Posterior Canal Occlusion Research Articles

Effectiveness of Canal Occlusion for Intractable Posterior Canal Benign Paroxysmal Positional Vertigo: A Systematic Review.

A last resort for therapy for intractable benign paroxysmal positional vertigo (BPPV) is mechanical occlusion of the posterior semicircular canal. The aim of this review was to assess the effect of posterior canal occlusion for intractable posterior canal BPPV on vertigo and to determine the risk of loss of auditory or vestibular function. A systematic literature search according to the PRISMA statement was performed on PubMed, the Cochrane Library, Embase, Web of Science, and CINAHL. The last search was conducted in June 2018. Cohort studies with original data and case reports describing >5 cases were included if they analyzed the effect of posterior semicircular canal obliteration in adults with intractable posterior BPPV on vertigo. Two authors screened titles and abstracts for eligibility. The first author screened full texts and analyzed the data. Eight retrospective studies met the eligibility criteria. The quality of all individual studies was rated fair. Canal occlusion was performed on 196 patients. All studies reported complete resolution of BPPV in all patients (100%). Among postoperatively tested patients, total loss of auditory function and vestibular function was reported in 2 of 190 (1%) and 9 of 68 (13%), respectively. Posterior semicircular canal plugging resulted in 100% resolution of BPPV in patients with intractable BPPV in all studies. However, the strength of evidence was weak. Potential serious complications, such as deafness and loss of vestibular function, should be taken into account.

Posterior canal occlusion for benign paroxysmal positional vertigo

Benign paroxysmal positional vertigo is the most common etiology of peripheral vertigo and is caused by the hydrodynamic influence from free-floating canaliths. Any of the 3 semicircular canals can be involved, but posterior canal BPPV is the predominant subtype. The condition is diagnosed clinically, and the preponderance of cases resolve spontaneously or are amenable to particle-repositioning maneuvers. A small subset of patients experience intractable symptoms for which surgical intervention can be considered. Transmastoid posterior canal occlusion surgery has been demonstrated to be a safe and curative procedure insofar as it can eradicate vertiginous symptoms while preserving auditory function.

Vestibular Outcomes in Bilateral Posterior Semicircular Canal Occlusion for Refractory Benign Positional Vertigo.

Bilateral posterior semicircular canal (PSCC) occlusion is a successful treatment of bilateral benign positional vertigo (BPV) refractory to particle repositioning manoeuvers. Little about the effects on the vestibular ocular reflex (VOR) postoperatively, which is the intent of this study. All patients who underwent bilateral posterior canal occlusion for BPV at the University Health Network by the senior author (J.A.R.) between 2001 and 2017 with pre- and postoperative vestibular testing were included in the study.All patients underwent a detailed history and neuro-otological examination including dynamic visual acuity (DVA). Laboratory testing including video head impulse testing or magnetic scleral search coil testing, video nystagmography, cervical and ocular vestibular evoked myogenic potentials and audiological testing before and following their procedure at 1, 6, and 12 months postoperatively. Three patients were included in the study, all females, with a mean age of 41 years (range 36-44 yr). All patients had developed bilateral BPV after head trauma. Mean length of follow-up was 26 months (range 6-84 mo). All patients demonstrated a reduction in the vertical VOR of between 0.37 and 0.57/s at 1 month postocclusion. Between 6 and 12 months postoperatively, an improvement in their vertical VOR between 0.45 and 0.75/s was observed. Clinically, all patients reported complete resolution of their positional vertigo with a negative Dix-Hallpike bilaterally at follow-up. None reported oscillopsia, which was confirmed with DVA testing. Bilateral PSCC occlusion results in a reduction in the vertical VOR of the PSCCs.Over a 6 to 12 month time period improvement in the VOR gain can be demonstrated, most likely due to central compensation. There is clinical correlation with improvement in DVA testing. Bilateral PSCC occlusion is a safe and effective treatment for bilateral BPV proved refractory to particle repositioning manoeuvers.

Otoconia and otolithic membrane fragments within the posterior semicircular canal in benign paroxysmal positional vertigo.

Benign paroxysmal positional vertigo (BPPV) is the most common vestibular disorder with an incidence between 10.7 and 17.3 per 100,000 persons per year. The mechanism for BPPV has been postulated to involve displaced otoconia resulting in canalithiasis. Although particulate matter has been observed in the endolymph of affected patients undergoing posterior canal occlusion surgery, an otoconial origin for the disease is still questioned. In this study, particulate matter was extracted from the posterior semicircular canal of two patients and examined with scanning electron microscopy. The samples were obtained from two patients intraoperatively during posterior semicircular canal occlusion. The particles were fixed, stored in ethanol, and chemically dehydrated. The samples were sputter coated and viewed under a scanning electron microscope. Digital images were obtained. Intact and degenerating otoconia with and without linking filaments were found attached to amorphous particulate matter. Many otoconia appeared to be partially embedded in a gel matrix, presumably that which encases and anchors the otoconia within the otolith membrane, whereas others stood alone with no attached filaments and matrix. The otoconia measured roughly 2 to 8 μm in length and displayed a uniform outer shape with a cylindrical bulbous body and a 3 + 3 rhombohedral plane at each end. These findings suggest that the source of the particulate matter in the semicircular canals of patients with BPPV is broken off fragments of the utricular otolithic membrane with attached and detached otoconia. NA Laryngoscope, 127:709-714, 2017.

Outcomes following Semicircular Canal Plugging

Objectives: 1) Examine audiometric outcomes following semicircular canal plugging for either superior semicircular canal dehiscence syndrome or refractory positional vertigo. 2) Review symptom control rates and complication rates for canal plugging procedures. Methods: Retrospective chart review at a private neurotologic tertiary referral center. Patients undergoing semicircular canal plugging for superior semicircular canal dehiscence syndrome or refractory positional vertigo from January 1, 2007, to December 31, 2012, were included. Pre- and postoperative audiometry, operative findings, and clinical symptoms were assessed through chart review. Acoustic reflex testing, vestibular testing, and canal dehiscence size were examined in superior canal dehiscence patients. Results: A total of 28 patients underwent a canal plugging procedure during the study period: 24 superior canal dehiscence syndrome patients and 4 posterior canal occlusion patients. Postoperative air conduction pure-tone averages were 22.5 and 13.0 dB for these two groups, respectively, compared to their preoperative values of 21.1 and 11.0 dB. The average pre- and postoperative word-recognition scores for the entire cohort were 96.2% and 94.0%. Vestibular evoked myogenic potential data showed reduced thresholds in 7 canal dehiscence patients. The average size of the canal dehiscence, based on preoperative radiological measurements, was 3.4 mm. Surgical complications were limited to one temporary facial weakness (Grade 2). Complete symptom improvement was noted in 35.7% of all patients, while 16.7% of canal dehiscence patients reported no change in symptoms. Conclusions: Semicircular canal plugging procedures are associated with excellent hearing outcomes and may reduce preoperative symptoms in patients with canal dehiscence and refractory positional vertigo.

Transmastoid semicircular canal occlusion: A safe and highly effective treatment for benign paroxysmal positional vertigo and superior canal dehiscence

Transmastoid occlusion of the superior semicircular canal in superior semicircular canal dehiscence (SSCD) syndrome and the posterior semicircular canal in intractable benign paroxysmal positional vertigo (BPPV) will produce resolution of preoperative symptoms. Retrospective review, quality assurance. Sixteen patients with SSCD and 61 patients (65 ears) with intractable BPPV who underwent canal occlusion were reviewed. All patients underwent occlusion of the affected semicircular canal through a transmastoid approach. Preoperative symptoms (vestibular, 13 patients; pulsatile tinnitus, 2 patients; or hyperacusis, 1 patient) were greatly improved or completely resolved in 15 of the 16 SSCD patients who underwent transmastoid occlusion of the superior canal. Hearing was preserved in 14 patients and improved in two patients. Vestibular symptoms were resolved in all intractable BPPV patients who underwent transmastoid occlusion of the posterior canal. One patient had a late recurrence of atypical BPPV. Almost all BPPV patients with normal preoperative hearing have an initial transient postoperative hearing loss, which when tested for is usually a mild to moderate mixed loss. Delayed sensorineural hearing loss was noted in three patients; one loss was profound whereas two were mild. The transmastoid approach to canal plugging is successful in the treatment of symptoms in both SSCD and intractable BPPV, and is a familiar approach for the otologist. This is a viable alternative to the middle fossa approach for SSCD, thereby avoiding a craniotomy. Transmastoid is the definitive approach for posterior canal occlusion.

Efficacy and Safety of Bilateral Posterior Canal Occlusion in Patients With Refractory Benign Paroxysmal Positional Vertigo

To highlight the effectiveness, safety, and adverse effects of treating intractable posterior canal benign paroxysmal positional vertigo (BPPV) with bilateral posterior canal occlusions. Included in this study are 6 patients diagnosed with bilateral BPPV refractory to medical treatment and particle repositioning maneuvers (PRMs) who underwent bilateral posterior semicircular canal occlusions. Patients were selected from tertiary hospital referral centers in London, Ontario, Canada, and St. Louis, Missouri, USA. This study used the following interventions: preoperative and postoperative audiogram testing to monitor long-term changes in hearing, computed tomography of the head to rule out central lesions and confirm normal inner ear anatomy before surgery, magnetic resonance imaging of the head as needed to rule out posterior fossa lesions causing persistent vertigo, Dix-Hallpike maneuver to diagnose BPPV, PRM and physiotherapy vestibular rehabilitation to attempt treating BPPV before surgical intervention, and sequential transmastoid posterior semicircular canal occlusion for treatment of intractable BPPV. Postoperative resolution of vertigo induced by head movement and hearing preservation by audiometric testing and postural stability. All patients with severe debilitating bilateral BPPV refractory to medical treatment and PRM had complete resolution of their positional vertigo after bilateral sequential posterior semicircular canal occlusion. Hearing was preserved at the preoperative level in all but 1 patient who developed bilateral postoperative, mild, high-tone sensorineural loss. Residual postoperative adverse effects included transient imbalance in all patients and episodic, nonpositional vertigo in 1 patient. When stressed by extreme head motion, some patients had mild residual instability. There were no other significant long-term complications. Bilateral sequential posterior semicircular canal occlusion is a definitive, effective, and safe treatment modality for intractable bilateral BPPV, providing patients with resolution of their vertiginous symptoms. All 6 patients stated that the alleviation of their BPPV symptoms far out-weighed the residual motion sensitivity resulting from the occluded canals.

Posterior semicircular canal occlusion for intractable benign positional vertigo: outcome in 55 ears in 53 patients operated upon over 20 years

To report the outcome of posterior semicircular canal occlusion surgery for intractable benign positional vertigo, regarding vertigo cure rate and hearing and balance outcomes. Retrospective review of 53 patients presenting with benign positional vertigo, unresponsive to repositioning manoeuvres, who eventually underwent posterior canal occlusion, over a 20 year period. From 1991 to 2011, 5364 benign positional vertigo patients were treated in our balance disorders clinic; 53 of those who failed to respond to repositioning underwent posterior canal occlusion. All 53 were cured of their benign positional vertigo. Nine suffered some symptomatic permanent hearing loss (>20 dB at low and >25 dB at high frequencies). Ten patients suffered caloric vestibular function deterioration, with mild but permanent subjective imbalance in five; a further 10 patients with no post-operative caloric test changes also had some permanent imbalance. Benign positional vertigo later developed in the operated ear lateral canal in two patients and in the opposite ear posterior canal in eight patients. Two patients needed bilateral sequential posterior canal occlusion. Posterior canal occlusion is a highly effective treatment for intractable benign positional vertigo, with what is probably an acceptable risk to hearing and balance: five of six patients will have no hearing problem and nine of 10 no balance problem after surgery.

The Diagnosis and Management of Benign Paroxysmal Positional Vertigo

Benign paroxysmal positional vertigo (BPPV) is a peripheral vestibular disorder that manifests as sudden, short-lived episodes of vertigo elicited by specific head movements. BPPV is one of the most common causes of dizziness or vertigo, and almost 10% of the elderly population experiences BPPV. It is often self-limiting but can become chronic and recurrent with considerable effects on a person's quality of life. Most cases result from the migration of free-floating canalith particles into the posterior (more commonly) or horizontal (less commonly) semicircular canals, rendering them sensitive to gravity. Diagnosis of BPPV is based on a suggestive history and physical examination, and other tests are not normally required. Repositioning maneuvers are highly efficacious in resolving BPPV. Medications are not an effective treatment option. Posterior canal occlusion surgery is highly effective and is reserved for intractable and severe cases.

Surgical Treatment of Benign Paroxysmal Positional Vertigo

Benign paroxysmal positional vertigo (BPPV) is a common condition most commonly caused by free-floating endolymph particles in the posterior semicircular canal. Well over 90% of patients can be successfully treated with the simple particle repositioning manoeuvre on an outpatient basis. A small percentage of patients have intractable, incapacitating, and multiply recurrent BPPV for whom surgical intervention should be considered. The singular neurectomy was introduced in the 1970s, but this has largely been replaced by the simpler posterior canal occlusion. A series of 48 ears having undergone posterior canal occlusion are presented as the largest series in the literature to date. All operated ears were relieved of BPPV, with one patient having a late recurrence. Of the 44 ears with normal preoperative hearing, one had a delayed (3-month) sudden and permanent profound loss, while another had a mild (20dB) loss. Six patients had protracted courses of imbalance and motion sensitivity. Both the history and t...

Surgical treatment of benign paroxysmal positional vertigo

Benign paroxysmal positional vertigo (BPPV) is reported to be the most common cause of inner ear vertigo seen in otologic practice. Symptoms, although distressing, are usually self-limited and resolve spontaneously over a few days to several weeks. Although conservative management, including repositioning maneuvers, is usually sufficient for relief of the symptoms of BPPV, a small group of patients will have refractory chronic or recurrent symptoms that they consider disabling. Of the options available for surgical treatment of BPPV, posterior canal occlusion seems to offer the most consistent and reproducible results, with excellent cure rates and low incidence of hearing loss and other complications.

Benign paroxysmal positional vertigo and otolith repositioning.

It is generally agreed that BPPV results from dysfunction of the posterior semicircular canal (PSCC). The characteristic rotary nystagmus seen in BPPV can be reproduced by electrical stimulation of the PSCC and eliminated by deafferentation of the PSCC. Two theories have been advanced to explain the pathophysiological characteristics of BPPV; these are cupulolithiasis and canalithiasis. The former is Schuknecht’s original theory of a substance adherent to the cupula, while the latter presumes the presence of free-floating debris within the posterior canal. Temporal bone studies may not be able to provide sufficient evidence to differentiate between the 2 theories. Moriarty et al showed that deposits are present on all of the semicircular canal ampullae, although the PSCC is most commonly involved. Supportive evidence for the canalithiasis theory is provided by surgeons who have noted freely moving particles within the semicircular canals during the translabyrinthine approach to the cerebellopontine angle and when performing posterior canal occlusion. Regardless of whether debris is fixed or free floating, it is surmised that if the debris could be removed from the canal, the patient would be rendered free of symptoms. Noninvasive techniques for the removal of this debris have been developed. Brandt and Daroff initially reported on the use of a positioning technique for elimination of BPPV. They noted abrupt resolution of symptoms in one third of their patients. While recognizing a propensity for spontaneous resolution of symptoms, they concluded the time course of the recovery was consistent with a mechanical removal of debris and did not represent central compensation. Renewed interest in physical therapy for BPPV followed descriptions of repositioning maneuvers by Semont et al and Epley. Semont et al adhered to the theory of cupulolithiasis. Therefore, their intervention is directed at dislodging a fixed deposit from the cupula. In performing this maneuver, a patient is asked to sit on the side of an examination table with the head turned away from the affected ear. The patient is then rapidly moved to a lateral decubitus position, with the head facing the ceiling. After a few minutes, the patient is quickly sat up and then moved to the opposite lateral decubitus position without changing the orientation of the head on the body. Thus the patient is now facing the floor. The patient then sits up and is asked to remain upright for 48 hours. Epley favored the canalithiasis theory. He devised a technique to move the head in a manner that rotates the posterior canal about its central axis, bringing the ampullated end from a dependent position to its zenith. This induces gravity-directed movement of particulate matter into the vestibule, where it should not produce symptoms. The patient is initially placed in the Hallpike position with the affected ear down. While remaining in the supine position, the patient’s head is rotated to the contralateral side. Next, the body is rolled onto the contralateral shoulder with no change in head position, thus effectively rotating the head 180° from the initial position. Finally, the patient is sat upright with the chin down. A handheld oscillator is applied to the skull throughout the positioning sequence to dislodge any fixed deposits in an effort to thoroughly clear the PSCC. Once again, the patient is asked to remain upright for 48 hours after the procedure. Most subsequent studies use these techniques exactly as described by the original authors or with minor variations. Reported results are quite encouraging. The Table lists data from selected studies, grouped according to the type of intervention. For accurate comparison, only those patients with no evidence of positional vertigo on follow-up are listed as cured. Some authors use a single treatment approach, while others repeat therapeutic measures at intervals from several days to weeks. A treatment session may include a single maneuver or multiple repetitions. Is one technique better as a single treatment? In a prospective randomized From the Department of Otolaryngology, University of Texas Medical Branch, Galveston. CLINICAL CHALLENGES IN OTOLARYNGOLOGY