Direction-Changing Positional Nystagmus in Acute Otitis Media Complicated by Serous Labyrinthitis: New Insights into Positional Nystagmus

Bilateral Sudden Hearing Loss in Iron Deficiency Anemia

The present study describes an unusual case of bilateral sudden hearing loss associated with iron deficiency anemia. Although hematologic disorders such as anemia or leukemia have been reported to be associated with sudden hearing loss, bilateral sudden hearing loss, which was presented as the first manifestation of iron deficiency anemia, has not been reported. A 74-year-old man presented with simultaneous bilateral sudden hearing loss without vertigo. A complete blood count test revealed a hemoglobin level of 6.4 g/dL and a ferritin level of 14.5 mg/mL, indicating iron deficiency anemia. Postcontrast 3D FLAIR MRI showed enhancement of the bilateral cochlea, vestibules, and lateral semicircular and posterior semicircular canals. After treatment, the patient's hearing loss partially improved.

Nystagmus in adult patients with acute otitis media or otitis media with effusion without dizziness

The present study aimed to investigate the incidence and patterns of nystagmus in adult patients with acute otitis media (AOM) or otitis media with effusion (OME) without dizziness or vertigo, and discuss possible mechanisms. From February 2018 to November 2018, 34 consecutive patients with AOM or OME without dizziness were included. Nystagmus was examined with video Frenzel glasses. Of 34 adult AOM or OME patients without dizziness, nystagmus was observed in 28 patients (82%). In unilateral AOM or OME (n = 30), the most commonly observed nystagmus pattern was irritative-type direction-fixed nystagmus (n = 13), followed by paretic-type direction-fixed nystagmus (n = 8), and direction-changing positional nystagmus (n = 4). In bilateral AOM or OME (n = 4), direction-fixed nystagmus and direction-changing positional nystagmus were observed in two and one patients, respectively. Nystagmus was observed in as many as 82% of adult AOM or OME patients even though they did not complain of dizziness, and the pattern of nystagmus was either direction-fixed or direction-changing. Direct effect of inflammatory mediators penetrated from the middle ear and biochemical alteration in the inner ear fluids due to blood-perilymph barrier dysfunction may result in the presence of nystagmus in AOM or OME patients without dizziness.

Case Report: Could Hennebert's Sign Be Evoked Despite Global Vestibular Impairment on Video Head Impulse Test? Considerations Upon Pathomechanisms Underlying Pressure-Induced Nystagmus due to Labyrinthine Fistula

We describe a case series of labyrinthine fistula, characterized by Hennebert's sign (HS) elicited by tragal compression despite global hypofunction of semicircular canals (SCs) on a video-head impulse test (vHIT), and review the relevant literature. All three patients presented with different amounts of cochleo-vestibular loss, consistent with labyrinthitis likely induced by labyrinthine fistula due to different temporal bone pathologies (squamous cell carcinoma involving the external auditory canal in one case and middle ear cholesteatoma in two cases). Despite global hypofunction on vHIT proving impaired function for each SC for high accelerations, all patients developed pressure-induced nystagmus, presumably through spared and/or recovered activity for low-velocity canal afferents. In particular, two patients with isolated horizontal SC fistula developed HS with ipsilesional horizontal nystagmus due to resulting excitatory ampullopetal endolymphatic flows within horizontal canals. Conversely, the last patient with bony erosion involving all SCs developed mainly torsional nystagmus directed contralaterally due to additional inhibitory ampullopetal flows within vertical canals. Moreover, despite impaired measurements on vHIT, we found simultaneous direction-changing positional nystagmus likely due to a buoyancy mechanism within the affected horizontal canal in a case and benign paroxysmal positional vertigo involving the dehiscent posterior canal in another case. Based on our findings, we might suggest a functional dissociation between high (impaired) and low (spared/recovered) accelerations for SCs. Therefore, it could be hypothesized that HS in labyrinthine fistula might be due to the activation of regular ampullary fibers encoding low-velocity inputs, as pressure-induced nystagmus is perfectly aligned with the planes of dehiscent SCs in accordance with Ewald's laws, despite global vestibular impairment on vHIT. Moreover, we showed how pressure-induced nystagmus could present in a rare case of labyrinthine fistulas involving all canals simultaneously. Nevertheless, definite conclusions on the genesis of pressure-induced nystagmus in our patients are prevented due to the lack of objective measurements of both low-acceleration canal responses and otolith function.

Positional Nystagmus after Acute Vertiginous Attack in Meniere's Disease

There have been no reports regarding nystagmus observed immediately after the end of an acute vertiginous attack in patients with Meniere’s disease. The aim of this study was to demonstrate positional direction-changing nystagmus in patients with Meniere’s disease, and to discuss the mechanism that underlies this nystagmus. Video-nystagmography was recorded in two patients with definite Meniere’s disease, who showed positional direction-changing nystagmus during the period immediately after a vertigo attack. In one patient, video-nystagmographic recording was conducted 5 h after an episode of vertigo attack, and it showed very weak, persistent positional geotropic direction-changing nystagmus. In the other patient, video-nystagmographic recording was conducted 23 h after an episode of vertigo attack, and it showed very weak, persistent positional apogeotropic direction-changing nystagmus. Our patients exhibited very weak, persistent positional direction-changing nystagmus, which was geotropic in one and apogeotropic in the other. This type of positional nystagmus has been reported in other inner ear disorders and it cannot be clearly explained by typical benign paroxysmal positional vertigo. The change in chemical composition and/or electrolyte concentration of the inner ear fluid, although still unclear, may underlie the production of this characteristic nystagmus in these patients.

Positional nystagmus in middle ear cholesteatoma with labyrinthine fistula

Chronic otitis media with cholesteatoma can cause erosion of the dense labyrinthine bone overlying the inner ear organs, and this labyrinthine fistula allows pressure or mass-induced motion of the underlying perilymphatic and endolymphatic compartment, evoking vestibular symptoms. While the mechanism of a positive fistula test, which is conducted by increasing or decreasing the external auditory canal pressure, has been well established, the mechanism underlying positional nystagmus in labyrinthine fistula has not been discussed yet. In the present study, we propose a new hypothesis accounting for positional nystagmus in labyrinthine fistula involving the lateral semicircular canal (LSCC), i.e., the change in intracranial cerebrospinal fluid pressure by position change is transmitted to the perilymphatic space, causing ampullopetal (excitatory) or ampullofugal (inhibitory) deflection of the LSCC cupula.

Benign Paroxysmal Positional Vertigo in the Elderly: A Single-center Experience

OBJECTIVES

Dizziness and balance problems are common in the elderly, and benign paroxysmal positional vertigo (BPPV) is one of the most common causes of dizziness. The aim of this study is to investigate the subtype distribution of geriatric BPPV in a single tertiary referral center, and compare the treatment efficacy according to the subtype of BPPV.

STUDY DESIGN

Retrospective study.

SETTING

Tertiary referral academic center.

PATIENTS

The consecutive 316 elderly patients diagnosed with BPPV between March 2013 and March 2019 were included.

MAIN OUTCOME MEASURES

Using a head-roll and Dix-Hallpike tests, subtype of BPPV was determined. Once the diagnosis of BPPV was made, patients were treated by its corresponding canalith repositioning maneuver (CRM).

RESULTS

Among 316 elderly patients with BPPV, 143 patients (45%) were diagnosed with posterior semicircular canal BPPV, 46 patients (15%) were diagnosed with lateral semicircular canal (LSCC) canalolithiasis, 126 patients (40%) were diagnosed with LSCC cupulolithiasis, and 1 patient (0%) was diagnosed with anterior semicircular canal BPPV. While 66 and 63% of the patients with posterior semicircular canal BPPV and LSCC canalolithiasis recovered after one session of CRM, only 32% of the patients with LSCC cupulolithiasis recovered after one session of CRM.

CONCLUSION

The proportion of LSCC cupulolithiasis was higher in the elderly, and treatment efficacy by CRM is lower in LSCC cupulolithiasis than other subtypes of BPPV. High prevalence of LSCC cupulolithiasis may be explained by a delay between onset of BPPV and patient's presentation to the tertiary referral hospital or pathophysiology of ageotropic positional nystagmus other than otoconial attachment on the LSCC cupula in the elderly.

An intact bony tympanic facial canal does not protect from secondary facial paresis in adult acute otitis media

OBJECTIVE

To investigate the prevalence of bony dehiscence in the tympanic facial canal in patients with acute otitis media with facial paresis compared to those without facial paresis.

METHOD

A retrospective case-control study was conducted on acute otitis media patients with facial paresis undergoing high-resolution temporal bone computed tomography.

RESULTS

Forty-eight patients were included (24 per group). Definitive determination of the presence of a bony dehiscence was possible in 44 out of 48 patients (91.7 per cent). Prevalence of bony dehiscence in acute otitis media patients with facial paresis was not different from that in acute otitis media patients without facial paresis (p = 0.21). Presence of a bony dehiscence was associated with a positive predictive value of 66.7 per cent in regard to development of facial paresis. However, an intact bony tympanic facial canal did not prevent facial paresis in 44.8 per cent of cases (95 per cent confidence interval = 34.6-55.6).

CONCLUSION

Prevalence of bony dehiscence in acute otitis media patients with facial paresis did not differ from that in acute otitis media patients without facial paresis. An intact tympanic bony facial canal does not protect from facial paresis development.

Positional alcohol nystagmus and serum osmolality: New insights into dizziness associated with acute alcohol intoxication

Positional alcohol nystagmus (PAN) is characterized by positional direction-changing nystagmus. Although the buoyancy cupulopathy, which implies that the cupula becomes lighter or heavier than the endolymph due to different diffusion rates of alcohol, has been accepted as possible mechanism of PAN, the evidence supporting this hypothesis is weak. The aim of present study is to investigate the possibility of serum osmolality change following alcohol intake as a cause of PAN. Nine healthy adults were recruited voluntarily. Positional nystagmus was examined before and every 1 hr after alcohol intake until 7 hr. Serum osmolality was measured before and 1 and 7 hr after alcohol intake. Before ingesting alcohol, no subject showed positional nystagmus, and mean serum osmolality was 285.9 ± 4.4 mOsm/kg. At 1 hr after drinking, mean serum osmolality increased to 302.9 ± 8.9 mOsm/kg, and all subjects exhibited geotropic positional nystagmus. At 7 hr after drinking, mean serum osmolality decreased to 289.1 ± 9.4 mOsm/kg, and all subjects showed ageotropic positional nystagmus. Change in serum osmolality following alcohol ingestion and subsequent change in specific gravity in the perilymph and endolymph may be a cause of PAN.

Dialysis disequilibrium syndrome revisited: Feeling "Disequilibrated" due to inner ear dyshomeostasis?

Dizziness is one of the most common hemodialysis-associated symptoms, and has been thought to be caused by cerebral edema or intravascular hypovolemia. However, the possibility of a peripheral vestibular disturbance due to hemodialysis has not been addressed as a cause of hemodialysis-associated dizziness. In the present study, we propose a new hypothesis accounting for hemodialysis-associated dizziness, i.e., the decrease in serum osmolality due to rapid removal of urea during dialysis causes inner ear fluid dyshomeostasis, leading to density difference between perilymph and endolymph.