Endolymphatic hydrops is a representing pathologic finding of Ménière's disease. For the induction of endolymphatic hydrops in an animal model, surgical ablation of endolymphatic sac has been used. Although traditional model with the blockage of endolymphatic sac induced severe hydrops, it has several limitations for the study of pathophysiology of Ménière's disease. Recently, modified experimental models have been introduced, in which additional procedure was performed to induce the acute aggravation of hydrops after the surgical ablation. These new models could be helpful to elucidate the mechanism and develop a new treatment of Ménière's disease. In this review, we introduce the characteristics of animal models using surgical ablation of endolymphatic sac from the classical model to novel modified models.
Falls are the most common cause of accidents among the older population, leading to both fatal and non-fatal injuries. Falls is a syndrome resulting from the cumulative effect of various extrinsic and intrinsic factors. It is considered to be a multifactorial disorder. Medication use is considered a risk factor for falls. We reviewed medications associated with falls in older individuals. In geriatrics populations, polypharmacy is associated with falls. Medical doctors should be aware of the possibility that starting a new medication, such as antihypertensive agents, benzodiazepine, antidepressants, opioid agents and antihistamines, may act as a trigger for the onset of a fall.
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According to the Barany Society classification of vestibular symptoms, positional dizziness or vertigo is defined as dizziness or vertigo triggered by and occurring after a change of head position in space relative to gravity. Thus, positional dizziness or vertigo should be differentiated from orthostatic dizziness or vertigo, which is triggered by and occurs upon rising. Benign paroxysmal positional vertigo (BPPV) is the most common positional vertigo and accompanied by a characteristic paroxysmal positional nystagmus. But a problem occasionally encountered in clinical practice is the presence of a positive history of BPPV with a negative diagnostic maneuver for positional nystagmus. Orthostatic hypotension may be dependent upon various neurogenic and non-neurogenic disorders and conditions. Combination of non-pharmacological and pharmacological treatment improve orthostatic tolerance.
Acute vestibular neuritis is the disorder characterized by acute, spontaneous vertigo with the unilateral vestibular loss. Reactivation of herpes simplex virus is considered as its cause. Its management consists of symptomatic therapy in the acute phase and following rehabilitation exercise to improve central compensation. The differential diagnosis should include central vestibular disorders mimicking peripheral vertigo. Ramsay-Hunt syndrome, which defined as a herpes zoster oticus with facial paresis, is also a disorder frequently accompanied with vestibular deficit. Combination therapy of acyclovir and corticosteroid is recommended for the treatment. In this review, diagnosis and management of the two disorders are described.
Objective: The purpose of this study was to identify the influence of sleep position on benign paroxysmal positional vertigo (BPPV).
Methods Four hundred sixty patients diagnosed as posterior or horizontal canal BPPV were analyzed retrospectively. All patients were asked about their preferred sleep positions among the following four choices: supine, right or left lateral, or no predominant side via questionnaire at initial visit and after 1month. Patients were classified into two groups: affected side group meaning that the patient preferred to sleep ipsilateral to the affected ear and other position group including all positions other than lying lateral to the affected side after treatment. We analyzed the change in the sleep pattern after treatment and compared the recurrence rate between the two groups.
Results Our study included 244 patients with posterior canal BPPV (PC-BPPV) and 216 patients with horizontal canal BPPV (HC-BPPV). Statistically significant correlation was demonstrated between sleep position side and the affected side by BPPV. The number of patients who slept on the affected side by BPPV decreased, while the number of patients who slept on the healthy side increased significantly after treatment. There was no statistically significant difference in the recurrence rate between the two groups.
Conclusion There was significant correlation between the sleep position side and the affected side in PC-BPPV and HC-BPPV. The patient had a tendency to avoid lying lateral to the affected side by BPPV during sleep after treatment, however the change in sleep position did not influence the recurrence rate of BPPV.
Objective: The purpose of this study was to identify the diverse patterns of nystagmus and analyze their clinical significance in benign paroxysmal positional vertigo (BPPV) of the anterior semicircular canal.
Methods Fifty-three patients diagnosed with anterior canal BPPV (AC-BPPV) were analyzed retrospectively. Patients were classified according to the presence or absence of the torsional component of the nystagmus and the direction of Dix-Hallpike test which induced the nystagmus. We compared the clinical characteristics and treatment outcomes among the different patient groups.
Results There were 11 patients with unilateral down beat (DB) nystagmus, 11 patients with bilateral DB nystagmus, 14 patients with ipsilateral torsional down beat (TDB) nystagmus, 7 patients with contralateral TDB nystagmus, and 7 patients with bilateral TDB nystagmus. There were no differences between the unilateral and the bilateral DB groups in terms of the duration of nystagmus or vertigo and the number of treatment sessions. In addition, the ipsilateral TDB group showed no significant clinical difference compared to the contralateral or bilateral TDB group.
Conclusion Various nystagmus patterns can be seen in AC-BPPV. There was no statistically significant difference in the clinical characteristics according to the different nystagmus patterns. This information may be helpful for clinicians in counseling and managing the patients with AC-BPPV.
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Benign Paroxysmal Positional Vertigo: Diagnostic Criteria and Updated Practice Guideline in Diagnosis Dae Bo Shim Research in Vestibular Science.2020; 19(4): 111. CrossRef
Objective: Growing hypotheses indicate the galvanic vestibular stimulation (GVS) as an alternative method to manage the symptoms of parkinson’s disease (PD). GVS is easy and safe for use, and non-invasive. However, it is elusive how the neural information caused by GVS is transmitted in the central nervous system and relieves PD symptoms. To answer this question, we investigated the transmission of neural information by GVS in the central vestibular system, focused on vestibular nucleus (VN).
Methods Twenty guinea pigs were used for this study for the extracellular neuronal recordings in the VN. The neuronal responses to rotation and GVS were analyzed by curve-fitting, and the numerical responding features, amplitudes and baselines, were computed. The effects of stimuli were examined by comparing these features.
Results Twenty six vestibular neurons (15 regular and 11 irregular neurons) were recorded. Comparing the difference of baselines, we found the neural information was linearly transmitted with a reduced sensitivity (0.75). The linearity in the neural transmission was stronger in the neuronal groups with regular (correlation coefficient [Cor. Coef.]=0.91) and low sensitive units (Cor. Coef.=0.93), compared with those with irregular (Cor. Coef.=0.86) and high-sensitive neurons (Cor. Coef.=0.77).
Conclusion The neural information by GVS was linearly transmitted no matter what the neuronal characteristics were.
Vestibular paroxysmia is the name given to the syndrome caused by vascular compression of the vestibulocochlear nerve. The main symptoms of vestibular paroxysmia are recurrent, spontaneous, brief attacks of spinning, non-spinning vertigo or positional vertigo that generally last less than one minute, with or without ear symptoms (tinnitus and hypoacusis). Prior to attributing a patient’s symptoms to vestibular paroxysmia, however, clinicians must exclude common conditions like benign paroxysmal positional vertigo, Menière’s disease, vestibular neuritis and vestibular migraine. This is usually possible with a thorough history and bedside vestibular/ocular motor examination. Herein, we describe a patient with vestibular paroxysmia that mimicked resolved BPPV with a literature review.
The anterior cerebellar vermis has been known to act in coordination of gait and postural adjustment of the trunk and legs. However, oculomotor abnormalities in an isolated anterior vermian lesion have not been described in the literature. A 59-year-old man presented with acute non-rotatory dizziness and disequilibrium. Neuro-ophthalmologic examination found impaired smooth pursuit and hypometric saccades in the contralesional direction, and disconjugate ipsiversive ocular torsion, but without spontaneous or gaze-evoked nystagmus. Imaging study showed an infarction restricted to the rostral end of right cerebellar vermis involving the lingual and central lobules. The anterior cerebellar vermis participates in the maintenance of axial posture and gait, and also in the control of ocular motor and vestibular systems.
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Free water imaging unravels unique patterns of longitudinal structural brain changes in Parkinson’s disease subtypes Abigail E. Bower, Sophia J. Crisomia, Jae Woo Chung, Justin P. Martello, Roxana G. Burciu Frontiers in Neurology.2023;[Epub] CrossRef