Introduction
Benign paroxysmal positional vertigo (BPPV) is a common inner-ear pathology, characterised by episodic vertigo lasting for a few seconds that is associated with sudden change in the head position. It has a favourable prognosis, based on the fact that BPPV can recover spontaneously in approximately 20 per cent of patients by one month and in up to 50 per cent at three months.Reference Lynn, Pool, Rose, Brey and Suman1, Reference Burton, Eby and Rosenfeld2
Benign paroxysmal positional vertigo is treated with canalolith repositioning manoeuvres such as Epley's or Semont's manoeuvres. Canalolith repositioning manoeuvres have a success rate of 98 per cent after three manoeuvres.Reference Fife, Iverson, Lempert, Furman, Baloh and Tusa3, Reference Steenerson, Cronin and Marbach4 However, a small group of patients do not improve with canalolith repositioning manoeuvres (persistent cases) or they relapse after improvement of initial symptoms (recurrent cases). These persistent and recurrent cases have been described by Horii et al.Reference Horii, Kitahara, Osaki, Imai, Fukuda and Sakagami5 as intractable BPPV.
Pérez et al.Reference Pérez, Franco, Oliva and López Escámez6 reported the incidence of intractable BPPV as about 5 per cent in tertiary referral hospitals; they defined BPPV as persistent in cases where the same posterior canal was still affected after at least six canalolith repositioning manoeuvres. Choi et al.Reference Choi, Lee, Lim, Park, Park and In7 reported the incidence of persistent BPPV as 12.5 per cent and that of recurrent BPPV as 10 per cent.
Intractable BPPV treatment generally involves various surgical techniques, such as semicircular canal occlusion, posterior ampullary nerve section and utricular ablation. Posterior ampullary nerve section was never widely adopted and seems to have been largely abandoned.Reference Corvera Behar and García de la Cruz8 Semicircular canal occlusion has a good success rate, but complications of hearing lossReference Ahmed, Pohl, MacDougall, Makeham and Halmagyi9 and a patient satisfaction rate of 85 per centReference Shaia, Zappia, Bojrab, LaRouere, Sargent and Diaz10 have been reported.
The use of intratympanic steroids to treat inner-ear pathologies such as Ménière's disease, sudden-onset hearing loss and autoimmune hearing loss is well established. We report two cases where intratympanic dexamethasone injections were used to treat intractable BPPV, resulting in good control of vertiginous symptoms.
Case reports
Case one
A 47-year-old female presented to our department in 2010 with a 4-year history of intermittent episodes of vertigo that lasted for 2 weeks. No triggering factors were identified and she was asymptomatic in the interval period between the episodes. She denied having hearing loss or tinnitus. Her otoneurological examination findings and pure tone audiogram were normal. She had a magnetic resonance imaging (MRI) scan to rule out central pathology and was then treated as having intermittent vestibulitis.
The following year, the patient re-presented with new symptoms of positional vertigo, which lasted for a few seconds while turning to the left and lying down. Dix–Hallpike test results were positive for the left side and she was treated with a left Epley's manoeuvre. The Epley's manoeuvre was repeated thrice in the next six months. However, she remained symptomatic. A vestibular function test did not identify any peripheral vestibular weakness. She was then advised to perform Brandt–Daroff exercises at home and was discharged from the clinic.
In 2012, the patient re-presented to our department. On that occasion, she was diagnosed with right posterior canal BPPV and treated with a right Epley's manoeuvre. Over the next four months, a right Epley's manoeuvre was repeated twice. She was then discharged with advice on performing Brandt–Daroff exercises.
In 2015, the patient re-presented to our department with similar symptoms of positional vertigo on both sides, with the left side being more symptomatic. She was tested to rule out anterior and lateral canal BPPV by head hyperextension and roll tests respectively. She was then subjected to bilateral grommet insertion, with left intratympanic dexamethasone injections as she was symptomatic on her left side. Dexamethasone drops (3.3 mg in 1 ml solution) were instilled in the ear canal in the out-patient clinic on an interval basis. She initially had four-weekly injections of intratympanic dexamethasone. The intervals were then increased and titrated according to her symptoms and the side affected.
To date, the patient has received 13 intratympanic dexamethasone injections (7 injections in the right ear and 6 in the left ear). She remains under follow up, with 10-weekly injections. Her symptoms are well controlled but tend to restart when the effect of intratympanic dexamethasone wears off. The Dix–Hallpike test results have been negative in every follow-up session since the intratympanic dexamethasone injections commenced.
Case two
A 66-year-old female presented to our department in 2015 with symptoms of positional vertigo while turning her head to the left and lying down. Her otoneurological examination findings and pure tone audiogram were normal, except for a positive Dix–Hallpike test result for the left side. She was treated with a left Epley's manoeuvre, but remained symptomatic despite three further Epley's manoeuvres, which were performed at two-month intervals.
The following year, when the patient was still under review, she started describing positional vertigo precipitated by turning in either direction. She was then tested to rule out anterior and lateral canal BPPV. The MRI and vestibular function test results were normal. She was then subjected to bilateral grommet insertion with bilateral intratympanic dexamethasone injections. Bilateral intratympanic dexamethasone injections were repeated at four-weekly intervals, and subsequently increased to six-weekly intervals.
To date, the patient has received six bilateral intratympanic dexamethasone injections and is under follow up, with eight-weekly injections. Her vertiginous symptoms are well controlled, with negative Dix–Hallpike test results in every follow-up session.
Discussion
Benign paroxysmal positional vertigo is a common cause of vertigo. It was first described by BaranyReference Barany11 in 1921 as a pathology of the otolith organ. In 1952, Dix and HallpikeReference Dix and Hallpike12 demonstrated geotropic and torsional nystagmus with provocation tests, and concluded that BPPV was a disorder of the utricular macula.
• Intratympanic steroids have an established role in the management of inner-ear disorders
• They should be considered for intractable benign paroxysmal positional vertigo (BPPV) following failure of repositioning manoeuvres
• Intratympanic steroids should be used on an interval basis, as the efficacy of steroids decreases with time
• There is likely an inflammatory pathology underlying intractable BPPV
Although the exact pathophysiology of BPPV is not yet completely understood, the most accepted theories are cupulolithiasisReference Schuknecht13 and canalolithiasis.Reference Epley14 It is postulated that otoconial debris, consisting of calcium carbonate crystals, is released from the degenerating macula of the utricle and freely floats in the endolymph within the semicircular canals (canalolithiasis). When it settles on the cupula of the posterior semicircular canal in a critical head position, it causes displacement of the cupula thereby inducing vertigo (cupulolithiasis).
Several studies have compared the MRI findings of patients with persistent BPPV, and have suggested that persistent symptoms could be caused by an underlying inflammatory process of the membranous labyrinth.Reference Horii, Kitahara, Osaki, Imai, Fukuda and Sakagami5, Reference Schratzenstaller, Wagner-Manslau, Alexiou, Arnold and Arnol15, Reference Dallan, Bruschini, Neri, Nacci, Segnini and Rognini16 Glucocorticoid receptors have been identified throughout the inner ear, including the utricular macula, saccule and semicircular canal duct epithelium.Reference Hargunani, Kempton, DeGagne and Trune17, Reference Yang, Wu, Zhang, Hou, Chen and Zhang18
Studies have suggested that steroids affect the electrolyte and fluid balance of the inner ear.Reference Shirway, Seidman and Tang19, Reference Slattery, Fisher, Iqbal, Friedman and Liu20 Intratympanic steroids have been effective in the management of inner-ear pathologies such as noise-induced hearing loss, idiopathic sudden-onset hearing loss, Ménière's disease and autoimmune hearing loss. We have extended these indications, supporting the use of intratympanic steroids in intractable BPPV.
A pilot study, conducted by Pérez et al.Reference Pérez, Franco, Oliva and López Escámez6 in 2016, which used intratympanic methylprednisolone for persistent posterior canal BPPV, highlighted an inflammatory process of the labyrinth, or an imbalance of sodium or calcium in endolymph, as being the cause of intractable BPPV. That study reported a success rate of 78 per cent in intractable BPPV cases using intratympanic steroids. The authors concluded that the combination of intratympanic steroids with repositioning manoeuvres can resolve intractable BPPV, with a lower rate of relapse compared to repeated canalolith repositioning manoeuvres alone.Reference Pérez, Franco, Oliva and López Escámez6
Unlike Pérez and colleagues’ study,Reference Pérez, Franco, Oliva and López Escámez6 where intratympanic injection was administered via a tympanic puncture, we inserted a grommet, which we believe is a safer method of delivering intratympanic steroids. Complications such as pain, tongue numbness and persistent tympanic membrane perforation have been reported with the tympanic puncture method.Reference Liu, Chi, Yang and Liu21
In our protocol, the symptomatic side is chosen for intratympanic dexamethasone injection, and instillation of the intratympanic dexamethasone can be extended to both ears if the disease is bilateral. The intervals between two intratympanic dexamethasone injections are titrated as per the patient's symptoms. At every interval, the injections are repeated thrice before increasing the intervals. This protocol is routinely used in our department for patients with Ménière's disease, and we have extended the use of intratympanic dexamethasone for intractable BPPV. In both the cases reported, no major complications related to intratympanic dexamethasone were apparent.
Conclusion
To our knowledge, this is the first case report from the UK where intratympanic dexamethasone has been used for the treatment of intractable BPPV. Intractable BPPV seems to have an underlying inflammatory pathology. Intratympanic steroids should be considered before proceeding to definitive surgical options. The use of intratympanic dexamethasone is safe, especially when delivered through a grommet. It is associated with good vertigo control, without affecting hearing. A multi-centric randomised controlled trial would be necessary to validate its use for intractable BPPV.
Competing interests
None declared
