A minute demyelinating lesion causing acute positional vertigo

Posterior semicircular canal cupulolithiasis during acute pontomedullary demyelination

Positional vertigo poses a diagnostic challenge in people with multiple sclerosis (MS). The characteristics of positional nystagmus and its response to repositioning manoeuvres are usually sufficient to diagnose benign paroxysmal positional vertigo (BPPV). However, certain BPPV variants respond poorly to repositioning manoeuvres and their nystagmus pattern can resemble that of central positional vertigo caused by infratentorial demyelination. This diagnostic difficulty is particularly challenging if positional vertigo occurs during an MS relapse. We describe a woman with MS who developed a sixth nerve palsy and gaze-evoked nystagmus, caused by demyelination near or within areas classically involved in central positional vertigo. However, she also had positional vertigo from coincident BPPV (and not central positional vertigo). This was initially a treatment resistant-posterior semicircular canal cupulolithiasis but it later progressed to a posterior semicircular canal canalolithiasis, with symptoms promptly resolving after a repositioning manoeuvre.

The Relationship Between Benign Paroxysmal Positional Vertigo and Vitamin D

Introduction Benign paroxysmal positional vertigo (BPPV) is a type of vertigo and its signs are short-time, severe attacks that occur in certain head and body positions. Recent studies have revealed that vitamin D deficiency correlates with BPPV and this is explained by cupulolithiasis and canalithiasis theories. Method In the present study, levels of serum vitamin D in the patients who were diagnosed as BPPV and those in the control group consisting of healthy individuals were investigated. In addition, it was examined whether vitamin D is influential on the rates of BPPV types. In our study, 258 patients who were diagnosed with BPPV after detailed ear-nose-throat and neurology examinations were examined. We compared the control group according to their ages, genders, and levels of vitamin D. In addition, we divided the BPPV group into two sub-groups according to their vitamin D levels (20-30 ng/ml and 20 g/ml lower), and each was compared by calculating vertigo types and ratios. Results The BPPV group included 187 females and 71 males, and their mean age was 43.70 ± 15.44. The control group consisted of 65 females and 35 males, and the mean age of this group was 44.63 ± 15.42. The mean vitamin D levels of the females and males were 18.42 ± 5.07 and 19.82 ± 5.11, respectively, in this study. On the other hand, the mean vitamin D levels of healthy females and males were found to be 30.88 ± 10.74. Conclusion Our study found that the vitamin D levels of the individuals in the BPPV group were statistically significantly lower than those of the individuals who were in the control group. However, it was observed that vitamin D did not affect the rate of vertigo subtypes.

Cervical vestibular evoked myogenic potentials and video head impulse test studies: alternative methods for detecting brainstem involvement in multiple sclerosis

BACKGROUND

Brainstem involvement (BSI) has been reported as a major predictive factor for future disability in Multiple Sclerosis (MS).

AIMS/OBJECTIVES

To evaluate whether Cervical Vestibular Evoked Myogenic Potentials (cVEMPs) and Video Head Impulse Test (vHIT) can be used to detect demyelinating lesions in vestibular pathways in MS.

MATERIAL AND METHODS

Fifty three people with MS and 40 controls were evaluated with Dizziness Handicap Inventory (DHI), vHIT and cVEMP.

RESULTS

The median value of DHI in MS group was significantly higher than controls (p<.001). According to vHIT results, while the results of horizontal canal vestibulo-ocular reflex gain in group with brain stem involvement (gBSI (+)) were significantly different from both controls and group without brain stem involvement (gBSI (-)) (p= .036 and .024, respectively), results of gBSI (-) were similar with controls (p= .858). When cVEMP results were examined, mean P1 wave latency in gBSI (+) was significantly longer than controls (p= .002), but difference between gBSI (-) and controls and gBSI (+) was not statistically significant (p= .104 and .279, respectively).

CONCLUSIONS AND SIGNIFICANCE

vHIT and cVEMP can be used in diagnosis and follow-up of people with MS without demyelinating brainstem lesions on MRI.

Central positional nystagmus: an update

Clinically, central positional nystagmus (CPN) is often suspected when atypical forms of its peripheral counterpart, i.e., benign paroxysmal positional vertigo (BPPV), are observed, namely a linear horizontal nystagmus as in horizontal canal BPPV or a downwardly and torsionally beating nystagmus as in anterior canal BPPV. Pathophysiologically, CPN is caused by cerebellar and/or brainstem dysfunction. Recent work has provided further insights into the different clinical phenotypes and the underlying pathomechanisms. We performed a PubMed review focused on the findings on CPN using the key words "Central Positional Nystagmus", "Central Positional Vertigo", "Positional Nystagmus" OR "Positioning Nystagmus" OR "Positional Vertigo" OR "Positioning Vertigo" AND "Central" from January 2015 to August 2021. CPN may account for up to 12% of patients with positional nystagmus. Clinical data on CPN are mostly based on case reports or small retrospective case series. CPN is frequently associated with cerebellar and/or brainstem structural lesions, namely stroke, tumours or demyelination, or diffuse involvement of these structures due to degenerative or autoimmune/paraneoplastic diseases; it is also found in patients with vestibular migraine. CPN can be paroxysmal or persistent. The direction of the nystagmus is often downward in head-hanging or apogeotropic in lateral supine positions; combinations of both forms also occur. Clinically it is important to note that CPN is often associated with other central, often cerebellar ocular motor or other neurological signs; typically, it is not improved by the therapeutic liberatory manoeuvres for BPPV. These additional features are also important for the diagnosis, in particular if no structural lesions are found. Pathophysiologically, CPN is believed to reflect an abnormal integration of semicircular canal-related signals by the cerebellar nodulus, uvula and/or tonsil, ultimately providing an erroneous estimation of the head tilt and/or eye position coordinates. The natural course of CPN remains, so far, largely unknown. Symptomatic treatment of CPN consists of pharmacotherapy, e.g., with 4-aminopyridine, and causative treatment of the underlying disease if known. CPN is an important differential diagnosis to BPPV and a clinically relevant entity with heterogenous clinical presentations and various pathomechanisms and etiologies. In particular, studies on the natural course and treatment of CPN are needed.

Acute vestibular syndrome and hearing loss mimicking labyrinthitis as initial presentation of multiple sclerosis

Acute vestibular syndrome is most often caused by vestibular neuritis or stroke, although demyelinating diseases may be responsible for 4% of all AVS episodes. The authors present the case of a previously healthy 17-year-old female patient complaining of spontaneous vertigo and right-sided hearing loss. Otoneurological examination suggested a peripheral vestibular cause and video head impulse test revealed a reduced vestibulo-ocular reflex gain. The presence of sensorineural hearing loss raised the suspicion of a central cause and prompted imaging evaluation. A brain MRI evidenced demyelinating lesions in the right middle cerebellar peduncle and the patient was ultimately diagnosed with Multiple Sclerosis.

Multiple Sclerosis Presenting as an Anterior Semicircular Canal Benign Paroxysmal Positional Vertigo: Case Report

We present the case of a 31-year-old woman with isolated symptomatology accusing positional vertigo. The videonystagmography (VNG) including Dix-Hallpike testing we have performed, highlighted atypical eye movements. We have observed a positional downbeating nystagmus with characteristics that could be accounted for anterior semicircular canal benign paroxysmal positional vertigo. Furthermore, examining the atypical nystagmus at the measurements performed during VNG recordings, we suspicioned a central positional vertigo. The abnormalities observed at the positional nystagmus were the lack of latency period, the downbeating component not limited in time, and the atypical torsional component. The magnetic resonance imaging examination recommended showed multiple white matter lesions characteristic for multiple sclerosis. The patient was referred to the neurology department for further evaluation and treatment. The diagnosis was unexpected because the patient did not have any other symptom that could have been linked to multiple sclerosis.

Autoimmune vertigo: an update on vestibular disorders associated with autoimmune mechanisms

The role of the immune system in mediating cochleovestibular pathologies has received increasing attention in recent years. Autoimmune vertigo may be an invalidating condition and may worsen the quality of life of affected patients, especially in the cases of delayed diagnosis. Since the etiopathogenesis is still not clear, also the treatment is not yet completely delineated. According to the clinical presentation, autoimmune vertigo can present as an isolated disorder or in association with systemic autoimmune diseases. The main feature in autoimmune vertigo is the presence of an abnormal immune response, in either absence or presence of systemic autoimmune disease, directed against delicate components of the inner ear. This may determine a functional or anatomical alteration, with an inflammatory reaction often devastating for hearing and balance. Being the exact pathogenesis unknown, the diagnosis of autoimmune vertigo is based either on clinical criteria or on a positive response to steroids. The earlier the diagnosis is made, the sooner the therapy can be installed, giving a chance to the recovery of inner ear damages. Corticosteroids represent the most effective and universally accepted treatment, even if other immunomodulatory drugs are now having a more extensive use. HIGHLIGHTS: Vertigo is relatively frequent in autoimmune diseases; however, it is often misdiagnosed or attributed to central nervous system alterations rather to specific inner ear involvement. Vertigo and other audiovestibular symptoms may be the first manifestation of an autoimmune disease and if correctly addressed could significantly contribute to early diagnosis of the underlying autoimmune disease. Early diagnosis of immune-related vertigo can lead to prompt initiation of targeted therapy with elevate chances of preventing irreversible damages to the inner ear. The presence of alternating phases of well-being and disabling symptoms in patients with vertigo should always been considered, as they could suggest an underlying autoimmune condition.

Central Positional Nystagmus: A Systematic Literature Review

Objective

To provide a systematic review of the clinical and radiological features of lesion-induced central positional nystagmus (CPN) and identify salient characteristics that differentiate central from peripheral positional nystagmus (PN).

Methods

Systematic literature search according to the preferred reporting items for systematic reviews and meta-analysis.

Results

A total of 82 patients from 28 studies met the participants intervention, comparison, outcomes, and study designs criteria for inclusion. An atypical direction of nystagmus for the stimulated canal was reported in 97.5% patients during Dix–Hallpike (D–H) and 54.5% upon supine roll testing. Five types of CPNs were identified during positional testing: positional horizontal nystagmus (pHN) (36.8%), positional downbeating nystagmus (pDBN) (29.2%), positional torsional nystagmus (pTN) (2.1%), positional upbeating nystagmus (pUBN) (2.1%), and a combination of the four profiles (29.9%). CPN was paroxysmal (<60 s) in 85% patients on straight head hanging (SHH), 63.9% on D–H, and 37.5% on supine roll, and had a latency <3 s upon positioning in 94.7% patients in which it was reported. Concurrent vertigo was reportedly present in 63.4% patients and 48.8% demonstrated other neurological signs. Radiologically, in 74.4%, there was mention of cerebellar involvement, isolated brainstem involvement in 8.5%, and 14.6% involved the fourth ventricle.

Conclusion

Currently, there is a lack of robust data on the clinical and radiological characteristics of CPN highlighting the need for better phenotyping of CPN to help differentiate this entity from peripheral causes of PN. With increased awareness of CPN, particularly in the acute setting, we may see a change in the estimated prevalence of CPN and improved clinical markers to promptly identify the frequently sinister underlying causes.

Vertigo and hearing loss

Symptoms referable to disorders affecting the inner ear and vestibulocochlear nerve (eighth cranial nerve) include dizziness, vertigo, tinnitus, and hearing loss, in various combinations. Similar symptoms may occur with involvement of the central nervous system, principally the brainstem and cerebellum, to which the vestibular and auditory systems are connected. Imaging choices should be tailored to patient symptoms and the clinical context. Computed tomography (CT) should be used primarily to assess bony structures. Magnetic resonance imaging (MRI) should be used primarily to assess soft-tissue structures. Vascular imaging by angiography or venography should be obtained when vascular lesions are suspected. No imaging should be obtained in patients with typical presentations of common peripheral vestibular or auditory disorders. In current clinical practice, neuroimaging is often overused, especially CT in the assessment of acute dizziness and vertigo in the emergency department. Despite low sensitivity for ischemic strokes, CT is often used to rule out neurologic causes. When ischemic stroke is the principal concern in acute vestibular presentations, imaging should almost always be by MRI with diffusion-weighted images, rather than CT. In this chapter, we describe recommended strategies for audiovestibular imaging based on patient symptoms and signs.

Diagnosis and Treatment of Anterior-Canal Benign Paroxysmal Positional Vertigo: A Systematic Review

Background and Purpose

In contrast to the posterior- and horizontal-canal variants, data on the frequency and therapeutic management of anterior-canal benign paroxysmal positional vertigo (AC-BPPV) are sparse. To synthesize the existing body of evidence into a systematic review regarding the incidence and treatment of AC-BPPV.

Methods

Systematic search of medical databases employing predefined criteria, using the term "anterior canal benign paroxysmal positional vertigo."

Results

The electronic search retrieved 178 unique citations, 31 of which were considered eligible for further analysis. Analysis of the collected data revealed an estimated occurrence of AC-BPPV among benign paroxysmal positional vertigo patients of 3% (range 1-17.1%). No controlled therapeutic trials could be identified, and so the analysis was focused on uncontrolled case series. Treatment was categorized into three groups: Epley maneuver, Yacovino maneuver, and specific, nonstandard maneuvers described in individual articles. All three categories demonstrated success rates of over 75%, and the overall sample-size-weighted mean was 85.6%.

Conclusions

The present analysis demonstrated that AC-BPPV comprises about 3% of all BPPV cases. It can be treated safely using the Epley, Yacovino, and other maneuvers with rates of symptom resolution lying in the range of that reported for the other, more frequent canal variants. Multicenter controlled trials are needed in order to develop evidence-based guidelines for the treatment of AC-BPPV.

Multiple sclerosis as a cause of the acute vestibular syndrome

Multiple sclerosis (MS) causes dizziness and vertigo. Reports suggest responsible lesions are often in the intra-pontine 8th nerve fascicle. We sought to determine frequency and clinical features of demyelinating acute vestibular syndrome (AVS). This is a prospective observational study (1999-2011). Consecutive AVS patients (vertigo, nystagmus, nausea/vomiting, head-motion intolerance, unsteady gait) with a risk for central localization underwent structured bedside examination and neuroimaging. When applicable, we identified MS based on clinical, imaging, and laboratory features. Of 170 AVS presentations, 4% (n = 7) were due to demyelinating disease. Five had an acute MS plaque likely responsible for the clinical syndrome. Lesion location varied-1 medulla; 1 inferior cerebellar peduncle; 1 middle cerebellar peduncle; 1 posterior pontine tegmentum; 1 in the intrapontine 8th nerve fascicle; 1 superior cerebellar peduncle; 1 midbrain. Only two had a lesion in or near the intra-pontine 8th nerve fascicle. Three were first presentations (i.e., clinically isolated demyelinating syndrome), while the others were known MS. All had central oculomotor signs. In two patients, the only central sign was a normal horizontal head impulse test (h-HIT) of vestibular function. All patients improved with steroid therapy. Demyelinating disease was an uncommon cause of AVS in our series. Symptomatic lesions were not restricted to the 8th nerve fascicle. Five patients had relatively obvious oculomotor signs, making differentiation from vestibular neuritis straightforward. Two patients had unidirectional, horizontal nystagmus that followed Alexander's law and was suppressed with fixation (true pseudoneuritis). The presence of a normal h-HIT in these suggested central localization.

Multiple sclerosis. Part I: neuro-ophthalmic manifestations

PURPOSE OF REVIEW

This update includes topics relating to multiple sclerosis (MS) for the ophthalmologist.

RECENT FINDINGS

Interest in the ophthalmology of MS is highlighted by the substantial amount of original research presented at recent medical conferences. At the 2008 World Congress on Treatment and Research in Multiple Sclerosis, 33 of 898 abstract presentations related to ophthalmology. The most represented topics were optical coherence tomography (OCT) and radiology of the visual system (19/33 posters). The 2009 North American neuro-ophthalmologic society (NANOS) conference featured MS-related topics in 6 of 24 platform presentations. This article reviews recent advancements in the neuro-ophthalmology of MS.

SUMMARY

Multiple sclerosis results in various ophthalmic abnormalities. Optic neuritis is the most widely studied visual disturbance in MS, but other unusual visual manifestations such as Charles Bonnet syndrome or the Pulfrich phenomenon also occur. OCT is used to measure thickness of the retinal nerve fiber layer. Because thinning of this layer in MS represents axonal loss, OCT is being used to evaluate neuroprotective treatments. The efferent visual system, in particular the medial longitudinal fasciculus pathway, may be a way to measure body temperature-induced changes in MS.