A Review and Future Prospects

Diagnostic Value of Straight Head Hanging in Posterior Canal Benign Paroxysmal Positional Vertigo

Background and Purpose

To determine the diagnostic value of straight head hanging (SHH) in benign paroxysmal positional vertigo involving the posterior semicircular canal (PC-BPPV).

Methods

We retrospectively included 62 patients (age=56.2±15.0 years, 47 female) with unilateral PC-BPPV who underwent both the Dix-Hallpike maneuver and SHH before receiving canalith repositioning therapy (CRT) between September 2017 and July 2020 at the Dizziness Center of Seoul National University Bundang Hospital in South Korea (16 patients, 25.8%) or the Neurology Outpatient Clinic of Aerospace Central Hospital in China (46 patients, 74.2%). SHH was performed before (n=29, group A) or after (n=33, group B) the Dix-Hallpike maneuver.

Results

Torsional upbeat nystagmus typical of PC-BPPV was induced during SHH in 52 (83.9%) patients, and the incidence of this type of positional nystagmus did not differ between the groups A and B (79.3% vs. 87.9%, p=0.569). The maximum slow-phase velocity of the induced upbeat nystagmus was higher during SHH than during the Dix-Hallpike maneuver toward the lesion side [range=2.0–60.0°/s (median=18.5°/s) vs. range=2.7–40.0°/s (median=13.4°/s), p<0.001]. Reversal of the positional nystagmus was observed upon resuming the sitting position after SHH in 47 (75.8%) patients and after the Dix-Hallpike maneuver in 54 (87.7%) patients, with no significant difference between the groups (p=0.082).

Conclusions

SHH is effective for diagnosing PC-BPPV. Given its simplicity, SHH may be performed before the Dix-Hallpike maneuver, and CRT may be attempted thereafter when the typical positional nystagmus for unilateral PC-BPPV is induced during SHH.

Clinical Features of Recurrent or Persistent Benign Paroxysmal Positional Vertigo

Objectives

To identify clinical features and causes of recurrent or persistent benign paroxysmal positional vertigo (BPPV) and to analyze the effectiveness of frequently repeated canalith repositioning procedures (CRPs).

Study Design

Case series with chart review.

Setting

Academic university hospital.

Methods

The authors retrospectively reviewed the clinical records of 120 patients who were diagnosed with BPPV at the Dizziness Clinic in Ajou University Hospital, Korea, between 2004 and 2008. “Persistent” and “recurrent” BPPV were respectively defined as BPPV continuing more than 2 weeks and recurring BPPV in the same canals after at least 2 weeks of a symptom-free interval following previous successful treatments. The authors treated patients with frequently repeated CRPs such as the modified Epley maneuver or a barbecue rotation every 2 or 3 days in the outpatient clinic.

Results

Among 120 patients with BPPV, 93 (77.5%) were typical, 15 (12.5%) were persistent, and 12 (10.0%) were recurrent. Although the most common cause was idiopathic in both recurrent and persistent BPPV, secondary causes, including trauma, were much more common in recurrent and persistent BPPV than in typical BPPV. Typical and recurrent BPPV developed most commonly in the posterior semicircular canals. Persistent BPPV was most commonly detected in the lateral semicircular canals. After frequently repeated CRPs, 91.7% and 86.7% of the patients with recurrent or persistent BPPV, respectively, had resolution of nystagmus and vertigo.

Conclusion

Recurrent and persistent BPPV are not rare diseases and occur with a higher incidence than expected, especially in patients with secondary causes. However, they can be successfully treated with frequently repeated CRPs.

Malignant paroxysmal positional vertigo

OBJECTIVE

An insidious percentage of paroxysmal positional vertigo appears to be intractable with canalith repositioning maneuver and also is not self-limiting. This type of positional vertigo is sustained by the action of intracranial tumors that mimics the clinical aspects of benign paroxysmal positional vertigo.Aim of this study is to clarify the features of these forms of positional vertigo, which we indicate as malignant paroxysmal positional vertigo.

METHODS

We retrospectively reviewed the clinical records of all the patients who presented with vertigo spells and were managed at our tertiary care referral centre over a three years period. Two hundred and eleven patients with diagnosis of positional paroxysmal vertigo were included in the final study.

RESULTS

Seven patients were affected by intracranial tumors causing a positional vertigo and were classified as malignant paroxysmal positional vertigo patients after radiological and histological diagnosis. These patients were affected by an internal auditory canal mass alone or with extension in the cerebello pontine angle that mimicked a benign positional vertigo.

CONCLUSION

We can conclude that the clinician should keep in mind the differentiation between benign positional vertigo and malignant positional vertigo. When the patients with positional vertigo presents a strange behaviour of symptoms, nystagmus or response to the canalith repositioning maneuver a radiological investigation must be undertaken in every doubtful case.

Revisiting benign paroxysmal positional vertigo pathophysiology

Benign paroxysmal positional vertigo is the most common peripheral cause of vertigo. Although its pathophysiologic mechanisms remain unclear, different locations have been attributed throughout the last century, from the days of Bárány. Disease was initially located by Dix and Hallpike in the utricle, but later, Schuknecht's works elicited the cupulolithiasis and canalolithiasis theories, localizing the pathology to the semicircular canal system and mainly to the posterior one. However, conflicting evidences from temporal bone studies accumulated against this theory, which suggest other explanations. Although this clinical entity is well defined, and can usually be effectively treated with certain physical maneuvers, its pathophysiology is still obscure and is being critically discussed in this article, which reviews the milestones of benign paroxysmal positional vertigo understanding.

Persistent geotropic nystagmus--a different kind of cupular pathology and its localizing signs

CONCLUSION

A persistent geotropic positional nystagmus indicates a dysfunction in the lateral semicircular canal with a cupula of less specific weight than the surrounding endolymph. It is possible to determine the side of the affected cupula by recording the nystagmus pattern in yaw and pitch plane.

OBJECTIVES

To identify the clinical features in patients with a persistent geotropic positional nystagmus, establish lateralizing signs and relate the findings to a pathophysiologic mechanism.

PATIENTS AND METHODS

Six patients with acute onset vertigo of a peripheral origin and persistent geotropic nystagmus were examined with videonystagmoscopy and the nystagmus characteristics in different positions of the head in yaw and pitch plane were studied.

RESULTS

Besides the persistent geotropic nystagmus, a zero zone was found with no nystagmus, beyond which the nystagmus changed direction when the head of the patient in supine position was gradually rotated from side to side. The zero zone was present when the head was turned slightly towards one side and is thought to represent a position where the affected cupula is aligned with the gravitational vertical. With the head bent forwards the nystagmus direction was to the non-affected side and when the head was bent backwards to the affected side.

Side-lying as an alternative to the Dix-Hallpike test of the posterior canal

OBJECTIVE

Limitations in passive or active range of motion preclude testing some patients suspected of benign paroxysmal positional vertigo of the posterior semicircular canal (BPPV) with the Dix-Hallpike maneuver. The goal of this study was to determine if an alternative test, brisk side-lying with the nose turned 45 degrees away from the tested side, yields the same results as the Dix-Hallpike maneuver.

STUDY DESIGN

Prospective, within-groups.

SETTING

Diagnostic laboratory at a tertiary care center.

PATIENTS

The 61 patients, seen before their physicians had determined their diagnoses, were all referred by their physicians for objective diagnostic tests. All subjects complained of vertigo elicited by up or down rotations of the head or turning over in bed, often provocative positions for BPPV.

METHODS

Results from the Dix-Hallpike maneuver and side-lying maneuver were compared. Group 1 was tested with the Dix-Hallpike maneuver followed up by side-lying; Group 2 was tested in reverse order.

MAIN OUTCOME MEASURES

Slow-phase eye velocity of nystagmus.

RESULTS

With the groups collapsed to eliminate possible order effects, no significant differences were found between the tests. Significantly more subjects had no response to testing than minimal or stronger responses.

CONCLUSIONS

Side-lying is a valid alternative test to the Dix-Hallpike maneuver, which could be useful when range-of-motion limitations or other problems preclude use of the Dix-Hallpike maneuver.

Benign paroxysmal positional vertigo: a clinician's perspective

The pathogenesis and epidemiology of benign paroxysmal positional vertigo are still not well defined. Treatment protocols have emerged along with complementary hypotheses regarding pathogenesis. Ultrastructural studies suggest a multistep process of otoconia metabolism responsible for forming the otolith membrane. A defect in otoconia metabolism leads to an excess of otoconia within the utricular sac (utriculolithiasis). Gravitational forces cause the entrapment of otoconia within the semicircular canal system (canalolithiasis). Localization of these otoconia within the semicircular canal system is deducted by combining the gravitational orientation of the canal involved with the vestibular neurophysiology of the resulting nystagmus recorded during testing and throughout treatment. New terminology is required to differentiate short-arm from long-arm canalolithiasis. Evidence from digital videonystagmography recordings of nystagmus is coupled with principles of gravitational fluid mechanics to explain the mechanisms of disease development and treatment. These observations lead to important questions that define future directions in research.

Current status of electronystagmography testing

ENG testing, whether computerized or not, remains the most useful means of assessing the vestibular system. The caloric test provides invaluable site-of-lesion information that objectively documents a peripheral vestibular lesion. Double (bithermal) caloric irrigation of each ear provides a more thorough and wider range test of inner ear function than a single caloric irrigation because the vestibular system is both excited and inhibited, causing responses in opposite directions, which are important in evaluating patients with underlying spontaneous nystagmus. In an age in which economically efficient and clinically effective diagnostic methods are in high demand, ENG testing remains the gold standard of vestibular function tests.

Ablation of Posterior Semicircular Canal for Benign Paroxysmal Positional Vertigo

Obstruction of the posterior semicircular canal to prevent fluid movement without injury to the neurosensory end organ has been shown to be effective treatment for benign paroxysmal positional vertigo. Risk of Injury to the inner ear with loss of hearing has been reported with a variety of techniques. This paper will describe a modification of the procedure to ablate the posterior semicircular canal and to minimize the risk of inner ear injury. The procedure has been performed on 17 patients with prompt and lasting relief of vertigo and no hearing loss. The procedure seems to be a valuable and effective treatment for the disturbing condition of benign paroxysmal positional vertigo.

Effect of the graft-versus-host reaction on the immunological responsiveness of the mouse

Graft-versus-host reaction has been induced in unirradiated adult ( C 57 BL x CBA ) F 1 hybrid mice by intravenous injection of parent-line spleen cells, and the capacity of the injected animals to react to first-set and second-set grafts of A -line skin, and to Salm. typhi H antigen, has been investigated. Injection of CBA cells resulted in little or no loss of weight, a low mortality, little or no impairment of the recipient’s capacity to react to A skin or to the bacterial antigen when encountered for the first time, and no loss of pre-existing immunity to A skin. Injection of (40 to 100) x 10 6 C 57 BL cells on the other hand resulted in severe loss of weight and diarrhoea, often culminating in death. Surviving non-immunized animals reacted feebly to the bacterial antigen and some were slower than normal in rejecting first-set grafts of A skin. Pre-existing immunity to A skin was lost except in the special case when the spleen cell donor had itself been immunized against A skin. It is concluded that severe graft-versus-host reaction depresses the host’s immunological reactivity, but that the foreign cells may enable the host to muster a variety of immunological reactions by proxy.

Positional Nystagmus in Asymptomatic Human Subjects

Nystagmus produced by static placement of the head in different orientations is termed positional nystagmus and is known to occur In human subjects who are free of vestibular sympitoms. This study provides quantitative data for horizontal positional nystagmus occurrence in 49 normal human subjects, in whom the number of nystagmus beats, the slow-phase velocity of each beat, and distribution statistics were determined. A metric for the possible differentiation of physiologic positional nystagmus from pathologic positional nystagmus is described.

Atypical Forms of Paroxysmal Positional Nystagmus

Benign paroxysmal positional vertigo (BPPV) is a common cause of vertigo, and has a typical constellation of physical findings. Atypical forms of paroxysmal positional nystagmus (APPN) also exist, and are thought to represent conditions which are in fact not “benign”. We studied 100 consecutive patients with positional vertigo in order to learn whether APPN differed from classic BPPV in etiology or clinical fate, and to learn the incidence of central nervous system (CNS) disorders in these patients.

APPN was present in 38% of these patients with diverse causes. One-fourth had CNS disorders or vascular insufficiency, the remainder, otogenic or idiopathic. APPN was more likely than BPPV to have a prolonged (persistent or recurring) clinical course. Although most cases eventually resolved, duration of symptoms tended to be longer, regardless of etiology. We conclude that APPN has a less favorable prognosis than typical BPPV, and that a CNS etiology should be suspected in prolonged cases.

Apogeotrophic type of direction-changing positional nystagmus related to slow vertebrobasilar blood flow

We examined the incidence of slow blood flow (SBF) in the vertebrobasilar system by magnetic resonance imaging (MRI) in 35 patients showing direction-changing positional nystagmus (DCPN). The subjects consisted of 20 patients with apogeotrophic type (group A) and 15 with geotrophic type (group B) of DCPN. Fifty-seven age-matched subjects without vestibular symptoms were examined as a control group (group C). SBF was detected in 11 (55%), 3 (20%) and 6 (11%) patients in groups A, B and C, respectively. Lacunae of the brainstem were found in 7 (35%) patients in group A and 1 (7%) in group B. The higher incidence of SBF in group A suggested a possible relationship between SBF and apogeotrophic type of DCPN. Apogeotrophic type of DCPN associated with SBF was considered to be caused by ischemia in the posterior circulation, though it was unclear whether the vestibular labyrinth or the hindbrain was mainly involved.

Three-dimensional (3-D) eye movement analysis in patients with positioning nystagmus

Benign paroxysmal positioning vertigo (BPPV), and nystagmus (BPPN) is the commonest type of rotational vertigo. Typical BPPN is generally believed to arise from one posterior semicircular canal. If this is true, the syndrome would offer the unique possibility to study vestibular responses when just one single semicircular canal is excited. In this study we used search coils to measure 3-D eye positions in 3 patients with BPPN. We present a complete 3-D description of the eye movements induced in BPPN. We found that in our patients the eyes rotate rather precisely in the plane of one posterior semicircular canal, suggesting that BPPN in our cases is indeed solely produced by the posterior semicircular canal.

ENG findings of shunt-treated hydrocephalus in children

Thirty-eight hydrocephalic children (mean age 11.5 years; range 5.1-17.9) were examined on average 7.9 years after initial shunting. The etiology of the hydrocephalus was divided into 5 groups: perinatal intraventricular hemorrhage 14, congenital obstructive hydrocephalus 14, central nervous system infections 4, intracranial cysts 3, and intracranial anomalies 3 children. Electronystagmographic (ENG) examination included recording of spontaneous and positional nystagmus, the pendular eye tracking test, saccadic eye movements, optokinetic and caloric reactions. Only 5 children (13%) had a normal ENG. Thirty-one children (82%) had ENG pathology of the central type and 12 (44%) of the 27 successfully studied had pathological caloric reactions. Ten children (26%) had a combination of both central and vestibular pathology. There was no statistical difference between the boys and the girls or between different etiological groups. The high prevalence of vestibular pathology among these hydrocephalic children may be relevant to their impaired motor performance, because only 7 (18%) of the children studied exhibited normal motor performance in the neurological tests.

Testing the vestibular-ocular reflexes: abnormalities of the otolith contribution in patients with neuro-otological disease

Conventional vestibular rotation testing with the head centered on the axis stimulates the semicircular canals evoking compensatory eye movements. If the head is placed forwards of the axis in an eccentric position the otoliths are also stimulated by a tangential linear acceleration acting laterally to the skull. In normal subjects the additional otolithic stimulus evokes compensatory eye movements with a higher gain than with head centred, particularly for high frequency (greater than 0.1 Hz) stimuli. The responses with head centred and eccentric in various patients with known/suspected neuro-otological abnormalities have been compared. Patients with vestibular neurinectomies who have asymmetrical head centred responses showed greater asymmetry with head eccentric at higher stimulus frequencies. Some patients with cerebellar lesions showed abnormally enhanced or depressed and asymmetrical responses with head eccentric in comparison with head centred responses, which could be normal. The enhancing effects could be specific to low frequency stimuli. All patients who showed abnormal responses with head eccentric also had positional nystagmus provoked by the gravity acceleration vector when the head was tilted laterally. The direction of the positional nystagmus with respect to the gravity vector was not necessarily the same as the direction of the effect on eye movements of lateral acceleration during eccentric oscillation. Patients with benign paroxysmal vertigo or chronic linear vertigo in whom otolithic abnormalities are suspected were not found to have abnormal responses with head eccentric. We conclude that this method of testing may be useful in elucidating pathophysiology but is not a decisive clinical test for the presence of disordered otolith function.

Peripheral labyrinthine causes of dizziness

A patient's complaint of dizziness must be defined specifically. Many dizzy patients do not have labyrinthine or balance system disease. The patient with dysequilibrium, on the other hand, often has a balance system disease but not necessarily a labyrinthine disorder. The patient with vertigo most likely has labyrinthine disease. Vertigo is accompanied by nystagmus, which can be identified only when the examiner specifically looks for it. Although vertigo is the classic symptom of labyrinthine disease, not all labyrinthine diseases have associated vertigo. Careful history taking, physical examination, audiometry, caloric testing, electronystagmography, and radiographic studies will identify patients with labyrinthine disorders. Treatment depends on the diagnosis. Usually it is medical, but occasionally it may be surgical. Most patients have no residual problems; a few have permanent disability.

Direction-changing positional nystagmus: incidence and meaning

Direction-changing positional nystagmus (DCPN) is a nystagmus that changes its direction with different body and head positions. Many authors consider that it indicates the presence of a central nervous system lesion. Of 1,196 patients whose abnormal electronystagmographic (ENG) traces were reviewed, 46 (3.8 per cent) showed DCPN. Of these, ten (22 per cent) had central neurologic diseases, 14 (30 per cent) had peripheral vestibular diseases, and for 22 (48 per cent) there was no definite clinical diagnosis. Nineteen patients (41 per cent) with DCPN had ENG findings suggesting a peripheral vestibular lesion, while only five (11 per cent) had ENG findings suggesting a central vestibular lesion. Four of 44 control subjects exhibited DCPN. Thus, the presence of DCPN does not necessarily indicate disease of the vestibular system and definitely does not localize the site of a lesion in the vestibular pathways, but more often indicates a peripheral vestibular site. As with spontaneous nystagmus, lack of suppression with fixation suggests a central lesion.

Virus-induced central positional nystagmus in mice

Geotropic direction-changing nystagmus in lateral body positions was observed in 4-week-old BALB/c mice after intracerebral injection with a temperature-sensitive mutant of mouse hepatitis virus. The positional nystagmus was detected already 2 days after infection and it lasted half a year at least. The nystagmic responses of the semicircular canals were also evaluated before and after infection. They were unaltered during the disease, which was clinically manifested by general weakness, ataxia and tremor. Histopathological examination 2 weeks after infection revealed demyelination in various parts of the CNS.