Search Results (15)

Introduction and Objectives: Skull vibration-induced nystagmus (SVIN) has become a validated tool for evaluating the vestibular function. The presence of SVIN is a useful indicator of the asymmetry of vestibular function between the two ears. In unilateral vestibular loss, a 100 Hz bone-conducted vibration given to either mastoid immediately causes a primarily horizontal nystagmus. The aim of this study is to review the usefulness of this tool in different clinical situations according to the results published. Methods: We performed an electronic search using PubMed and BVS. Eleven studies were discussed. Results: A progressive linear relationship has been identified between the slow-phase velocity (SPV) of SVIN determined using a 100 Hz skull vibrator and the gain difference (healthy ear/affected ear) measured by video head impulse test (vHIT). The SPV of SVIN may be more sensitive than vHIT in identifying the recovery of vestibular function following intratympanic gentamicin (ITG) administration. A link between a reduction in SPV and the likelihood of vertigo episodes in patients with MD who have been treated with intraympanic gentamicin (ITG) has been illustrated. SVIN in superior canal dehiscence (SCD) patients has greater sensitivity than the air-conducted Tullio phenomenon (ACTP) or the Hennebert sign. SVIN can be combined with vHIT to reveal vestibular asymmetry in nonprogressive vestibular schwannomas. An upbeating SVIN may reveal superior branch vestibular neuritis. Vibration-induced downbeat nystagmus should be added to the list of central vestibular signs and is likely due to cerebellar dysfunction. Conclusions: SVIN has become an interesting screening tool for diagnosing or during the follow-up of many different vestibular pathologies. Full article

Background: Vestibular Neuritis (VN) can induce unilateral acute vestibular syndrome (AVS). This study aimed to identify predictive factors of recovery from vestibular neuritis considering total restitution and/or compensation. Methods: In this longitudinal study, 40 patients were included. The initial assessment, performed within 36 to 72 h from the onset (T0), included medical history taking (general and specific), including screening for cardiovascular risk factors (CVRFs), and a battery of diagnostic vestibular tests, comprising the bithermal caloric test (BCT), video head impulse test (VHIT), and skull vibration-induced nystagmus (SVIN) test. All patients also completed a Dizziness Handicap Inventory (DHI). All assessments were repeated 90 ± 15 days later (T3). Subjective compensation criteria were based on the DHI total score, and objective compensation criteria were based on laboratory test results. Four groups of patients (A, B, C, D) were delineated by combining patients with normal vs. abnormal vestibular tests and patients with normal vs. abnormal DHI. Results: CVRFs (but not age or body mass index (BMI)) were associated with a poorer recovery of symptoms. The BCT (lateral semicircular canal paresis %), VHIT (lateral semicircular canal gain), and SVINT (nystagmus slow phase velocity) recovered to normal values in 20%, 20%, and 27% of patients, respectively, at T3. Conclusions: Vascular risk factors (hypercholesterolemia) are correlated with patients who do not recover their symptoms via either total restitution or compensation. There was no significant difference between high- and low-frequency vestibular tests in patients recovering from their symptoms. Some patients with objective recovery may continue to have persistent subjective symptoms. Full article

In recent years, an innovative approach has emerged in the field of toxicology for managing acute intoxications caused by lipophilic substances: intravenous lipid emulsions (ILEs). Through numerous experiments and case reports, the efficacy of lipid emulsions in counteracting toxicities induced by lipophilic agents, including a significant number of antiepileptic (AE) drugs, have become increasingly evident. Data spanning a 10-year period (2010–2020) were analyzed by searching through multiple scientific publication platforms like PubMed, Science Direct, Research Gate, and Springer Link. This study focused on reviewing relevant case reports detailing successful intravenous lipid emulsion (ILE) administration in patients with acute intoxications with antiepileptics, specifically examining the impact of fat emulsions on neurological status, Glasgow Coma Scale (GCS) scores, and corrected QT interval concerning hemodynamic instability. The typical symptoms of antiepileptic toxicity include central nervous system depression, ataxia, and nystagmus. Intravenous lipid emulsion application resulted in an increase in Glasgow Coma Scale scores and enhanced recovery from drug intoxication. This study provides a comprehensive overview of the potential utility of ILE as a component to antidote therapy in cases of acute AE poisoning involving neurotropic drugs. The process involves the engagement of various mechanisms of antitoxic activity. Full article

Benign paroxysmal positional vertigo (BPPV) represents the most frequent cause of peripheral vertigo. In most cases, it is successfully treated using the canalith repositioning procedure, but it is often followed by continuous lightheadedness in the absence of vertigo or nystagmus (residual dizziness, RD). Our aim is to describe the clinical effectiveness and the urine metabolomics profile of treating these patients with polyphenol compound supplementation. We enrolled 30 patients reporting RD after BPPV of the posterior semicircular canal (PSC) successfully treated using the Semont maneuver. Supplementation with a polyphenol compound was administered for 60 days, and patients were evaluated after 30 and 60 days of treatment using self-administered questionnaires (Visual Analog Scales for Dizziness and Nausea, Dizziness Handicap Inventory, DHI) and urine metabolomics analysis performed using 1H-NMR spectroscopy and multivariate followed by univariate analysis. Most patients reported excellent or good efficacy in the treatment of RD with a significant decrease in VAS and DHI values. The metabolomics analysis identified six significant metabolites related to the treatment, namely 1-methylnicotinamide, anserine, hippurate, lysine, methyl succinate and urea, indicating the inflammatory activities and antioxidant properties of the polyphenol compound. These preliminary data suggest that supplementation with a polyphenol compound could induce some metabolic changes that can help in recovery from RD. However, future steps will require confirmation with a more significant cohort of patients and an extension of the metabolomics evaluation to other problems concerning the different clinical aspects of BPPV, such as the high rate of relapse. Full article

Background: This study aimed to investigate the effects of unilateral labyrinthectomy (UL) on monoamine neurotransmitters in the medial vestibular nucleus (MVN) of rats. Methods: Adult Sprague–Dawley rats were utilized for the vestibular impaired animal model through UL. The success of the model establishment and the recovery process were evaluated using vestibular behavioral tests, including spontaneous nystagmus, postural asymmetry, and balance beam test. Additionally, the expression levels of c-Fos protein in the MVN were assessed by immunofluorescence. Furthermore, changes in the expression levels of monoamine neurotransmitters, including 5-hydroxytryptamine (5-HT), norepinephrine (NE), dopamine (DA), and histamine in the MVN, were analyzed using high-performance liquid chromatography (HPLC) at different time points after UL (4 h, 8 h, 1 day, 2 days, 4 days, and 7 days). Results: Compared to the sham control group, the UL group exhibited the most pronounced vestibular impairment symptoms at 4 h post-UL, which significantly decreased at 4 days and almost fully recovered by 7 days. Immunofluorescence results showed a notable upregulation of c-Fos expression in the MVN subsequent to the UL-4 h, serving as a reliable indicator of heightened neuronal activity. In comparison with the sham group, HPLC analysis showed that the levels of 5-HT and NE in the ipsilesional MVN of the UL group were significantly elevated within 4 days after UL, and peaked on 1 day and 2 days, respectively. DA showed an increasing trend at different time points up to 7 days post-UL, while histamine levels significantly increased only at 1 day post-UL. Conclusions: UL-induced dynamic changes in monoamine neurotransmitters during the early compensation period in the rat MVN may be associated with the regulation of the central vestibular compensation mechanism by the MVN. Full article

The effects of concurrent ketamine and propofol (ketofol) constant rate infusion (CRI) were examined in six dogs. The K:P ratio was 1:2, with an initial CRI of 0.25/0.5 mg/kg/min over ten minutes, followed by a 0.5 mg/kg ketamine bolus for induction. During induction, a comprehensive EEG frequency spectrum from delta to gamma was observed, accompanied by subanesthetic-dose ketofol-induced behavioral excitation, including nystagmus, tongue flicking, salivation and active muscle activity. The dogs were maintained on three 15 min decremental doses of ketofol CRI (0.8/1.6, 0.4/0.8 and 0.2/0.4 mg/kg/min). This phase featured a significant decrease in the Patient State Index, electromyographic activity and a shift to low beta waves (SEF95: 13–18 Hz). Additionally, profound antinociception to electric stimulation and a stable heart rate and blood pressure (MBP 81.5–110 mmHg) were observed, as well as a merging of ketamine and propofol EEG characteristics during maintenance. In the recovery phase, a return to beta and gamma EEG patterns and excitement behavior occurred, accompanied by a significant reduction in antinociception, highlighting features of low doses of ketofol. This study reveals biphasic EEG dynamic changes, associated behaviors and robust antinociception and cardiovascular function, suggesting the utility of ketofol as a total intravenous anesthetic combination in dogs. Full article

We evaluated the clinical features of patients admitted to the ED with acute vertigo, verifying symptoms after one month and one year to establish epidemiological factors and predictors of resolution. We reviewed 233 records of patients admitted to ED for acute vertigo (125 F and 85 M, mean age 56.12 years). We analyzed the correlation between time of resolution (at one month and one year) and symptoms duration (subjective and/or objective vertigo, instability, cervical pain, audiological, neurological, and neurovegetative symptoms), comorbidities, and therapies, the result of the clinical and instrumental vestibular examination. Resolution of acute vertigo occurred in 81.1%, while persistence of vertigo one year after ED access was reported in 18.8%. There were 135 patients who recovered in one month. The presence of instability, auditory and neurovegetative symptoms, and neck pain represents a significant factor for recovery within one year. Age over 65 and a history of hypertension are associated with a worst recovery. Patients with spontaneous Nystagmus or positive HIT showed a significant difference in symptoms recovery within one month and one year. Presence of positional Nystagmus represents a positive prognostic factor. Our findings emphasize the importance of clinical evaluation of the acute vertigo, helping the clinicians to define central or peripheral diagnosis and predict the resolution of vertigo. Full article

A 13-year-old neutered, blue-eyed female Siamese cat with a bodyweight of 4.8 kg was admitted for enucleation of the right eye. An ultrasound guided retrobulbar block with 1 mL of ropivacaine was performed under general anaesthesia. When the tip of the needle was visualised inside the intraconal space, negative aspiration of the syringe before injection and no obvious resistance during injection were confirmed. Instantly, after ropivacaine was administered, the cat became apnoeic, and its heart rate and the blood pressure increased significantly for a short period of time. During surgery, the cat needed cardiovascular support to maintain blood pressure and was under continuous mechanical ventilation. Spontaneous breathing returned 20 min after the end of anaesthesia. Brainstem anaesthesia was suspected, and after recovery, the contralateral eye was examined. A reduced menace response, horizontal nystagmus, mydriasis, and absence of the pupillary light reflex were present. The following day, mydriasis was still present, but the cat was visual and was discharged. The inadvertent intra-arterial injection of ropivacaine was suspected to be the cause of the spread into the brainstem. To the current authors’ knowledge, possible brainstem anaesthesia has only been reported in a cat 5 min after a retrobulbar block but never instantly. Full article

Objectives. The aim was to analyze and compare the compensatory process, vestibular dysfunction, postural control, and perceived disability in a population of patients with vestibular neuritis (VN). Material and Methods. This is a prospective and longitudinal study of 67 patients diagnosed with VN. Inclusion criteria were sudden onset of vertigo, unidirectional spontaneous horizontal nystagmus, and impairment in vestibular test. Exclusion criteria were imaging or clinical findings of any neurotologic disorder. All vestibular tests were performed; vHIT, vestibular evoked myogenic potentials (VEMPs), caloric test and computerized dynamic posturography (CDP), dizziness handicap inventory (DHI), and visual analogue scale (VAS) were also performed at every follow up. Results. We observed a correlation between the composite score of CDP and baseline vestibular function elicited either by caloric test, VEMPs, or vHIT. There was a significant correlation between baseline vestibular function and first visit questionnaire scores. The main gain recovery for the horizontal canal was 0.1 ± 0.04 for the first three months. After that, the gain recovery significantly decreased. The presence of covert and overt saccades’, latency and amplitude decreased, respectively, after the 6-month period, when compared to the baseline results. We also observed a decrease in the PR score from 3 months after the vestibular insult until the last follow up. We observed a significant decrease in DHI and VAS from the first visit until the last one. Those patients with an initial HC gain below 0.5 had significantly higher DHI and VAS scores at every follow up. Conclusions. There are different measurements that could become a complete measurement of the state of compensation, postural control, and disability of the patients. There is a time window in which the vestibular restoration could give us clinical insights regarding the management of VN patients. Full article

The aim of this study was to evaluate the vestibulo-ocular reflex (VOR) gain and the saccade regrouping pattern PR score of the Video Head Impulse Test (vHIT) and its relationship with the slow-phase velocity (SPV) of skull vibration-induced nystagmus (SVIN) in recovery after a unilateral vestibular loss (UVL). A total of 36 patients suffering from vestibular neuritis (VN) were recruited and followed up for twelve months. In every visit, horizontal vHIT and an SVIN were performed, as well as VOR gain; PR score and the SPV of SVIN were measured. We observed a positive association between the VOR gain difference and the SPV of SVIN over time (probability greater than 0.86). Additionally, we obtained a positive association between the SPV of SVIN and the PR score in successive visits (odds ratio (OR) = −0.048; CI [0.898, 1.01]), with a probability of 0.95. Our results confirm that SPV of SVIN; VOR gain difference; and PR score decrease over time after a UVL. Both tests are useful in the follow-up of VN, as they could reflect its clinical compensation or partial recovery. Full article

Recovery nystagmus in vestibular neuritis patients is a reversal of spontaneous nystagmus direction, beating towards the affected ear, observed along the time course of central compensation. It is rarely registered due either to its rarity as a phenomenon per se, or to the fact that it is missed between follow-up appointments. The aim of the manuscript is to describe in detail a case of recovery nystagmus found in an atypical case of vestibular neuritis and discuss pathophysiology and clinical considerations regarding this rare finding. A 26-year-old man was referred to our Otorhinolaryngology practice reporting “dizziness” sensation and nausea in the last 48 h. Clinical examination revealed left beating spontaneous nystagmus (average slow phase velocity aSPV 8.1°/s) with absence of fixation. The head impulse test (H.I.T.) was negative. Cervical vestibular evoked myogenic potentials (cVEMP) and Playtone audiometry (PTA) were normal. Romberg and Unterberger tests were not severely affected. A strong directional preponderance to the left was found in caloric vestibular test with minimal canal paresis (CP 13%) on the right. The first follow-up consultation took place on the 9th day after the onset of symptoms. Right beating weak (aSPV 2.4°/s) spontaneous nystagmus was observed with absence of fixation, whereas a strong right directional preponderance (DP) was found in caloric vestibular test. A brain MRI scan was ordered to exclude central causes of vertigo, which was normal. The patient was seen again completely free of symptoms 45 days later. He reported feeling dizzy during dynamic movements of the head and trunk for another 15 days after his second consultation. The unexpected observation of nystagmus direction reversal seven days after the first consultation is a typical sign of recovery nystagmus. Recovery nystagmus (RN) is centrally mediated and when found, it should always be carefully assessed in combination with the particularities of vestibular neuritis. Full article

Pain management is necessary for all surgical procedures. Little scientific evidence about drug efficacy in donkeys is available. The aim of this study was to evaluate the analgesic effect of butorphanol in donkeys undergoing orchiectomy under total intravenous anaesthesia with guaifenesin-ketamine-detomidine. A randomized blinded prospective clinical trial (Protocol n. 2021/0000338), was carried out on 18 clinically healthy donkeys undergoing bilateral orchiectomy. Patients were assigned to Group D (n = 8) or Group DB (n = 10) if receiving intravenous detomidine or detomidine-butorphanol respectively, before induction of general anaesthesia with ketamine-diazepam. Intraoperative muscle relaxation, nystagmus, palpebral reflex, heart and respiratory rate, and non-invasive blood pressure were evaluated every 2 min; time to prepare the patient, duration of surgery and anaesthesia and recovery score were recorded. Group D had significantly longer surgical time, higher heart rate, higher systolic and mean blood pressure (p < 0.05; repeated measure ANOVA), increased muscle rigidity and expression of palpebral reflex (p < 0.05; Mann–Whitney U test) than group DB. Top-ups with thiopental were statistically higher in Group D. Butorphanol and detomidine together produced a more stable anaesthetic plan. The low dosage of opioid and alpha-2-agonists and reduced rescue anaesthesia are responsible for a safer and more superficial anaesthesia, which is mandatory under field conditions. Full article

Achromatopsia is characterized by amblyopia, photophobia, nystagmus, and color blindness. Previous animal models of achromatopsia have shown promising results using gene augmentation to restore cone function. However, the optimal therapeutic window to elicit recovery remains unknown. Here, we attempted two rounds of gene augmentation to generate recoverable mouse models of achromatopsia including a Cnga3 model with a knock-in stop cassette in intron 5 using Easi-CRISPR (Efficient additions with ssDNA inserts-CRISPR) and targeted embryonic stem (ES) cells. This model demonstrated that only 20% of CNGA3 levels in homozygotes derived from target ES cells remained, as compared to normal CNGA3 levels. Despite the low percentage of remaining protein, the knock-in mouse model continued to generate normal cone phototransduction. Our results showed that a small amount of normal CNGA3 protein is sufficient to form “functional” CNG channels and achieve physiological demand for proper cone phototransduction. Thus, it can be concluded that mutating the Cnga3 locus to disrupt the functional tetrameric CNG channels may ultimately require more potent STOP cassettes to generate a reversible achromatopsia mouse model. Our data also possess implications for future CNGA3-associated achromatopsia clinical trials, whereby restoration of only 20% functional CNGA3 protein may be sufficient to form functional CNG channels and thus rescue cone response. Full article

An 84-year-old man presented to the emergency department for acute vomiting associated with rotational vertigo and a sudden right sensorineural hearing loss. A left peripheral vestibular nystagmus was highlighted. The patient was afebrile, without respiratory signs or symptoms. Blood sampling at admission showed lymphopenia, thrombopenia and neutrophil polynucleosis, without elevation of C reactive protein. Cerebral magnetic resonance imaging eliminated a neurovascular origin. Vestibule, right semicircular canals and cochlear FLAIR hypersignals were highlighted, leading to the diagnosis of right labyrinthitis. A nasopharyngeal swab sampled at admission returned positive for SARS CoV2 by polymerase chain reaction. The etiologic investigation, including syphilitic and viral research, was otherwise negative. An oral corticotherapy (prednisone 70 mg daily) was introduced, followed by a progressive clinical recovery. Although acute otitis media have already been highlighted as an unusual presentation of COVID-19, radiology-proven labyrinthitis had to our knowledge, never been described to date. Full article

Variants of Guillain-Barre syndrome such as Bickerstaff encephalitis and Miller-Fisher syndrome have been reported. We report a 15-year-old boy who presented, after a prodromal illness, with 3-day progressive limb weakness, diplopia, and acute urinary retention. Clinically, he had horizontal gaze-evoked and upbeat nystagmus, bilateral extensor plantars in addition to quadriparesis and areflexia. Magnetic resonance imaging of the brain and spine was unremarkable and cerebral spinal fluid analysis showed lymphocytic pleocytosis. Nerve conduction study revealed symmetrical axonal neuropathy. Anti-GQ1b antibody was positive. A combination of IV methylprednisone followed by IVIg was instituted which led to remarkable clinical recovery. This case underpins the importance of recognizing atypical presentations of acute autonomic dysfunction and central nervous system features such as nystagmus, which may be associated with anti-GQ1b antibody syndrome. Features mimicking myelitis and brainstem encephalitis may pose diagnostic and therapeutic dilemma among the treating physicians. Full article