Earbuds Induced Benign Paroxysmal Positional Vertigo?

Abstract

Background:

Benign paroxysmal positional vertigo (BPPV) is the most common cause of peripheral vertigo. BPPV is usually idiopathic but can also result from trauma, viral labyrinthitis, or Meniere’s disease. We present a case of BPPV caused by earbuds.

Case Descripton:

This is the case of a 43-year-old male, a health care management and emergency medicine specialist, with no history of inner- or middle ear disease, vertigo and dizziness, or other medical conditions. The subject began using earbuds while driving and during routine exercise. He reported suffering from nausea and temporary vertigo after head movements in the hours following the use of the earbuds. Physical exam findings during an acute episode of vertigo correlated to BPPV with positive Dix Hallpike, suggesting posterior semicircular canal BPPV in the right ear. The use of plug-ins was stopped.

Results:

As a result of stopping the use of earbuds, the episodes of dizziness, tinnitus, and tingling sensations in the ear completely resolved. Attempting to find a replacement, he used bone-conduction headphones and did not experience any subsequent symptoms. After 6 months of using bone-conduction headphones, he had not experienced any dizziness.

Conclusion:

We suggest that earbuds may induce benign paroxysmal positional vertigo. Further research should evaluate the safety of such products.

Introduction

Benign paroxysmal positional vertigo (BPPV) is the most common cause of peripheral vertigo, ¹ characterized by sudden onset of positional vertigo with positional nystagmus. BPPV is typically idiopathic but can also occur due to trauma (eg, head trauma, dental treatment, and ear surgery), inflammatory etiologies (eg, viral labyrinthitis), or inner ear disorders (eg, Meniere’s disease). ² In the most characteristic and prevalent form of BPPV, symptoms and nystagmus start 1 to 5 seconds following head movement and last less than 60 seconds. ³ This latency period is due to the inertia of the endolymph particles, usually lasting around 2 to 5 seconds. ⁴ Diagnosis of BPPV is established by gathering a detailed medical history, including characteristic short-lasting positional vertigo triggered by head position. ⁵ The physical examination includes the Dix-Hallpike maneuver (DHM), considered the gold standard for diagnosing posterior canal BPPV. ⁶ During the Dix-Hallpike maneuver, nystagmus is provoked by head tilting. ⁷ The test begins with the patient upright on an exam table with their head turned 45° to one side. The patient then quickly lies back, so their head hangs slightly over the edge of the table. ⁶ If BPPV is present, this movement will cause the loose crystals in the semicircular canals to move, triggering symptoms of vertigo and characteristic nystagmus. ⁷ We present a case of BPPV induced by earbuds. To our knowledge, no previous research has demonstrated such an effect due to earbuds.

Case Presentation

This is the case of a 43-year-old male admitted to the Emergency Department at Shamir Medical Center. The patient is a health care management and emergency medicine specialist with no history of inner or middle ear disease, vertigo, dizziness, or other medical conditions. The patient denies any medication or other risk factors for BPPV; however, his mother had been diagnosed with BPPV when she was 60 years old.

The patient started using earbuds during his regular exercise routine and while driving. Subsequently, he began to experience episodes of vertigo and nausea, which seemed to be triggered by head movements occurring several hours post-usage. The recurrent nature of these symptoms raised concerns toward a vestibular origin, specifically BPPV. In a detailed clinical evaluation during an episode of acute vertigo, the Dix-Hallpike maneuver was employed, which is essential for diagnosing BPPV. The test provoked characteristic torsional nystagmus with a latency period, confirming BPPV in the right posterior semicircular canal. Following the diagnosis, the patient was advised to discontinue use of the earbuds, leading to complete resolution of symptoms, which underscored the connection between the earbuds use and the onset of BPPV.

We noticed temporality relations as the vertigo-related complaints started upon earbuds use, never without them, and faded away while discontinuing their use.

Attempting to find a replacement, he used bone-conduction headphones and did not experience any of his previous symptoms. After 6 months of using bone-conduction headphones, he reported no episodes of dizziness.

Discussion

Physiology and Pathology

The vestibular system encompasses three semicircular canals (SCC) (posterior, lateral, and anterior) that are perpendicular to one another to sense the angular acceleration of the head in coronal, sagittal, and transverse planes, respectively. Each SCC is filled with an endolymph fluid and hair cells in a gelatinous structure called the cupula. Acceleration in a particular direction causes movement of the endolymph in the specific SCC, which in turn induces the hair cells to signal the shift to the brain. The primary pathophysiologic mechanism of BPPV involves Canalithiasis—calcium debris (otoconia) within the SCCs that can cause disrupted movements of the endolymph by linear accelerations, such as gravity, creating a spinning sensation with head tilts. ³ Traumatic events, such as head trauma, are suspected to induce vertigo by the detachment of otoconia from the utricle’s otolithic membrane. ⁴

Earbuds as a Cause

Several possible mechanisms can be suspected to induce vertigo from earbuds use.

1. An increased pressure in the ear canal by loud noise can cause dizziness by overstimulating the hair cells. It is suspected that loud noise can induce vertigo by acting like acoustic trauma, causing vibrations in the inner ear dislodging otoconia into the SCC, resulting in vertigo. Acoustic trauma was found to lower the threshold of vestibular stimulation to voice, which can result in oversensitivity to vertigo. ⁷

2. The presence and the effects of magnetic fields produced in proximity to the inner ear may cause vertigo, as demonstrated by Strzelczyk et al in which BPPV was provoked by magnetic stimulation. ⁸

3. In noise-cancelling earbuds, another mechanism was proposed. Active noise cancellation is produced by creating frequencies opposing the background noise, thus constantly stimulating the inner ear. Such stimulation with the addition of exercising or driving, which can cause motion sickness, ⁹ can amplify this effect by further overstimulating the inner ear. By trying to eliminate background sounds, active noise cancellation can disrupt the ability of proprioception.

Vibration as a Cause

The effects of regional vibrations on the skull as potential triggers of vertigo were first studied by Lackner and Graybiel. ¹⁰ Vibrations were also found to induce nystagmus in patients with unilateral vestibular dysfunction. ¹¹ A case report described a whole-body vibration plate as an exercise that provoked BPPV in a 44-year-old female. ¹²

Today, the primary treatment option for BPPV is the Epley maneuver, which tries to reposition the otoliths back into the utricle by utilizing gravity. ¹³ Simoceli et al showed the addition of mastoid vibration during the Epley maneuver improves outcomes of those patients by inducing the mobilization of otoliths. ¹⁴ A case-control study by Tzu-Pu Chang demonstrated the correlation between dental procedures and BPPV and proposed that the vibratory or percussive tools in dental therapy might result in loosening and detachment of otoliths over time. ¹⁵

A recent study by Sayal et al has shown that the mechanical vibrations from electric toothbrushes are not associated with recurrent BPPV. ¹⁶

Bone Conduction

The bone-conducting abilities of the inner ear have been known and utilized for many years, mainly with aiding in conductive hearing loss disorders with products such as BAHA (bone-anchored hearing aid). ¹⁷ In recent years, these technologies have become more prevalent in headphones, mainly for leisure, such as listening to music during sports and swimming. These bone-conduction headphones are placed on the zygomas, leaving the ear canal open to enable a higher surrounding awareness than earbuds and an over-ear headset. The bone-conduction headphones enable sound conduction to the cochlea by producing regional vibrations.

Conclusions

Our study describes the case of BPPV due to earbuds in a 43-year-old male with no risk factors aside from family history. We suspect that the earbuds induced BPPV by mechanical stimulation of vibrations that were transmitted to the inner ear, causing dislodgement of the otoliths. As far as we know, no research has demonstrated this effect.

We suggest further research to establish recommendations regarding the safe use of earbuds.