Publications by authors named "Takao Imai"

Objective: To compare the feasibility and outcomes of vestibular rehabilitation (VR) for persistent postural-perceptual dizziness (PPPD) with those for chronic unilateral vestibular hypofunction (UVH).

Study Design: Prospective study.

Setting: Tertiary referral center.

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  • - The study focuses on how aging affects the vestibular system, particularly the otolith organs in mice, which are critical for balance and can increase fall risk in older adults.
  • - Researchers used young and old mice to analyze the morphology and function of the otoliths, finding significant differences in otolith density and structural changes that correlated with age.
  • - The results suggest that aging leads to a decline in otolith function, evidenced by reduced responsiveness in eye movement during tests, which may contribute to increased falls in the elderly.
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Objectives: The Epley maneuver (EM) shows immediate effect, wherein disappearance of positional nystagmus occurs soon after the EM. Our previous study showed that setting interval times during the EM reduced the immediate effect. The purpose of this study is to identify the head position for which interval time reduces the immediate effect.

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  • The case report discusses a unique instance of infantile nystagmus syndrome (INS) where the nystagmus exhibited was vertical instead of the more common horizontal.
  • A 66-year-old woman experienced abnormal eye movements and had a lower left quadrant homonymous hemianopia due to right occipital lobe atrophy and reduced blood flow, but did not report any visual blurriness (oscillopsia).
  • The findings suggest that her vertical nystagmus was a result of an atypical visual field and how her eyes compensated due to the hemianopia, which typically leads to horizontal nystagmus in most INS patients.
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Autoimmune inner ear disease (AIED) is an organ-specific disease characterized by irreversible, prolonged, and progressive hearing and equilibrium dysfunctions. The primary symptoms of AIED include asymmetric sensorineural hearing loss accompanied by vertigo, aural fullness, and tinnitus. AIED is divided into primary and secondary types.

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Purpose: Diagnosis of Menière's disease (MD) relies on subjective factors and the patients diagnosed with MD may have heterogeneous pathophysiologies. This study aims to stratify MD patients using two objective data, nystagmus videos and contrast-enhanced magnetic resonance imaging (CE-MRI).

Methods: This is a retrospective cross-sectional study.

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  • A study examined the effectiveness of repeated Dix-Hallpike tests (DHt) versus the Epley maneuver (EM) in treating patients with posterior canal benign paroxysmal positional vertigo (pc-BPPV), focusing on "BPPV fatigue," where nystagmus decreases with repeated testing.
  • In a multicenter, randomized controlled trial involving 180 patients, both groups showed similar success rates in eliminating positional nystagmus after one week, with 50% for EM and 47.8% for repeated DHt.
  • The results indicated that repeated DHt is as effective as EM in treating pc-BPPV, suggesting that disintegrated otoconial debris might provide a therapeutic effect
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Coronavirus disease 2019 (COVID-19) generally presents with fever, shortness of breath and a sore throat. These symptoms are also common in oral and pharyngeal infections, such as peritonsillar abscess (PA). The present study describes a case of PA and COVID-19 co-infection.

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  • Facial paralysis leads to a decrease in facial expressions and can stem from various causes, requiring new treatment options due to its poor prognosis.
  • A silicon (Si)-based agent was tested in mice with facial paralysis, showing promise in promoting nerve regeneration and reducing oxidative stress related to nerve injuries.
  • The combination of the Si-based agent with methylcobalamin (MeCbl) resulted in better recovery outcomes, enhancing myelination and overall clinical improvements compared to using either treatment alone.
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  • Researchers conducted a genome-wide association study (GWAS) with 2,393 COVID-19 patients and 3,289 controls in Japan, identifying a specific genetic variant (rs60200309-A) on chromosome 5 linked to severe cases in individuals under 65.
  • The variant is more common in East Asians and associated with reduced expression of the DOCK2 gene, which was found to be lower in severe COVID-19 cases, particularly in non-classical monocytes.
  • Additionally, inhibiting DOCK2 in hamsters worsened pneumonia symptoms, indicating its potential as a biomarker and therapeutic target for severe COVID-19.
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Benign paroxysmal positional vertigo (BPPV) is characterized by positional vertigo (brief attacks of rotatory vertigo triggered by head position changes in the direction of gravity) and is the most common peripheral cause of vertigo. There are two types of BPPV pathophysiology: canalolithiasis and cupulolithiasis. In canalolithiasis, otoconial debris is detached from the otolithic membrane and floats freely within the endolymph of the canal.

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Objective: To clarify therapeutic effect of caloric stimulation for acute peripheral vertigo.

Patients: Two patients with acute peripheral vertigo accompanied by spontaneous nystagmus.

Interventions: Therapeutic.

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Objectives: It is shown that eliminating hearing loss in mid-life may reduce the risk for deterioration in cognitive function. Cochlear implantation (CI) is the only available therapy that can eliminate hearing loss in patients who suffer from profound sensorineural hearing loss. This suggests there may be positive effects of hearing level on cognition in older adults following CI.

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The V-shaped arrangement of hair bundles on cochlear hair cells is critical for auditory sensing. However, regulation of hair bundle arrangements has not been fully understood. Recently, defects in hair bundle arrangement were reported in postnatal Dishevelled-associating protein (ccdc88c, alias Daple)-deficient mice.

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In the interaural direction, translational linear acceleration is loaded during lateral translational movement and gravitational acceleration is loaded during lateral tilting movement. These two types of acceleration induce eye movements via two kinds of otolith-ocular reflexes to compensate for movement and maintain clear vision: horizontal eye movement during translational movement, and torsional eye movement (torsion) during tilting movement. Although the two types of acceleration cannot be discriminated, the two otolith-ocular reflexes can distinguish them effectively.

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In benign paroxysmal positional vertigo (BPPV), positional nystagmus becomes generally weaker when the Dix-Hallpike test is repeated. This phenomenon is termed BPPV fatigue. We previously reported that the effect of BPPV fatigue deteriorates over time (i.

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The organ of Corti is an auditory organ located in the cochlea, comprising hair cells (HCs) and other supporting cells. Cellular shape changes of HCs are important for the development of auditory epithelia and hearing function. It was previously observed that HCs and inner sulcus cells (ISCs) demonstrate cellular shape changes similar to the apical constriction of the neural epithelia.

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Objective: Posturography (PG) shows various patterns corresponding to a patient's equilibrium condition; however, PG is not useful for the differential diagnosis of peripheral vestibular diseases (PVDs). The aim of this study was to identify parameters of PG that can distinguish between PVDs.

Methods: The differences in PG parameters between PVDs were evaluated retrospectively.

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When vestibular function is lost, vestibular compensation works for the reacquisition of body balance. For the study of vestibular dysfunction and vestibular compensation, surgical or chemical labyrinthectomy has been performed in various animal species. In the present study, we performed chemical labyrinthectomy using arsanilic acid in mice and investigated the time course of vestibular compensation through behavioral observations and histological studies.

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Purpose: As the pathological cause of benign paroxysmal positional vertigo (BPPV), the dislocation or degeneration of otoconia in the utricle and saccule is suggested. Vestibular evoked myogenic potential (VEMP) could reflect otolithic dysfunction due to these etiologies of BPPV. The aim of this study was to validate the clinical significance of cervical (c) and ocular (o) VEMP in BPPV by a meta-analysis of previous articles.

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The major symptoms of Ménière's disease are episodic vertigo, fluctuating hearing loss, and tinnitus. Direction-changing spontaneous nystagmus is a characteristic vestibular finding in Ménière's disease. In the acute stage, spontaneous nystagmus beating to the affected side (irritative nystagmus) is often observed, while paralytic nystagmus beating to the healthy side is found in the chronic stage.

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Cholesteatoma starts as a retraction of the tympanic membrane and expands into the middle ear, eroding the surrounding bone and causing hearing loss and other serious complications such as brain abscess and meningitis. Currently, the only effective treatment is complete surgical removal, but the recurrence rate is relatively high. In rheumatoid arthritis (RA), osteoclasts are known to be responsible for bone erosion and undergo differentiation and activation by receptor activator of NF-κB ligand (RANKL), which is secreted by synovial fibroblasts, T cells, and B cells.

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Objective: Bell's palsy (BP) is the most common cause of unilateral peripheral facial paralysis, and inflammation has been proposed as the main pathological cause. The study aim was to investigate the relationship between hematologic inflammatory markers, including the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR), and BP.

Data Sources: The following key words were used to search PubMed and Scopus for English language articles: Bell's palsy, facial palsy, facial paresis or facial paralysis, neutrophil, lymphocyte, and platelet.

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The Epley maneuver (EM) has an immediate effect: rapid reduction of positional nystagmus. Benign paroxysmal positional vertigo (BPPV) causes BPPV fatigue, which constitutes fatigability of positional nystagmus and vertigo with repeated performance of the Dix-Hallpike test; notably, BPPV fatigability becomes ineffective over time. We hypothesized that the immediate effect of the EM is caused by BPPV fatigue.

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Objective: The aim of this study was to investigate whether the insertion of an implant into the cochlea is accompanied by a deterioration in otolith function. Cervical and ocular vestibular evoked myogenic potentials (cVEMP and oVEMP) and linear vestibulo-ocular reflex (lVOR) during eccentric rotation were assessed before and after cochlear implantation (CI) to evaluate otolith function.

Methods: Twelve patients with bilateral severe sensorineural hearing loss who had undergone CI surgery in our hospital between May 2016 and November 2017 were included in this study.

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