Representation of Body Orientation in Vestibular-Defective Patients Before and After Unilateral Vestibular Loss.

Introduction: The unilateral vestibular syndrome results in postural, oculomotor, perceptive, and cognitive symptoms. This study was designed to investigate the role of vestibular signals in body orientation representation, which remains poorly considered in vestibular patients. Methods: The subjective straight ahead (SSA) was investigated using a method disentangling translation and rotation components of error. Participants were required to align a rod with their body midline in the horizontal plane. Patients with right vestibular neurotomy (RVN; n =8) or left vestibular neurotomy (LVN; n = 13) or vestibular schwannoma resection were compared with 12 healthy controls. Patients were tested the day before surgery and during the recovery period, 7 days and 2 months after the surgery. Results: Before and after unilateral vestibular neurotomy, i.e., in the chronic phases, patients showed a rightward translation bias of their SSA, without rotation bias, whatever the side of the vestibular loss. However, the data show that the lower the translation error before neurotomy, the greater its increase 2 months after a total unilateral vestibular loss, therefore leading to a rightward translation of similar amplitude in the two groups of patients. In the early phase after surgery, SSA moved toward the operated side both in translation and in rotation, as typically found for biases occurring after unilateral vestibular loss, such as the subjective visual vertical (SVV) bias. Discussion and Conclusion: This study gives the first description of the immediate consequences and of the recovery time course of body orientation representation after a complete unilateral vestibular loss. The overall evolution differed according to the side of the lesion with more extensive changes over time before and after left vestibular loss. It is noteworthy that representational disturbances of self-orientation were highly unusual in the chronic stage after vestibular loss and similar to those reported after hemispheric lesions causing spatial neglect, while classical ipsilesional biases were reported in the acute stage. This study strongly supports the notion that the vestibular system plays a major role in body representation processes and more broadly in spatial cognition. From a clinical point of view, SSA appeared to be a reliable indicator for the presence of a vestibular disorder.

Signs of spatial neglect in unilateral peripheral vestibulopathy.

BACKGROUND AND PURPOSE: In this study, the question of whether egocentric representation of space is impaired in chronic unilateral vestibulopathies was examined. The objective was to test current theories attributing a predominant role to vestibular afferents in spatial cognition and to assess whether representational neglect signs are common in peripheral vestibular loss. METHODS: The subjective straight-ahead (SSA) direction was investigated using a horizontal rod allowing the translation and rotation components of the body midline representation to be dissociated in 21 patients with unilateral vestibular loss (right, 13; left, eight) and in 12 healthy controls. RESULTS: Compared to the controls, the patients with unilateral vestibulopathy showed a translation bias of their SSA, without rotation bias. The translation bias was not lateralized towards the lesioned side as typically found for biases reported after unilateral vestibular loss. Rather, the SSA bias was rightward whatever the side of the vestibular loss. The translation bias correlated with the vestibular loss, as measured by caloric response and vestibulo-ocular reflex gain, but not with the subjective visual vertical or the residual spontaneous nystagmus. CONCLUSION: The present data suggest that the dysfunctions of neural networks involved in egocentred and allocentred representations of space are differentially compensated for in unilateral vestibular defective patients. In particular, they suggest that asymmetrical vestibular inputs to cortical regions lead to representational spatial disturbances as does defective cortical processing of vestibular inputs in spatial neglect after right hemisphere stroke. They also highlight the predominant role of symmetrical and unaltered vestibular inputs in spatial cognition.

Intracanalicular Vestibular Schwannomas: Initial Clinical Manifestation, Imaging Classification, and Risk Stratification for Management Proposal.

INTRODUCTION: There is no consensus about the use of observation as a therapeutic modality for intracanalicular vestibular schwannoma (ICVS). The objective of this study was to describe tumor evolution, its correlation with initial size, stage of vestibular schwannoma, clinical presentation and to propose a risk classification for tumor growth with a therapeutic decision algorithm. METHODS: Fifty-three patients with ICVS were followed prospectively from 2010 to 2015. The mean follow-up was 32 months. Patients underwent clinical examination, audiogram, magnetic resonance imaging at 6, 12, and then 12 months intervals within the first 5 years of initial diagnosis. We analyzed the patient's clinical course, audiologic changes, initial tumor location, and correlation of different parameters with ICVS growth. RESULTS: Fourteen patients (26%) deteriorated their hearing level and 17 patients (27%) showed tumor growth during the follow-up period. Growth was noted during the first year of observation in 13 patients (76.5%). Considering initial presentation: tumor size, intracanalicular staging, and hearing level, patients with larger vestibular schwannoma, extension to the fundus regardless of tumor size, higher initial pure-tone average, and speech recognition test showed a significantly higher rate of tumor growth. ICVS evolution was not correlated with hearing deterioration with time. DISCUSSION: We should consider observation a therapeutic modality. We valid the intrameatal staging as prognostic factor and propose a stratification of patients into low, moderate, or high risk for potential tumor growth to guide the initial management of ICVS.

Prenatal diagnosis of congenital dacryocystocele.

Congenital bilateral dacryocystocele was diagnosed prenatally by ultrasonography in 3 female fetuses at 32.5 weeks gestation. After birth, first baby developed respiratory distress and was treated with endoscopic marsupialization of the cysts; the second baby had no respiratory symptoms and had spontaneous resolution of the cysts without surgery. The last one was expected to have a left dacryocystocele in US but the clinical examination after birth showed a bilateral lesion, with predominance on the right side and underwent an endoscopic marsupialization for nasal obstruction. Prenatal diagnosis with ultrasonography facilitated the education of the mothers and staff and helped minimize the risk of potential complications.