Abstract
Benign paroxysmal positional vertigo (BPPV) is a common cause of vertigo. Etiology may vary across the lifespan, with repetitive, strenuous, or traumatic head movements more likely in children and young adults. Migraine may be a contributory factor in both children and adults, and a search for a migraine history is appropriate in recurrent BPPV in younger age groups. BPPV is more commonly reported in older adults, and the incidence increases with age. The pathophysiology and treatment of posterior and lateral semicircular canal BPPV are reviewed, and evidence-based outcome data are summarized.
Keywords
BPPV, Canalith repositioning, Dix-Hallpike, Lateral semicircular canal, Nystagmus, Posterior semicircular canal, Vertigo
Introduction
Benign paroxysmal positional vertigo (BPPV) is one of the most common vestibular disorders with an estimated lifetime prevalence of 2.4% in the general adult population. Out of the 5.6 million clinic visits in the United States for dizziness per year, it is estimated that 17%–42% of patients with vertigo receive a diagnosis of BPPV. Although this disorder ranges across the lifespan, it tends to disproportionately affect older individuals aged 50–70 years and therefore has some noteworthy societal burdens. For example, it is estimated that $2000 is spent on average to diagnose BPPV, and that 86% of patients have interruption in their daily activities and lost workdays because of their vertigo symptoms. Furthermore, older patients with BPPV have a greater incidence of falls and impairments to their daily activities. These falls can result in secondary injuries including hip fractures and can lead to additional costs from hospital and nursing home admissions. Therefore, this disorder not only affects an individual’s quality of life but adversely affects society as well.
The true incidence and prevalence of BPPV are difficult to accurately estimate. Older studies have looked at the incidence of BPPV. For example, a study in Japan estimated the incidence of BPPV to be 0.01%, while a study in Minnesota estimated the incidence to be 0.06%, with a 38% increase in incidence with each decade of life. However, it is likely that these early epidemiologic studies were underestimates, as they only included patients who presented to physicians with their acute vestibular problem and did not include those who never sought medical care for their symptoms. A more recent study done in Germany looked at the estimated prevalence and incidence of BPPV in the general adult population using a cross-sectional, nationally representative survey of the general adult population in Germany. A prevalence of 2.4% overall with 3.2% in females and 1.6% in males was reported, and the 1-year incidence was calculated at 0.6%, approximately 10 times higher than earlier estimates. The 1-year prevalence was also determined as a function of age in this study. In patients aged 18–39 years, the estimated prevalence was 0.5%, whereas the 1-year prevalence for patients aged 40–59 years was 1.7%. Finally, for patients older than 60 years, the estimated prevalence was 3.4%.
Benign Paroxysmal Positional Vertigo Across the Lifespan
There are very few published reports of patients with BPPV younger than 18 years. However, one series of case reports by Giacomini described nine patients who developed BPPV after intense physical activity. Seven of these patients were younger than 36 years. There was one 16-year-old girl who developed BPPV after an intense dolphin stroke–style swimming activity. She was diagnosed with posterior semicircular canal (PSC) BPPV on the left. Our personal communication with Giacinto Asprella-Libonati, MD, noted that in his experience, approximately 1% of BPPV patients seen per year are pediatric patients aged 3–14 years. He reports that it is important to examine these children within 24–48 hours, as the diagnosis was able to be made in only 25% of patients referred to him by pediatricians. There seems to be a higher spontaneous resolution of BPPV in children, probably due to their continuous head movements when playing games. PSC-BPPV was the most common form (about 80% of patients), followed by lateral semicircular canal (LSC) BPPV (20% of patients). The patients’ BPPV was generally related to recent minor head trauma in the previous 24–48 hours (domestic injuries, sports injuries, school injuries, dental care). Interestingly, pediatric patients with recurrent BPPV usually had a family history of migraine. These patients had more episodes of typical BPPV not preceded by head injury, often with involvement of multiple canals (LSC and PSC) in subsequent episodes (Giacinto Asprella-Libonati, MD, Italy, personal communication, August 2010).
In our experience with adults aged 18–39 years, risk factors for BPPV include certain activities such as yoga, pounding activities such as running on pavement, working underneath objects such as cars, and repetitively reaching high up for things such as books. Giacomini also found that activities such as intense aerobic activity, jogging, running on the treadmill, and swimming were associated with BPPV in individuals aged 18–39 years.
Finally, in people older than 40 years, causes of BPPV include head trauma or association with other ear disorders, such as vestibular neuritis or labyrinthitis. In adults of all ages, certain movements and head positions are likely to provoke the vertigo associated with BPPV, including lying back in bed, arising quickly, looking up, bending over, or reclining for dental or hairdressing procedures.
Recent work has suggested a correlation of recurrent episodes of positional vertigo with migraine, which is why the prevalence in females may be higher, as there is a higher incidence of migraine in women. Vestibular migraine may cause episodic positional nystagmus that is difficult to differentiate from BPPV (see Chapter 11 ). The short duration of episodes (1–2 days) and frequent recurrence in otherwise healthy young patients with a history of migraine meeting International Headache Society criteria often aid in making this diagnosis. Particle repositioning maneuvers are usually not effective in vestibular migraine. The positional nystagmus seen with vertigo during vestibular migraine attacks may also appear atypical or have central features.
Pathophysiology of Benign Paroxysmal Positional Vertigo
Regardless of age, the pathophysiology of BPPV does not change. BPPV is likely caused by otoconia that fall into the PSC or LSC after becoming detached from the utricle. The reasons for the detachment are many but include age, trauma, and infection. Schuknecht was the first to suggest that these basophilic deposits on the cupula of the PSC are the cause of BPPV. However, further work and intraoperative observations suggest that these canalithic particles are likely to be floating in the PSC or LSC where they render the canal gravitationally sensitive.
Approximately 94% of BPPV cases involve the PSC-BPPV. Dix and Hallpike first observed this in 1952 and developed the head maneuver that produces the characteristic ipsidirectional torsional nystagmus used to identify BPPV. During this maneuver, the patient’s head is turned 45 degrees to one side while seated. The patient is then moved quickly to a supine position with the neck slightly extended and the head remaining turned. The characteristic ipsidirectional torsional nystagmus is seen when the undermost ear is affected. The patient is then brought back up to a sitting position, and the nystagmus is often noted to reverse direction as the canalithic particles fall back into the canal by gravity. The characteristics of BPPV nystagmus include onset after several seconds, a decline in eye speed velocity over 10–30 seconds and diminished nystagmus velocity on immediately repeating the Dix-Hallpike test ( Fig. 9.1 ). Although Dix-Hallpike testing needs no special equipment, visualization of nystagmus can be aided by the use of infrared video or optical Frenzel lenses, which eliminate visual fixation.
Lateral (horizontal) canal involvement is the next most common variant of BPPV, constituting 5%–15% of BPPV cases. LSC-BPPV was first described by McClure in 1985 and is characterized by nystagmus provoked by supine bilateral head turns beating toward the undermost ear. Two distinct subtypes of LSC-BPPV based on the direction of horizontal nystagmus during supine head turns are geotropic and apogeotropic. Geotropic LSC-BPPV beats toward the undermost ear on supine positional testing. The horizontal nystagmus has a short latency and prolonged duration with poor fatigability. This is thought to be caused by canalithic particles moving under the influence of gravity within the long arm of the LSC, which in turn causes the stimulation of utriculopetal endolymph flow when the affected ear is undermost ( Fig. 9.2 ). Apogeotropic LSC-BPPV is characterized by a similar short latency and prolonged duration of horizontal nystagmus, but the direction beats away from the undermost ear, during supine positional testing. Apogeotropic LSC-BPPV was reported by Pagnini and Baloh in 1995. Factors likely responsible for apogeotropic LSC-BPPV include otoconial debris that adheres to the cupula of the lateral canal, causing the cupula to become gravity sensitive (cupulolithiasis), or otoconia trapped in the proximal segment of the lateral canal near the cupula ( Fig. 9.3 ).
Diagnosis and Treatment
Initially, BPPV treatments were exercise based and emphasized compensation and habituation. However, specific canalith repositioning maneuvers based on an improved understanding of the pathophysiology of BPPV have been developed in the last 20 years and are now the standard of treatment. Canalith repositioning maneuvers for PSC-BPPV include the Semont, the Epley, and a modified Epley maneuver performed without mastoid vibration ( Fig 9.4 ). There is good evidence that vestibular suppressant medication is not as effective as repositioning maneuvers and vestibular therapy for treatment of BPPV.
Although Dix-Hallpike testing is highly sensitive to PSC-BPPV, it lacks sensitivity in LSC-BPPV. For this reason, testing patients suspected of having BPPV should include Dix-Hallpike positioning to head hanging right and left positions and supine position testing in the head center, right ear down, and left ear down positions. The Dix-Hallpike test was entirely negative in case reports of two patients whose horizontal nystagmus with lateral supine head turns reached 12 and 16 degrees/second. In four other patients, the horizontal nystagmus observed in Dix-Hallpike positions appeared to beat in the contralateral direction to that observed during supine positional testing (one geotropic and three apogeotropic). Furthermore, in most of the other patients with LSC-BPPV, the nystagmus that occurred during Dix-Hallpike testing had a lower velocity than that seen on supine positional testing.
Identification of the involved ear in LSC-BPPV can be especially difficult because the semicircular canals are coplanar, and nystagmus is seen in both lateral supine positions. Order effect and head tilt may also affect the direction of nystagmus. In geotropic LSC-BPPV, the nystagmus velocity is highest with the affected ear down. Treatment for geotropic LSC-BPPV consists of full-body 360-degree roll maneuvers toward the unaffected ear at 90-degree increments every 30–60 seconds, beginning with the patient in the supine position with the head flexed to 30 degrees and laterally rotated toward the affected ear. The Gufoni maneuver is also highly effective and is performed with the patient beginning in the sitting position and lying quickly to the unaffected side and then rotating the head 45 degrees downward, maintaining this position for 2 to 3 minutes as described in Casani.
Treatment for apogeotropic LSC-BPPV consists of a variety of maneuvers because none is universally effective. Identification of the affected ear can be more challenging in apogeotropic LSC-BPPV. Nystagmus velocity is usually higher with the affected ear uppermost, and spontaneous nystagmus (which usually beats toward the involved side) is occasionally seen in the supine position. The Lempert 360-degree roll maneuver toward the unaffected ear may be used first. The modified Gufoni maneuver can also be performed with the patient beginning in the sitting position and lying quickly to the affected side and then rotating the head 45 degrees upward, maintaining this position for 2–3 minutes, as described by Appiani. Vannucchi-Asprella maneuvers are performed by briskly moving the patient from the sitting to the supine position and turning the head rapidly to the unaffected side, and then returning to sitting and moving the head back to midline. This maneuver is repeated five to eight times in rapid succession.
Finally, anterior semicircular canal BPPV is a controversial entity. Some investigators suggest that the paroxysmal nystagmus has a pure or torsional downbeat component in contrast to posterior canal, which has a vertical upbeat component. Because the same maneuvers used to treat PSC-BPPV appear effective for suspected anterior canal involvement (although they may be performed on the contralateral side in some reports), the question may have more theoretical than clinical relevance.
Efficacy of Treatment
Multiple studies have investigated efficacy of treatment by comparing subjective assessment of patient self-reported vertigo frequency and severity and an objective assessment using repeated Dix-Hallpike testing. These studies have noted a poor correlation between self-report and Dix-Hallpike test results. Studies by Pollack, Dornhoffer, and Ruckenstein found that 22%–38% of patients continue to report symptoms despite negative Dix-Hallpike test results, whereas Sargent noted reports of subjective improvement despite persistent positive Dix-Hallpike test results in his study sample. Lynn suggested that objective Dix-Hallpike testing should be considered the gold standard of outcome measures in BPPV. Controlled trials performed without Dix-Hallpike testing are generally excluded from evidence-based reviews.
The impact of canalith repositioning on the quality of life in patients with BPPV has been demonstrated using the Medical Outcomes Study 36-item Short Form (SF-36) and the Dizziness Handicap Inventory Short Form (DHI-S). In one study, patients with active BPPV scored worse than population norms on both measures and had improved scores 1 month after canalith repositioning maneuvers were performed (DHI-S mean decrease 8.1 [ P < .001, n = 40] ; SF-36 subscales normalized [ P < .05]).
Recurrence is common after successful canalith repositioning for BPPV. One or two treatments are commonly effective in eliminating the current episode in greater than 90% of cases; however, treatment does not prevent future episodes. Although the average recurrence rate is approximately 15% per year, reported rates have ranged from 5% per year to 45% at 30 weeks.
Conversion between the PSC and LSC can occasionally occur when Dix-Hallpike testing is repeated after canalith repositioning has been performed. When this occurs, the patient develops brisk horizontal nystagmus that responds well to a 360-degree supine roll maneuver toward the unaffected side. In a study done by our group, we found that 241 cases of PSC-BPPV resulted in 15 LSC conversions, a rate of 6.2%. Repeat Dix-Hallpike testing after repositioning increases the diagnostic sensitivity for lateral canal conversions, allowing for rapid identification and immediate management ( Fig. 9.5 ).
