Characteristics and Possible Mechanisms of Direction-Reversing Nystagmus During Positional Testing in Patients With Benign Paroxysmal Positional Vertigo.

OBJECTIVES: The occurrence of direction-reversing nystagmus during positional testing in patients with benign paroxysmal positional vertigo (BPPV) is not uncommon. Further in-depth analysis of the characteristics and possible mechanisms of direction-reversing nystagmus will help us to diagnose and treat BPPV more precisely. The study aimed to analyze the incidence and characteristics of direction-reversing nystagmus during positional testing in BPPV patients, evaluate the outcomes of canalith repositioning procedure for these patients, and further explore the possible mechanism of reversal nystagmus in BPPV patients. STUDY DESIGN: Retrospective study. SETTING: Single-center study. PATIENTS: A total of 575 patients with BPPV who visited the Vertigo Clinic of our hospital between April 2017 and June 2021 were enrolled. MAIN OUTCOME MEASURES: Dix-Hallpike and supine roll tests were performed. The nystagmus was recorded using videonystagmography. The characteristics of direction-reversing nystagmus and the possible underlying mechanism were analyzed. RESULTS: Patients with BPPV who showed reversal nystagmus accounted for 9.39% (54 of 575) of all BPPV patients visiting our hospital during the same period, of which 5.57% (32 of 575) had horizontal semicircular canal BPPV (HC-BPPV), and 3.83% (22 of 575) had posterior semicircular canal BPPV (PC-BPPV). The maximum slow-phase velocities (mSPVs) of the first-phase nystagmus were greater in HC-BPPV and PC-BPPV patients with reversal nystagmus than those without ( p = 0.04 and p = 0.01, respectively). In all HC-BPPV and PC-BPPV patients with reversal nystagmus, the mSPV of the first-phase nystagmus was greater than that of the second-phase nystagmus ( p < 0.01). The duration of the second-phase nystagmus was longer than 60 seconds in 93.75% (30 of 32) of the HC-BPPV patients and 77.27% (17 of 22) of the PC-BPPV patients ( p = 0.107, Fisher exact test). HC-BPPV and PC-BPPV patients with reversal nystagmus both required more than one canalith repositioning procedure compared with those without (HC-BPPV: 75 versus 28.13%, p < 0.001; PC-BPPV: 59.09 versus 13.64%, p = 0.002). CONCLUSIONS: The cause of second-phase nystagmus in BPPV patients with direction-reversing nystagmus may be related to the involvement of central adaptation mechanisms secondary to the overpowering mSPV of the first-phase nystagmus.

[Bilateral peripheral vestibulopathy]. / Dvustoronnyaya perifericheskaya vestibulopatiya.

Bilateral vestibulopathy is a relatively widespread and at the same time rarely diagnosed cause of chronic postural instability. Numerous toxic factors, dysmetabolic, autoimmune and neurodegenerative processes can lead to this condition. The main clinical manifestations of bilateral vestibulopathy are balance disorders and visual disturbances (oscillopsia), which can significantly increase the risks of falls in such patients. In addition, cognitive and affective disorders, which also reduce the quality of life in patients with bilateral vestibulopathy, have been described and actively studied in recent years. The diagnosis of bilateral vestibulopathy is based on the results of a clinical neurovestibular study, including a dynamic visual acuity test and a Halmagyi test. A video head impulse test, a bithermal caloric test and a sinusoidal rotation test are used as instrumental methods confirming the dysfunction of the peripheral vestibular system. However, they are still not widespread in neurological practice. Treatment of bilateral vestibulopathy is reduced to vestibular rehabilitation. Encouraging results have been obtained in a number of studies using galvanic vestibular stimulation and the use of vestibular implants. In addition, cognitive rehabilitation methods are currently being developed, which presumably can also improve compensation for bilateral vestibular loss.

Can hyperventilation test and duration of spontaneous nystagmus help differentiate between vascular and inflammatory aetiology of acute unilateral vestibular deficit?

Objective: To relate clinically the duration of spontaneous nystagmus and hyperventilation-induced nystagmus (HVIN) to vascular or inflammatory aetiology of acute unilateral vestibulopathy observed in a very early stage. Methods: This is a retrospective study on 198 patients with acute unilateral vestibulopathy. Results: In the short-lasting nystagmus group (spontaneous nystagmus < 48 h), mean age and cardiovascular risk were significantly higher; the rates of negative HVIN and paretic HVIN were 41.7% and 58.3%, respectively. In the long-lasting nystagmus group (spontaneous nystagmus > 48 h), mean age and vascular risk were lower; HVIN was absent in 12.6% of the cases, HVIN excitatory patterns were observed in 40.3% of cases and a paretic pattern in 47.1%. Conclusions: A vascular aetiology should be considered the most likely in patients with spontaneous nystagmus < 48 hours: all patients were > 60 years old, cardiovascular risk was higher and HVIN was always absent or paretic. In the group with nystagmus > 48 hours, similarly, data indicate a higher incidence of paretic HVIN in older patients and higher vascular risk, even if the data does not allow us to lean clearly towards one of the two aetiological hypotheses.

Vestibular Testing: Patient Perceptions, Morbidity, and Opportunity Costs.

OBJECTIVE: To characterize patient tolerance and nonmonetary cost burdens of vestibular testing. Rigorously acquired data are essential for patient counseling and to determine if proposed additions/modifications to current protocols improve quality, experience, and efficiencies of care. STUDY DESIGN: Prospective observational study. SETTING: Tertiary center. PATIENTS: 130 adults (67% women, mean age 55 yr), referred to audiology clinic for vestibular testing. INTERVENTION(S): Surveys administered to patients and audiologists immediately and 1 week following videonystagmography (VNG) with caloric and/or rotary chair (RC) testing. MAIN OUTCOME MEASURE(S): Symptoms, visual analog scale ratings of dizziness, distress, and nausea during testing; test completion; and opportunity costs (time, missed work). RESULTS: Seventy-five patients (58%) experienced undesirable symptoms during testing, including nausea (50%), vomiting (5%), and headaches (12%). Distress and nausea ratings during testing were low (<3/10), with RC ratings lower than VNG. Nineteen patients (15%) discontinued testing early, rating distress and nausea two to three times higher than those who completed testing (p < 0.05). Greater dizziness was associated with younger age and female sex, not migraine and total eye speed. Women had increased distress. Test times were 71 [23] and 26 [13] minutes for VNG with calorics and RC, respectively. Testing required 48% to miss work (range 2-120 h) and 78% obtained assistance to/from testing. Posttest symptoms included drowsiness/fatigue (44%), nausea (31%), and headache (33%). CONCLUSIONS: This work provides baseline patient tolerance data for vestibular testing. While eliciting distress ratings comparable to other in-office otolaryngology procedures, there are high frequencies of undesirable symptoms, posttest morbidity, and opportunity costs.

Exploración de los conductos semicirculares verticales con estimulación rotatoria inducida / Exploration of vertical semicircular ducts with induced rotatory stimulation

Las pruebas rotatorias han sido utilizadas durante más de un siglo para el estudio de la función vestibular por ser un estímulo fisiológico controlado muy efectivo sobre el laberinto posterior, habitualmente son los conductos semicirculares horizontales los que se exploran, pues se afectan con más frecuencia y son más fáciles de estudiar, sin embargo en ocasiones son los verticales los lesionados y por tanto deben emplearse otras alternativas para llegar a un diagnóstico certero. Se presenta un caso donde se evalúa la función fisiológica de los conductos semicirculares verticales a través de la electronistagmografía con estimulación rotatoria, empleando la técnica de estimulación tiempo-velocidad, con fases sucesivas de aceleración, velocidad constante, desaceleración y parada brusca, con una silla rotatoria computarizada, acoplada a un electronistagmógrafo. Se obtuvo arreflexia del canal vertical anterior derecho. A velocidades inferiores a 1 Hz es posible evaluar el reflejo vestíbulo ocular en los conductos semicirculares verticales, a pesar de que la frecuencia del estímulo está por debajo del nivel en que este reflejo funciona en las actividades diarias(AU)

Rotatory tests have been used for over a century for the study of vestibular function because it is a very effective physiological controlled stimulus on the posterior labyrinth, usually the horizontal semicircular ducts that are explored, since they are affected more frequently and are more easy to study, however sometimes the injured are vertical and therefore other alternatives must be used to arrive at a correct diagnosis. The aim of this study is to evaluate the range of physiological function of vertical semicircular ducts using electronystagmography and rotary stimulation. The method used was the technique of time - speed stimulation, with successive phases of acceleration, constant speed, deceleration and abrupt stop, with a computerized rotating chair. Vestibulo-ocular arreflexia of the right anterior vertical channel. It was shown that at speeds lower than 1 Hz it is possible to evaluate the Ocular Lobe Reflex in the vertical semicircular ducts, although the frequency of the stimulus is below the level at which this reflex works in daily activities(AU)

Exploración de los conductos semicirculares verticales con estimulación rotatoria inducida / Exploration of vertical semicircular ducts with induced rotatory stimulation

Las pruebas rotatorias han sido utilizadas durante más de un siglo para el estudio de la función vestibular por ser un estímulo fisiológico controlado muy efectivo sobre el laberinto posterior, habitualmente son los conductos semicirculares horizontales los que se exploran, pues se afectan con más frecuencia y son más fáciles de estudiar, sin embargo en ocasiones son los verticales los lesionados y por tanto deben emplearse otras alternativas para llegar a un diagnóstico certero. Se presenta un caso donde se evalúa la función fisiológica de los conductos semicirculares verticales a través de la electronistagmografía con estimulación rotatoria, empleando la técnica de estimulación tiempo-velocidad, con fases sucesivas de aceleración, velocidad constante, desaceleración y parada brusca, con una silla rotatoria computarizada, acoplada a un electronistagmógrafo. Se obtuvo arreflexia del canal vertical anterior derecho. A velocidades inferiores a 1 Hz es posible evaluar el reflejo vestíbulo ocular en los conductos semicirculares verticales, a pesar de que la frecuencia del estímulo está por debajo del nivel en que este reflejo funciona en las actividades diarias(AU)

Rotatory tests have been used for over a century for the study of vestibular function because it is a very effective physiological controlled stimulus on the posterior labyrinth, usually the horizontal semicircular ducts that are explored, since they are affected more frequently and are more easy to study, however sometimes the injured are vertical and therefore other alternatives must be used to arrive at a correct diagnosis. The aim of this study is to evaluate the range of physiological function of vertical semicircular ducts using electronystagmography and rotary stimulation. The method used was the technique of time - speed stimulation, with successive phases of acceleration, constant speed, deceleration and abrupt stop, with a computerized rotating chair. Vestibulo-ocular arreflexia of the right anterior vertical channel. It was shown that at speeds lower than 1 Hz it is possible to evaluate the Ocular Lobe Reflex in the vertical semicircular ducts, although the frequency of the stimulus is below the level at which this reflex works in daily activities(AU)

Hyperventilation-induced nystagmus in vestibular neuritis: pattern and clinical implication.

BACKGROUND: It was the aim of this study to investigate the pattern of evolution of hyperventilation-induced nystagmus (HIN) in vestibular neuritis (VN) and to determine whether HIN influences the dizziness outcome at the last follow-up visit. METHODS: Fifty-three consecutive patients with VN underwent a quantitative vestibular function test including hyperventilation and the Korean version of the Dizziness Handicap Inventory during the acute period and the follow-up visit. RESULTS: The incidence of HIN was higher in the acute (62%, 33/53) than in the chronic (17%, 9/53) stages of VN. Approximately 70% (6/9) of patients who continued to have persistent HIN at the last follow-up reported dizziness compared to only 27% (12/44) of patients who had no HIN. Patients who complained of persistent dizziness were significantly more likely to have persistent HIN and high Korean Dizziness Handicap Inventory scores at the last follow-up compared with patients who did not suffer from dizziness. In terms of the degree of recovery of dizziness, patients with HIN initially beating toward the contralesional side exhibited significantly more improvement than patients with HIN initially beating toward the ipsilesional side. CONCLUSIONS: The presence of either HIN beating toward the ipsilesional side at the acute stage of VN or persistent HIN at the follow-up visit is associated with persistent dizziness.

Relación entre las fracturas de base craneal y la electronistagmografía / Relation between the cranial base and the electro-nystagmography

Introducción: la electronistagmografía se usa en la actualidad con fines de diagnóstico, es el proceso por el cual se hace un registro de la posición y movimiento del globo ocular, para identificar cambios en el campo eléctrico alrededor del ojo al modificar su posición. Objetivo: evaluar la utilidad de la electronistagmografía, al compararla con la prueba vestibular tradicional para el diagnóstico topográfico de las secuelas audiológicas vestibulares presentes en pacientes con fractura de base craneal. Métodos: se realizó un estudio observacional, analítico, de corte transversal, en el Hospital Militar Dr Carlos Juan Finlay, en el período comprendido de enero de 2006 a enero de 2008. El universo estuvo representado por 210 pacientes, divididos en 2 grupos: uno de estudio con secuelas auditivas vestibulares posteriores a fractura de base de cráneo, y otro de control, con sujetos sanos. Resultados: el síntoma que se encontró en el 100 por ciento de los pacientes fue el vértigo. Del total de 118 casos con electronistagmografía positiva, 47 (39,8 por ciento) habían arrojado resultados negativos en la prueba vestibular. Conclusiones: la electronistagmografía resultó positiva en el mayor número de casos estudiados, y presentó una alta sensibilidad, al demostrar, que casos con debilidad laberíntica y preponderancia direccional presentes, no fueron diagnosticados con la prueba vestibular tradicional(AU)

Introduction: nowadays, the electro-nystagmography is used for diagnosis; it is the process by which it is possible to register the position and movement of ocular eyeball to identify the changes in the electric field around the eye in modifying its position. Objective: to assess the usefulness of the electro-nystagmography in comparison with the traditional vestibular test for topographic diagnosis of auditory sequelae present in the patients presenting with cranial base fracture. Methods: a cross-sectional, analytical and observational study was conducted in the Dr Carlos J Finlay Military Hospital from January, 2006 to January, 2008. Universe included 210 patients divided into two groups: a study group with vestibular auditory sequealae after a fracture of cranial base and a control group consisting of healthy subjects. Results: dizziness was the symptom present in the 100 percent of patients. From the total of 118 cases with positive electro-nystagmography, 47 (39.8 percent) had negative results in the vestibular test. Conclusions: the electro-nystagmography was positive en most of study cases with a high sensitivity demonstrating that cases presenting with labyrinth weakness and directional predominance were not diagnosed by means of traditional vestibular test(AU)

[Side effects and patients expectations after vestibular tests]. / Effets secondaires et expectatives des patients après tests vestibulaires.

OBJECTIVE: Patients satisfaction and side effects assessment after vestibular tests. MATERIALS AND METHODS: Questionnaires were sent to 150 patients after vestibular testing in 2006. Forty-two questionnaires were sent back to us. On each questionnaire there were 5 questions regarding patient expectations, 4 questions about side effects after vestibular tests and one question was related to follow-up medical attention. RESULTS: Most of the patients think that the delay between clinical consultation and vestibular test was not too long. Information patients received beforehand regarding vestibular tests aim, duration, possible side effects and diagnostic expectations are good enough for most of the patients. However patient's assessment of the informed consent document and location of vestibular tests is diverse. The vast majority of patients feel "very important" to receive information about vestibular tests results on the same day. For most of the subjects caloric test is the most disconfortable tests. In the following days, more than half of the subjects feel vestibular symptoms. The most frequent suggestion we received from patients is to give them a phone calls after vestibular tests. CONCLUSION: It is worth mentioning the importance of informing the patient about vestibular test results upon completion. Our aim is to make some changes on the informed consent document given to patients and to make a phone call to patients after vestibular tests.

Effect of vestibular rehabilitation on dizziness in the elderly.

OBJECTIVES: Dizziness in the elderly is relatively common, but only a few studies are available. The purpose of this study was to analyze the effect of vestibular rehabilitation on dizziness in elderly patients. MATERIALS AND METHODS: A total of 240 patients older than 70 years with dizziness who visited the dizziness center of a tertiary care university hospital from January 2000 to January 2004 were studied. The patients' charts were retrospectively reviewed. Thorough otolaryngologic and neurotologic evaluations and vestibular function testing were performed in every case to determine the specific causes of dizziness. General vestibular rehabilitation therapy (VRT) was performed in 103 cases (VRT group) and it was not done on the other 46 cases (non-VRT group). The intensity of dizziness and disequilibrium was evaluated by the verbal analogue scale and Activities-specific Balance Confidence questionnaires that were obtained at 3 weeks and at 3 months after the initiation of general VRT. RESULTS: The average age of the patients was 76.5 +/- 6.2 years. In 153 cases (63%), no specific causes for dizziness were found, which was attributed to presbyastasis. Improvement in dizziness in the VRT group was significantly higher than in the non-VRT group by the verbal analogue scale and Activities-specific Balance Confidence scale obtained at 3 weeks and at 3 months after the initiation of VRT. CONCLUSION: In the majority of elderly patients with dizziness, the etiology of dizziness is not found and is attributed to presbyastasis. General VRT seems to be an effective treatment for this elderly group.

Safety of repeated sessions of galvanic vestibular stimulation following stroke: a single-case study.

PRIMARY OBJECTIVE: Galvanic vestibular stimulation (GVS) involves the delivery of small electrical current to the part of the scalp that overlies the vestibular nerves. A single, brief session transiently reduces certain types of stroke impairment with no reported side-effects. It is anticipated that further reductions will occur if the duration and frequency of stimulation is increased. The aim of the present study was to assess whether this increased exposure is well-tolerated and consistent with patient well-being. METHODS AND PROCEDURES: GVS was administered to a stroke sufferer on 5 consecutive days, each for 30 minutes at an intensity of 1 milliamp. Tolerability was monitored via a range of behavioural scales sensitive to side-effects experienced during and after stimulation. RESULTS: No unpleasant sensations were reported during stimulation and no deterioration in global function was observed over the 5-day period. CONCLUSION: The results imply that repeated applications of GVS are tolerable at the parameter settings applied and provide the basis for larger-scale investigations of safety and efficacy.

Un método alternativo para determinar si hay respuesta vestibular en un oído anatómicamente alterado / An alternative method to determine the vestibular response of an ear with anatomic alteration

Hay situaciones en que no conviene aplicar la prueba calórica habitual tal como la describieron Dix y Hallpike. Generalmente se tratan de secuelas de procesos inflamatorios o quirúrgicos en las que se altera la simetría anatómica entre ambos oídos por lo que es difícil la interpretación de las respuestas. En otras ocasiones la irrigación con agua puede producir complicaciones por lo que se prefiere la estimulación por aire lo que implica un alto costo en equipamiento. El autor aprovecha el enfriamiento que se produce durante la aspiración del aire tibio de las cavidades del oído externo y medio para estimular inhibitoriamente los elementos sensoriales de la ampolla del canal semicircular horizontal y de comprobar si hay excitabilidad o no, dependiendo de la presencia de sensación vertiginosa con nistagmo en dirección al oído contralateral. Expresa además que este fenómeno no es equivalente al mal llamado signo de la fístula, y que el conocimiento de la fisiología de esta situación permite, además, evitar la sensación vetiginosa con sus implicaciones neurovegetativas en beneficio del paciente, realizando el procedimiento mediante lapsos repetidos de corta duración evitando así el enfriamiento del oído