Out-of-Body Experiences and Other Complex Dissociation Experiences in a Patient with Unilateral Peripheral Vestibular Damage and Deficient Multisensory Integration

Out-of-body experiences (OBEs) are illusory perceptions of one's body from an elevated disembodied perspective. Recent theories postulate a double disintegration process in the personal (visual, proprioceptive and tactile disintegration) and extrapersonal (visual and vestibular disintegration) space as the basis of OBEs. Here we describe a case which corroborates and extends this hypothesis. The patient suffered from peripheral vestibular damage and presented with OBEs and lucid dreams. Analysis of the patient's behaviour revealed a failure of visuo-vestibular integration and abnormal sensitivity to visuo-tactile conflicts that have previously been shown to experimentally induce out-of-body illusions (in healthy subjects). In light of these experimental findings and the patient's symptomatology we extend an earlier model of the role of vestibular signals in OBEs. Our results advocate the involvement of subcortical bodily mechanisms in the occurrence of OBEs.

A influência da reeducação vestibular nas medidas objetivas e subjetivas em pacientes com défice vestibular periférico unilateral

Mestrado em Fisioterapia.

Névrite vestibulaire: traitement et pronostic [Vestibular neuritis: treatment and prognosis].

Vestibular neuritis is a sudden unilateral peripheral vestibular deficit of unknown origin without associated hearing loss. It is the second cause of peripheral vertigo after Benign Paroxysmal Positional Vertigo (BPPV). The etiology remains unclear and some treatments are still controversial. The prognosis is good. The differential diagnosis of the disease mainly includes an acute vertigo of central origin. This article summarizes the management and prognosis of vestibular neuritis.

The effect of virtual reality on visual vertigo symptoms in patients with peripheral vestibular dysfunction: a pilot study.

Individuals with vestibular dysfunction may experience visual vertigo (VV), in which symptoms are provoked or exacerbated by excessive or disorientating visual stimuli (e.g. supermarkets). VV can significantly improve when customized vestibular rehabilitation exercises are combined with exposure to optokinetic stimuli. Virtual reality (VR), which immerses patients in realistic, visually challenging environments, has also been suggested as an adjunct to VR to improve VV symptoms. This pilot study compared the responses of sixteen patients with unilateral peripheral vestibular disorder randomly allocated to a VR regime incorporating exposure to a static (Group S) or dynamic (Group D) VR environment. Participants practiced vestibular exercises, twice weekly for four weeks, inside a static (Group S) or dynamic (Group D) virtual crowded square environment, presented in an immersive projection theatre (IPT), and received a vestibular exercise program to practice on days not attending clinic. A third Group D1 completed both the static and dynamic VR training. Treatment response was assessed with the Dynamic Gait Index and questionnaires concerning symptom triggers and psychological state. At final assessment, significant betweengroup differences were noted between Groups D (p = 0.001) and D1 (p = 0.03) compared to Group S for VV symptoms with the former two showing a significant 59.2% and 25.8% improvement respectively compared to 1.6% for the latter. Depression scores improved only for Group S (p = 0.01) while a trend towards significance was noted for Group D regarding anxiety scores (p = 0.07). Conclusion: Exposure to dynamic VR environments should be considered as a useful adjunct to vestibular rehabilitation programs for patients with peripheral vestibular disorders and VV symptoms.

The effect of virtual reality on visual vertigo symptoms in patients with peripheral vestibular dysfunction: a pilot study

Individuals with vestibular dysfunction may experience visual vertigo (VV), in which symptoms are provoked or exacerbated by excessive or disorientating visual stimuli (e.g. supermarkets). VV can significantly improve when customized vestibular rehabilitation exercises are combined with exposure to optokinetic stimuli. Virtual reality (VR), which immerses patients in realistic, visually challenging environments, has also been suggested as an adjunct to VR to improve VV symptoms. This pilot study compared the responses of sixteen patients with unilateral peripheral vestibular disorder randomly allocated to a VR regime incorporating exposure to a static (Group S) or dynamic (Group D) VR environment. Participants practiced vestibular exercises, twice weekly for four weeks, inside a static (Group S) or dynamic (Group D) virtual crowded square environment, presented in an immersive projection theatre (IPT), and received a vestibular exercise program to practice on days not attending clinic. A third Group D1 completed both the static and dynamic VR training. Treatment response was assessed with the Dynamic Gait Index and questionnaires concerning symptom triggers and psychological state. At final assessment, significant betweengroup differences were noted between Groups D (p = 0.001) and D1 (p = 0.03) compared to Group S for VV symptoms with the former two showing a significant 59.2% and 25.8% improvement respectively compared to 1.6% for the latter. Depression scores improved only for Group S (p = 0.01) while a trend towards significance was noted for Group D regarding anxiety scores (p = 0.07). Conclusion: Exposure to dynamic VR environments should be considered as a useful adjunct to vestibular rehabilitation programs for patients with peripheral vestibular disorders and VV symptoms.

Diagnostic value of vestibulo-ocular reflex parameters in the detection and characterization of labyrinthine lesions.

OBJECTIVE: To evaluate the power of various parameters of the vestibulo-ocular reflex (VOR) in detecting unilateral peripheral vestibular dysfunction and in characterizing certain inner ear pathologies. STUDY DESIGN: Prospective study of consecutive ambulatory patients presenting with acute onset of peripheral vertigo and spontaneous nystagmus. SETTING: Tertiary referral center. PATIENTS: Seventy-four patients (40 females, 34 males) and 22 normal subjects (11 females, 11 males) were included in the study. Patients were classified in three main diagnoses: vestibular neuritis: 40; viral labyrinthitis: 22; Meniere's disease: 12. METHODS: The VOR function was evaluated by standard caloric and impulse rotary tests (velocity step). A mathematical model of vestibular function was used to characterize the VOR response to rotational stimulation. The diagnostic value of the different VOR parameters was assessed by uni- and multivariable logistic regression. RESULTS: In univariable analysis, caloric asymmetry emerged as the most powerful VOR parameter in identifying unilateral vestibular deficit, with a boundary limit set at 20%. In multivariable analysis, the combination of caloric asymmetry and rotational time constant asymmetry significantly improved the discriminatory power over caloric alone (p<0.0001) and produced a detection score with a correct classification of 92.4%. In discriminating labyrinthine diseases, different combinations of the VOR parameters were obtained for each diagnosis (p<0.003) supporting that the VOR characteristics differ between the three inner ear disorders. However, the clinical usefulness of these characteristics in separating the pathologies was limited. CONCLUSION: We propose a powerful logistic model combining the indices of caloric and time constant asymmetries to detect a peripheral vestibular loss, with an accuracy of 92.4%. Based on vestibular data only, the discrimination between the different inner ear diseases is statistically possible, which supports different pathophysiologic changes in labyrinthine pathologies.

Potencial evocado auditivo para diagnóstico de surdez em gato com síndrome vestibular periférica

The brainstem auditory evoked potential is an electrodiagnostic test that allows a functional assessment of the auditory pathways from the middle ear to the brainstem. This test, in veterinary medicine, is not commonly used in Brazil. This paper reports the use of auditory evoked potential for deafness detection in a cat with unilateral peripheral vestibular syndrome secondary to otitis media.

Static postural balance study in patients with vestibular disorders using a three dimensional eletromagnetic sensor system

The vestibular-ocular reflex assessment is important, but not enough. Tridimensional electromagnetic sensor systems represent a new method to assess posturography. Aim: To assess body sway in healthy subjects who had positive Dix Hallpike and Epley maneuvers and with other vestibular dysfunctions by means of a three-dimensional system. Study design: Prospective. Materials and Methods: We had 23 healthy women, 15 with peripheral vestibular dysfunction found upon caloric test and 10 with positive Epley and Dix Hallpike maneuvers. All tests performed in the following positions: open and closed eyes on stable and unstable surfaces. Results: With the Eyes Open and on a stable surface, p < 0.01 between the control group and the one with peripheral vestibular dysfunction in all variables, except the a-p maximum, full speed and mediolateral trajectory velocity, which had a p < 0.01 between the group with vestibular dysfunction and controls in all positions. The group with positive Epley and Dix Hallpike maneuvers had p < 0.01 at full speed and in its components in the x and y in positions with open and eyes closed on an unstable surface. Conclusion: The tridimensional electromagnetic sensors system was able to generate reliable information about body sway in the study volunteers.

Vestibular deficits do not underlie looping behavior in achiasmatic fish

Zebrafish belladonna (bel) mutants carry a mutation in the lhx2 gene that encodes a Lim domain homeobox transcription factor, leading to a defect in the retinotectal axon pathfinding. As a result, a large fraction of homozygous bel mutants is achiasmatic. Achiasmatic bel mutants display ocular motor instabilities, both reserved optokinetic response (OKR) and spontaneous eye oscillations, and an unstable swimming behavior, described as looping. All these unstable behaviors have been linked to the underlying optic nerve projection defect. Looping has been investigated under different visual stimuli and shown to be vision dependent and contrast sensitive. In addition, looping correlates perfectly with reversed OKR and the spontaneous oscillations of the eyes. Hence, it has been hypothesized that looping is a compensatory response to the perception of self-motion induced by the spontaneous eye oscillations. However, both ocular and postural instabilities could also be caused by a yet unidentified vestibular deficit. Here, we performed a preliminary test of the vestibular function in achiasmatic bel larval mutants in order to clarify the potential role of a vestibular deficit in looping. We found that the vestibular ocular reflex (VOR) is normally directed in both bel mutants and wild types and therefore exclude the possibility that nystagmus and looping in reverse to the rotating optokinetic drum can be attributed to an underlying vestibular deficit.

Fabry's disease: otoneurologic findings in twelve members of one family

Fabry's disease corresponds to an inherited disorder transmitted by an X-linked recessive gene. It generates a dysfunction of glycosphingolipid metabolism due to an enzymatic deficiency of alpha-galactosidase activity, resulting in glycosphingolipid deposits in all areas of the body. The clinical (heart, kidney, and central nervous system) manifestations are more severe in hemizygous boys than in heterozygous girls. They appear during childhood or adolescence: acroparesthesia, joint pain, angiokeratoma, corneal dystrophy, hypohydrosis or anhydrosis, and renal failure. The otoneurologic symptoms consist of hearing fluctuation, progressive unilateral or bilateral hearing loss, and episodes of vertigo or dizziness. Otoneurologic findings in 12 of 26 members of the same family are presented: the mother and 9 of her 12 children, as well as 2 of her 14 grandchildren: 4 healthy persons, 4 heterozygous female carriers, and 4 hemizygous male patients. Three of the male patients had fluctuation of hearing, sudden hearing loss, and episodes of vertigo and dizziness. The otoneurologic examinations showed a bilateral cochleovestibular deficit (n = 1), a right cochleovestibular deficit (n = 1), and a bilateral hearing loss combined with a right vestibular deficit (n = 1). Histopathologic evidence of glycosphingolipid accumulation in vascular endothelial and ganglion cells, as well as atrophy of the stria and spiral ligament, might explain the otoneurologic symptoms and findings.

An unusual stroke-like clinical presentation of Creutzfeldt-Jakob disease: acute vestibular syndrome

INTRODUCTION Vertigo and dizziness are common neurological symptoms in general practice. Most patients have benign peripheral vestibular disorders, but some have dangerous central causes. Recent research has shown that bedside oculomotor examinations accurately discriminate central from peripheral lesions in those with new, acute, continuous vertigo/dizziness with nausea/vomiting, gait unsteadiness, and nystagmus, known as the acute vestibular syndrome. CASE REPORT A 56-year-old man presented to the emergency department with acute vestibular syndrome for 1 week. The patient had no focal neurological symptoms or signs. The presence of direction-fixed, horizontal nystagmus suppressed by visual fixation without vertical ocular misalignment (skew deviation) was consistent with an acute peripheral vestibulopathy, but bilaterally normal vestibuloocular reflexes, confirmed by quantitative horizontal head impulse testing, strongly indicated a central localization. Because of a long delay in care, the patient left the emergency department without treatment. He returned 1 week later with progressive gait disturbance, limb ataxia, myoclonus, and new cognitive deficits. His subsequent course included a rapid neurological decline culminating in home hospice placement and death within 1 month. Magnetic resonance imaging revealed restricted diffusion involving the basal ganglia and cerebral cortex. Spinal fluid 14-3-3 protein was elevated. The rapidly progressive clinical course with dementia, ataxia, and myoclonus plus corroborative neuroimaging and spinal fluid findings confirmed a clinicoradiographic diagnosis of Creutzfeldt-Jacob disease. CONCLUSIONS To our knowledge, this is the first report of an initial presentation of Creutzfeldt-Jacob disease closely mimicking vestibular neuritis, expanding the known clinical spectrum of prion disease presentations. Despite the initial absence of neurological signs, the central lesion location was differentiated from a benign peripheral vestibulopathy at the first visit using simple bedside vestibular tests. Familiarity with these tests could help providers prevent initial misdiagnosis of important central disorders in patients presenting vertigo or dizziness.

Conduct after Epley`s maneuver in elderly with posterior canal BPPV in the posterior canal

Benign Paroxysmal Positional Vertigo is the most common peripheral vestibular disorder, especially in the elderly and presents as the predominant etiology in this population of the degeneration of the utricular macula. Aim: To compare the effectiveness of the approaches after Epley maneuver. Study Design: longitudinal cohort. Materials and Methods: The study included 53 volunteers with Benign Paroxysmal Positional Vertigo of the posterior semicircular canal, divided into Group 1, who underwent Epley maneuver associated with the use of neck collar and post-maneuver instructions, Group 2 underwent the Epley maneuver without the use cervical collar and/or post-maneuver restrictions, and Group 3 underwent the Epley maneuver associated with the use of a mini vibrator, without the use of neck collar and/or post-maneuver restrictions. Results: In the three groups, the number of Epley maneuvers ranged from one to three. We employed the Brazilian Dizziness Handicap Inventory - pre- and post-treatment and observed a statistically significant difference on most scores pre- and post-treatment for both groups. Conclusion: Regardless of the post Epley maneuver treatment selected for the treatment of Benign Paroxysmal Positional Vertigo, it was effective when comparing the Brazilian Dizziness Handicap Inventory pre- and post-treatment.

Reparação Híbrida do Arco Aórtico: Experiência Inicial do Hospital de Santa Marta

Objectives: To retrospectively review the hybrid treatment of the aortic arch with supra-aortic debranching and endo- vascular stent-graft repair in a single institution. Methods: From 2007 to 2010, all patients submitted to aortic debranching procedures were entered into a prospective database analysis. For the present study, only patients with sealing zones 0 and 1, according to the Ishimaru classification, were included. Procedure-related morbimortality was analysed for the open and endovascular procedures. Results: During the study period, we electively performed 6 total aortic debranching and 4 partial aortic debranching procedures in 10 patients. According to the etiology the indications were: 6 aortic arch aneurysms, 2 post-dissection aneu- rysms, 1 false aneurysm and 1 type I endoleak following TEVAR. The proximal sealing zone was Ishimaru zone 0 in six patients and zone 1 in four patients. The TEVAR procedure was delayed in all patients with a completion success of 80% (1 patient died from ruptured aortic aneurysm; 1 patient denied the second procedure and was lost to follow-up). The 30d mortality rate was 10% (patient mentioned above). The main morbidity was: 1 axillar venous thrombosis, 1 case of subclinical myocardial infarction, 1 case of terminal renal insufficiency and 1 case of prolonged ventilation. No permanent cerebral or peripheral neurologic deficit was noted. Conclusions: The hybrid repair of the aortic arch is a feasible and reproducible procedure, and our results are similar to the previously published series. Medium and long-term results are necessary to confirm whether the technique can be regarded as a safe alternative to open surgery in high-risk patients.

Clinical evaluation of the bicoronal flap in the treatment of facial fractures. Retrospective study of 132 patients

The aim of the present study was to evaluate the postoperative complications of bicoronal flaps used to treat facial fractures. One hundred and thirty two patients that received bicoronal flaps for the treatment of upper and middle third facial fractures were called for clinical and radiographic examination. Minimum follow-up was 1 year and all patients had charts with adequate information about their perioperative care pertinent to the study. Results showed as complications hypoesthesia (17%), partial unilateral frontal motor deficit (11%), infection (3%), hypertrophic scars (3%), varying degrees of alopecia (18%), seroma or hematoma in the immediate postoperative period (5%). The flap provided wide surgical access to the upper and middle facial thirds with very few serious complications, most frequently allowing good aesthetic results. (C) 2011 European Association for Cranio-Maxillo-Facial Surgery.

Clinical evaluation of the bicoronal flap in the treatament of facial fractures: retrospective study of 132 patients

The aim of the present study was to evaluate the postoperative complications of bicoronal flaps used to treat facial fractures. One hundred and thirty two patients that received bicoronal flaps for the treatment of upper and middle third facial fractures were called for clinical and radiographic examination. Minimum follow-up was 1 year and all patients had charts with adequate information about their perioperative care pertinent to the study. Results showed as complications hypoesthesia (17%), partial unilateral frontal motor deficit (11%), infection (3%), hypertrophic scars (3%), varying degrees of alopecia (18%), seroma or hematoma in the immediate postoperative period (5%). The flap provided wide surgical access to the upper and middle facial thirds with very few serious complications, most frequently allowing good aesthetic results.