Spontaneous plugging of the horizontal semicircular canal with reversible canal dysfunction and recovery of vestibular evoked myogenic potentials.

OBJECTIVE: To evaluate the clinical pathophysiology of oculomotor changes in a patient presenting with a spontaneous semicircular horizontal canal plug. PATIENT: A 42-year-old man with acute spontaneous vertigo with spinning and persistent left-horizontal nystagmus, intensity but not direction dependent on head orientation with respect to gravity, indicating a benign paroxysmal positional vertigo due to otoconia causing a plug in the horizontal semicircular canal. INTERVENTION: Electrophysiological and video-oculographic testing; vestibular rehabilitation. MAIN OUTCOME MEASURES: Cervical and ocular vestibular evoked myogenic potentials (VEMPs); video head impulse testing. RESULTS: The video head-impulse test revealed an eye velocity cutoff at 80°/s in the time interval from 40 to 90 ms after initiation of head impulses to the right. This normalized within 2 days after liberatory maneuvers, documenting for the first time a reversible deficiency of the cupular-endolymph high-frequency system dynamics. Cervical and ocular vestibular myogenic potentials were absent during stimulation of the affected side before the liberatory maneuvers but normalized within 30 to 80 days. CONCLUSION: This case is special in 4 respects: 1) nystagmus intensity, but not direction, was dependent on head orientation with respect to gravity, indicating a horizontal canal plug; 2) VEMPs were asymmetrical before liberatory maneuvers; 3) VEMPs recovered after Day 30; and 4) video head-impulse test asymmetry recovered. These observations challenge the common belief that VEMPs are evoked by otolith stimulation only. Instead, the assumption of a reversible canal dysfunction by a plug offers a more plausible explanation for all effects.

Disequilibrium and its management in elderly patients.

Dizziness, a frequent occurrence in the elderly, carries substantial health and quality-of-life consequences for patients. Disequilibrium of the elderly refers to dizziness or ataxia (or both) without apparent localizing signs and is typically attributed to the aging process.In many cases, disequilibrium is multifactorial and worsened or triggered by multiple medications and iatrogenicity. This review provides an update of the literature concerning elderly multifactorial imbalance and discusses factors that may trigger falls. The author reviewed the underlying pathophysiology of disequilibrium along with an assessment of how current evaluation methods and exercise protocols are used to help prevent falls in the elderly. Patients must be stimulated to perform customized physical exercises under safe conditions, considering their general state of health. The objectives of current programs are to encourage patients to develop an efficient personalized strategy of equilibrium and to increase their level of physical activity, autonomy, and safety to reduce the potential for falls.