1,720,968 research outputs found
Residual dizziness after the first BPPV episode: role of otolithic function and of a delayed diagnosis
No full textResidual dizziness (RD) following the resolution of a benign paroxysmal positional vertigo (BBPV) episode is frequently reported by patients. Possible causes are still under debate in the literature. This study discusses the possible role of otolithic function and of elapsed time from onset of symptoms to diagnosis in the genesis of RD. In total, 116 patients younger than 65 years with their first episode of BPPV and without any other comorbidities were enrolled in the study. Before a bedside examination, subjective visual vertical (SVV) was determined in the case of a history suggestive of BPPV. SVV was tested 1 week later in those patients with BPPV of the posterior semicircular canal, and in whom positioning maneuvers showed resolution of BPPV. At 1 week control, reported RD and Dizziness Handicap Inventory (DHI) were recorded. Diagnosis and treatment of BPPV occurred within 4 days in 43 patients (group A), between 5 and 8 days in 38 patients (group B) and in more than 9 days in 35 patients (group C). Higher values of reported RD and DHI were recorded in group C, while higher values of SVV deviation were recorded in group A with an inverse relationship between SVV and DHI. Initial peripheral vestibular function asymmetry due to BPPV can induce a new central adaptation. This adaptation becomes better established the longer otoconia remain floating in the endolymph. Because of these changes, the brain is unable to quickly readapt to the old pattern after resolution resulting in more persistent RD
Loop characteristics and audio-vestibular symptoms or hemifacial spasm: is there a correlation? A multiplanar MRI study
No full textWe investigated if loop characteristics correlate with audio-vestibular symptoms or hemifacial spasm in patients with a vascular loop in the root entry zone (VII and VIII) and in the internal auditory canal
Self-motion perception and vestibulo-ocular reflex during whole body yaw rotation in standing subjects: the role of head position and neck proprioception
No full textSelf-motion perception and vestibulo-ocular reflex (VOR) were studied during whole body yaw rotation in the dark at different static head positions. Rotations consisted of four cycles of symmetric sinusoidal and asymmetric oscillations. Self-motion perception was evaluated by measuring the ability of subjects to manually track a static remembered target. VOR was recorded separately and the slow phase eye position (SPEP) was computed. Three different head static yaw deviations (active and passive) relative to the trunk (0°, 45° to right and 45° to left) were examined. Active head deviations had a significant effect during asymmetric oscillation: the movement perception was enhanced when the head was kept turned toward the side of body rotation and decreased in the opposite direction. Conversely, passive head deviations had no effect on movement perception. Further, vibration (100 Hz) of the neck muscles splenius capitis and sternocleidomastoideus remarkably influenced perceived rotation during asymmetric oscillation. On the other hand, SPEP of VOR was modulated by active head deviation, but was not influenced by neck muscle vibration. Through its effects on motion perception and reflex gain, head position improved gaze stability and enhanced self-motion perception in the direction of the head deviation
Different time course of compensation of subjective visual vertical and ocular torsion after acute unilateral vestibular lesion
No full textPurpose Time course of the recovery of otolithic dis-function caused by superior vestibular neuritis has been examined in fifteen patients. Methods The subjective visual vertical (SVV) and the ocular cyclotorsion (OT) have been measured four times after the acute episode up to 1 year Results In most of the patients the SVV tilt returned to control values within few months (3-6 months) after the acute episode, while OT remained out of normal range in almost all patients a year later. Conclusion The abnormal OT observed after 1 year from the acute episode of vestibular neuritis, suggests that the otolithic receptors remained altered for several months and the OT may be a good indicator of the entity of the residual peripheral otolithic lesion. Moreover, the dissociation between the SVV tilt recovery and that of OT supports the issue that the two signs of the otolithic disfunction are only partially linked each other with centrally or peripherally distinct re-balancing circuits
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Balance control impairment induced after OKS in patients with vestibular migraine: an intercritical marker
No full textThe aim of the study was to assess the effects of optokinetic stimulation (OKS) on vestibular postural control in migraine patients with recurrent vertigo. 15 patients with vestibular migraine (VM) were enrolled in a posturographic study in eyes open (OE) and eyes closed (CE) condition. The tests were performed between attacks of headache and vertigo at three different time: before, during, and 60 min after OKS. Data of patients with VM were compared with those obtained from two control groups matched for sex and age (15 for each group): (a) normal subjects not suffering from migraine without history of recurrent vertigo (N group); (b) subjects suffering from migraine with no history of recurrent vertigo (M group). Mean sway path velocity and sway area were analyzed. OKS increased the instability in all groups during the stimulus, and both the velocity and area values were higher in M and VM group. However, there was not significant difference between these two groups when stability was examined in OE condition before, during and after OKS stimulation. Conversely, in CE condition a significant greater instability was induced after OKS stimulation only in VM. In particular, post-stimulus values were significantly higher than the pre-stimulus one only in this group, while no significant difference was observed in other groups. A spatial analysis of the sway area evidenced that the instability induced by the OKS in VM group occurred along the direction of OKS. We suggest that this enhanced instability observed after OKS during the intercritical period may be considered an useful marker to support the diagnostic definition of VM in the absence of other vestibular signs
Downbeat nystagmus: a clinical and pathophysiological review
Full text linkDownbeat nystagmus (DBN) is a neuro-otological finding frequently encountered by clinicians dealing with patients with vertigo. Since DBN is a finding that should be understood because of central vestibular dysfunction, it is necessary to know how to frame it promptly to suggest the correct diagnostic-therapeutic pathway to the patient. As knowledge of its pathophysiology has progressed, the importance of this clinical sign has been increasingly understood. At the same time, clinical diagnostic knowledge has increased, and it has been recognized that this sign may occur sporadically or in association with others within defined clinical syndromes. Thus, in many cases, different therapeutic solutions have become possible. In our work, we have attempted to systematize current knowledge about the origin of this finding, the clinical presentation and current treatment options, to provide an overview that can be used at different levels, from the general practitioner to the specialist neurologist or neurotologist
The integration of multisensory motion stimuli is impaired in vestibular migraine patients
No full textBackground Vestibular migraine (VM) is a relatively recently acknowledged vestibular syndrome with a very relevant prevalence of about 10% among patients complaining of vertigo. The diagnostic criteria for VM have been recently published by the Barany Society, and they are now included in the latest version of the International Classification of Headache Disorders, yet there is no instrumental test that supports the diagnosis of VM. Objective In the hypothesis that the integration of different vestibular stimuli is functionally impaired in VM, we tested whether the combination of abrupt vestibular stimuli and full-field, moving visual stimuli would challenge vestibular migraine patients more than controls and other non-vestibular migraineurs. Methods In three clinical centers, we compared the performance in the functional head impulse test (fHIT) without and with an optokinetic stimulus rotating in the frontal plane in a group of 44 controls (Ctrl), a group of 42 patients with migraine (not vestibular migraine, MnoV), a group of 39 patients with vestibular migraine (VM) and a group of 15 patients with vestibular neuritis (VN). Results The optokinetic stimulation reduced the percentage of correct answers (Ê) in all groups, and in about 33% of the patients with migraine, in as many as 87% of VM patients and 60% of VN patients, this reduction was larger than expected from controls' data. Conclusions The comparison of the fHIT results without and with optokinetic stimulation unveils a functional vestibular impairment in VM that is not as large as the one detectable in VN, and that, in contrast with all the other patient groups, mainly impairs the capability to integrate different vestibular stimuli
Reliability of an anamnestic questionnaire for the diagnosis of benign paroxysmal positional vertigo in the elderly
No full textBackground: There is common agreement in the literature that it can result in an underestimation of benign paroxysmal positional vertigo (BPPV) in the elderly. Aims: The aim of this work was to analyze the role of anamnesis in the diagnosis of BPPV in patients of different ages through the development and validation of a scored questionnaire. Methods: The questionnaire is based on the presence/absence of six typical anamnestic features of BPPV. The Mini-Mental State Exam (MMS) was also administered to patients over 65 years of age. Bedsides, examination for BPPV was then carried out, assigning the outcome of the questionnaire and eventual MMS to the final diagnosis for each patient. Results: The sensitivity and specificity of the questionnaire for high scores (>8) were found to be, respectively, 86 % and 80 % in all patients, 94 and 71 % in those under 65 years of age, 78 and 90 % in patients over 65, and, in particular, 63 and 83 % in those with MMS >24 and 100 and 100 % in those with MMS ≤24. Discussion: The reliability and average score of the questionnaire were statistically significantly lower in the group of elderly patients without cognitive deficits. The lower reliability of the questionnaire in the geriatric population, rather than the presence of cognitive deterioration, seems to correlate with other comorbidities or simply to a lower mobility of the head triggering positional symptoms. Conclusion: The use of the questionnaire could however reduce the risk of a missed diagnosis of BPPV given its good reliability across all ages
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