Selective asymmetry of ocular vestibular-evoked myogenic potential in patients with acute utricular macula loss

OBJECTIVES: We retrospectively evaluated a chart review of 3,525 patients evaluated for any acute disturbance. A total of 1,504 patients with acute vestibular syndrome (AVS) received an instrumental vestibular assessment within 72 h from the onset of the symptoms evaluated using simultaneously a combination of ocular vestibular-evoked myogenic potential (oVEMPs), cervical vestibular-evoked myogenic potential (cVEMPs), video head-impulse test (vHIT), and subjective visual vertical (SVV) were included in this study. MATERIALS and METHODS: A total of 41 patients with AVS that showed a normal horizontal canal function tested with vHIT, a normal cVEMP function, unilaterally reduced or absent oVEMP n10, and an altered SVV were enrolled. RESULTS: We found that although these patients referred acute vertigo and presented spontaneous nystagmus, they showed physiological values of vHIT and a normal saccular function, as shown by symmetrical cVEMPs. CONCLUSION: Our findings support the hypothesis that a percentage of patients evaluated during an AVS using an instrumental vestibular assessment could present selective utricular macula dysfunction

Editorial: Gaze and postural stability rehabilitation

Proprioceptive, Visual, Vestibular, and Cognitive systems interact in a continuous sensorial re-weighting, ensuring gaze and postural control (1, 2). The central nervous system integrates the information originating from these systems into a continuous sensorial re-weighting that ensures postural control in both static and dynamic conditions (3, 4). The contribution of each sensory system changes depending on environmental conditions and the motor task performed by the person (5–7). To tailor a rehabilitative program for patients with gaze and postural stability disorders, a multidimensional assessment is required. A wide range of both clinical and instrumental evaluations could be performed before the rehabilitative approach in order to obtain quantitative and qualitative information about the patient's balance and gait disorders, supporting the rehabilitative staff in designing the most suitable therapeutic intervention. Instrumental assessment of the vestibular system has made significant progress in recent years. Two protocol tests are available in the clinical practice to evaluate the Vestibular Ocular Reflex (VOR) function through the use of Video Head Impulse Test (vHIT): Head Impulse Paradigm (HIMP) and Suppression Head Impulse Paradigm (SHIMP) (8–10). The head turn stimulus and the eye movement recording are identical. All that is changed are the instructions—from “look at that fixed target on the wall” to “look at the moving target.” At the same time, vestibular-evoked myogenic potentials are the most suitable test to evaluate otolith functions in patients with unilateral vestibular hypofunction in the acute and sub-acute phase

First report of Scolothrips dilongicornis (Thys.: Thripidae) from Iran

در بررسی فونستیک بال‏ریشک‏داران استان خراسان رضوی طی سال‎‏های‌1391-92، نمونه‏هایی متعلق به گونه‌Scolothrips dilongicornis Han & Zhang, 1982 جمع‏آوری و شناسایی شد. این گونه برای اولین‌بار از ایران گزارش می‌شود و به‌این‌ترتیب تعداد گونه‌های جنس Scolothrips Hinds در ایران به چهار عدد می‌رسد

Video Suppression Head Impulses and Head Impulses Paradigms in Patients with Vestibular Neuritis: A Comparative Study

Background: This study aims to explore the clinical relevance of the Suppression Head Impulse Paradigm (SHIMP) to better understand if it represents an additional clinical value compared to the Head Impulse Paradigm (HIMP) in patients with vestibular neuritis (VN) in different stages of the disease. Methods: From January 2020 to June 2022, patients with unilateral VN were found in a database of an ENT vestibular clinic. Clinical presentation, vestibular test outcomes, therapy, and recovery were examined in medical records. Results: A total of 42 patients (16 Females, mean age 51.06 ± 12.96; 26 Male, mean age 62.50 ± 9.82) met the inclusion criteria and were enrolled in the study. The means of the VOR gain for both paradigms were respectively 0.38 ± 0.12 (SHIMP) and 0.46 ± 0.13 (HIMP) at T0 and 0.55 ± 0.20 (SHIMP) and 0.64 ± 0.19 (HIMP) at T1 for the lesional side. For the HIMP, the gain value <0.76 identified the affected side of VN with 100% sensitivity (92–100) and 100% specificity (91–100). For the SHIMP, the gain value <0.66 identified the affected side of VN with 100% sensitivity (92–100) and 100% specificity (91–100) and an AUC of 1.0 (0.96–1.0, p < 0.0001). Conclusion: The SHIMP paradigm has a diagnostic accuracy equal to the classic HIMP paradigm in patients with VN. The assessment of VOR slow phase velocity and vestibulo-saccadic interaction in patients with VN could be easier with the use of the SHIMPs paradigm. SHIMPs paradigm provides helpful information about the evaluation of VOR slow phase velocity and vestibulo-saccadic interaction as new recovery strategies in patients with VN

Otolithic receptor mechanisms for vestibular-evoked myogenic potentials: A review

Air-conducted sound and bone-conduced vibration activate otolithic receptors and afferent neurons in both the utricular and saccular maculae, and trigger small electromyographic (EMG) responses [called vestibular-evoked myogenic potentials (VEMPs)] in various muscle groups throughout the body. The use of these VEMPs for clinical assessment of human otolithic function is built on the following logical steps: (1) that high-frequency sound and vibration at clinically effective stimulus levels activate otolithic receptors and afferents, rather than semicircular canal afferents, (2) that there is differential anatomical projection of otolith afferents to eye muscles and neck muscles, and (3) that isolated stimulation of the utricular macula induces short latency responses in eye muscles, and that isolated stimulation of the saccular macula induces short latency responses in neck motoneurons. Evidence supports these logical steps, and so VEMPs are increasingly being used for clinical assessment of otolith function, even differential evaluation of utricular and saccular function. The proposal, originally put forward by Curthoys in 2010, is now accepted: that the ocular vestibular-evoked myogenic potential reflects predominantly contralateral utricular function and the cervical vestibular-evoked myogenic potential reflects predominantly ipsilateral saccular function. So VEMPs can provide differential tests of utricular and saccular function, not because of stimulus selectivity for either of the two maculae, but by measuring responses which are predominantly determined by the differential neural projection of utricular as opposed to saccular neural information to various muscle groups. The major question which this review addresses is how the otolithic sensory system, with such a high density otoconial layer, can be activated by individual cycles of sound and vibration and show such tight locking of the timing of action potentials of single primary otolithic afferents to a particular phase angle of the stimulus cycle even at frequencies far above 1,000 Hz. The new explanation is that it is due to the otoliths acting as seismometers at high frequencies and accelerometers at low frequencies. VEMPs are an otolith-dominated response, but in a particular clinical condition, semicircular canal dehiscence, semicircular canal receptors are also activated by sound and vibration, and act to enhance the otolith-dominated VEMP responses

The effect of vestibular stimulation on motor functions of children with cerebral palsy

Background: Cerebral palsy (CP) has been defined as a nonprogressive disease of movement and posture development. Physical therapy techniques use different forms of sensory stimulation to improve neuromotor development. Aim: The aim of this study was to assess the efficacy of a vestibular stimulation training in improving motor functions in cerebral palsy. Population: Fourteen children with CP were randomly separated into two different groups in a cross-over trial. Methods: Over a period of 10 weeks, each group performed 10 sessions of 50 min of neurodevelopmental treatment (NDT) and 10 sessions of vestibular training (VR). Children were evaluated with the Gross Motor Function Measurement-88 scale, the Goal Attainment Scale and the root mean square of head accelerations. Results: A significant improvement in the GAS-score (p =.003) was noted after NDT+VR. Conclusions: Vestibular stimulation integrated with NDT proved to be an effective complementary strategy for facilitating motor functioning

Meniere's disease and the use of proton pump inhibitors.

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