Incidence of vertigo and dizziness disorders at a university hospital

Subjects were 626 patients reporting vertigo or dizziness seen at the University Hospital Department of Otolaryngology from April 2001 to September 2003. Patients were diagnosed based on diagnostic criteria prescribed by the Japan Society for Equilibrium Research. The most common peripheral vestibular disorder was benign paroxysmal positional vertigo (32%), followed by Meniere's disease (12%). All peripheral vestibular disorders accounted for 65%. Central vestibular disorder accounted for 7%, of which space-occupying lesions in the posterior fossa accounted for 1.0% and cerebral infarction 1.9%. Dizziness due to orthostatic hypotension accounted for 4.0%. Among past reports on clinical statistics of vertigo, the incidence of vertigo and dizziness disorders differed greatly, but our research and the past 2 reports based on diagnostic criteria prescribed by the Japan Society for Equilibrium Research showed almost the same incidence, i.e., BPPV of 30-40%, Meniere's disease of 7-10%, other peripheral vestibular disorders of 15-20%, and central vestibular disorder of 6-8%. Unified diagnostic criteria are thus important in the statistical analysis of vertigo disorders.     

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.     

Bilateral multicanal benign paroxysmal positional vertigo coexisting with a vestibular schwannoma: case report

We describe a rarely encountered case of coexisting bilateral multicanal benign paroxysmal positional vertigo (BPPV) and vestibular schwannoma in a 56-year-old woman. The patient had presented with a 10-year history of dizziness and imbalance, and her vestibular findings were perplexing. We decided on a working diagnosis of BPPV and began treatment. After several months of canalith repositioning maneuvers had failed to resolve her symptoms, we obtained magnetic resonance imaging, which revealed the presence of the vestibular schwannoma. This case serves as a reminder of the importance of differentiating between central and peripheral vestibular disorders, as well as central and anterior canal BPPV-induced down-beating nystagmus in order to establish the correct diagnosis and initiate appropriate treatment.     

Study on 242 inpatients reporting vertigo and dizziness

We studied 242 inpatients--men (34%) and women (66%) reporting vertigo and dizziness while hospitalized at Hakodate Municipal Hospital from July 1999 to June 2002. Adults over 65 years old accounted for 47.3% of all subjects. Reports of symptoms tended to increase in March, August, and December. Cases were classified into 4 groups: 1) peripheral disorders (35.7%), 2) central disorders (7.9%), 3) disorders of other origins (8.3%), and 4) disorders of unknown origin (47.1%). Group 1) involved vestibular neuritis (10.1% of all cases), Meniere diseases (12.4%), benign paroxysmal positional vertigo (BPPV) (5.8%), and sudden deafness with vertigo (5.8%). Patients with vestibular neuritis--25 subjects including men (68%) and women (32%)--tended to be admitted mainly in July. Vestibular compensation in 15 patients with vestibular neuritis was studied using the platform stabilometry. The total length of a locus and the area of surroundings with open eyes decreased significantly (p < 0.05) as the condition of patients improved. In conclusion, many subjects reporting vertigo and dizziness had vestibular neuritis and few had BPPV. We found platform stabilometry to be useful in estimation of improvement in patients with vestibular neuritis.     

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。     

Benign Paroxysmal Positional Vertigo

Benign paroxysmal positional vertigo (BPPV) has received renewed clinical interest. At the Johns Hopkins Otological Vestibular Laboratory, 781 patients were tested on more than one occasion between September 1976 and November 1992. Of these patients, 187 (24%) were found to have positional nystagmus consistent with a diagnosis of BPPV. A retrospective analysis of these patients' records, including vestibular test and eye movement reports, audiograms, questionnaires, and hospital charts was performed. After this review, the nystagmus, initially diagnosed as due to BPPV, was believed to be a manifestation of another disease process in 36 cases. Of the remaining 151 diseases, 52 (34%) presented with no significant preceding disorder and have been termed primary BPPV. In the remaining 99 patients we found coexisting or associated disorders which included Meniere's disease, head trauma, prior ear surgery, vestibular neuronitis, migraine, and others. Forty-five of these 151 patients (31%) had an associated diagnosis of Meniere's disease. To our knowledge a significant association between Meniere's disease and BPPV has not been reported. A review of the literature with discussion of BPPV and the associated disorders is offered.     

Prospective study of positional nystagmus in 100 consecutive patients

OBJECTIVES: The purpose of this study was to investigate the various diagnoses of patients who present with positional nystagmus. METHODS: Positional maneuvers were systematically performed in the plane of the posterior canal (PC; Dix-Hallpike maneuver) and the horizontal canal (HC; patients were rolled to either side in a supine position) on 490 consecutive patients essentially referred for vertigo and/or gait unsteadiness. RESULTS: One hundred patients (20%) presented positional nystagmus. This nystagmus had a peripheral origin in 83 patients, including 80 patients with benign paroxysmal positional vertigo (BPPV). In BPPV, the PC was involved in 61 patients, the HC in 18 patients (geotropic horizontal nystagmus in 11 and ageotropic in 7; changing from geotropic to ageotropic or the reverse in 4 patients), and both the PC and HC in 1 patient. There was evidence of central positional nystagmus in 12 patients, including positional downbeat nystagmus during the Dix-Hallpike maneuver in 7 patients with various neurologic disorders, and ageotropic horizontal nystagmus during the HC maneuver in 2 patients with, respectively, cerebellar ischemia and definite migrainous vertigo. The peripheral or central origin of the positional nystagmus could not be ascertained in 5 patients, including 1 patient with probable migrainous vertigo and another with possible anterior canal BPPV. CONCLUSIONS: A rotatory-upbeat nystagmus in the context of PC BPPV, a horizontal nystagmus, whether geotropic or ageotropic, due to HC BPPV, and a positional downbeat nystagmus related to various central disorders are the 3 most common types of positional nystagmus. Geotropic horizontal positional nystagmus and, most certainly, horizontal positional nystagmus changing from geotropic to ageotropic or the reverse point to HC BPPV. In contrast, an ageotropic horizontal positional nystagmus that is not changing (from ageotropic to geotropic) may indicate a central lesion.     

Clinical features of benign paroxysmal positional vertigo

Our understanding of the pathomechanism of benign paroxysmal positional vertigo (BPPV) has improved dramatically. A type of BPPV featuring mixed torsional and vertical nystagmus induced by the Dix-Hallpike maneuver involves the posterior semicircular canal (P-BPPV). The other type of BPPV featuring horizontal nystagmus induced by spine-to-lateral head positioning involves the horizontal canal BPPV (H-BPPV). In complaints of vertigo or dizziness, 619 patients visited our department last year. Of these, 142 (23%) was had positional nystagmus consistent with a diagnosis of BPPV, 118 (19%) had no nystagmus but were suspected of BPPV due to vertigo episodes. BPPV was the most frequent diagnosis. H-BPPV was not rare, but accounted for 30% of BPPV. Of H-BPPV, 73% featured direction changing geotropic nystagmus, and 27% direction changing apogeotropic nystagmus. H-BPPV resolved faster than P-BPPV. Most cases caused by head trauma were P-BPPV. Transition between P- and H-BPPV was found in 6 cases. Women outnumbered men by about 3 to 2 in both P- and H-BPPV. Peak incidence was found in the those in their 60s and 70s, suggesting that the etiologies of both types of BPPV are essentially the same.     

Relevance of function tests in the diagnosis of vestibular disorders

The diagnostic value or relevance of a vestibular function test is dependent on the whole clinical and functional context of each particular case. It is not the ability to show‘abnormality’in a high number of patients complaining of whatever kind of vertigo, that indicates the relevance of a function test. Neither is relevance of a test based upon the possibility that this test can re-categorize some patients in the same way as has been done by other tests. Each test evaluates some particular functional aspect and this is very different from one test to another. A test is more relevant, i. e. indicates more abnormality when the type of vertigo caused by the dysfunction is also considered. These statements are confirmed by experience in peripheral vestibular disorders, especially benign paroxysmal positional vertigo (BPPV). A paroxysmal positional nystagmus (ppn) (nystagmus and vertigo elicited by movements and manoeuvres) is linked to the problem of provoked vertigo and gives a confirmation of this vertigo by reproducing it in some manoeuvres. Some inconstancy in the reproduction of this ppn may cause difficulties in diagnosis. Caloric tests are the clue for diagnosis of sudden unilateral loss (so-called neuronitis), whereas they give only complementary information for patients with BPPV. Posturography adds information in all categories concerning the standing position and can be interesting in the scope of rehabilitation treatment. The findings of a retrospective study in patients with BPPV (n= 95), compared with patients with Ménière's disease (n= 89) and others with sudden unilateral loss syndrome (n= 48), illustrate these concepts.     

Results of subjective visual vertical tests in patients with vertigo/dizziness

ObjectiveWe previously established the head-tilt subjective visual vertical (HT-SVV) test to evaluate head-tilt perception gain (HTPG) in addition to the original head-upright SVV (HU-SVV) test (Wada-Y et al.: Laryngoscope Investig Otolaryngol, 2020). In this study, we aimed to investigate the HU-SVV and HT-SVV abnormality rates among patients with vertigo/dizziness.MethodsBetween July 2014 and December 2020, 357 patients were hospitalized for examining the HU-SVV and HT-SVV at our vertigo/dizziness center. Among these patients, 120 had Meniere's disease (MD), 99 had unilateral vestibular disease (UVD), 76 had benign paroxysmal positional vertigo (BPPV), 14 had vestibular migraine (VM), 13 had orthostatic dysfunction (OD), 12 had bilateral vestibular disease (BVD), 12 had central dizziness (CD), 7 had vestibular schwannoma (VS), and 4 had psychogenic dizziness (PD). We determined the reference values of the absolute HU-SVV (<2.5°) and HTPG (0.80–1.25) for the sitting position and used these for calculating the HU-SVV and HT-SVV abnormality rates in each type of vertigo/dizziness.ResultsAmong the 357 patients, 111 had abnormal HU-SVV results (31.1%), 132 had abnormal HT-SVV results (37.0%), and 185 had abnormal HU-SVV and/or HT-SVV results (51.8%). The modified HT-SVV test in combination with the original HU-SVV test could detect gravity perception disturbance in patients with vertigo/dizziness significantly better than the original test alone (chi-square: p=0.00019). The HU-SVV, HT-SVV, and HU-SVV and/or HT-SVV abnormality rates were significantly higher in patients with peripheral vestibular diseases, i.e., MD, UVD, BPPV, and BVD than in those with other types of vertigo/dizziness, i.e., VM, OD, CD, VS, and PD (chi-square: p=0.010, p=0.020, and p=0.0025, respectively).ConclusionThese findings suggest that the combined HT-SVV and HU-SVV test could be a powerful neuro-otologic examination for detecting pathologies in the vestibular otolithic pathway.     

Diagnosis of common causes of vertigo using a structured clinical history

The structured clinical history is the most sensitive test for diagnosing vertigo. Its diagnostic effectiveness on the first visit was analyzed and key signs and symptoms with high predictive value for common causes of vertigo were identified. One hundred outpatients who complained of dizziness or loss of balance were evaluated using a structured clinical interview. Each questionnaire was examined independently by three blinded investigators, who assigned a diagnosis and identified the elements of the history that figured most prominently in the diagnosis. The gold standard was defined as independent selection of the same diagnostic category by all three investigators. A first-visit diagnosis was obtained in 40% of patients (95% confidence interval 30-50%): 38% women and 42% men. Causes included benign positional paroxysmal vertigo (BPPV, 13 patients), headache-associated vertigo (9), Meniere disease (7), cervical vertigo (3), psychiatric dizziness (2), post-traumatic vertigo (2), vertebro-basilar transient ischemic attack (1), vestibular neuritis (1), convulsive seizure (1), and presyncope (1). The best predictors of BPPV were the precipitating mechanism (specificity [SP] 100%), positional nystagmus (sensitivity [SE] 90%, SP 63%), and the Dix-Hallpike test (SE 82%, SP 71%). Elements predictive of headache-associated vertigo were duration of the attack (minutes) and a personal history of headache (both, SP 100%). Other predictors were facial hypoesthesia (SE 92%, SP 47%) and associated neurological disease (SE 82%, SP 58%).     

Residual dizziness after successful repositioning maneuvers for idiopathic benign paroxysmal positional vertigo in the elderly

Even after successful repositioning maneuvers for benign paroxysmal positional vertigo (BPPV), some patients report dizziness lasting for a certain period afterwards. We studied the prevalence and clinical factors associated with residual dizziness in a sample of elderly patients. Sixty outpatients over 65 years of age, affected by idiopathic BPPV were recruited; the exclusion criterion was a history of previous episodes of vertigo, including positional. The patients were asked to describe their self-perceived anxiety for vertigo on a Visual Analogue Scale (VAS) and successively treated with appropriate maneuvers till resolution of nystagmus. Data concerning the demographic and clinical features of BPPV were collected. Patients were followed until complete resolution of subjective dizziness and imbalance without positional nystagmus. Data about residual dizziness were collected from the second day from resolution of BPPV. Clinical and demographic factors related to residual dizziness were analyzed. Twenty-two subjects (37%) reported residual dizziness. In these subjects, the mean duration of residual dizziness was 13.4 ± 7.5 days. No association was observed between residual dizziness and gender, involved canal and the number of repositioning maneuvers before resolution. On the other hand, age older than 72 years, symptom duration greater than 9 days and VAS scale for anxiety greater than 10/100 were associated with an increased risk of residual dizziness. The odds ratio were respectively 6.5 (age—residual dizziness, Confidence Interval 95%), 6.5 (duration of vertigo—residual dizziness, Confidence Interval 95%) and 15.5 (anxiety levels—residual dizziness, Confidence Interval 95%). Longer symptom duration before diagnosis was associated with higher anxiety levels. The results underline the necessity for an early and correct diagnosis of BPPV, especially in the elderly.     

Diagnostic criteria for central versus peripheral positioning nystagmus and vertigo: a review

Head positioning can lead to pathological nystagmus and vertigo. In most instances the cause is a peripheral vestibular disorder, as in benign paroxysmal positioning vertigo (BPPV). Central lesions can lead to positional nystagmus (central PN) or to paroxysmal positioning nystagmus and vertigo (central PPV). Lesions in central PPV are often found dorsolateral to the fourth ventricle or in the dorsal vermis. This localization, together with other clinical features (associated cerebellar and oculomotor signs), generally allows one to easily distinguish central PPV from BPPV. However, in individual cases this may prove difficult, since the two syndromes share many features. Even if only BPPV as a peripheral lesion is considered, differentiation based on such features as latency, course, and duration of nystagmus during an attack, fatigability, vertigo, vomiting, and time period during which nystagmus bouts occur, may be impossible. Only the direction of nystagmus during an attack can allow differentiation.     

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%.     

Assessment of sensory organization testing in benign paroxysmal positional vertigo patients before and after repositioning manoeuvre

Introduction and objectiveBenign paroxysmal positioning vertigo is considered the most common disorder of the peripheral vestibular system. After successful physical manoeuvres for BPPV, a number of patients complain of non-positional sustained imbalance of variable duration called residual dizziness lasting for several days. The objective of this study was to compare the posturographic changes before and one week after successful repositioning manoeuvres in patients with idiopathic BPPV.Materials and methodsThis study was a case–control study, where the first group was composed of 20 patients with confirmed BPPV diagnosis regardless of the affected canal or pathology. Twenty age and gender matched normal subjects constituted the control group. The sensory organization test was performed before and one week after a repositioning manoeuvre in BPPV patients.ResultsAll 20 BPPV patients, except 6 who had no significant improvement of symptoms even after disappearance of classic vertigo and nystagmus, had substantial improvement in sensory scores after CRPs in the antero-posterior visual and vestibular scores and the medio-lateral visual and global scores. All antero-posterior and medio-lateral scores before and after CRPs, except for the AP preferential score, were considerably poorer in BPPV patients than healthy subjects. The 6 patients, who showed no improvement after CRPs, presented with a history of non-specific symptoms i.e., light-headedness or sense of floating.ConclusionsSensory organization test might have a role in the assessment of residual dizziness in patients with BPPV after CRPs.     

“Sitting-up vertigo as an expression of posterior semicircular canal heavy cupula and posterior semicircular canal short arm canalolithiasis”

BackgroundVestibular symptoms on sitting-up are frequent on patients seen by vestibular specialists. Recently, a benign paroxysmal positional vertigo (BPPV) variant which elicits vestibular symptoms with oculomotor evidence of posterior semicircular canal (P-SCC) cupula stimulation on sitting-up was described and named sitting-up vertigo BPPV. A periampullar restricted P-SCC canalolithiasis was proposed as a causal mechanism.ObjectiveTo describe new mechanisms of action for the sitting-up vertigo BPPV variant.MethodsEighteen patients with sitting-up vertigo BPPV were examined with a pre-established set of positional maneuvers and follow-up until they resolved their symptoms and clinical findings.ResultsAll patients showed up-beating torsional nystagmus (UBTN) and vestibular symptoms on coming up from either Dix-Hallpike (DHM) or straight head-hanging maneuver. Sixteen out of 18 patients presented a sustained UBTN with an ipsitorsional component to the tested side on half-Hallpike maneuver (HH). A slower persistent contratorsional down-beating nystagmus was found in eleven out 18 patients tested on nose down position (ND).ConclusionsPersistent direction changing positional nystagmus on HH and ND positions indicative of P-SCC heavy cupula was found in 11 patients. A sustained UBTN on HH with the absence of findings on ND, which is suggestive of the presence of P-SCC short arm canalolithiasis, was found on 5 patients. All patients were treated with canalith repositioning maneuvers without success, but they resolved their findings by means of Brandt-Daroff exercises. We propose P-SCC heavy cupula and P-SCC short arm canalolithiasis as two new putative mechanisms for the sitting-up vertigo BPPV variant.     

Electronystagmographic findings among 127 dizzy patients: correlation with the aetiology of dizziness

Electronystagmography (ENG) was performed on 127 dizzy patients and the findings were compared with the diagnosis obtained with a comprehensive neurological test battery. ENG was found to be abnormal in 49 (39%) of the patients: 19 with unilateral vestibular hyporeactivity, eight with directional preponderance, 12 with spontaneous or undirectional positional nystagmus, eight with abnormal smooth pursuit, and 13 with other abnormalities. Among the patients with abnormal ENGs, established central nervous system lesions were found in 28 cases (19 of these infratentorial lesions); nine peripheral vestibular lesions and five undefined vestibular lesions were found. Patients with normal ENGs showed fewer peripheral vestibular lesions and more dizziness of psychogenic aetiology. Almost half the patients with infratentorial lesions had normal ENGs. Patients with rotatory vertigo had fewer ENG abnormalities than those with other types of dizziness. These results suggest that ENG alone is of limited value in the diagnosis of dizziness. A comprehensive test battery is needed to establish the diagnosis.     

Diagnostic problems in patients with benign paroxysmal positional vertigo

The steps of the examination procedure applied for a correct diagnosis of benign paroxysmal positional vertigo (BPPV) are reviewed. A precise diagnosis is important in view of treatment of this type of vertigo by rehabilitation therapy. Clinical experience supports the concept that the diagnosis has to be based not only on a typical history, but also on the presence of a reproducible vertigo and paroxysmal positioning nystagmus. In the procedure applied in the department, this nystagmus can be reproduced by the Dix-Hallpike maneuver under Frenzel's glasses, during electronystagmography (ENG) recording in the position tests, or it can be present in the vestibular habituation training test battery (a battery of 19 maneuvers applied for defining the adequate exercises in the rehabilitation treatment for BPPV). Analysis of the reviewed data in 95 patients showed that one third of the patients described the vertigo in a rather atypical way, while the further testing revealed a typical BPPV. This experience denies any absolute reliability to only history. In fact, only the finding of such a paroxysmal positioning nystagmus is conclusive for confirming BPPV. However, also the presence of such a nystagmus appeared not to be a constant datum, so that in some patients more than one examination was necessary to come to a reliable diagnosis. It is obvious that, for detecting a paroxysmal positioning nystagmus, ENG is less reliable than the Dix-Hallpike maneuver under Frenzel's glasses.     

False-negative diffusion-weighted MRI in acute cerebellar stroke

Objective

To heighten physician awareness of false-negative diffusion-weighted (DW) magnetic-resonance imaging findings in patients with acute cerebellar infarction and the importance of periodically observing nystagmus after symptom onset.

Methods

Between April 2007 and March 2010, we retrospectively reviewed the medical records of eight patients who had all complained of severe isolated vertigo or dizziness, and had visited an emergency department within 2-6 h of its onset. Intracranial findings on initial magnetic resonance imaging (MRI) were normal. All patients had consulted our department for peripheral vestibular disorders. We periodically observed spontaneous and positional nystagmus 6-24 h after symptom onset.

Results

In three of the patients, the direction and/or type of nystagmus changed periodically. In four of the patients, severe vertigo, nausea, and vomiting persisted after the nystagmus had been resolved. A repeat MR examination was performed 24 h after symptom onset because of the atypical pattern of nystagmus for benign peripheral vestibular disorders, at which point cerebellar infarction was detected.

Conclusions

Physicians who examine patients with acute severe isolated vertigo or dizziness should consider the possibility of false-negative DW MRI findings in case of hyperacute ischemic stroke. It is important to observe the nystagmus periodically after onset. The MR examination should be repeated more than 24 h after symptom onset in patients with an atypical pattern of nystagmus for benign peripheral vestibular disorders.