Assessment of head shaking test in neuro-otological practice

The head shaking test (HST) is an important test in neuro-otological diagnosis. In our study of 277 patients complaining of dizziness we verified this importance. The results thus obtained were compared with the results recorded in 73 normal subjects. Head shaking nystagmus was observed in 73 patients. Of these 73 cases, 42 involved central diseases and 31 cases involved peripheral diseases. Head shaking nystagmus was observed in 7 subjects of the control group. A highly significant correlation was noted between head shaking nystagmus and positional nystagmus, between head shaking nystagmus and the caloric test and between head shaking nystagmus and all the other spontaneous types of nystagmus that were investigated (eyes open in light/gaze straight ahead; eyes open behind Frenzel's glasses; eyes closed; eyes open in darkness). No correlation was found between head shaking nystagmus and cervical nystagmus and positioning nystagmus. The sensitivity of head shaking nystagmus, in comparison with other types of spontaneous nystagmus, was found to be slightly higher in cases with peripheral lesions than in those with central lesions. These data confirm the diagnostic importance of this simple test. It is also important to keep in mind that the HST has no importance for topodiagnostic purposes.     

Persistent Direction-Fixed Nystagmus Following Canalith Repositioning Maneuver for Horizontal Canal BPPV: A Case of Canalith Jam

The authors report a 64-year-old man who developed persistent direction fixed nystagmus after a canalith repositioning maneuver for horizontal canal benign paroxysmal positional vertigo (HC-BPPV). The patient was initially diagnosed with right HC-BPPV given that the Dix-Hallpike test showed geotropic horizontal nystagmus that was more pronounced on the right side, although the roll test did not show any positional nystagmus. The patient was treated with a canalith repositioning maneuver (Lempert maneuver). The next day, the patient experienced a different character of dizziness, and left-beating spontaneous nystagmus regardless of head position was observed. After a forced prolonged left decubitus and frequent head shaking, his symptoms and nystagmus resolved. This condition, referred to as canalith jam, can be a complication after the repositioning maneuver in patients with BPPV. Atypical positional tests suggest that abnormal canal anatomy could be the underlying cause of canalith jam.     

Patients with vertigo/dizziness of unknown origin during follow-ups by general otolaryngologists at outpatient town clinic

ObjectivesThe purpose of this study was to access the contribution of vertigo/dizziness-related patients’ interview and examinations during short-term hospitalization in determining the accurate final diagnosis of vertigo/dizziness of unknown origin.MethodsWe reviewed 1905 successive vertigo/dizziness patients at the Vertigo/Dizziness Center of Nara Medical University, who were introduced from general otolaryngologists at outpatient town clinic from May 2014 to April 2020. However, 244 patients were diagnosed with vertigo/dizziness of unknown origin (244/1905; 12.8%). Of these patients, 240 were hospitalized and underwent various examinations, including caloric test (C-test), video head impulse test (vHIT), vestibular evoked cervical myogenic potentials (cVEMP), subjective visual vertical (SVV), inner ear magnetic resonance imaging (ieMRI), Schellong test (S-test), and self-rating questionnaires of depression score (SDS).ResultsAccording to the examination data, together with interviewed vertigo/dizziness characteristics and daily changeable nystagmus findings, the final diagnoses were as follows: benign paroxysmal positional vertigo (BPPV: 107/240; 44.6%), orthostatic dysregulation (OD: 56/240; 23.3%), vestibular peripheral disease (VPD: 25/240; 10.4%), vestibular migraine (VM: 14/240; 5.8%), Meniere's disease (MD: 12/240; 5.0%), gravity perception disturbance (GPD: 10/240; 4.2%), psychogenic vertigo (Psycho: 10/240; 4.2%), and unknown (Unknown: 6/240; 2.5%). Supporting factors of final diagnosis was seen in gender, evoked dizziness, and positional nystagmus as BPPV; in evoked dizziness, S-test, and hypertension as OD; in evoked dizziness, head shaking after nystagmus, C-test, and vHIT as VPD; in gender, headache, and S-test as VM; in ear fullness and ieMRI as MD; in gender, evoked dizziness, and SVV as GPD; and in SDS as Psycho. To sum up, the ratios of Unknown were significantly reduced by this short-term hospitalization (244/1905→6/240).ConclusionsThe answer lists for vertigo/dizziness of unknown origin obtained in the present study may be helpful for future general otolaryngologists at outpatient town clinic to better attain an accurate final diagnosis.     

Somatosensory shift of postural control in dizzy patients

Conclusions: Postural control is dependent on the visual system in normal conditions. Shift from visual to somatosensory dependence in dizzy patients suggests that utilizing the stable visual references is recommended for the rehabilitation of dizzy patients. Objectives: To investigate which of the visual or somatosensory system is mainly used for substitution of the impaired spatial orientation in dizzy patients. Methods: We recruited 189 consecutive patients with or without dizziness and vestibular dysfunction. Dizzy patients were divided into three groups: acute, episodic, and chronic dizziness. Vestibular function was assessed by caloric test, traditional head impulse test, and head shaking nystagmus. Visual or somatosensory dependence of spatial orientation was assessed by posturography on a solid surface or on foam in eyes open or closed condition. The foam ratio (posturography with/without foam) when eyes were closed was indicative of somatosensory dependence of postural control, whereas the Romberg ratio on foam showed visual dependence. (Romberg ratio on foam)/(foam ratio with eyes closed) was calculated and used as an index of the visual/somatosensory dependence of postural control. Results: The visual/somatosensory ratio of postural control was significantly lower in dizzy patients as well as patients with vestibular dysfunction, however, no differences were found between acute, episodic, and chronic dizziness.     

Head shaking nystagmus in the follow‐up of patients with vestibular diseases

We examined 420 patients with vestibular diseases of different origin; 273 with peripheral vestibular disease and 147 with both peripheral and central vestibular disease. Recurrent vestibulopathy like Menière's disease, or benign paroxysmal positional vertigo, were not included. Patients were evaluated initially and 6 months after pharmacological and/or rehabilitation therapy. At the initial assessment, the head‐shaking test was specific for the side of the lesion in both groups, even if spontaneous nystagmus was no longer present. Thus, head‐shaking nystagmus is a physical sign that can be easily evoked and gives useful information about the presence of vestibulo‐ocular reflex asymmetry. At the follow‐up at 6 months, many changes in the head‐shaking nystagmus were noted: in some cases it appeared, in some others it changed direction and more often it disappeared. There is actually no acceptable explanation for the disappearance of the head‐shaking nystagmus, despite some evidence that vestibular compensation could play a role. It is definitely proved that sensitivity of the head‐shaking test is really poor, especially in the course of time and, therefore, it should not be used alone in the follow‐up of patients with vestibular disease.     

Spontaneous and positional nystagmus in healthy persons demonstrated only by electronystagmography: physiological spontaneous nystagmus or "functional scar"?

We wanted to ascertain whether a physiological horizontal vestibular spontaneous nystagmus is existent, or whether the spontaneous and positional nystagmus seen in clinically healthy persons in the electronystagmogram -- when fixation had been excluded completely -- was always the result of earlier damages to the vestibular system (Jatho). For this purpose we tried to detect a spontaneous and positional nystagmus in 102 healthy persons from 6 age groups (17 each) between 11 and 70 years of age. When the ENG was registered with open eyes in darkness, 63 out of the 102 test persons had a horizontal spontaneous or positional nystagmus, however, under the Frenzel glasses there was a nystagmus in only 2 out of these test persons. With open eyes in darkness, the frequency and intensity was the same in all age groups. With this, we believe to have proved that a physiological horizontal vestibular nystagmus does exist. We share Kornhuber's opinion that the examination with the Frenzel glasses in a dark room, together with the head shaking test and positional test, at the present time represents the best method for differentiating between physiological and pathological spontaneous nystagmus.     

Video-nystagmography findings in healthy elderly subjects

This study investigated 44 healthy elderly subjects aged between 64 and 87, who were analysed with videonystagmoscopy and quantitative videonystagmography, for establishing new standards for normal limits into this new diagnostic tool. 15.9% of the subjects were found to have spontaneous and provoked nystagmus at least in one position studied. Vertical nystagmus in head hanging position was the most frequent finding. In the Dix-Hallpike test we found one case of torsional nystagmus. No subject had seated position nystagmus. Nystagmus after head shaking and evoked nystagmus were not found.     

头晕眩晕与眼震强度的关系研究

目的 通过冷热试验诱发头晕和/或眩晕时的眼震强度,探讨头晕眩晕与眼震强度的关系。 方法 对399例前庭周围性疾病患者进行常规冷热试验检查,以双耳冷热气刺激诱发出头晕和/或眩晕感时的眼震强度为指标,比较分析头晕及眩晕感与眼震强度的关系。 结果 冷热刺激诱发头晕眩晕及关联眼震总体分析,出现眩晕时的眼震强度总是大于头晕。左右耳冷热气刺激诱发头晕、眩晕的眼震阈值分别为:左耳冷4.2°/s、5.9°/s,左耳热4.2°/s、8°/s,右耳冷4.6°/s、6.2°/s,右耳热5.3°/s、 6.5°/s。399例患者进行双耳冷热交替刺激,共计1 596次试验,诱发出头晕513次(32.14%),其中312次仅有头晕、201次在头晕后10 s左右还出现眩晕;诱发出眩晕906次(56.77%),其中705次直接出现眩晕,无从头晕向眩晕进行过渡,另201次眩晕出现在头晕10 s左右之后;未引出头晕眩晕378次(23.68%)。 结论 眩晕对应的眼震强度阈高于头晕,眼震较弱时患者表现为头晕,较强时则呈现眩晕。冷热气刺激诱发眼震强度由弱到强及同时存在的由头晕到眩晕现象,提示头晕眩晕症状与两侧前庭张力差的大小相关。     

Spontaneous and positional nystagmus in healthy persons demonstrated only by electronystagmography: Physiological spontaneous nystagmus or “functional scar”?

Summary We wanted to ascertain whether a physiological horizontal vestibular spontaneous nystagmus is existent, or whether the spontaneous and positional nystagmus seen in clinically healthy persons in the electronystagmogram — when fixation had been excluded completely — was always the result of earlier damages to the vestibular system (Jatho). For this purpose we tried to detect a spontaneous and positional nystagmus in 102 healthy persons from 6 age groups (17 each) between 11 and 70 years of age. When the ENG was registered with open eyes in darkness, 63 out of the 102 test persons had a horizontal spontaneous or positional nystagmus, however, under the Frenzel glasses there was a nystagmus in only 2 out of these test persons. With open eyes in darkness, the frequency and intensity was the same in all age groups. With this, we believe to have proved that a physiological horizontal vestibular nystagmus does exist. We share Kornhuber's opinion that the examination with the Frenzel glasses in a dark room, together with the head shaking test and positional test, at the present time represents the best method for differentiating between physiological and pathological spontaneous nystagmus.This study is dedicated to Prof. Dr. D. Zühlke commemorating his 50th Birthday     

Head‐shaking nystagmus in patients with a vestibular schwannoma

Head‐shaking nystagmus in patients with a vestibular schwannoma The aim of this study was to calculate the sensitivity of the head‐shake test for peripheral and central vestibular dysfunction associated with unilateral sporadic vestibular schwannoma and to discuss the feasibility of using the head‐shake test as a screening test. The study group consisted of 102 patients with unilateral sporadic vestibular schwannomas, who were seen consecutively for preoperative vestibular assessment, including the head‐shake test. The sensitivity of the head‐shake test for vestibular schwannoma was found to be 22%, and the sensitivity and specificity of the head‐shake test for canal paresis (≥25%) were found to be 27% and 88%, respectively. Patients with abnormalities in the central vestibular system and with a greater canal paresis were more likely to have head‐shake nystagmus, although, even for severe canal paresis, the sensitivity of the test remained low at 36%. The direction of nystagmus was found to be contra‐lateral to the side of the tumour in 86% of patients. It was concluded that the head‐shake test is of insufficient sensitivity to be used as a screening test either for vestibular schwannoma or for vestibular‐system abnormalities associated with vestibular schwannoma. The deduction is made that the head‐shake test is of insufficient sensitivity or specificity to be of clinical value as a screening test for vestibular dysfunction in a general population with symptoms of imbalance.     

An objective testing method to determine driving ability

The pendular test was used to study turning sensations of aspirants with "physiological spontaneous nystagmus". A steering wheel was attached to the pendular chair and persons were asked to turn against the chair rotation. Chair movement, steering wheel and horizontal nystagmus were computer-analysed. The correlation between cumulogram of slow nystagmus phases and steering wheel rotations was evaluated and the value of the steering wheel and eye movement were calculated. It could be shown that the compensation of the pendular chair by the means of the steering wheel was symmetric in healthy persons in spite of the presence of spontaneous nystagmus. In patients with dizziness, no symmetric reaction was recorded.     

Dynamics of canal response to head-shaking test in benign paroxysmal positional vertigo

CONCLUSIONS: Time constant and maximum slow phase velocity (SPV) of head-shaking nystagmus (HSN) demonstrated a differential canal response to head shaking in 24% of patients with posterior canal benign paroxysmal positional vertigo (BPPV). We suggest that vestibular lithiasis has a limited contribution to the mechanism that generates HSN. OBJECTIVE: To determine the canal response to head shaking in BPPV. PATIENTS AND METHODS: This was a case-control study including 104 individuals with BPPV. The diagnosis was based on the presence of vertigo and nystagmus during the positional test. Subjects were examined by the horizontal and vertical head-shaking test. Eye movements were recorded on a video camera to analyze the nystagmus. The head was shaken passively in the horizontal and sagittal planes, respectively, for horizontal and vertical HSN at a frequency of 2 Hz. HSN was considered when six consecutive beats of nystagmus with an SPV of at least 2 degrees/s were detected. Main outcome measures were the presence of horizontal and vertical HSN, maximum SPV of HSN, time constant of HSN, and canal paresis. RESULTS: Maximum SPV of vertical HSN was higher in BPPV patients with posterior canal BPPV (n = 10) than in controls (p = 0.04). Moreover, the time constant of vertical HSN was significantly lower for posterior canal BPPV when compared with controls (p < 0.02).     

Functional loss of the horizontal doll's eye reflex following unilateral vestibular lesions

The doll's eye reflex represents the vestibulo-ocular reflex (VOR) elicited by high-acceleration head rotation. After complete unilateral vestibular lesions, the ipsilateral, horizontal doll's eye reflex is replaced by a series of “catch-up” saccades. These cause permanent symptoms of blurred vision and dizziness during ipsilateral turns. We compared normal controls and patients with complete surgical lesions or canal paresis of up to 9 years duration via electronystagmography (ENG) to determine the usefulness of the doll's eye test as a diagnostic test for complete vestibular lesions. This test was found to be more sensitive in diagnosis of such lesions than head-shaking nystagmus, rotatory directional preponderance, and spontaneous nystagmus. It is also useful to document VOR function in patients in whom caloric irrigation is contraindicated.     

Dynamic vestibular compensation in vestibular peripheral diseases

Vestibular compensation, or neuronal plasticity in the central vestibular system, is quite an important process in patients with acute unilateral peripheral vestibular disease, allowing them to lead a comfortable daily life when medical treatments fail to cure the peripheral vestibular function. Is the residual unilateral vestibular input from damaged vestibular endo-organs a positive or negative factor for the development of dynamic vestibular compensation in the central nervous system? To elucidate the true mechanism of vestibular compensation, we examined the ENG findings and dizziness handicap inventory questionnaire in patients with vestibular neuronitis (VN), sudden deafness with vertigo (SDV), Meniere's disease (MD) and acoustic tumor (AT) during remission of the vertigo attacks. We obtained neuro-otological findings from caloric tests and head shaking after nystagmus using ENG and information on motion-evoked dizziness in daily life using the questionnaire. There were no significant differences in the sex, age or canal paresis % (CP%) among the four groups. The results of the present study showed that dynamic vestibular compensation processes developed progressively in the order of patients with SDV, VN, MD and AT (Kruskal-Wallis : p < 0.05). This finding suggests that processes of dynamic vestibular compensation could be accelerated in patients with fixed vestibular lesions caused by SDV and VN more than in those with fluctuating vestibular functions caused by MD and AT. In patients with fixed vestibular lesions caused by SDV and VN, patients with lower CP% showed dynamic vestibular compensation (i.e. disappearance of head shaking after nystagmus (chi-square: p < 0.05) and motion-evoked dizziness (Mann-Whitney: p < 0.0005)) more rapidly than those with higher CP%. In patients with fluctuating vestibular functions caused by MD and AT, patients with lower CP% did not always develop dynamic vestibular compensation more smoothly than those with higher CP%.     

Head-shaking nystagmus in patients with unilateral peripheral vestibular lesions

In certain patients with peripheral or central vestibular lesions, a transient nystagmus appears after shaking the head rapidly for 10 to 20 cycles. We recorded such a "head-shaking nystagmus" using the scleral eye coil in six subjects with unilateral peripheral vestibular lesions. Horizontal head shaking elicited horizontal nystagmus with slow phases that were initially directed toward the side of the lesion and upward. All subjects showed a prolonged, lower-amplitude reversal phase after the initial response following horizontal head shaking. The main features of these results can be explained by an analytic model that incorporates a central velocity-storage mechanism that perseverates vestibular inputs, Ewald's second law, and adaptation of primary vestibular afferent activity.     

Vestibular Disease Unmasked by Hyperventilation

Hyperventilation-induced dizziness is often thought to be psychogenic, but its effects in the presence of known vestibular disease have not been adequately examined. In this study hyperventilation was tested in two models of vestibular disease. These were, first, patients with profound unilateral vestibular deficit (prior translabyrinthine acoustic neuroma resection [postsurgery group]) and, second, patients with variable unilateral vestibular deficit (unoperated unilateral acoustic neuroma [presurgery group]). Patients were hyperventilated for 90 seconds. Using infrared videonystagmography, 100% of the 32 postsurgery patients and 82% of the 28 presurgery patients developed nystagmus with hyperventilation. Hyperventilation was more sensitive than head shake for eliciting nystagmus in these models. The false-positive rate for nystagmus in 29 normal volunteers was 3.5% for hyperventilation and 10% for head shake. Our results show that hyperventilation can unmask underlying vestibular disease.     

Dynamics of canal response to head-shaking test in benign paroxysmal positional vertigo

Conclusions. Time constant and maximum slow phase velocity (SPV) of head-shaking nystagmus (HSN) demonstrated a differential canal response to head shaking in 24% of patients with posterior canal benign paroxysmal positional vertigo (BPPV). We suggest that vestibular lithiasis has a limited contribution to the mechanism that generates HSN. Objective. To determine the canal response to head shaking in BPPV. Patients and methods. This was a case-control study including 104 individuals with BPPV. The diagnosis was based on the presence of vertigo and nystagmus during the positional test. Subjects were examined by the horizontal and vertical head-shaking test. Eye movements were recorded on a video camera to analyze the nystagmus. The head was shaken passively in the horizontal and sagittal planes, respectively, for horizontal and vertical HSN at a frequency of 2 Hz. HSN was considered when six consecutive beats of nystagmus with an SPV of at least 2°/s were detected. Main outcome measures were the presence of horizontal and vertical HSN, maximum SPV of HSN, time constant of HSN, and canal paresis. Results. Maximum SPV of vertical HSN was higher in BPPV patients with posterior canal BPPV (n=10) than in controls (p=0.04). Moreover, the time constant of vertical HSN was significantly lower for posterior canal BPPV when compared with controls (p<0.02).     

Neuro-otological study on Beh?et disease]

It seems acceptable that pathological brain stem lesions exist in the patient with Neuro-Beh?et disease (NB). However, only few reports have been published in this field. We report the neuro-otological findings in 33 patients who fulfilled the diagnostic criteria of Beh?et disease completely or incompletely. The patients were classified into 2 groups: one is group of NB and the other is a group of Beh?et disease without NB (non-NB). Furthermore, the latter was divided into 2 subgroups of patients with dysequilibrium and patients with normal equilibrium. They underwent equilibrium function tests, such as body balance test, gaze test, spontaneous and positional nystagmus test, eye tracking test (ETT) and optokinetic pattern test (OKP) by using electro-nystagmography (ENG). The following results were obtained. 1. Cerebellar and brain stem lesions were confirmed in all cases of NB group. 2. Most cases (6 of 8 cases) in the subgroup of dysequilibrium of the non-NB group showed peripheral vestibular disturbance. The other two patients were diagnosed to be vertebro-basilar insufficiency (VBI) and vascular Beh?et disease with CNS disorder, respectively. 3. Nine of 13 patients in the normal equilibrium subgroup of the non-NB group were diagnosed to be neuro-otologically normal. However, we found two patients with peripheral vestibular disturbance and CNS disorder associated with hearing disturbance of the retrocochlear origin, respectively. 4. The neuro-otological examination is assumed to be useful to diagnose neuro-Beh?et disease, to reveal the lesion site and the state of dysequilibrium in patients with Beh?et disease.     

震动眼震在单侧前庭外周疾病中的临床意义

目的研究震动眼震（vibration—induced nystagmu，VIN）在前庭外周疾病诊断中的临床意义，并确定震动实验（vibration test，VT）的灵敏度和特异度。方法30例健康成人和眩晕门诊112例单侧外周前庭疾病患者纳入本研究，排除具有自发性眼震患者，采用置于乳突和前额的震动刺激（92Hz）进行震动实验，观察记录VIN的诱发情况，患者和正常受试者同时还进行摇头眼震（headshaking nystagmus，HSN）和前庭双温冷热试验检查，并进行比较。结果112例患者中，有91例（81％）出现VIN，主要是水平眼震，VIN在乳突比在前额更常诱发出，其中76例VIN的方向朝向健侧，然而15例梅尼埃病患者VIN方向朝向患侧。30例健康受试者，均未出现VIN。随着前庭双温冷热试验中半规管轻瘫（canal paresis，CP）值的增加，VIN出现率增加。分别有70例（63％）单侧外周前庭疾病患者和9例健康受试者（30％）出现HSN。前庭双温检查，112例患者中CP值〈25％有10例，25％≤CP值≤40％有32例，40％〈CP值〈70％有48例，cP值≥70％有22例，30例健康受试者CP值均〈25％，VIN出现率随着cP值的增加而增加。结论VIN检查是一项简单、非侵入性的、患者能很好耐受的检测单侧外周前庭功能障碍的临床测试方法，具有比HSN检查更高的灵敏度和特异度。     

Machine learning method intervention: Determine proper screening tests for vestibular disorders

ObjectiveTo evaluate the performance of different vestibular indicators in disease classification based on machine learning method.MethodsThis study use retrospective analysis of the vertigo outpatient database from a tertiary care general hospital. 1491 patients with definite clinical diagnoses were enrolled in this study. Spontaneous nystagmus, head-shaking nystagmus, positional nystagmus, unilateral weakness in caloric test, and gain and saccade in video head impulse test (vHIT) were recorded as variables. Diagnoses were mainly reorganized as acute vestibular syndrome, episodic vestibular syndrome, and chronic vestibular syndrome. The trained random forest model was applied based on exploratory data analysis results.ResultsRandom forest accuracies on acute, episodic, and chronic vestibular syndrome are 90%, 81.74%, and 91.3%, respectively. The most important features in acute vestibular syndrome are spontaneous nystagmus, and vHIT variables. In episodic vestibular syndrome, unilateral weakness in caloric test, gain and saccades on lateral semicircular canal are the top three parameters. Lateral vHIT gain, head-shaking nystagmus, and unilateral weakness in caloric test are the main parameters on chronic vestibular syndrome. In acute vestibular syndrome, spontaneous nystagmus and vHIT make major contributions in vestibular disorders distinction. When the disease course prolongation, unilateral weakness and head-shaking nystagmus become increasingly important.ConclusionFast clinical test sets including spontaneous nystagmus, head shaking nystagmus, and vHIT should be the first consideration in screening vestibular disorders.