Visual Suppression Test Research Articles

Vestibular Impairment in Frontotemporal Dementia Syndrome

Background: No studies to date have attempted to evaluate frontotemporal lobar degeneration from the perspective of the vestibular system. Objective: The present study examined vestibular function in patients with frontotemporal dementia (FTD) clinical syndrome and evaluated whether vestibular disorders are involved in the clinical symptoms due to FTD. Methods: Fourteen patients with FTD syndrome, as well as healthy elderly controls without dementia, were included in the present study. All subjects underwent vestibular function tests using electronystagmography, such as caloric tests and visual suppression (VS) tests, in which the induced caloric nystagmus was suppressed by visual stimuli. The association between clinical symptoms and vestibular function in the FTD syndrome group was further examined. Results: In the FTD syndrome group, caloric nystagmus was not necessarily suppressed during VS tests. Furthermore, VS was observed to be significantly impaired in FTD syndrome patients with gait disturbance as compared to those without such disturbance. Conclusion: The present study revealed that impairment of VS in patients with FTD results in an inability to regulate vestibular function by means of visual perception, regardless of multiple presumed neuropathological backgrounds. This could also be associated with gait disturbance in patients with FTD syndrome.

Vestibular Function Impairment in Alzheimer's Disease.

Falls and fractures due to impaired balance in patients with Alzheimer's disease (AD) have an adverse effect on the clinical course of the disease. To evaluate balance impairment in AD from the viewpoint of vestibular functional impairment. The subjects were 12 patients with AD, 12 dementia-free elderly adults, and 12 younger adults. Vestibular function was assessed using a stepping test, caloric nystagmus, and a visual suppression (VS) test. The stepping test was abnormal in 9 of the 12 patients in the AD group. An abnormal stepping test was not associated with self-reported dizziness or tendency to fall. Significant VS abnormalities were present in the AD group. The suppression rate of VS was lower in AD patients with either a tendency to fall or constructional apraxia than in AD patients without either. The velocity of the rapid phase of caloric nystagmus before the VS test was similar in the AD group and the elderly control group. Significant abnormalities of both caloric nystagmus and VS were not present in either the elderly or the younger control groups. AD could involve impairments in the vestibular control of balance. The VS test is useful for assessing the tendency to fall in AD. Impairment of VS in AD might arise from cerebral vestibular cortex impairment rather than comorbid peripheral vestibular disorders.

Visual Suppression is Impaired in Spinocerebellar Ataxia Type 6 but Preserved in Benign Paroxysmal Positional Vertigo.

Positional vertigo is a common neurologic emergency and mostly the etiology is peripheral. However, central diseases may mimic peripheral positional vertigo at their initial presentation. We here describe the results of a visual suppression test in six patients with spinocerebellar ataxia type 6 (SCA6), a central positional vertigo, and nine patients with benign paroxysmal positional vertigo (BPPV), the major peripheral positional vertigo. As a result, the visual suppression value of both diseases differed significantly; e.g., 22.5% in SCA6 and 64.3% in BPPV (p < 0.001). There was a positive correlation between the visual suppression value and disease duration, cerebellar atrophy, and CAG repeat length of SCA6 but they were not statistically significant. In conclusion, the present study showed for the first time that visual suppression is impaired in SCA6, a central positional vertigo, but preserved in BPPV, the major peripheral positional vertigo, by directly comparing both groups. The abnormality in the SCA6 group presumably reflects dysfunction in the central visual fixation pathway at the cerebellar flocculus and nodulus. This simple test might aid differential diagnosis of peripheral and central positional vertigo at the earlier stage of disease.

Eye movement disturbance in multiple system atrophy: chronological study of 50 patients

To clarify the features of the eye movement disturbance in the patients with multiple system atrophy (MSA), we retrospectively examined chronological changes of 9 oculomotor parameters as described below in 50 MSA patients including 12 autopsied cases. Patients with MSA were consisted of 35 patients with cerebellar ataxia-preceding type and 15 patients with parkinsonism-preceding type. Nine parameters include saccade test, eye tracking test, positioning/positional/gaze/caloric nystagmus tests, and visual suppression test. Each parameter was evaluated by three categories; normal and the two abnormal findings according to their characteristic features. In all of the 9 parameters, no significant differences were found between the cerebellar ataxia- and the parkinsonism-preceding types of MSA both in the early (disease duration less than 3 years) and in the advanced stages (duration between 8 to 11 years). From the chronological analysis, 9 oculomotor parameters could be divided into three groups: the first group with the higher frequency of the abnormality from the early stage, the second with gradual increase of the frequency, and the third with less increased frequency even in the advanced stage. We here focused on the three representatives corresponding with the above-described each group; positioning nystagmus test mainly showing downbeat nystagmus as a first group, visual suppression test showing a qualitative change from depressed into increased response as the second, and the caloric nystagmus test showing decreased response as the third. Based on these chronological changes of the oculomotor parameters, we supposed that in MSA the dorsal vermis is involved at first, followed by the flocculus in the cerebellum, and then the degenerative lesions might expand to the vestibular nucleus, and the cerebral cortex including the vestibular cortex.

Disorders Affecting the Fourth Ventricle

The fourth ventricle encompasses many vital structures including the brainstem as its floor and the cerebellum as its lateral wall and roof. Therefore, lesions affecting the fourth ventricle may present as cerebellar or brainstem manifestations. Herein, we presented our experience in the diagnosis of disorders affecting the fourth ventricle during the past 15 years. Retrospective study. University hospital. From September 1995 to August 2010, 24,838 patients with vertigo/dizziness visited the clinic. Of them, 13 patients (0.5%) had tumor/stroke affecting the fourth ventricle. All patients underwent a battery of audiovestibular function test. All patients had vertigo (100%) and then ataxia (92%) and nausea/vomiting (85%). Eight patients (68%) displayed persistent nystagmus. Most (>75%) patients showed central signs in electronystagmographic recordings and abnormal caloric coupled with visual suppression test. Three patients underwent both ocular and cervical vestibular-evoked myogenic potential tests, and abnormal results were noted in all 3 patients indicating a brainstem involvement. However, magnetic resonance imaging failed to demonstrate brainstem lesion in these 3 patients. Final diagnoses consisted of the following: cavernoma, n = 3; metastatic cancer, n = 3; astrocytoma, n = 2; meningioma, n = 2; epidermoid cyst, n = 1; ependymoma, n = 1; and lymphoma, n = 1. The prognosis was poor as 10 patients (77%) died within 2 years. When a vertiginous patient displayed ataxia, persistent vomiting, and persistent nystagmus, lesion affecting the fourth ventricle should be kept in mind because its prognosis is poor. Abnormal results in electronystagmography and in ocular and cervical vestibular-evoked myogenic potentials may serve as a supplementary to magnetic resonance imaging to delineate the involvement of the lesion.

Differentiating cerebellar and brainstem lesions with ocular vestibular-evoked myogenic potential test

This study applied both ocular vestibular-evoked myogenic potential (oVEMP) and cervical VEMP (cVEMP) tests in patients with cerebellar disorders to determine whether VEMP test can differentiate between cerebellar and brainstem lesions. A total of 12 patients with cerebellar disorder, including extended cerebellar lesion (involving the brainstem) in 8 and localized cerebellar lesion (excluding the brainstem) in 4, were enrolled in this study. All patients underwent caloric, visual suppression, and oVEMP and cVEMP tests via bone-conducted vibration stimuli. The abnormal rates for the caloric, visual suppression, and oVEMP and cVEMP tests were 62, 83, 88 and 75% in patients with extended cerebellar lesion and 0, 25, 0 and 0% in those with localized cerebellar lesion, respectively. The rate of abnormal oVEMP results significantly differed between the two groups, but caloric, visual suppression and cVEMP test results did not differ. In another ten healthy subjects, characteristic parameters of oVEMPs obtained under light and dark conditions did not significantly differ. In conclusion, ocular VEMP test can differentiate between cerebellar and brainstem lesions. Abnormal oVEMPs in patients with cerebellar disorder may indicate adjacent brainstem involvement.

Impaired fixation suppression is a risk factor for vertigo after cochlear implantation

To analyse the correlation between visual fixation suppression test results and the occurrence of post-operative vertigo in patients receiving a cochlear implant, and to compare this with other possible risk factors. In a prospective study setting, caloric vestibular responses, visual fixation suppression and subjective vertigo symptoms were assessed in 59 adult patients undergoing cochlear implantation. These parameters were compared in patients with post-operative vertigo versus vertigo-free patients. Vertigo symptoms were reported by 49 per cent of patients. Thirty-nine per cent of the patients had a decrease in caloric response on the implanted side. There was no statistically significant difference between the two patient groups regarding canal paresis, age, sex, implanted electrode type, implant side, surgeon, cause of deafness, petrous bone computed tomography findings and incidence of pre-operative vertigo. Patients with post-operative vertigo had a significantly greater prevalence of insufficient visual fixation suppression. All patients who suffered long-term post-operative vertigo had insufficient visual fixation suppression. Pre-operative impaired visual fixation suppression is a major risk factor for the occurrence of vertigo after cochlear implantation.

Posterior fossa lymphoma with initial vertigo presentation

This study retrospectively reviewed our experience in the diagnosis of six patients with posterior fossa lymphoma during the past decade. Initial manifestation included vertigo in all patients (100%) and ataxia in 4 (67%), with a mean duration of 40 days. Audiometry revealed sensorineural hearing loss in five patients (83%). Gaze-evoked nystagmus was also noted in five patients (83%). Electronystagmography (ENG) showed multiple central signs, e.g., abnormal eye tracking test, abnormal optokinetic nystagmus test, abnormal caloric and/or visual suppression tests. MR imaging demonstrated single or multiple or diffuse enhanced mass lesions in the cerebellum and/or brainstem. Two patients received lumbar puncture for cytological examination of cerebrospinal fluid (CSF) which disclosed lymphoma cells, while the other four patients underwent craniotomy for tissue proof, and the histopathological study confirmed as lymphoma. Then, all patients underwent irradiation coupled with chemotherapy. At the close of this study, three patients died, two were lost and one was alive. Although rare, aggressive posterior fossa lymphoma should be kept in mind when seeing a patient with persistent vertigo and ataxia accompanied by multiple central signs in ENG examination. An MRI scan followed by CSF cytological examination or histopathological study may help to confirm the diagnosis.

Impact of Alcohol on Vestibular Function in Relation to the Legal Limit of 0.25 mg/l Breath Alcohol Concentration

The aim of this study was to investigate the effect of alcohol on sacculocollic and vestibulo-ocular reflex systems, when the breath alcohol concentration (BrAC) is close to the legal limit of 0.25 mg/l. Twenty healthy male volunteers underwent vestibular evoked myogenic potential and caloric coupled with visual suppression tests. These tests were conducted prior to imbibing alcohol at a dosage of 0.5 g/kg to achieve a peak BrAC of around 0.25 mg/l. Once the peak BrAC was reached, these tests were performed again. Predosing and postdosing analytical results were compared, as were those with BrAC levels ≧ 0.25 mg/l and <0.25 mg/l. After ingesting alcohol, 36 ears (90%) showed vestibular evoked myogenic potential responses, with a significantly increased latency of peak p13. The mean slow-phase velocity of caloric nystagmus in 40 ears after dosing was significantly reduced, and that with BrAC ≧0.25 mg/l was significantly less than that with BrAC <0.25 mg/l. Likewise, the visual suppression index decreased considerably after alcohol ingestion. In conclusion, from the perspective of vestibular function, the 0.25-mg/l BrAC limit gains clinical significance, because the vestibulo-ocular reflex performance deteriorates further, when the BrAC exceeds 0.25 mg/l. However, impaired performance of sacculocollic reflex and vestibulocerebellar interaction has occurred, when the BrAC was <0.25 mg/l, suggesting that a lower legal threshold is appropriate.

Clinical investigation on hypotensive patients with vertigo

The aim of this study was to investigate the characteristic of hypotensive patients with vertigo. Twenty hypotensive patients with rotatory vertigo, 15 hypotensive subjects without vertigo, and 15 mitral valve prolapse subjects without vertigo underwent a battery of tests including audiometry, electronystagmography (ENG), and vestibular evoked myogenic potential (VEMP) test. The abnormal rates in terms of audiometry, eye tracking, optokinetic nystagmus, visual suppression, and caloric tests were 15, 35, 35, 10, and 42% for the first group; 13, 20, 33, 0, and 0% for the second group; and 7, 13, 60, 0, and 3% for the third group, respectively. Comparison of the first group with the other two control groups revealed that significant difference existed only in the abnormality of caloric responses. Fifteen (75%) of 20 hypotensive patients with vertigo having abnormal ENG results, asymmetric caloric responses, or delayed VEMPs were attributed to vertigo of central origin, possibly from ischemic disorder. In contrast, five patients (25%) had neither central signs in ENG nor abnormal VEMPs, but showing bilateral normal or hyperactive caloric responses were classified as autonomic dysfunction. After 3 months of medication, all patients with autonomic dysfunction had their vertigo and autonomic symptoms subsided, whereas 27% of the patients with ischemic disorder had vertigo persisted, showing a significant difference. In conclusion, hypotensive patients with vertigo could be due to either direct autonomic dysfunction or ischemic disorder mediated by autonomic deficits.

進行性感音難聴を呈し聴神経腫ようが疑われた第４脳室上衣腫症例

The authors presented a case of a 46-year old male with a complaint of unilateral progressive sensorineural hearing loss and dizziness, diagnosed with fourth ventricle ependymoma. A Large unilateral acoustic neuroma compressing the cerebellum and brainstem was suspected at first, however results of detailed equilibrium tests including eye tracking test, optokinetic pattern test, caloric test and visual suppression test indicated bilateral lesions of the cerebellum and brainstem. MR images depicted a tumor mass from the fourth ventricle invading the bilateral cerebellum and brainstem, and the postoperative histological examination demonstrated typical findings of ependymoma. The possibility of a fourth ventricle ependymoma mimicking acoustic neuroma should be considered when we encounter cases with not only unilateral progressive sensorineural hearing loss and dizziness but also abnormal equilibrium test findings indicating bilateral cerebellum and brainstem lesions.

ルーチンＥＮＧ検査としてのＥＴＴ，ＯＫＮ，ＶＳ検査の診断学的意義

In order to clarify the diagnostic significance of eye tracking tests (ETT), optokinetic nystagmus tests (OKN), and visual suppression test (VST) on routine ENG tests, we investigated the findings of ETT, OKN, and VST in 1, 225 patients who complained of vertigo and dizziness, and in 440 of the patients, we compared these findings with MRI abnormalities.Abnormal results of ETT, OKN, and VST were seen in 433 patients (35.1%), 399 patients (32.6%), and 128 patients (10.5%), respectively. All tests showed impairment in 66 patients (5.4%). Both ETT and OKN abnormalities with normal VST were observed in 173 patients (14.1%), while 356 patients (29.1%) had abnormal findings for ETT, OKN, or VST. In the patients who had severely impaired ETT, OKN, or VST, there was a significantly higher proportion of infratentorial lesions on MRI than in the other patients. In the patients with abnormalities on both ETT and OKN, infratentorial le-sions were more frequently found by MRI, and the patients who had abnormalities on all tests had the highest incidence (61.7%) of infratentorial lesions on MRI.We conclude that the evaluation of ETT, OKN, and VST abnormalities should be quite useful in the diagnosis of infratentorial lesions.

重心動揺におけるパワースペクトルと眼球運動検査所見との関連性について

Stabilometry and oculomotor examination was used to study 17 patients with spinocerebellar degeneration. The patients with a peak of over 2 Hz in the power spectra in stabilometry were examined for characteristic abnormalities in eye movement.The results of tests for pursuit eye movements, optokinetic nystagmus and visual suppression test were not related to the peak over 2 Hz in the power spectra of stabilometry. However, the occurrence of vertical saccadic eye movements was associated with the high frequency component over 2 Hz. The center of vertical saccade exists in the mesencephalic tegmentum.The cause of postural tremor at over 2 Hz is atrophy of the anterior lobe of the cerebellum, to which the proprioceptive afferents project via the mesencephalic tegmentum. The relationship between postural tremor and abnormalities in the vertical saccade may be due to a common lesion in the mesencephalic tegmentum.

オリーブ橋小脳萎縮症の神経耳科学的検討

The main clinical findings of OPCA include cerebellar symptoms, extrapyramidal symptoms, autonomic nerve symptoms, in addition to various oculo-motor disturbances. We reported a case of OPCA where neuro-otological examination facilitated the diagnosis. Neuro-otological examination was carried out in 6 cases of OPCA, and duration of illness and experimental findings were compared.Subject: Neuro-otological examination was undertaken in 6 OPCA patients over a 5 year period 1993-1997. The mean patient age was 53.8 years, and the ratio of males to females was 2:4. Duration of illness was 3 years for 2 patients, 4 years for 2 patients, 6 years for 1 patient and 8 years for 1 patient.Method: For all patients, the following examinations were carried out. (1) audiogram, ABR (2) nystagmus (3) eye tracking (4) optokinetic nystagmus, saccade (5) visual suppression.Results: Smooth pursuit eye movement impairment was independent of the duration of illness. Nystagmus findings, saccadic eye movement and the visual suppression test revealed that impairment increased in patients whose duration of illness was more than around 4 to 6 years. The oculo-motor disturbances of OPCA start with impairment of cerebellar and smooth pursuit eye movement, and eventually result in brainstem disorders such as saccadic eye movement and visual suppression. As the duration of illness lengthens, the oculo-motor system itself will no longer function and response to all of the examinations will be lost. Neuro-otological examinations were found to be valuable for the diagnosis of OPCA.

Symptomatic tonsillar ectopia.

OBJECTIVE: To determine if slight descent of the cerebellar tonsils (< 5 mm below the foramen magnum; tonsillar ectopia) may cause surgically treatable symptomatology. METHODS: A consecutive series of nine...

神経変性疾患におけるＶｉｓｕａｌ ｓｕｐｐｒｅｓｓｉｏｎ ｔｅｓｔについて

IntroductionThe visual suppression test reported by Takemori and her colleagues, was already widely known as a test for detecting disturbance of the cerebellar flocculus. Thereafter, this method was also available for detection of central disturbances of the paramedian pontine reticular formation (PPRF) and inferior parietal lobule.In this report, we adopted this test to examine each disease causing spinocerebellar degeneration, Parkinson disease and Parkinson syndrome.SubjectsSubjects were 34 patients with spinocerebellar degeneration. The cerebellar type comprised 12 cases, and spinocerebellar type 22 cases. Furthermore we studied 7 cases of Parkinson disease with disturbance of the basal nuclei and 24 cases of Parkinson syndrome.All cases were in the early or middle stage of the clinical course. We rejected cases that did not show any response to caloric nystagmus, since this was recognized as indicating the progressive stage.ResultsAs a result of the visual suppression test, we recognized that there was no enhancement of reaction in LCCA cases and no abnormalities in the visual suppression test in Parkinson disease cases. Some patients with spinocerebellar type degeneration and Parkinson syndrome showed enhanced reaction. Eight PSP patients showed enhanced reaction and their percentages were the highest of all disease groups.Visual suppression test was considered a useful supplementary diagnostic technique for the differential diagnosis of degenerative disease.

ENG検査におけるコンピューター分析-健常者を対象として-

A quantitative analysis of eye movement with optokinetic and caloric nystagmus was undertaken in normal subjects using a digital computer. Fifteen parameters were established to differentiate nystagmus from artifacts. Eight of the parameters were used to diagnose the quick phase and the other 7 parameters were used to diagnose the slow phase. On OKN (optokinetic nystagmus), the velocity gain was calculated. The adaptation limits of slow phase velocity were a maximum slow phase velocity, while the velocity gain was over 0.8. In 20 normal subjects, the average slow phase velocity was 90°/sec (S. D.15.5). In the caloric test, the average maximum slow phase velocity was 32°/sec (S. D.11) and the average with the visual suppression test was 70% (S. D.10.5) in 31normal ears. In this analysis, the frequency of nystagmus was not necessarily reduced with visual suppression, so that the FFI (failure of fixation suppression index) was not a valid parameter.

Vertical oculomotor disorders in progressive supranuclear palsy and spino-cerebellar degeneration

We performed neuro-otological investigation of vertical oculomotor disorders in 35 patients with degenerative disease [progressive supranuclear palsy (PSP) and spino-cerebellar degeneration], and obtained the following results: 1) In the patients with PSP, in addition to vertical oculogyric disorder both saccade and pursuit eye movements were disturbed, and the disturbance of saccade movement was greater. Even the patients without an oculogyric disorder were all found to have decreased saccade velocity, suggesting that this disorder may occur earliest in PSP. 2) In olivo-ponto-cerebellar atrophy (OPCA), saccade movement was less disturbed than that in PSP. In contrast, pursuit movement was disturbed more frequently. 3) In late cortical cerebellar atrophy (LCCA), vertical ocular movement was hardly disturbed compared with OPCA. 4) Concerning dentate nuclear degeneration, we cannot reach a conclusion because of the few cases studied, but a variety of oculomotor disorders were seen; both saccade and pursuit movements were disturbed, but saccade movement was less disturbed than in PSP. 5) In visual suppression tests, enhancement in the light area was frequently seen in the patients with PSP and OPCA, but none with LCCA showed such change. In addition, enhancement of the light area under visual suppression was significantly correlated with vertical oculomotor disorder.

バレエダンサーの技能の熟練度を見い出す１検査方法 回転後眼振を用いたＶｉｓｕａｌ Ｓｕｐｐｒｅｓｓｉｏｎ Ｔｅｓｔについて

1. Twelve ballet dancers with various levels of dancing experience and skill were examined with the visual suppression test using post-rotatory nystagmus (PRVST) and caloric stimulation (CVST).2. The PRVST results showed a suppression rate of 80.7 %, higher than in untrained subjects. The CVST results showed a suppression rate of 80.1%, similar to that in untrained subjects.3. A correlation between the PRVST and CVST suppression rates and length of dancing experience showed that the suppression rate increased as the level of experience and skill rose.4. However, the CVST suppression rates in the two groups with fewer than 3 years and with 3 to 10 years of experience were close to those of untrained subjects. This is different from the PRVST supperssion rates.5. These results indicated that the PRVST and CVST tests can aid in the clinical and quantitative assessment of the functions of the central nervous system in the visual-vestibular interaction in ballet dancers. It is also possible that we have examined the function of the vestibulo-cerebellum in a state that can be thought to be the habituation of visual-vestibular interaction.6. It may also be possible to use the suppression rates of PRVST and CV ST to determine the approximate level of a dancer's experience and skill.

Neuro-Otological Findings in Patients with Spinocerebellar Degeneration: With Special Regard to the Duration of Illness

Neuro-otological findings in 150 patients with spinocerebellar degeneration were analyzed based on the duration of illness since onset. The results of each kind of neuro-otological examination varied in close relation to the duration of illness. Also, the results of each kind of examination correlated closely. In particular, the optokinetic nystagmus test and the visual suppression test correlated most closely. Neuro-otological examinations were confirmed to be of great value in gauging progression in spinocerebellar degeneration.