Cortical Activity During an Attack of Ménière's Disease-A Case Report.

Background: Ménière's disease (MD) is a chronic peripheral vestibular disorder with recurrent episodes of vertigo accompanied by fluctuating hearing loss, tinnitus and aural fullness in the affected ear. There are several unanswered fundamental questions regarding MD, one of these being cortical activity during a MD attack. However, it is not possible to plan an investigation in an episodic disease as MD. Objective: To visualize cortical activity during an attack of MD. Method: 18F-FDG PET scans were used to visualize cortical activity in a 62 years old male suffering from definite MD. Two 18F-FDG PET scans were performed. One to show activity during the attack and one to show normal baseline brain activity 7 days after the attack. Results: A number of low-magnitude fluctuations in the 18F-FDG FDG uptake were found in 18F-FDG PET examination following the MD attack compared to the patient's own baseline 18F-FDG FDG scan. Across both hemispheres no significant changes were seen. However, reduced activity was observed in most of the orbitofrontal, frontal cortices as well as Heschl's gyrus and insula. Conclusion: This is the first neuroimaging showing alteration of brain activity during an attack in a patient with MD. No strong focal alterations was seen. It is noteworthy that the decreased activity observed was in the insula and Heschl's gyrus that seems to be core areas for processing information from the labyrinth. It is also of interest that decreased activity rather than hyperactivity was observed.

PET Visualized Stimulation of the Vestibular Organ in Menière's Disease.

Introduction: The cortical metabolic activity in patients with Menière's disease has not been investigated. The aim of this study was to investigate the 18F-FDG cerebral uptake in Menière's patients compared to healthy controls. Method: Eight patients with right-sided Menière's disease and fourteen healthy controls underwent a video head impulse test (vHIT), test of utricular function with ocular vestibular evoked myogenic potentials (oVEMP) and three 18F-FDG-based PET examinations of the brain. Participants were seated in a self-propelled chair, injected with 18F-FDG and then exposed to 35 min of chair motion stimulation, followed by a PET scan. Two types of natural vestibular stimuli were applied, predominantly toward the right horizontal semicircular canal (angular acceleration) and right utriculus (linear acceleration). For baseline scans, participants were injected with 18F-FDG while seated without movement. Results: Analyses of baseline scans revealed decreased 18F-FDG-uptake in the medial part of Heschl's gyrus in the left hemisphere in patients with Menière's disease compared to healthy controls. During angular vestibular stimulation there was also a significantly decreased 18F-FDG uptake in the intersection between the medial part of Heschl's gyrus and the parietal operculum in the left hemisphere and bilaterally in the posterior part of insula. During linear stimulation, Menière's patients showed decreased 18F-FDG uptake in the medial part of Heschl's gyrus in the right hemisphere and also bilaterally in the posterior insula. In addition, decreased 18F-FDG uptake was seen in the thalamus during vestibular stimulation. Conclusion: Heschl's gyrus, the posterior part of insula, and thalamus have previously been shown to be core areas for processing vestibular inputs. Patients with Menière's disease solely differed from the healthy controls with lower cortical activity in these areas at baseline and during natural vestibular stimulation.

Positron emission tomography visualized stimulation of the vestibular organ is localized in Heschl's gyrus.

The existence of a human primary vestibular cortex is still debated. Current knowledge mainly derives from functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) acquisitions during artificial vestibular stimulation. This may be problematic as artificial vestibular stimulation entails coactivation of other sensory receptors. The use of fMRI is challenging as the strong magnetic field and loud noise during MRI may both stimulate the vestibular organ. This study aimed to characterize the cortical activity during natural stimulation of the human vestibular organ. Two fluorodeoxyglucose (FDG)-PET scans were obtained after natural vestibular stimulation in a self-propelled chair. Two types of stimuli were applied: (a) rotation (horizontal semicircular canal) and (b) linear sideways movement (utriculus). A comparable baseline FDG-PET scan was obtained after sitting motion-less in the chair. In both stimulation paradigms, significantly increased FDG uptake was measured bilaterally in the medial part of Heschl's gyrus, with some overlap into the posterior insula. This is the first neuroimaging study to visualize cortical processing of natural vestibular stimuli. FDG uptake was demonstrated in the medial-most part of Heschl's gyrus, normally associated with the primary auditory cortex. This anatomical localization seems plausible, considering that the labyrinth contains both the vestibular organ and the cochlea.

Suppression head impulse paradigm in healthy adolescents - A novel variant of the head impulse test.

BACKGROUND: Suppression Head Impulse Paradigm (SHIMP), a novel variant of the Head Impulse Test has been introduced. At the same time, the Head Impulse Test was renamed to the Head Impulse Paradigm (HIMP). Contrary to HIMP saccades, SHIMP saccades are a sign of vestibular function. OBJECTIVE: 1) To compare SHIMP and HIMP feasibility, vestibular-ocular reflex (VOR) gain value and the saccadic pattern in healthy adolescents. 2) To compare SHIMP and HIMP feasibility in the hands of an experienced and an inexperienced HIMP examiner. METHOD: A total of 29 adolescents from Skåde Municipal School, Denmark were tested with HIMP and then with SHIMP. RESULTS: Neither covert nor overt saccades were observed in the HIMP, whereas SHIMP saccades were observed in all SHIMP reports. SHIMP gain values were statistically lower than HIMP gain values. A statistically significant difference was observed between the two examiners' right SHIMP gain values, but not for the left SHIMP gain values or the HIMP gain values. CONCLUSIONS: We found that HIMP and SHIMP tests are feasible in healthy adolescents for experienced as well as inexperienced examiners. However, one must be aware of potential pitfalls in the execution and interpretation of both tests. This is a well-known fact for the HIMP test, but additional considerations are needed to obtain reliable results from the SHIMP test.

The Use of Computer-Assisted Home Exercises to Preserve Physical Function after a Vestibular Rehabilitation Program: A Randomized Controlled Study.

Objective. The purpose of this study was to evaluate whether elderly patients with vestibular dysfunction are able to preserve physical functional level, reduction in dizziness, and the patient's quality of life when assistive computer technology is used in comparison with printed instructions. Materials and Methods. Single-blind, randomized, controlled follow-up study. Fifty-seven elderly patients with chronic dizziness were randomly assigned to a computer-assisted home exercise program or to home exercises as described in printed instructions and followed for tree month after discharge from an outpatient clinic. Results. Both groups had maintained their high functional levels three months after finishing the outpatient rehabilitation. No statistically significant difference was found in outcome scores between the two groups. In spite of moderate compliance levels, the patients maintained their high functional level indicating that the elderly should not necessarily exercise for the first three months after termination of the training in the outpatient clinic. Conclusion. Elderly vestibular dysfunction patients exercising at home seem to maintain their functional level, level of dizziness, and quality of life three months following discharge from hospital. In this specific setup, no greater effect was found by introducing a computer-assisted training program, when compared to standard home training guided by printed instructions. This trial is registered with NCT01344408.

Computer-assisted training as a complement in rehabilitation of patients with chronic vestibular dizziness--a randomized controlled trial.

OBJECTIVE: To compare a computer-assisted home exercise program with conservative home-training following printed instructions in the rehabilitation of elderly patients with vestibular dysfunction. DESIGN: Single-blind, randomized, controlled trial. SETTING: Geriatric department of a university hospital. PARTICIPANTS: Patients with chronic dizziness due to vestibular dysfunction (N=63) were randomly assigned to either rehabilitation in the clinic followed by computer-assisted home exercises (intervention group: n=32) or rehabilitation in the clinic followed by home exercises according to printed instructions (control group: n=31). INTERVENTIONS: Patients in the intervention group received assisted rehabilitation by a computer program. MAIN OUTCOME MEASURES: Measurements at baseline and at 8 and 16 weeks were compared. These included the One Leg Stand Test, Dynamic Gait Index, Chair Stand Test, Motion Sensitivity Test, Short Form-12, Dizziness Handicap Inventory, and visual analog scale. RESULTS: Both groups improved significantly during 16 weeks of rehabilitation. However, neither t tests nor repeated-measures analysis of variance demonstrated any significant differences between the 2 groups. The overall compliance rate to computer program exercises during 16 weeks was 57%. CONCLUSIONS: A computer-assisted program to support the home training of elderly patients with vestibular dysfunction did not improve rehabilitation more than did printed instructions.

Bacteremia during quinsy and elective tonsillectomy: an evaluation of antibiotic prophylaxis recommendations for patients undergoing tonsillectomy.

AIMS: Bacteremia during elective tonsillectomy is well recognized, whereas bacteremia during quinsy tonsillectomy has never been studied. The aim of the present study was to explore the incidence of bacteremia during elective and quinsy tonsillectomy in order to evaluate the antibiotic prophylaxis recommendations to patients at high risk of infective endocarditis who are undergoing tonsillectomy. METHODS: A prospective study was conducted on 80 patients undergoing elective tonsillectomy and 36 patients undergoing acute tonsillectomy due to peritonsillar abscess. Blood cultures, tonsillar swabs, core tissue, and pus aspirates were analyzed by standard microbiological techniques. RESULTS: Bacteremia was detected in 73% of patients during elective tonsillectomy compared to 56% during quinsy tonsillectomy (P = .089, Fishers exact test). Significantly more blood culture bottles were positive for each isolate obtained from elective tonsillectomy cases compared to quinsy tonsillectomy cases (P < .001, Spearman rank correlation). In all, 59% and 42% of electively and acutely tonsillectomized patients, respectively, had bacteremia with microorganisms that are predominant in bacterial endocarditis. Ninety-three percent of the isolated strains were sensitive to amoxicillin, and all were sensitive to amoxicillin with clavulanic acid. DISCUSSION: Our results challenge the distinction made by the European Society of Cardiology between elective and quinsy tonsillectomy, with regard to antibiotic prophylaxis recommendation only to patients undergoing procedures to treat an established infection. To provide full empiric coverage, including coverage for Staphylococcus aureus, we advocate the use of amoxicillin with clavulanic acid in patients at high risk of infective endocarditis.

Similar recovery rates of Fusobacterium necrophorum from recurrently infected and non-infected tonsils.

INTRODUCTION: Recent studies implicate the presence of Fusobacterium necrophorum (FN) in recurrent tonsillitis (RT), acute tonsillitis and peritonsillar abscess. The objective of the present study was to determine whether FN plays a role in RT by comparing bacteriologic results from patients suffering from RT, tonsillar hypertrophy and halitosis or persistent sore throat syndrome (PSTS). We analyzed both tonsils to determine the degree of concordance. MATERIAL AND METHODS: A prospective study was conducted in 80 patients aged 8-30 years who were undergoing elective tonsillectomy. The patients were divided into four groups according to indication for surgery. Aerobic and anaerobic cultures from the tonsillar surface and core were analyzed. RESULTS: FN was detected less frequently in the tonsillar cores of RT patients (22%) than in those of patients without RT (30%) (p=0.44). FN detection frequencies ranged between 20% and 35% across the four groups. Betahaemolytic streptococci groups A/C/G (BHS) were detected significantly (p=0.007) more often in the RT group than in the halitosis/PSTS group. CONCLUSION: A possible role of FN in RT was not substantiated. Our results indicate that FN is likely to be part of the normal flora. The tonsillar surface and core flora carry considerable interpersonal diversity, but is very similar bilaterally in each individual. Other factors seem to play a major role in the development of the represented tonsillar diseases. FUNDING: Not relevant. TRIAL REGISTRATION: The study was approved by The Research Ethics Committee of Aarhus County (no. 20050034).