Evaluation and Treatment of Benign Paroxysmal Positional Vertigo

Introduction

Benign paroxysmal positional vertigo (BPPV) is the single most common cause of vertigo. BPPV accounts for 26% of all cases of vertigo¹ and was found in 9% of geriatric patients in an urban clinic.² The incidence of BPPV increases with age.^1,3 BPPV affects the quality of life of elderly patients and is associated with reduced activities of daily living scores, falls, and depression.² The purpose of this article is to review the evaluation and treatment of BPPV.

Clinical Features of BPPV

BPPV is characterized by brief periods of vertigo triggered by a change in the position of the patient’s head relative to gravity. Brief periods of vertigo typically occur when the patient rolls in bed towards one side, gets in and out of bed (“bed-spins”), bends over and straightens up, or looks up (top-shelf syndrome).^4,5 If one observes the patient’s eyes during these periods, one can sometimes observe that the eyes are jumping. The rapid, involuntary oscillation of the eyes is referred to as nystagmus. Patients with BPPV are usually most symptomatic while lying flat in bed and often adopt sleeping strategies such as propping themselves up in bed.

There are three main variants of BPPV. Each variant is characterized by a specific direction of nystagmus, and the direction is dependent on the part of the inner ear that is causing the vertigo. In the most common variant, posterior canal BPPV (PC-BPPV; see Figure 1 for the location of the posterior canal), the eyes jump upward as well as twist. In the second most common variant, horizontal canal BPPV (HC-BPPV), the eyes jump horizontally. The least common type is anterior canal BPPV (AC-BPPV), where the eyes jump downward.

Most BPPV is caused by loose particles within the inner ear. This is more formally called canalithiasis (Figure 1).⁶ In canalithiasis, heavy debris from another part of the ear (the utricle) becomes dislodged and enters a semicircular canal. The debris, being made of calcium carbonate (limestone), is heavier than the fluid in the canal. Thus, when the position of the head changes relative to gravity, the debris falls downward in the semicircular canal. As the debris falls, the patient experiences a brief burst of vertigo and nystagmus. Once the debris comes to rest, typically in 10-60 seconds, the nystagmus and vertigo stops. PC-BPPV is the most common because the PC is at the bottom of the inner ear, and this promotes accumulation of heavy debris.

Differential Diagnosis of BPPV

BPPV causes about 85% of all positional vertigo. Orthostatic hypotension and other conditions that cause low blood pressure also result in positional symptoms, but symptoms are triggered by standing up, and typically no symptoms are noted when the person is supine. Damage to the brainstem or cerebellum can also cause positional vertigo. Central positional vertigo is far less common than BPPV, is accompanied by other neurological signs, and also generally shows a different pattern of nystagmus on positional testing, as discussed subsequently. Low spinal fluid pressure can also cause orthostatic symptoms, but again like orthostatic hypotension, they are not prominent when lying in bed. All types of BPPV are accompanied by nystagmus, and this is the main feature that distinguishes BPPV from other types of positional vertigo. More about the nystagmus follows in the next section.

Positional Testing to Diagnose BPPV

The diagnosis of BPPV is established through two positional tests; the Dix-Hallpike maneuver⁷ and the supine with lateral head turns maneuver.⁸ Determining the canal involved is based on the direction and characteristics of the nystagmus found during the positional testing. Positional testing is best performed with an examination tool that prevents fixation, such as the patient wearing Frenzel goggles or using video-oculography. When positional testing is done without a method of removing fixation, only very strong nystagmus may be easily appreciated.

The Dix-Hallpike maneuver (Figure 2A) is used to diagnose both PC- and AC-BPPV. It tests for BPPV in the ipsilateral PC and contralateral AC. In both cases, debris within the canals moves to a new lowest position, in response to a repositioning of the head (Figure 2B). For PC-BPPV, the top of the eye jumps upward and twists rapidly towards the lowermost ear (Figure 2B). For AC-BPPV, the maneuver generates a mainly downbeating nystagmus. In both PC-BPPV and AC-BPPV, the nystagmus occurs as a burst (lasting < 60 sec), because after the debris has moved to the new lowest part of the canal there is no further stimulation. For both types, there is a brief burst of nystagmus with reversed direction when the patient sits up and the debris moves back towards the cupula.

The other positional test, supine with lateral head turns (Figure 3) is used to detect HC-BPPV.⁸ In this test, the patient begins by lying supine, but the head is tilted forward 30 degrees, aligning the plane of the HC with gravity. This can be conveniently done using a pillow. Then the head is rotated 90 degrees towards the right, to center, and 90 degrees towards the left, pausing about 30 seconds in each position. A positive test and diagnosis of HC-BPPV occurs when there is a strong horizontal nystagmus that changes direction between the head-right and head-left positions.

In addition to direction, the timing of nystagmus also varies with the canal involved (Table I). The vertigo of HC-BPPV tends to be more intense than PC- or AC- BPPV and is more likely to be associated with nausea and vomiting.^{9, 10}

In the clinic, BPPV is predominantly PC in type. However, when one records the eyes using more sensitive methods such as video-oculography, there is a broader mixture of types of BPPV, with about 41-65% being unilateral PC-BPPV, about 20% multiple-canal BPPV, 21-33% HC-BPPV, and 17% AC-BPPV.^11,12 The difference between clinical observation, and laboratory data may be caused by a difference in technique. In the clinic, especially when optical Frenzel goggles are used, fixation may be impaired but still possible. Thus, only nystagmus that cannot be suppressed with fixation, such as the torsion of PC-BPPV, may be observed.

With respect to the natural history, in patients diagnosed with BPPV within 3 days of onset of symptoms, 30% of the patients with PC-BPPV and 53% of the patients with HC-BPPV went into remission within 7 days.¹² This is probably because debris tends to spontaneously move out of the HC into the vestibule, but tends to stay in the lower part of the inner ear, the PC.

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Treatment of BPPV

Once the involved canal is identified, BPPV may be effectively treated with a particle repositioning maneuver designed to treat the canal involved.

Treatment of PC-BPPV
Several particle repositioning maneuvers have been developed to treat the PC. Historically, the first maneuver was the Brandt-Daroff exercise,¹³ designed to self-treat BPPV with repeated symptom-provoking movements. The patient moves from sitting on the edge of the bed to lying on the side, placing the plane of the PC of the lowermost ear vertical with gravity. The patient alternates between movements towards the left and right sides. Therefore, identification of the side involved was not necessary. This exercise has fallen out of favor, as newer maneuvers are more effective.

The canalith repositioning procedure, or Epley maneuver,¹⁴ is presently the most commonly used treatment for BPPV. It uses gravity to move particles out of the sensitive part of the ear (ampullary region) into an insensitive part of the ear, the vestibule (Figure 1). The clinician moves the patient through a series of positions (Figure 4). With each position, the otoconia fall to the lowest part of the canal. This results in the movement of the debris around the arc of the long arm of the PC, through the common crus, and into the insensitive vestibule. Each position is maintained for a minimum of 30 seconds. While Epley applied vibration to the mastoid process of the involved side during the maneuver, this does not appear to be necessary.^15-17 Another maneuver, the Liberatory or Semont maneuver, is also in common use.¹⁸ The geometry and results of the Semont maneuver are very similar to the canalith repositioning procedure.

The canalith repositioning procedure has been modified to enable patients to treat themselves at home. With the self-canalith repositioning procedure,^19,20 (Figure 5), the patient moves through the same four positions as the canalith repositioning procedure, except that the head is extended over the edge of a pillow instead of the end of a treatment table.

Treatment of HC-BPPV
Multiple treatment techniques have been advocated for HC-BPPV.^21-25 Again, there is an attempt to use gravity to move the debris out of the canal into the vestibule by rotating the patient around the body’s vertical axis in the recumbent position. We will call these variants the log roll maneuvers. The maneuvers vary with the degree of rotation about the vertical axis, the initial position of the head in the supine position, and the amount of cervical flexion in the supine position. A common variant (Figure 6) described by Epley²³ is a 360-degree turn towards the unaffected side, beginning supine, with the head rotated 90 degrees towards the affected side. This maneuver may also be used at home.

Treatment of AC-BPPV
Ordinarily, clinicians will first attempt to treat AC-BPPV with the canalith repositioning maneuver done on the side that elicits nystagmus, and if this fails, they proceed to a more specific maneuver. Maneuvers designed specifically to treat AC-BPPV are based on taking the head into a “deep” position, beyond supine, so as to allow debris to fall away from the cupula (Figure 7). Because of the more sagittal orientation of the AC, maneuvers may start with the head straight back. An example of this is the forced positional procedure of Crevits.²⁶ In this maneuver, the patient is positioned supine with the head extended over the edge of the treatment table as far as possible, and the head is then brought back forward.

Activity Restrictions Post-Maneuvers
Post-maneuver activity restrictions are often advocated. They are intended to prevent the debris from moving back into the semicircular canals. Patients without activity restrictions require more treatment sessions before being cured than patients with activity restrictions.²⁷ Restrictions include sleeping upright or at a 45-degree angle, avoiding lying on the involved side, refraining from vertical and rapid head movements, and wearing a cervical collar to prevent head movements.²⁸ Restrictions are maintained from 24 hours up to 1 week.

Complications. Complications are reported with maneuvers performed by the clinician^29-32 and self treatment.^33,34 Complications include those related to movement of debris into another location, nausea, vomiting, imbalance, and anxiety related to treatment.^29-34

Canal conversion is the result of debris from the canal being treated, refluxing into another semicircular canal. Horizontal canal conversion is common. It is most frequently seen after treatments for PC-BPPV or AC-BPPV. It is easily diagnosed by observing replacement of the vertical/torsional nystagmus of BPPV involving the vertical canals with a powerful horizontal, direction-changing nystagmus. Canal conversion is particularly common in persons who self-treat with the Brandt-Daroff exercises. During the office maneuvers, eye movements are monitored, allowing easy identification of canal conversion. Once identified, the appropriate canal is treated.

A far rarer complication is canal jamming. In this case, debris moves from a wider to a narrower segment and plugs the canal.³⁵ The patient experiences extreme vertigo and develops a persistent nystagmus irrespective of the head position. To treat a canal jam, reverse the direction of the maneuver that created the jam. Apply gentle vibration to the mastoid process of the involved side.

Nausea and vomiting are an intrinsic risk of provoking vertigo in diagnostic or treatment maneuvers. Patients known to be susceptible to vomiting may be given antiemetics such as ondansetron, promethazine, or meclizine 30 minutes prior to the treatments.³⁶

The majority of patients respond very well to treatment. However, following treatment, some patients may complain of an increase in symptoms of generalized dizziness lasting a few hours to several days. This situation is more likely when patients are treating themselves with home exercises. Typically, with self-treatments, patients perform many more cycles of the maneuvers per week than in the clinic. Some may not tolerate this due to nausea and vomiting, and medication may be necessary to reduce these symptoms. When self-treating, a canal conversion may occur, necessitating a visit to the clinic to diagnose and change the exercise appropriately. Patients should stop exercises and contact their clinician if symptoms that are initially unilateral become bilateral, or if symptoms switch sides.

Recurrence of BPPV. BPPV often recurs. For PC-BPPV, 25% of cured patients redevelop BPPV within 1 year, and 44% redevelop BPPV within 2 years.^15,37 A daily routine of Brandt-Daroff exercises does not affect the time to recurrence or the rate of recurrence of PC-BPPV.³⁸

Evidence Supports Particle Repositioning Maneuvers in BPPV Treatment

Overall, PC-BPPV is treated effectively with particle repositioning maneuvers such as the canalith repositioning procedure.¹⁴ The short-term success rate of the canalith repositioning procedure ranges from 67-95%,^{3,28,31,32,34,39,40} the average success rate being 79 + 16%.^{3,28,31,32,34,39,40} The average success rate of the self-canalith repositioning procedure is 93 + 4%.^33,34 The short-term success rate of the Brandt-Daroff exercises varies between 24% within 1 week and 97% within 6 weeks.^31,13 The Brandt-Daroff exercises are less favored because they are slower to cure BPPV than the other maneuvers, and there is a greater chance of canal conversion. If patients are not treated, symptoms will spontaneously resolve within 7 days in 30% of patients with PC-BPPV and 53% of patients with HC-BPPV.¹² This suggests that the success rates of the maneuvers are due to the effects of the maneuver, not spontaneous resolution.

Although there are numerous articles reporting success for the maneuvers in the treatment of HC-BPPV and AC-BPPV, there are no randomized controlled trials or controlled before-and-after trials for these procedures. The general consensus at this writing is that the maneuvers for HC-BPPV are better than no treatment, but also that they are slower to work and less reliable than the maneuvers for PC-BPPV. There is presently no consensus regarding treatment of AC-BPPV. However, we believe that they make sense from a biomechanical perspective, and there is anecdotal evidence of effectiveness. We presently feel that the maneuvers are worthwhile attempting in a symptomatic patient.

Conclusion

To effectively treat BPPV, the canal involved needs to be identified with positional maneuvers. Based on the findings of the positional testing, the canal identified may be treated with the appropriate repositioning maneuver.

The authors report no relevant financial relationships.