Does vestibular damage cause cognitive dysfunction in humans?

For more than a decade, evidence from animal studies has suggested that damage to the vestibular system leads to deficits in spatial navigation which are indicative of impaired spatial learning and memory. More recently, direct evidence has emerged to demonstrate that humans with vestibular disorders exhibit a range of cognitive deficits that are not just spatial in nature, but also include non-spatial functions such as object recognition memory. Vestibular dysfunction has been shown to adversely affect attentional processes and increased attentional demands can worsen the postural sway associated with vestibular disorders. Recent MRI studies also show that humans with bilateral vestibular damage undergo atrophy of the hippocampus which correlates with their degree of impairment on spatial memory tasks. These results are consistent with those from animal studies and, together, suggest that humans with vestibular disorders are likely to experience cognitive dysfunction which is not necessarily related to any particular episode of vertigo or dizziness, and therefore may occur even in patients who are otherwise well compensated. These findings may be related to the observation that patients with vestibular deficits experience a high incidence of depression and anxiety disorders.     

Does asbestos cause laryngeal cancer?

Asbestos is a known carcinogen. Its role in the aetiology of laryngeal cancer has been investigated and debated for the last three decades. Here, we consider much of the published evidence from post-mortem studies, cross-sectional, case-control and cohort studies. We feel that the weight of evidence does not support a causal association for asbestos with laryngeal cancer. The 'positive studies' raise important questions regarding an association; the opportunity may present itself to answer some of these as the incidence of asbestos-related malignancy is increasing in the UK and Europe.     

Does subjective tinnitus cause sexual disturbance?

OBJECTIVE: Tinnitus can cause psychological problems, which can affect sexual performance. The aim of this study was to investigate sexual disturbance related to the psychological problems of patients with subjective tinnitus. MATERIALS AND METHOD: The subjective tinnitus group with normal hearing levels consisted of 20 patients (10 male, 10 female) who were nonpsychiatric. The control group consisted of 20 healthy patients (10 male, 10 female) with normal hearing levels who did not have tinnitus and were nonpsychiatric. All subjects were married and had an active sexual life. Using a questionnaire, the subjective tinnitus loudness level score (STLL-Sc) was found. Using Zung Anxiety and Depression Scale, self-rating depression scale (SDS) was found in the study and control groups. Sexual function was assessed in all male subjects with the International Index of Erectile Functions (IIEF) and in all female subjects with the Female Sexual Function Index (FSFI). RESULTS: In females, the satisfaction subscore was slightly lower than normal limits in both the study and control groups. In males, the IIEF showed an insignificant, negative correlation with the STLL-Sc and the SDS and a positive correlation with tinnitus duration. In females, the FSFI showed an insignificant negative correlation with the STLL-Sc and a positive correlation with tinnitus duration and the SDS. CONCLUSION: Sexual disturbance is seen in very quiet- and intermediate-level tinnitus sufferers in the early period of the disease. Over time, they become used to living with their tinnitus, and no loss in sexual performance is seen. In the future, we plan to investigate the sexual disturbance of patients with severe STLL-Scs.     

Does acute dysfunction of the saccular afferents affect the subjective visual horizontal in patients with vestibular neurolabyrinthitis?

CONCLUSIONS: The results of a series of studies including the present study suggest that acute dysfunction of the utricular afferents accompanied by acute dysfunction of the saccular afferents might require more time for the compensation of the otolith-ocular system than acute utricular dysfunction that was not accompanied by acute saccular dysfunction. Perhaps the inputs from the saccule also have some contribution to the subjective visual horizontal (SVH). OBJECTIVE: To clarify if acute dysfunction of the saccular afferents affects the SVH. PATIENTS AND METHODS: Twenty-six patients with vestibular neurolabyrinthitis (20 men and 6 women, 23-67 years of age) were enrolled in this study. They had undergone measurement of SVH at the early stage (within 1 month after the attack) and 3 months after the attack. For the measurement of SVH, we used a device that has a red bar of light-emitting diodes with a head fixing frame. They also underwent vestibular evoked myogenic potentials (VEMPs) testing. For the recording of VEMPs, 95 dBnHL clicks were presented. RESULTS: Patients with vestibular neurolabyrinthitis showed deviation of SVH toward the affected side-down at the early stage after the attack, irrespective of VEMP results. However, 3 months after the attack SVH was significantly more deviated toward the affected side-down in patients who showed absent VEMPs than those with VEMPs present (p<0.01 Mann-Whitney U test).     

Is microvascular compression of the vestibulocochlear nerve a cause of unilateral hearing loss?

OBJECTIVES: We sought to confirm earlier findings in the literature that microvascular compression of the vestibulocochlear nerve might cause unilateral sensorineural hearing loss. We measured the length and width of the internal auditory canal (IAC) to investigate a possible association between a narrow porus, the presence of an anterior inferior cerebellar artery (AICA) loop, and the development of a microvascular compression syndrome. METHODS: We performed a prospective blinded analysis of 167 magnetic resonance imaging scans of the cerebellopontine angle. The presence of an AICA loop was scored. We analyzed these 167 patients for unilateral sensorineural hearing loss, which was defined as an interaural difference of 20 dB at 1 frequency or 10 dB at 2 or more frequencies. Furthermore, the width and length of the IAC on magnetic resonance imaging were measured. RESULTS: An AICA loop was identified in 94% of the 167 patients. There were 196 type I loops, 106 type II loops, and 14 type III loops. Sixty-six patients had unexplained unilateral hearing loss. There was no association between type II and III vascular loops, the width of the IAC, and unilateral hearing loss (p > .05). CONCLUSIONS: In this study we found no association between the depth of extension of the AICA loop into the IAC and the presence of unilateral hearing loss.     

Does laryngopharyngeal reflux cause intraoral burning sensations? A preliminary study

Intraoral burning sensations are a common problem in the otolaryngological practice. The aim of this study was to evaluate if laryngopharyngeal reflux can cause intraoral burning sensations by measuring oropharyngeal acid reflux. Patients with recurring intraoral burning sensations underwent oropharyngeal pH monitoring in our outpatient clinic. The pH catheter was placed at the level of the uvula. The catheter contained an externally worn transmitter, which wirelessly sent the data to a monitor. In addition, patients were instructed to indicate meals or the occurrence of burning sensations by pressing provided buttons on the monitor. Corresponding events of burning sensations and a significant decrease in oropharyngeal pH values should be visualized. Twenty two patients suffering from recurring intraoral burning sensations underwent oropharyngeal pH measurement for 21–25 h. We could find oropharyngeal reflux episodes in 11 patients. However, we could not detect any episodes of burning sensations in the mouth corresponding with a decrease in oropharyngeal pH values. Our results suggest that there is no causal connection between LPR episodes and the occurrence of intraoral burning sensations in the examined patients. Although further studies with more patients are necessary in the future, we conclude from our findings that recurring intraoral burning sensations are not an indication for proton pump inhibitor therapy.     

The COCH gene: a frequent cause of hearing impairment and vestibular dysfunction?

The identification of genes leading to hereditary hearing impairment is one of the ways to elucidate the functioning of the inner ear. Over the past few years, several genes responsible for non-syndromal hereditary hearing impairment have been identified. One of these genes, named COCH, is responsible for autosomal dominant progressive sensorineural hearing loss associated with vestibular impairment (DFNA9). Histopathological analysis in patients with a COCH mutation revealed the presence of an acidophylic mucopolysaccharide deposit in the inner ear. An overview of the clinical, pathological and genetic studies on COCH is given, and the possible role of COCH in the pathology of DFNA9 is discussed.     

Does intratympanic gentamicin treatment for Meniere's disease cause complete vestibular ablation?

OBJECTIVE: To determine changes in vestibular function following intratympanic gentamicin (ITG) treatment for Meniere's disease and to correlate changes with the need for further treatment. STUDY DESIGN: Prospective case series. PATIENTS: One hundred and three patients with disabling unilateral Meniere's disease who had failed a minimum of 6 months medical treatment. MAIN OUTCOME MEASURES: Vestibular function was measured by electronystagmography (ENG) caloric testing before and serially following treatment. Caloric responses were classified as normal (excitability difference [ED] < 25%), bithermal response (ED > or = 25%), positive response to ice water only, and absent ice water response. RESULTS: Twenty-one percent of patients had a bithermal caloric response, 62% had an absent ice water response, and 17% had an ice water response only 1 month following treatment. Mean follow-up was 27.3 months (range = 1-106 months). Eighty-four patients had one treatment course only. Fourteen patients required a further course of treatment due to recurrence of vertigo; 38% of these had recovery of caloric function. Significantly more patients with normal caloric function prior to initial treatment required further treatment compared to those with initial reduced caloric function (p < .05). Patients rendered absent ice water responsive were significantly less likely to require further treatment than those with a persistent caloric response (p < .0001). CONCLUSION: An absent ice water response is highly predictive of adequate vertigo control. Regimens of ITG that aim to completely ablate vestibular function are recommended.     

Identification of early-stage Meniere’s disease as a cause of unilateral tinnitus

Introduction:Meniere’s disease(MD)is characterized by episodic symptoms,including vertigo,hearing loss,and tinnitus.Objectives:in this study,cases of unilateral tinnitus were investigated for MD.Method:Twenty-two patients who presented with chronic unilateral tinnitus on puretone audiograms showing an average threshold better than 25 dB HL and thresholds in the lower frequencies worse than those in the higher frequencies by more than 10 dB were suspected to have early-stage MD and underwent electrocochleography(ECochG).Patients showing ECochG findings conclusive for MD were compared to a control group of patients presenting with chronic unilateral tinnitus on pure-tone audiograms showing an average threshold better than 25 dB and thresholds in the higher frequencies worse than those in the lower frequencies by more than 10 dB.Results:Eighteen of the 22 patients included in this study showed elevated summating potential amplitude to action potential amplitude ratios in ECochG(suggestive of endolymphatic hydrops due to MD)and were followed up for 2 months;14 of them experienced at least two attacks of vertigo or unsteadiness.In contrast,only one patient in the control group reported two or more attacks of vertigo or unsteadiness in the 2 month observation period.The incidence of this finding in the two groups was significantly different.Conclusion:Patients with early-stage MD can present with only unilateral tinnitus.Thus,the addition of“pure-tone audiograms showing lower-frequency thresholds worse than higher-frequency thresholds”to the probable MD category in the globally.     

In whom does horizontal canal BPPV recur?

Purpose

The objective of this study is to examine the rate of horizontal canal BPPV recurrence of the same type and search for predisposing factors.     

Periodic alternating nystagmus in Meniere's disease: the peripheral type?

Periodic alternating nystagmus (PAN) is a spontaneous horizontal nystagmus that reverses direction periodically. PAN has been reported in acquired and congenital forms. The lesion site of the acquired form of PAN has been attributed to the caudal brainstem or cerebellum. We report an extremely rare case (a 59-year-old woman) with bilateral Meniere's disease, who presented PAN. PAN in this patient was suppressed in the light. This patient had smooth pursuit and normal optokinetic nystagmus, although patients with PAN usually show saccadic pursuit and impaired optokinetic nystagmus. These findings were different features from those of the central or congenital form of PAN. It should be kept in mind that peripheral vestibular disorders such as Meniere's disease could produce PAN.     

Periodic alternating nystagmus in Meniere's disease: the peripheral type?

Periodic alternating nystagmus (PAN) is a spontaneous horizontal nystagmus that reverses direction periodically. PAN has been reported in acquired and congenital forms. The lesion site of the acquired form of PAN has been attributed to the caudal brainstem or cerebellum. We report an extremely rare case (a 59-year-old woman) with bilateral Meniere's disease, who presented PAN. PAN in this patient was suppressed in the light. This patient had smooth pursuit and normal optokinetic nystagmus, although patients with PAN usually show saccadic pursuit and impaired optokinetic nystagmus. These findings were different features from those of the central or congenital form of PAN. It should be kept in mind that peripheral vestibular disorders such as Meniere's disease could produce PAN.