Case Study: Depersonalization and Vestibular Impairment

Background We describe herein the case of a patient whose primary complaints were episodic vertigo and “depersonalization,” a sensation of detachment from his own body. Purpose This case study aims to further clinical knowledge and insight into the clinical evaluation of vertiginous patients with complaints of depersonalization. Research Design This is a case study. Data Collection and Analysis A retrospective chart review of vestibular function testing done on a vertiginous patient with complaints of depersonalization was performed. Results Vestibular function testing revealed absent cervical and ocular vestibular evoked myogenic potentials on the left side with normal vHIT or video Head Impulse Test, videonystagmography, and rotational chair results, suggesting peripheral vestibular impairment isolated to the left saccule and utricle. Conclusion The otolith end organ impairment explains the patient's postural deviation to the left side during attempts to ambulate. We recommend that clinicians should be attentive to patient complaints of depersonalization and perform vestibular evoked myogenic potential testing to determine whether evidence of at least a unilateral peripheral otolith end organ impairment exists.

Vestibular assessment of a patient with myasthenia gravis: case report

Vestibular Assessment in patients with Myasthenia Gravis (MG) is challenging, as diagnostic evaluation requires good recording of eye movements. Reports on Vestibular Function Testing (VFT) in MG patients have been scant and it is arguable that VFT will have little clinical value in the MG population. A 75-year-old man, with late onset acquired autoimmune MG presented with dizziness for evaluation. He completed VFT with no significant abnormalities in all tests and was elated to have vestibular ruled out as a contributing factor to his dizziness and imbalance. However, his functional impairments were still addressed and managed regardless of the test results. MG is a heterogenous condition that may be well-controlled with treatment. Patients with dizziness can still be diagnostically evaluated to rule in or out a vestibular involvement and should not be precluded from VFT. Patients should also be assessed for their functional impairments and not based on symptom checklist and objective test results alone. Hence, patients with normal VFT results can still benefit from a hybrid of vestibular rehabilitation therapy (VRT) with focus on habituation.

Dizziness demystified

Four vestibular presentations caused by six different disorders constitute most of the neuro-otology cases seen in clinical practice. ‘Acute vestibular syndrome’ refers to a first-ever attack of acute, spontaneous, isolated vertigo and there are two common causes: vestibular neuritis / labyrinthitis and cerebellar infarction. Recurrent positional vertigo is most often caused by benign paroxysmal positional vertigo and less commonly is central in origin. Recurrent spontaneous vertigo has two common causes: Ménière's disease and vestibular migraine. Lastly, chronic vestibular insufficiency (imbalance) results from bilateral, or severe unilateral, peripheral vestibular impairment. These six disorders can often be diagnosed on the basis of history, examination, audiometry, and in some cases, basic vestibular function testing. Here we show that most common neuro-otological problems can be readily managed by general neurologists.

Quantitative Vestibular Function Testing in the Pediatric Population

Quantitative tests of vestibular function include the caloric test, cervical and ocular vestibular evoked myogenic potential (VEMP), rotary chair, and head impulse test, either at the bedside or utilizing video head impulse test (vHIT). The purpose of this article is to provide an overview of how to perform these tests in children, including which tests are recommended based on the child's age and any modifications or considerations that can be made. A variety of clinical measures have been recommended as screening measures for vestibular loss, which will be reviewed. Symptom questionnaires designed to assess the functional impact of dizziness and vestibular loss in children will also be discussed. If a child complains of dizziness or if vestibular loss is suspected (either by case history or positive screening measure), vestibular function testing is warranted. For vestibular function testing, children aged 0 to 2 years typically receive rotary chair, cervical VEMP, and vHIT if a remote system is available. For children aged 3 to 7 years, vHIT, cervical VEMP, and ocular VEMP are completed, and for children aged 8+ years, vHIT, caloric testing if vHIT is normal, and cervical and ocular VEMP are completed. For all children, modifications to testing can be made, as needed.

The Influence of Caffeine on Rotary Chair and Oculomotor Testing

When patients are given instructions before vestibular function testing, they are often asked to refrain from ingesting caffeine 24 h before testing. However, research regarding the effects of caffeine on the outcome of vestibular function testing is limited.To evaluate whether the results from rotational chair tests are influenced by caffeine.Participants were tested after consuming a caffeinated beverage (i.e., coffee containing ∼300 mg of caffeine), as well as after abstaining from caffeinated beverages. The participants underwent oculomotor testing, sinusoidal harmonic acceleration testing, optokinetic testing, visual enhancement/suppression testing, subjective visual vertical/horizontal testing, trapezoidal step testing, and unilateral utricular centrifugation testing.Thirty healthy young controls aged 18–40 yr (mean = 23.28 yr; 9 males, 21 females) participated in the study.Rotational chair tests were completed with the Neuro Kinetics rotary chair (Pittsburgh, PA). VEST 7.0 software was used to collect and analyze the participants’ eye movements (I-Portal VOG; Neuro Kinetics). IBM SPSS was used to statistically analyze the results.Statistically significant differences were found for the results from several oculomotor tests (i.e., vertical saccades [SCs], horizontal SCs, and optokinetics), whereas the remaining rotational chair tests did not reveal any statistically significant differences between sessions. If a statistically significant difference was found, the participants were then stratified based on the amount of caffeine they consumed on a daily basis. This stratification was accomplished based on the guidelines from the International Coffee Organization. When the data were analyzed based on the stratified groups, statistically significant results remained in the no/low caffeine intake group, whereas no statistically significant results remained in the moderate/high caffeine intake group. Clinically speaking, the largest effect was seen in those individuals who did not typically ingest large amounts of caffeine, whereas the results were not found to be significantly different in those individuals who were typical caffeine consumers. This strengthens the argument that it is not necessary to require that individuals refrain from consuming caffeinated beverages before oculomotor/rotary chair testing as the results from typical caffeine consumers are not significantly affected.Although statistically significant results were found for a number of the oculomotor function tests, the ingestion of caffeine had little influence on the clinical interpretation of the responses. Therefore, the results from the present study indicate that it is not necessary to require that healthy young individuals abstain from caffeine before undergoing rotary chair/oculomotor testing. Further research is necessary to determine whether there is also a limited effect of caffeine on rotary chair/oculomotor test results from older individuals, as well as individuals diagnosed with a vestibular impairment.