Vertical Nystagmus in the Bow and Lean Test may Indicate Hidden Posterior Semicircular Canal Benign Paroxysmal Positional Vertigo: Hypothesis of the Location of Otoconia.

The 'Bow and Lean Test' (BLT) was developed for proper diagnosis of horizontal semicircular canal benign paroxysmal positional vertigo (HSC-BPPV). Occasionally, down- and/or up-beating vertical nystagmus is observed during the BLT. This study analyzed patients who exhibited vertical nystagmus in the BLT to comprehend the clinical significance of this sign. Of 2872 patients with vertigo between 2010 and 2015, 225 patients who showed vertical nystagmus in the BLT were enrolled. All patterns of vertical nystagmus were described based on their types of BPPV. After performing therapeutic maneuvers for BPPV, remnant symptoms in the BLT findings were investigated. Of the 225 patients with vertical nystagmus, 163 were posterior semicircular canal BPPV (PSC-BPPV). Down-beating in the bowing position and no nystagmus in the leaning position ('Down/-') was the most common type (190 of 225 patients). In addition, the nystagmus occurred in the form of '-/Up', 'Down/Up', and '-/Down'. The pattern of vertical nystagmus may be related to the position of otoconia in the canals. The location of the otoconia enables the diagnosis of hidden PSC-BPPV. Even after treatment for BPPV, patients with vertical nystagmus in the BLT tended to complain remnant vertigo symptoms (44.8% vs. 23.9%, P = 0.022, in PSC-BPPV; 70.0% vs. 24.0%, P = 0.020, in HSC-BPPV). We thought that they actually had hidden PSC-BPPV and the otoconial debris may still in the PSC; this untreated PSC-BPPV might cause the remnant symptoms. In conclusion, vertical nystagmus in the BLT may indicate the presence of PSC-BPPV. Moreover, vertical nystagmus during the BLT may occur in patients with hidden PSC-BPPV who complain of remnant vertigo symptoms. Vertical nystagmus shown in the BLT may not include the possibility of central vertigo.

[VESTIBULAR PROSTHETICS: CONCEPT, APPROACHES, RESULTS].

Unlike prosthetic hearing, which develops technology for more than 30 years, the problem of the vestibular prosthesis developed a little more than one and half decades. Meanwhile, the involvement of the vestibular system in ensuring the normal functioning of the visual, motor and other systems of the body determines its decisive contribution to the spatial orientation of humans and animals. In case of damage of the vestibular apparatus (the labyrinth), there are serious violations of posture control, stabilization of sight, spatial orientation, psychological status, that is, in the aggregate quality of human life deteriorates. At present, on the animals developed technology of prosthetic semicircular canals, sensing angular acceleration, and control eye movements in dynamic situations. New approaches based on the replacement of the lost natural vestibular afferent impulses by electrical stimulation through multichannel vestibular prosthesis, are successfully introducing into the clinic.

Usher's Syndrome: Evaluation of the Vestibular System with Cervical and Ocular Vestibular Evoked Myogenic Potentials and the Video Head Impulse Test.

OBJECTIVE: The Usher's syndrome (USH) is composed of a group of inherited disorders characterized by a dual sensory impairment of the audiovestibular and visual systems. Despite the established hearing loss, few authors have investigated vestibular dysfunction in these patients.The aim of this article is to investigate otolith or ampullary dysfunction in a group of patients affected by USH by means of a diagnostic protocol using caloric vestibular tests, cervical vestibular evoked myogenic potentials (C-VEMPs), ocular vestibular evoked myogenic potentials (O-VEMPs), and video head impulse test (v-HIT) to show any selective damage of the vestibular nerve and also to identify if it is present in patients with a previous diagnosis of USH Type II. STUDY DESIGN: Prospective study with C-VEMPs, O-VEMPs, and v-HIT. SETTING: Tertiary referral center. PATIENTS: Fifteen patients with USH. INTERVENTION: Evaluation of otolith dysfunction with caloric test, C-VEMPs, and O-VEMPs and the measurement of the vestibular-ocular reflex using the v-HIT. RESULTS: Only three cases showed normal values of all the vestibular tests performed. O-VEMPs and C-VEMPs appeared pathologic in nine and seven cases, respectively. V-HITs showed ampullary dysfunction in 10 patients. In our study, eight of the 11 patients belonging to the group of USH Type II showed a pathologic response to at least one of the vestibular tests performed. CONCLUSION: Today, in patients affected by USH, any vestibular diagnostic protocol must include VEMPs and v-HIT to confirm the vestibular damage, identify selective deficit of the vestibular nerve, and provide useful information for a correct classification of USH.

[Isolated functional loss of the lateral semicircular canal in vestibular neuritis]. / Isolierte Rezeptorfunktionsstörung des horizontalen Bogengangs.

Today, modern tools in vestibular testing are feasible to provide information about functional status of all five peripheral vestibular receptors. Isolated or combined loss of crista and macula receptor function can be determined in the diagnostic process. We describe a seldom case of isolated functional loss of lateral semicircular canal receptor function in a 55-year-old patient. Whereas there was no ispilateral caloric response and video head impulse test revealed a catch-up saccade, air-conducted (AC) cervical and ocular vestibular-evoked myogenic potentials (cVEMP, oVEMP), subjective visual vertical and MRI were normal.

A cupulolith repositioning maneuver in the treatment of horizontal canal cupulolithiasis.

OBJECTIVE: We evaluated outcomes and their significance of a new treatment method for horizontal canal cupulolithiasis that could be applied regardless of the side of the cupula where otoliths are attached. METHODS: Consecutive 78 patients who showed persistent apogeotropic horizontal canal positional vertigo (horizontal canal cupulolithiasis) were enrolled, and they were treated with the new cupulolith repositioning maneuver. RESULTS: Horizontal semicircular canal cupulolithiasis was alleviated in 97.4% of patients, after an average of 2.1 repetitions of the maneuver. Otoliths were suspected to be attached to the canal side of the cupula in 30 cases and the utricular side in 44 cases. CONCLUSION: The cupulolith repositioning maneuver is an effective method for treating horizontal canal cupulolithiasis. It may also provide an insight into the side of the cupula where otoliths are attached.

[Analysis of the dysfunction frequency and characteristics of semicircular canal in benign paroxysmal positional vertigo].

OBJECTIVE: To assess the characteristics of the dysfunction of semicircular canal in benign paroxysmal positional vertigo and the relationship with the ectopic otoconia. METHODS: There were 214 patients with benign paroxysmal positional vertigo (BPPV), including 107 cases of posterior semicircular canal canalithiasis (PSC-Can) 80 cases of horizontal semicircular canal canalithiasis (HSC-Can), 27 cases of horizontal semicircular canal cupulolithiasis (HSC-Cup). One hundred and ninety (88.8%) patients were accompany with relevant diseases while 24 (11.2%) cases were not. They accepted low, middle and high frequency vestibular function tests, including caloric test (CT), head shaking test (HST) and video head impulse test (vHIT) respectively. The parameters of the unilateral weakness (UW), head shaking nystagmus (HSN) and video head impulse test gain (vHIT-G) were observed. Patients classified into three groups (PSC-Can, HSC-Can, HSC-Cup) according to the involvement semicircular canal. The results of the three tests were analyzed with SPSS16.0 software. RESULTS: The positive cases of the three tests were vHIT: 15 (7.0%), HST: 52 (24.3%), CT: 152 (71.0%), a statistically significant difference (P < 0.05) was found between the three tests. When compared the Caloric Test, HST and vHIT between the BPPV patients with and without relevant diseases, there were no significant differences (P > 0.05). The variance without statistical significance (P > 0.05) was showed between three tests' results in each groups, it was also showed that the variance between the three groups in each tests reached no statistical significance (P > 0.05). The test of affected side UW between PSC-Can, HSC-Can and HSC-Cup showed the variance without statistical significance (F = 0.970, P = 0.383). CONCLUSIONS: The lesion of semicircular canals has the same etiological factors with the utricle pathological change in benign paroxysmal positional vertigo, and the dysfunction mostly happens in low frequency range of semicircular canal frequency band. The ectopic otoconia is not the main etiological factors for that. HST and vHIT of middle and high frequency can not be ultimately used for the screening test evaluating due to the semicircular canal function in BPPV.

Nueva causa de vértigo estructural: la dehiscencia del canal semicircular superior / A new cause of structural vertigo: superior semicircular canal dehiscence

Resumen. La anamnesis del vértigo debe adaptarse a los conocimientos actuales. En 1998 se describió una nueva causa devértigo asociado a una anomalía estructural, que es la dehiscencia del canal semicircular superior. Ésta causa alteraciones vestibulares y auditivas, frecuentemente asociadas, y una anamnesis bien dirigida permite sospechar el diagnóstico: el sujeto afectado puede sufrir vértigo desencadenado por sonidos intensos (fenómeno de Tullio) y por cambios de presión en el oído o en el espacio intracraneal, con ocasión de maniobras de Valsalva o al presionar sobre el trago del oído (signo de Hennebert). No es infrecuente que el sujeto padezca un desequilibrio crónico empeorado con dichos desencadenantes. Un síntoma auditivo frecuente de la dehiscencia de canal semicircular superior es la autofonía en el oído dehiscente, asociado a una hipoacusia de su transmisión. En este artículo se exponen las preguntas que deben incluirse en la anamnesis del vértigo a fin de evaluar la presencia de estas dehiscencias. También se abordan los procedimientos diagnósticos adecuados para confirmarla. La dehiscencia del canal semicircular superior tiene una solución quirúrgica satisfactoria (AU)

Summary. The medical history of vertigo must be updated to accommodate current knowledge. In 1998 a new cause of vertigo associated with a structural anomaly was reported: superior semicircular canal dehiscence. This condition causes vestibular and auditory disorders, which are frequently associated, and a well-directed medical history allows a suspected diagnosis to be reached: the subject may suffer from vertigo triggered by loud sounds (Tullio’s phenomenon) and by changes in pressure within the ear or in the intracranial space, when Valsalva’s manoeuvres are performed or on pressing on the tragus (Hennebert’s sign). It is not uncommon for subjects to suffer from a chronic imbalance that is exacerbated by the aforementioned precipitating factors. One frequent auditory symptom of superior semicircular canal dehiscence is autophony in the dehiscent ear, associated with hypoacusis of its transmission. This article outlines the questions that must be included in the medical history of vertigo in order to determine whether these dehiscences are present or not. The diagnostic procedures that are best suited to confirming it are also addressed. Superior semicircular canal dehiscence can be resolved satisfactorily by surgery (AU)

Why do patients with PSP fall? Evidence for abnormal otolith responses.

BACKGROUND: Patients with progressive supranuclear palsy (PSP) fall frequently, beginning early in the course of their disease. Abnormal vestibulospinal reflexes are suspected, but the angular vestibulo-ocular reflex, which is mediated by the labyrinthine semicircular canals, survives late into the course of the disease. OBJECTIVE: To test the hypothesis that otolithic-mediated reflexes are abnormal in PSP. METHODS: We tested otolith-ocular reflexes (the translational vestibulo-ocular reflex [tVOR]) during combined rotation-translation in nine patients with PSP and nine age-matched control subjects; subjects viewed far and near targets. We also tested click-induced otolith-spinal reflexes (vestibular-evoked myogenic potentials [VEMPs]) in 10 patients with PSP and 30 age-matched controls. RESULTS: All patients with PSP had small tVOR responses during near viewing that were, on average, only 12% of those of control subjects (p = 0.001). Patients with PSP also showed a reduction of the amplitude of VEMPs compared to control subjects (median [range]: 54.3 [16.8 to 214] vs 149 [11.6 to 466], p = 0.001). CONCLUSIONS: Taken together, these results indicate that abnormal otolith-mediated reflexes may be at least partly responsible for frequent falls in progressive supranuclear palsy, and deserve further study.

The clinical utility of search coil horizontal vestibulo-ocular reflex testing.

CONCLUSION: Testing of the horizontal vestibulo-ocular reflex (VOR) with head rotations (including head impulses) using the magnetic scleral search coil technique (SCT HHI) provides valuable additional diagnostic information in patients with persistent dizziness, oscillopsia or imbalance. It identifies high and low frequency/acceleration vestibular abnormalities that are frequently missed using other methods. OBJECTIVES: To evaluate the diagnostic utility of SCT measurement of the horizontal VOR in the multidisciplinary neurotology clinic of a tertiary referral centre. PATIENTS AND METHODS: The records of 127 consecutive patients referred for persistent dizziness, oscillopsia, imbalance, or with clinical findings suggestive of high frequency/acceleration vestibular dysfunction were reviewed. All had been tested with clinical head impulses, bithermal calorics and vestibular-evoked myogenic potentials. VOR gain (peak eye velocity/peak head velocity) had been measured both in response to sinusoidal oscillations in a rotating chair (0.1-11 Hz) and to manually delivered horizontal head rotations (peak head velocities 50-500 degrees/s) using SCT. RESULTS: Agreement between the different test modalities of horizontal semicircular canal function was moderate. Relative to SCT HHI, clinical HHI showed the highest sensitivity and the lowest specificity (both 70%). SCT HHI appeared to have the greatest diagnostic yield, when compared with calorics and SCT ROT (23% of all abnormalities shown were detected only by SCT HHI) and also allowed detection of significant asymmetries in patients with bilateral vestibular dysfunction.