NEJM Resident E-Bulletin
J.-S. Kim and D.S. Zee
Benign paroxysmal positional vertigo (BPPV) is by far the most common type of vertigo, with a reported prevalence between 10.7 and 64.0 cases per 100,000 population and a lifetime prevalence of 2.4%.
The condition is characterized by brief spinning sensations, usually lasting less than 1 minute, which are generally induced by a change in head position with respect to gravity. Vertigo typically develops when a patient gets in or out of bed, rolls over in bed, tilts the head back, or bends forward. Even though patients with BPPV occasionally report persistent dizziness and imbalance, a careful history taking almost always reveals that their symptoms are worse with changes in head position. Many patients also have nausea, sometimes with vomiting. Attacks of BPPV usually do not have a known cause, although cases may be associated with head trauma, a prolonged recumbent position (e.g., at a dentist’s office), or various disorders of the inner ear. Spontaneous remissions and recurrences are frequent; the annual rate of recurrence is approximately 15%. Patients with BPPV are at increased risk for falls and impairment in the performance of daily activities. The prevalence of idiopathic BPPV is increased among elderly persons and among women, with peak onset between 50 and 60 years of age and a female-to-male ratio of 2:1 to 3:1.
The fundamental pathophysiological process in BPPV involves dislodged otoconia from the macula of the utricular otolith that enter the semicircular canals. When there is a change in the static position of the head with respect to gravity, the otolithic debris moves to a new position within the semicircular canals, leading to a false sense of rotation. BPPV usually arises from the posterior semicircular canal, which resides in the most gravity-dependent area of the labyrinth; this type of BPPV accounts for 60 to 90% of all cases.
A. In patients with BPPV that involves the posterior canal, nystagmus is typically induced with the use of the Dix–Hallpike maneuver. In this maneuver, with the head turned to one side at angle of 45 degrees, the patient is moved from a sitting position to supine position, with the head hanging below the examination table. The induced nystagmus is upbeat and ipsiversive torsional (the upper pole of the eyes beats toward the side of the affected [lower] ear). When there is movement of otolithic debris (canalolithiasis) in the posterior canal away from the cupula, the endolymph flows away from the cupula, stimulating the posterior canal. The nystagmus usually develops after a brief latency period (2 to 5 seconds), resolves within 1 minute (typically within 30 seconds), and reverses direction when the patient sits up. With repeated testing, the nystagmus diminishes, owing to fatigability. If the otoconia become attached to the cupula (cupulolithiasis), the evoked nystagmus is similar to that observed in canalolithiasis but is usually longer in duration. A positive response to the Dix–Hallpike maneuver, in which the nystagmus beats in the correct direction, is the standard for diagnosing BPPV involving the posterior canal.
Table 2. Diagnosis and Treatment of Benign Paroxysmal Positional Vertigo According to the Affected Canal.
Figure 1. Use of the Dix–Hallpike Maneuver to Induce Nystagmus in Benign Paroxysmal Positional Vertigo Involving the Right Posterior Semicircular Canal.
A. BPPV typically resolves without treatment. A prospective longitudinal study showed that the median interval between the onset of symptoms and spontaneous resolution in untreated patients was 7 days when the horizontal canal was affected and 17 days when the posterior canal was affected. However, canalith-repositioning maneuvers can be used to treat BPPV promptly and effectively. Medications are primarily used to relieve severe nausea or vomiting. For example, Epley’s canalith-repositioning maneuver was designed to flush mobile otolithic debris out of the posterior canal and back into the vestibule. The otoconia move around the canal with each step of the maneuver and eventually drop out into the vestibule, where they can be resorbed. Each position should be maintained until the induced nystagmus or vertigo dissipates, but always for at least 30 seconds. The success rate with Epley’s maneuver is about 80% after one session and increases to 92% with repetition up to four times. The Semont maneuver can also be used to treat BPPV involving the posterior canal.
Figure 2. Epley’s Canalith-Repositioning Maneuver for the Treatment of Benign Paroxysmal Positional Vertigo Involving the Right Posterior Semicircular Canal.
Figure 3. Semont’s Repositioning Maneuver for Benign Paroxysmal Positional Vertigo Involving the Right Posterior Semicircular Canal