out benign paroxysmal positional vertigo.
Diagnoses and treatment
KM was diagnosed with convergence insufficiency, deficit of pursuits and saccadic eye movements, visual–vestibular dysfunction, visual–motion sensitivity, hyperopia with presbyopia, and post-concussion syndrome. In this case, it was decided that KM would be best managed by the vision clinic initially as the symptoms were primarily visually related.
After a trial of several tint colors (Chadwick Optical NORA Polytrauma Filter Kit), KM was prescribed E-30 blue tint. She reported feeling most comfortable with this color and scrolling through screens was more tolerable. Binasal occlusion was prescribed to help reduce the binocular visual field overlap and potentially decreased “visual noises,” allowing for KM to feel more grounded.5 Base-in prism was prescribed to alleviate some of KM’s symptoms of convergence insufficiency, while she completed a program of neuro–optometric rehabilitation therapy (NORT).
For her final spectacle prescription, therefore, KM was prescribed single-vision distance glasses with binasal occlusion and single-vision near glasses with 3pd base-in prism (even split between OD and OS) with E-30 blue tint. Binasal occlusion was only prescribed for the distance glasses as KM reported a general sensation of disequilibrium that was provoked in busy environments such as grocery stores. Sheard’s criterion was used as an estimate for the magnitude of prism required, which suggested about 2.67pd of base-in. However, when we trialed the prisms, starting with 2pd, then 2.5pd, then 3pd of base-in, KM reported best binocularity and comfort with the latter.
KM was also prescribed 20 sessions of NORT to improve ocular motor control, fusional vergence ranges, automaticity of fusional vergence, and the loading of visual–vestibular processing, which in turn improved balance and reduced symptoms of dizziness and disequilibrium. The vision rehabilitation treatment plan was individualized to KM’s subjective and clinical presentation, but it followed a general progression as follows: 1) enhance accuracy and awareness of fixation, pursuit, and saccade; 2) establish strong relative depth awareness; 3) enhance fusion stability and increase speed of fusion recovery; 4) expand fusional vergence ranges and accommodative amplitude; 5) integrate visual–vestibular loading in a controlled fashion; and 6) load additional multisensory information processing (auditory, cognition, and balance).
Treatment outcome
After approximately 5 months of NORT, KM reported that she was able to read with no diplopia or eyestrain and felt more stable when walking, and she reported significant improvement in her symptoms of dizziness. Her ocular motor control was full and smooth with no saccadic intrusions. NPC was “to the nose” with fast regrasp and recovery. Her binocular function showed low exophoria at near (4pd exophoria) with adequate compensating fusional ranges (near BI: x/16/12; BO: x/24/20). KM also passed the dynamic visual acuity test with no report of blur or double vision with five rounds of head shaking. We also reevaluated the peripheral OKN test, and KM reported no discomfort in the left, right, and superior quadrant, and a 1 level of discomfort in the inferior quadrant (initially, she reported a 4). Additionally, she was able to complete 10 cycles of the TFT, an improvement from 8 cycles at the initial evaluation.
Binasal occlusion was removed after 12 sessions of NORT and base-in prism was removed at the conclusion of therapy. We considered reducing the amount of base-in prism as KM progressed through NORT. However, due to financial constraints, KM did not want to purchase a new pair of single-vision reading glasses. We advised KM to return to using her old PALs (which had no prism) to build up tolerance. We informed her that, if she began experiencing double vision and eyestrain with prolonged near work, she can switch back to the single-vision reading glasses with prism.
At the final evaluation, KM was prescribed updated spectacle PALs with E-15 blue tint. As a result of the improvement in her binocular vision, she was able to tolerate PAL glasses, such as looking up and down through the lenses. KM also preferred PALs because they were more convenient as she did not have to switch between single-vision distance and near glasses.
Conclusion
Overall, an interprofessional approach allows for the most effective management of the dizzy patient. This case demonstrates that, when symptoms of dizziness and disequilibrium are exacerbated by head movement and peripheral motion with underlying binocular vision dysfunctions, optometrists with special training in neuro–vision rehabilitation are the most appropriate providers to begin treatment.
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Additional Info
- Cohen AH. Vision rehabilitation for visual-vestibular dysfunction: the role of the neuro-optometrist. NeuroRehabilitation. 2013;32(3):483-492.
- Maskell F, Chiarelli P, Isles R. Dizziness after traumatic brain injury: overview and measurement in the clinical setting. Brain Inj. 2006 Mar;20(3):293-305.
- Huh YE, Kim JS. Bedside evaluation of dizzy patients. J Clin Neurol. 2013 Oct;9(4):203-213.
- Tannen B, John J, Ciuffreda K, Shelley-Tremblay J. Assessment of Three Clinical Tests for Evaluation of Concussion/Mild Traumatic Brain Injury. Vision Dev & Rehab. 2021; 7(1): 43-49.
- Ciuffreda KJ, Yadav NK, Ludlam DP. Binasal Occlusion (BNO), Visual Motion Sensitivity (VMS), and the Visually-Evoked Potential (VEP) in mild Traumatic Brain Injury and Traumatic Brain Injury (mTBI/TBI). Brain Sci. 2017;7(8):98.