Downbeat nystagmus: a clinical and pathophysiological review.

Downbeat nystagmus (DBN) is a neuro-otological finding frequently encountered by clinicians dealing with patients with vertigo. Since DBN is a finding that should be understood because of central vestibular dysfunction, it is necessary to know how to frame it promptly to suggest the correct diagnostic-therapeutic pathway to the patient. As knowledge of its pathophysiology has progressed, the importance of this clinical sign has been increasingly understood. At the same time, clinical diagnostic knowledge has increased, and it has been recognized that this sign may occur sporadically or in association with others within defined clinical syndromes. Thus, in many cases, different therapeutic solutions have become possible. In our work, we have attempted to systematize current knowledge about the origin of this finding, the clinical presentation and current treatment options, to provide an overview that can be used at different levels, from the general practitioner to the specialist neurologist or neurotologist.

Bone-Anchored Hearing Aid Effects on Vestibular Function: A Preliminary Report.

OBJECTIVE: Cochlear receptors are sensitive to vibratory stimuli. Based on this sensibility, bone-anchored hearing aids have been introduced to correct unilateral or bilateral conductive or mixed hearing loss and unilateral deafness. The vestibular system is also sensitive to the vibratory stimulus and this type of response is used in clinics to test its functionality. Being aware of this double separated sensibility, we wondered whether bone vibration, which activates the acoustic receptors of patients with bone conduction aids, can also influence the functionality of the vestibular system. METHODS: To this end, we recruited 12 patients with a bone-anchored hearing aid and evaluated their vestibular function with and without an activated vibratory acoustic device. RESULTS: Our results show that the vibratory stimulus delivered by the bone conduction aid also reaches and stimulates the vestibular receptors; this stimulation is evidenced by the appearance or modification of some nystagmus findings during bedside vestibular testing. Despite this, none of these patients complained of dizziness or vertigo during prosthesis use. Nystagmus that appeared or changed during acoustic vibratory stimulation through the prosthesis was almost all predominantly horizontal, unidirectional with respect to gaze or body position, inhibited by fixation, and most often consistent with vestibular function tests indicating peripheral vestibular damage. CONCLUSIONS: The findings of sound-evoked nystagmus seem to indicate peripheral rather than central vestibular activation. The occurrence of some predominantly horizontal and high-frequency induced nystagmus seems to attribute the response mainly to the utricle and lateral semicircular canal.

A Clinical Infrared Video-Oculoscopy Suppression Head Impulse (IR-cSHIMP) Test.

BACKGROUND: We propose a Suppression Head IMPulse (SHIMP) test method that provides for equipment only through the use of InfraRed Video-OculoScopy (IR-VOS) and allows horizontal and vertical semicircular canal function evaluation in bedside mode. We therefore named the test InfraRed clinical SHIMP (IR-cSHIMP). METHODS: To check IR-cSHIMP diagnostic efficiency, we studied 22 normal subjects, 18 patients with unilateral, and 6 with bilateral deficient vestibulopathy. Each subject first underwent a vestibular examination and, only later, an IRc-SHIMP test. RESULTS: When the IR-cSHIMP test was performed in the horizontal plane, all normal subjects showed anti-compensatory saccades. When the vertical semicircular canal function was evaluated, the same result was obtained in all normal subjects except three, which were considered false positives. In patients with vestibular deficits, the test performed in the horizontal and vertical planes were always pathological, with 100% agreement between clinical and instrumental tests. CONCLUSIONS: Our bedside method proved to be fast, simple, and effective in discriminating between healthy and pathological subjects. It required only the same skill as the better-known cHIT. For these reasons, we believe that the IR-cSHIMP should be part of daily clinical practice as a useful tool in the selection of patients to undergo more sophisticated investigations.

Treating benign paroxysmal positional vertigo of the lateral semicircular canal with a shortened forced position.

Benign paroxysmal positional vertigo (BPPV) is the peripheral vestibular disorder that is most frequently encountered in routine neuro-otological practice. Among the three semicircular canals, the lateral semicircular canal (LSC) is the second most frequently interested in the pathological process. In most cases, LSC BPPV is attributable to a canalithiasis or cupulolithiasis mechanism. The clinical picture of LSC BPPV is that of positional nystagmus and vertigo evoked by turning the head from the supine to the side lateral position. With such a movement, a horizontal positional (and often also paroxysmal) direction-changing nystagmus is generated. Depending on whether the pathogenetic mechanism is that of canalithiasis or cupulolithiasis and depending on where the dense particles are located, LSC BPPV direction-changing positional nystagmus is geotropic or apogeotropic on both lateral sides. Due to its mechanical nature, BPPV is effectively treated by means of physical therapy. In the case of a LSC BPPV, one of the most effective therapies is the forced prolonged position (FPP), in which the patient is invited to lie for 12 h on the lateral side on which vertigo and nystagmus are less intense, to move the canaliths out from the canal (or to shift them inside of the canal from one tract to another) exploiting the force of gravity. Despite its efficacy, FPP is not always well tolerated by every patient, and it cannot be done during the diagnostic session because of its duration. The present study aimed to verify the efficacy of a different forced position, shortened forced position (SFP), with respect to the original FPP. SFP treatment would allow patients to more easily bear the forced position and physicians to control the outcome almost immediately, possibly enabling them to dismiss patients without vertigo. After 1 h of lying on the side where vertigo and nystagmus are the less intense, 38 out of 53 (71.7%) patients treated with SFP were either healed or improved. Although the outcomes are not as satisfying as those of the original FPP, SFP should be considered as a therapeutic prospect, especially by those physicians who work in collaboration with emergency departments or otherwise encounter acute patients to cure them of vertigo as soon as possible.

Otoendoscopy in the era of narrow-band imaging: a pictorial review.

PURPOSE: Otoendoscopy represents the initial non-invasive diagnostic cornerstone for external and middle ear disorders. Recently, new techniques of enhanced imaging such as narrow-band imaging (NBI) have been introduced but their role as a potential aid in otological practice remains unproven. In this pictorial review, we want to present the potential application of this endoscopic method, highlight its limitations, and give some hints regarding its future implementation. METHODS: Representative cases of external and/or middle ear pathologies were selected to illustrate the role of NBI in this regard. RESULTS: NBI may represent a useful aid in the otological work-up, in the differential diagnosis of ear tumor-like masses, and, possibly, in the prognosis of tympanic perforations. For other ear disorders, instead, this technique does not seem to add anything to the standard clinical practice. CONCLUSIONS: NBI might prove useful in the assessment of selected external and middle ear disorders but its role must be prospectively validated.

Hearing outcomes and patient satisfaction after stapes surgery: local versus general anaesthesia.

Objective: Otosclerosis is a frequent ear disorder causing a stapedo-ovalar ankylosis and conductive hearing loss. Stapedoplasty, performed under both general (GA) and local anaesthesia (LA), is the most advisable surgical solution. Auditory recovery relies on the patient's conditions and on the intervention itself. The aim of our work was to compare hearing outcomes with stapedoplasty performed under GA or LA and to investigate patients' compliance to both methods. Methods: Fifty-five otosclerotic patients underwent stapedoplasty both under GA (32/55) and LA (23/55). Pre- and post-operative air and bone tone audiometry threshold values as well as the air-bone gap and its closure score, were analysed. All patients filled in a satisfaction questionnaire regarding their concern and level of appreciation of the type of anaesthesia. Results and conclusions: Our data show that the auditory results with stapedoplasty are good and do not differ between LA and GA. Even considering the advantages and limits of the two methods, one cannot favour one or the other type of anaesthesia. Finally, the patient's satisfaction cannot be considered a criterion of choice, since this was found to be high in both cases.

Vitamin D Insufficiency/Deficiency in Patients with Recurrent Benign Paroxysmal Positional Vertigo.

BACKGROUND: The aim of this study is to verify if (1) there is a link between hypovitaminosis D and benign paroxysmal positional vertigo, (2) the number of benign paroxysmal positional vertigo relapses decreases after vitamin D supplementation; and (3) benign paroxysmal positional vertigo response to physical therapy improves after hypovitaminosis D correction. METHODS: We enrolled 26 patients with benign paroxysmal positional vertigo and 24 subjects, who never suffered from vertigo, as a control group. All benign paroxysmal positional vertigo patients underwent physical therapy, once a week, until benign paroxysmal positional vertigo resolution. All participants were subjected to a dosage of serum 25(OH) vitamin D. In patients with hypovitaminosis D, we prescribed cholecalciferol. After 3 months of therapy, all patients were asked to undergo a second dosage of serum 25(OH) vitamin D. For each patient, we counted the number of maneuvers required to resolve each episode of benign paroxysmal positional vertigo before and after vitamin D supplementation. RESULTS: Our results suggest that (1) there is a relationship between vitamin D deficiency and the onset of BPPV and (2) hypovitaminosis correction is able to reduce both the number of patients relapsing and the number of relapses per patient. CONCLUSIONS: We have not found a significant effect of vitamin D supplementation as regards the responsivity of benign paroxysmal positional vertigo to physical therapy.

Papillary-cystic neoplasms of the middle ear are distinct from endolymphatic sac tumours.

AIMS: Papillary neoplasms of the middle and inner ear are rare and poorly characterised. The current World Health Organization classification divides them into two major subtypes: aggressive papillary tumours (APTs) and endolymphatic sac tumours (ELSTs). The aim of this article is to present two papillary neoplasms of the middle ear that do not fit into either the classic APT category or the classic ELST category, and compare them with three ELSTs. METHODS AND RESULTS: The patients were a 48-year-old female and a 59-year-old male without a history of other neoplasms. Histology showed papillary-cystic growth of predominantly oncocytic (Case 1) or mucinous (Case 2) cells surrounded by a p63-positive basal layer. The overall histology was reminiscent of oncocytic sinonasal papilloma (Case 1) and pancreatobiliary or salivary intraductal papillary mucinous neoplasms (Case 2). Ovarian-type stroma, invasion and malignant features were absent. Immunohistochemistry revealed expression of cytokeratin (CK) 7, but not carbonic anhydrase IX (CAIX) or paired box gene 8 (PAX8) (except for very focal PAX8 expression in Case 1). The TST15 gene panel and HRAS sequencing revealed no pathogenic mutations in BRAF, KRAS, EGFR, AKT1, or HRAS. The TruSight RNA fusion panel revealed an MKRN1-BRAF fusion in Case 1. No fusion was detected in Case 2. The three ELSTs showed classic features of the entity, expressed CK7, epithelial membrane antigen, PAX8, and CAIX, and lacked a basal cell layer. CONCLUSION: These novel cases suggest that papillary tumours of the ear represent a heterogeneous spectrum of distinct neoplasms unified by a prominent papillary-cystic pattern rather than a single entity. Future studies should clarify whether the MKRN1-BRAF fusion is a defining recurrent driver event, especially in those cases reported as sinonasal-type middle ear papillomas.

Double-Blind Randomized Trial on the Efficacy of the Forced Prolonged Position for Treatment of Lateral Canal Benign Paroxysmal Positional Vertigo.

OBJECTIVES/HYPOTHESIS: The need for class I and II studies on the efficacy of liberatory maneuvers in the treatment of lateral canal benign paroxysmal positional vertigo (LC-BPPV) motivated the present double-blind randomized trial on the short-term efficacy of the forced prolonged position (FPP). STUDY DESIGN: Double-blind, randomized controlled trial. METHODS: Two hundred twenty-one patients with unilateral LC-BPPV met the inclusion criteria for a multicentric study. Patients were randomly assigned to treatment by FPP (116 subjects) or sham treatment (105 subjects). Subjects were followed up at 24 hours with the supine roll test by blinded examiners. RESULTS: Among the sample, 67.4% and 32.6% of the patients showed respectively geotropic and apogeotropic variant of LC-BPPV. At the 24-hour follow-up, the effectiveness of FFP compared to the sham maneuver was, respectively, 57.8% versus 12.4% (P < .0001) in the total sample, 76.9% versus 11.3% (P < .0001) in the geotropic variant group, and 60.5% versus 17.6% (P = .0003) in the apogeotropic variant group, including resolution or transformation to geotropic variant. CONCLUSIONS: FPP proved highly effective compared to the sham maneuver. The present class 2 study of the efficacy of the FPP changes the level of recommendation of the method for treating LC-BPPV into a strong one. LEVEL OF EVIDENCE: 2 Laryngoscope, 131:E1296-E1300, 2021.

Upright BPPV Protocol: Feasibility of a New Diagnostic Paradigm for Lateral Semicircular Canal Benign Paroxysmal Positional Vertigo Compared to Standard Diagnostic Maneuvers.

Background: The diagnosis of benign paroxysmal positional vertigo (BPPV) involving the lateral semicircular canal (LSC) is traditionally entrusted to the supine head roll test, also known as supine head yaw test (SHYT), which usually allows identification of the pathologic side and BPPV form (geotropic vs. apogeotropic). Nevertheless, SHYT may not always allow easy detection of the affected canal, resulting in similar responses on both sides and intense autonomic symptoms in patients with recent onset of vertigo. The newly introduced upright head roll test (UHRT) represents a diagnostic maneuver for LSC-BPPV, supplementing the already-known head pitch test (HPT) in the sitting position. The combination of these two tests should enable clinicians to determine the precise location of debris within LSC, avoiding disturbing symptoms related to supine positionings. Therefore, we proposed the upright BPPV protocol (UBP), a test battery exclusively performed in the upright position, including the evaluation of pseudo-spontaneous nystagmus (PSN), HPT and UHRT. The purpose of this multicenter study is to determine the feasibility of UBP in the diagnosis of LSC-BPPV. Methods: We retrospectively reviewed the clinical data of 134 consecutive patients diagnosed with LSC-BPPV. All of them received both UBP and the complete diagnostic protocol (CDP), including the evaluation of PSN and data resulting from HPT, UHRT, seated-supine positioning test (SSPT), and SHYT. Results: A correct diagnosis for LSC-BPPV was achieved in 95.5% of cases using exclusively the UBP, with a highly significant concordance with the CDP (p < 0.000, Cohen's kappa = 0.94), regardless of the time elapsed from symptom onset to diagnosis. The concordance between UBP and CDP was not impaired even when cases in which HPT and/or UHRT provided incomplete results were included (p < 0.000). Correct diagnosis using the supine diagnostic protocol (SDP, including SSPT + SHYT) or the sole SHYT was achieved in 85.1% of cases, with similar statistical concordance (p < 0.000) and weaker strength of relationship (Cohen's kappa = 0.80). Conclusion: UBP allows correct diagnosis in LSC-BPPV from the sitting position in most cases, sparing the patient supine positionings and related symptoms. UBP could also allow clinicians to proceed directly with repositioning maneuvers from the upright position.

Congruous Torsional Down Beating Nystagmus in the Third Position of the Semont's Maneuver in Patients Treated for Canalithiasis of Posterior Semicircular Canal Benign Paroxysmal Positional Vertigo: Its Significance and Prognostic Value.

Due to its mechanical pathogenesis, benign paroxysmal positional vertigo treatment is mainly physical: when posterior semicircular canal is involved, Semont's maneuver is reported as one of the most effective liberating procedures. In the case of a canalolithiasis, the efficacy of the maneuver is corroborated by the appearance of some nystagmus findings during its performance. Liberating nystagmus, that can occur in the second position of Semont's maneuver and whose direction is congruous with the excitation of the affected posterior semicircular canal has proven to be a favorable prognostic sign. On the other hand, in clinical experience, we've frequently verified the appearance of another nystagmus during the execution of the maneuver: upon reaching the third position, when replacing the patient seated, a torsional down beating nystagmus, with the torsional component "congruous" with the stimulation of the vertical semicircular canals of the affected side, can often be appreciated. Such a sign can occur with or without having had the previous liberating nystagmus in the second position and is almost always associated with an intense vertigo and/or body pulsion. In this study, we describe the incidence and characteristics of the congruous torsional down beating nystagmus that can arise by assuming the third position of Semont's maneuver in a cohort of patients treated for posterior semicircular canal benign paroxysmal positional vertigo due to canalolithiasis. In the best of our knowledge, such a sign has never been described and explained before. On the basis of the pathophysiology and of the possible canal receptors stimulation during the different phases of Semont's maneuver, we formulated different hypothesis on how such a nystagmus can be generated. We observed that such a sign, when elicited, has a very good prognostic meaning for healing purposes, even better than that of liberating nystagmus. Therefore, congruous torsional down beating nystagmus should always be checked when performing Semont's maneuver because it could help in predicting success of physical treatment and in managing patients.

Apogeotropic Posterior Semicircular Canal Benign Paroxysmal Positional Vertigo: Some Clinical and Therapeutic Considerations.

We lately reported the cases of patients complaining positional vertigo whose nystagmic pattern was that of a peripheral torsional vertical positional down beating nystagmus originating from a lithiasis of the non-ampullary arm of the posterior semicircular canal (PSC). We considered this particular pathological picture the apogeotropic variant of PSC benign paroxysmal positional vertigo (BPPV). Since the description of the pilot cases we observed more than 150 patients showing the same clinical sign and course of symptoms. In this paper we describe, in detail, both nystagmus of apogeotropic PSC BPPV (A-PSC BPPV) and symptoms reported by patients trying to give a reasonable explanation for these clinical features. Moreover we developed two specific physical therapies directed to cure A-PSC BPPV. Preliminary results of these techniques are related.

Double-blind randomized trial on the efficacy of the Gufoni maneuver for treatment of lateral canal BPPV.

OBJECTIVES/HYPOTHESIS: The need for class I and II studies on the efficacy of liberatory maneuvers in the treatment of lateral canal benign paroxysmal positional vertigo (LC-BPPV) motivated the present double-blind randomized trial on the short-term efficacy of the Gufoni liberatory maneuver (GLM). STUDY DESIGN: Double-blind randomized controlled trial. METHODS: Seventy-two patients with unilateral LC-BPPV were recruited for a multicentric study. Patients were randomly assigned to treatment by GLM (n = 37) or sham treatment (n = 35). Subjects were followed up twice (at 1 hour and 24 hours) with the supine roll test by blinded examiners. RESULTS: At 1- and 24-hour follow-up, 75.7% and 83.8% of patients, respectively, undergoing GLM had recovered from vertigo, compared to around 10% of patients undergoing the sham maneuver (P < 0.0001). CONCLUSION: To the best of our knowledge, this is the first class I study on the efficacy of the GLM in the treatment of LC-BPPV in both geotropic and apogeotropic forms. GLM proved highly effective compared to the sham maneuver (P < 0.0001). The present class I study of the efficacy of the GLM changes the level of recommendation of the method for treating LC-BPPV from level U to level B for the geotropic variant and from level B to level A for the apogeotropic variant of LC-BPPV.

Posterior semicircular canal benign paroxysmal positional vertigo presenting with torsional downbeating nystagmus: an apogeotropic variant.

The aim of this study is to verify the hypothesis that free-floating particles could sometimes localize into the distal portion of the non ampullary arm of the posterior semicircular canal (PSC) so that assuming the Dix-Hallpike's positions, the clot could move towards the ampulla eliciting a inhibitory torsional-down beating paroxysmal positional nystagmus (PPNy), instead of typical excitatory torsional-up beating PPNy. Among 45 patients with vestibular signs suggesting anterior semicircular canal paroxysmal positional vertigo (PPV), collected from February 2003 to August 2006, we detected a group of 6 subjects whose clinical findings showed a singular behaviour during follow-up. At the first check-up, all patients were submitted to different types of physical manoeuvres for ASC canalolithiasis. Patients were controlled during the same session and after one week. When we found that nystagmus was qualitatively changed we adopted the appropriate physical therapies for that sign. At a next check-up, after having performed some physical therapies, all patients had a typical PSC PPNy of the opposite side, with respect to that of the ASC initially diagnosed. Basing on these observations we conclude that PSC PPV, similarly to lateral semicircular canal PPV, could manifests in a apogeotropic variant.

Double-blind randomized trial on short-term efficacy of the Semont maneuver for the treatment of posterior canal benign paroxysmal positional vertigo.

The need for Class I and II studies on the efficacy of Semont's liberatory maneuver (SLM) in the treatment of posterior canal benign paroxysmal positional vertigo (PC-BPPV) motivated the present double-blind randomized trial on the short-term efficacy of SLM. A total of 342 patients with unilateral PC-BPPV were recruited for a multicenter study. Patients were randomly assigned to treatment by SLM (n = 174) or sham treatment (n = 168). Subjects were followed up twice (1 and 24 h) with the Dix-Hallpike maneuver by blinded examiners. At the 1 and 24 h follow-up, 79.3 and 86.8%, respectively, of patients undergoing SLM had recovered from vertigo, compared to none of the patients undergoing the sham maneuver (p < 0.0001). Patients who manifested liberatory nystagmus at the end of SLM showed a significantly higher percentage of recovery (87.1 vs. 55.7%; p < 0.0001). To the best of our knowledge, this is the first Class I study on the efficacy of SLM. SLM proved highly effective with respect to the sham maneuver (p < 0.0001). Liberatory nystagmus was demonstrated to be a useful prognostic factor for the efficacy of treatment. The present Class I study of efficacy of SLM changes the level of recommendation of the maneuver for treating PC-BPPV from level C to level B.