Phenotypes and clinical subgroups in vestibular migraine: a cross-sectional study with cluster analysis.

OBJECTIVE: The aim of this multicentric cross-sectional study was to collect phenotypes and clinical variability on a large sample of 244 patients enrolled in different university centers in Italy, trying to differentiate subtypes of VM. BACKGROUND: VM is one of the most frequent episodic vertigo characterized by a great clinical variability for duration of attacks and accompanying symptoms. Diagnosis is based only on clinical history of episodic vertigo in 50% of cases associated with migrainous headache or photo/phonophobia. METHODS: We enrolled in different university centers 244 patients affected by definite VM according to the criteria of the Barany Society between January 2022 and December 2022. An audiometric examination and a CNS MRI were performed before inclusion. Patients with low-frequency sensorineural hearing loss were not included, as well as patients with an MRI positive otherwise that for microischemic lesions. Patients were asked to characterize vestibular symptoms choosing among (multiple answers were allowed): internal vertigo, dizziness, visuo-vestibular symptoms/external vertigo; onset of vertigo and duration, neurovegetative, and cochlear accompanying symptoms (hearing loss, tinnitus, and fullness during attacks) were collected as well as migrainous headache and/or photo/phonophobia during vertigo; autoimmune disorders were also analyzed. A bedside examination was performed including study of spontaneous-positional nystagmus with infrared video goggles, post head shaking ny, skull vibration test, and video head impulse test. RESULTS: We included 244 subjects, 181 were females (74.2%). The age of onset of the first vertigo was 36.6 ± 14.5 while of the first headache was 23.2 ± 10.1. A positive correlation has been found between the first headache and the first vertigo. The mean duration of vertigo attacks was 11 ± 16 h. We carried on a cluster analysis to identify subgroups of patients with common clinical features. Four variables allowed to aggregate clusters: age of onset of vertigo, duration of vertigo attacks, presence of migrainous headache during vertigo, and presence of cochlear symptoms during vertigo. We identified 5 clusters: cluster 1/group 1 (23 subjects, 9.4%) characterized by longer duration of vertigo attacks; cluster 2/group 2 (52 subjects, 21.3%) characterized by absence of migrainous headache and cochlear symptoms during vertigo; cluster 3/group 3 (44 subjects, 18%) characterized by presence of cochlear symptoms during vertigo but not headache; cluster 4/group 4 (57 subjects, 23.4%) by the presence of both cochlear symptoms and migrainous headache during vertigo; cluster 5/group 5 (68 subjects, 27.9%) characterized by migrainous headache but no cochlear symptoms during vertigo. CONCLUSION: VM is with any evidence a heterogeneous disorder and clinical presentations exhibit a great variability. In VM, both symptoms orienting toward a peripheral mechanism (cochlear symptoms) and central ones (long lasting positional non-paroxysmal vertigo) may coexist. Our study is the first published trying to characterize subgroups of VM subjects, thus orienting toward different pathophysiological mechanisms.

A Systematic and Critical Review on the Anatomy of the Ethmoidal Foramina.

PURPOSE: The osteologic anatomy of the orbit is still a field of intense research, particularly as far as vascular channels are concerned. Among them, ethmoidal foraminas (EFs) are certainly those that have more clinical importance and indeed have been deeply investigated. Unfortunately, the vast production of articles, far from clarifying their anatomy, generated a certain degree of confusion. METHODS: A search on Pubmed and Scopus databases updated up to December 31, 2023, has been carried out with the keyword "ethmoidal foramen" yielding a list of 357 items. With a careful screening process, 31 articles were enlisted to be included in the present review. RESULTS: A critical review process confirmed that many results published over the years appear inconsistent, particularly as far as EFs topography is concerned. The possible reasons for this lack of consistency can be traced back to inter-ethnical differences, uncertainty on the anterior bony landmarks employed in the investigations, and lack of a general consensus over EFs classification. A novel approach, based on the normalization of the distance of the anterior landmarks relative to the length of the orbit (relative depth index), should overcome some of the major problems encountered so far. CONCLUSIONS: Novel and clear guidelines to classify EFs and to locate them on the medial wall are required. Determining the relative depth index of EFs may be an interesting approach to solve the matter. Other methods can be also devised. However, direct measurements from bony landmarks, without any further analysis seem inadequate and possibly misleading.

Conventional approaches versus laser CO2 surgery in stapes surgery: a multicentre retrospective study.

PURPOSE: To analyze and compare surgical and audiological outcomes of conventional approaches versus laser CO2 surgery in stapes surgery. METHODS: 333 patients who underwent stapes surgery were enrolled in the study; the patient population was divided into three groups: group 1: 170 patients treated with conventional stapedotomy with manual microdrill (average age 49.13 years); group 2: 119 patients treated with conventional stapedotomy with electrical microdrill (average age 51.06 years); group 3: 44 patients (average age 50.4 years) who underwent CO2 laser stapedotomy. Intra-operative, postoperative outcomes and audiological results were investigated. RESULTS: The average surgical time of laser CO2 surgery was longer than for other surgical procedures. No statistical differences emerged in post-operative abnormal taste sensation. There was also no difference in postoperative dizziness. Air-bone gap (ABG) went down from 29.7 ± 10 dB (group 1) and 27.32 ± 9.20 (group 2) to 10 ± 6.9 dB (group 1) and 10.7 ± 6.03 dB (group 2). In group 3 the preoperative ABG was lowered from 28.3 ± 10.1 to 11.8 ± 10.9, with a statistical difference in auditory recovery (p = 0.0001); The group of patients treated with laser CO2 showed a percentage of patients with an ABG closure of between 0 and 10 dB higher than in the group treated with manual microdrills (77.2% vs. 60%, respectively; p = 0.03). CONCLUSION: Overall surgical results of CO2 laser and conventional stapedotomy are comparable without any significant difference; however, the group treated with CO2 laser appears to have a percentage of patients with an ABG closure 0-10 dB higher than the group treated using the conventional technique.

The impact of the COVID-19 pandemic on the quality of life of head and neck cancer survivors.

BACKGROUND: Head and neck cancer (HNC) survivors are particularly vulnerable to the deleterious consequences of lockdown and social distancing. The psychosocial effects of the COVID-19 pandemic on this group are still unknown, and we want to explore how their quality of life (QoL) has changed in this unique situation. MATERIALS AND METHODS: An online survey, composed of pandemic-specific items, plus the EORTC QLQ-C30, was administered to a cohort of HNC survivors. Using previously published reference values as a control group, we have evaluated the impact of the pandemic on their QoL. We have also explored the differences between those who had received a total laryngectomy (LP, laryngectomized population) vs other HNC patients, in order to assess the role of tracheostomy in this regard. RESULTS: One hundred and twenty-one HNC patients completed the survey. The scores of the physical (80.5 vs 85, p = 0.028), role (78 vs 84, p = 0.030), and emotional functioning (76 vs 81, p = 0.041) were significantly different in the two groups, with worse functioning in our patients. Comparing LP with the other HNC patients, social (76.6 vs 88.9, p = 0.008) and physical functioning (75.5 vs 86.1, p = 0.006) were significantly worse in the former group. LP also reported a greater perception that others are afraid to be close to them (1.67 vs 1.32, p = 0.020). No differences were found between LP with and without voice prosthesis. CONCLUSIONS: Our results show how HNC patients are at high risk for a worsening in QoL because of the ongoing COVID-19 global pandemic.

Benign Paroxysmal Positional Vertigo: What We Do and Do Not Know.

Benign paroxysmal positional vertigo (BPPV) is common, sometimes terrifying, but rarely portends serious disease. It is usually easily diagnosed and treated, and both the patient and the physician are immediately gratified. While much has been learned about the pathogenesis of BPPV in the past decades, many of its features remain mysterious, and one must still be wary of the rare times it mimics a dangerous brain disorder. Here we review common, relatively well understood clinical features of BPPV but also emphasize what we do not know and when the physician must look deeper for a more ominous cause.

Peripheral vestibular disorders: an update.

PURPOSE OF REVIEW: To provide an update on the most frequent peripheral vestibular disorders. RECENT FINDINGS: The on-going classification of vestibular disorders by the Bárány Society represents major progress. The diagnosis of bilateral vestibulopathy (BVP) requires quantitative testing of vestibular function. 'Acute unilateral peripheral vestibulopathy' (AUPVP) is now preferred over 'vestibular neuritis.' Menière's disease is a set of disorders with a significant genetic contribution. The apogeotropic variant of horizontal canal benign paroxysmal positional vertigo (hcBPPV) and anterior canal BPPV (acBPPV) can be distinguished from a central vestibular lesion. Vestibular paroxysmia is now an internationally accepted clinical entity. The diagnosis of SCDS is based on conclusive findings. SUMMARY: Diagnosis of BVP requires significantly reduced vestibular function. The clinical picture of AUPVP depends on how much the vestibular end organs or their innervation are affected. Menière's disease phenotype is a constellation of symptoms. Although diagnostic and therapeutic criteria for pc and hcBPPV are well defined, a number of less frequent and controversial are increasingly diagnosed and can be treated. Diagnosis of vestibular paroxysmia requires that a patient responds to treatment with a sodium channel blocker. The diagnosis of SCDS requires conclusive findings with various methods. There is still a great need for state-of-the-art randomized controlled treatment trials in most peripheral vestibular disorders.

Clinical Features, Familial History, and Migraine Precursors in Patients With Definite Vestibular Migraine: The VM-Phenotypes Projects.

OBJECTIVE: The aim of this work was to assess through a questionnaire the features of vertiginous episodes, accompanying symptoms, familial history, and migraine precursors in a sample of 252 subjects with a diagnosis of definite vestibular migraine. BACKGROUND: Migraine is a common neurological disorder characterized by episodic headaches with specific features. About two-thirds of cases run in families, and patients may refer symptoms occurring in infancy and childhood, defined as episodic syndromes that may be associated with migraine. Migraine is associated with episodic vertigo, called vestibular migraine, whose diagnosis mainly relies on clinical history showing a temporary association of symptoms. METHODS: In this cross-sectional multicentric study, 252 subjects were recruited in different centers; a senior specialist through a structured questionnaire assessed features of vestibular symptoms and accompanying symptoms. RESULTS: The age of onset of migraine was 23 years, while onset of vertigo was at 38 years. One hundred and eighty-four subjects reported internal vertigo (73%), while 63 subjects (25%) reported external vertigo. The duration of vertigo attacks was less than 5 minutes in 58 subjects (23%), between 6 and 60 minutes in 55 (21.8%), between 1 and 4 hours in 29 (11.5%), 5 and 24 hours in 44 (17.5%), up to 3 days in 14 (5.5%), and more than 3 days in seven (2.8%); 14 subjects (5.5%) referred attacks lasting from less than 5 minutes and up to 1 hour, nine (3.6%) referred attacks lasting from less than 5 minutes and up to 1 to 4 hours, six (2.4%) referred attacks lasting from less than 5 minutes and up to 5 to 24 hours, and five (2%) cases referred attacks lasting from less than 5 minutes and up to days. Among accompanying symptoms, patients referred the following usually occurring, in order of frequency: nausea (59.9%), photophobia (44.4%), phonophobia (38.9%), vomiting (17.8%), palpitations (11.5%), tinnitus (10.7%), fullness of the ear (8.7%), and hearing loss (4%). In total, 177 subjects referred a positive family history of migraine (70.2%), while 167 (66.3%) reported a positive family history of vertigo. In the sample, 69% of patients referred at least one of the pediatric precursors, in particular, 42.8% of subjects referred motion sickness. The age of onset of the first headache was lower in the subsample with a familial history of migraine than in the total sample. Among the pediatric precursors, benign paroxysmal vertigo - BPV, benign paroxysmal torticollis, and motion sickness were predictive of a lower age of onset of vertigo in adulthood; cyclic vomiting was predictive for vomiting during vertigo attacks in adults. CONCLUSIONS: Our results may indicate that vestibular symptoms in pediatric patients may act as a predisposing factor to develop vestibular migraine at an earlier age in adulthood.

Regional flaps in head and neck reconstruction: a reappraisal.

PURPOSE: Starting from our experience with 45 consecutive cases of regional pedicled flaps, we have underlined the effectiveness and reliability of a variety of flaps. The marketing laws as applied to surgical innovations are reviewed to help in the understanding of why regional flaps are regaining wide popularity in head and neck reconstruction. MATERIALS AND METHODS: From January 2009 to January 2014, 45 regional flaps were harvested at San Paolo Hospital to reconstruct head and neck defects. These included 35 pectoralis major muscular and myocutaneous flaps, 4 lower trapezius island or pedicled flaps, 3 supraclavicular flaps, 2 latissimus dorsi pedicled flaps, and 1 fasciocutaneous temporal flap. The basic literature of marketing regarding the diffusion of new products was also reviewed. RESULTS: Two myocutaneous pectoralis major flaps were complicated by necrosis of the cutaneous paddle (one complete and one partial). No complete loss of any of the 45 flaps was observed. At 6 months of follow-up, 2 patients had died of multiple organ failure after prolonged sepsis. The 43 remaining patients had acceptable morphologic and functional results. CONCLUSIONS: Regional and free flaps appear to compete in many cases for the same indications. From the results of the present case series, regional flaps can be considered reliable reconstructive choices that are less expensive than their free flap alternatives. The "resurrection" of regional flaps can be partially justified by the changes in the global economy and the required adaptation of developed and developing countries.

Comprehensive surgical management of cocaine-induced midline destructive lesions.

PURPOSE: This article presents a review of the literature and proposes a protocol for managing acute and chronic midfacial cocaine-induced injuries. MATERIALS AND METHODS: This report describes a series of 4 patients affected by cocaine-induced midline destructive lesions. Three patients came to the authors' attention after 18 months of drug withdrawal and underwent surgical treatments to restore nasal and palatal morphology and function, and the fourth patient was referred because of acute cocaine-induced destructive lesions and was treated by aggressive debridement. An 18-month drug-free period is planned before beginning any reconstructive procedures in this latter patient. RESULTS: Long-term follow-up showed stable results without relapse of palatal fistulas and good esthetic nasal appearance in all 3 patients undergoing reconstruction. The fourth patient did not show any disease progression and will be monitored for drug withdrawal. CONCLUSION: Chronic cocaine consumption may cause multiple types of damage to the soft and hard tissues of the midface. Acute lesions must be addressed with aggressive debridement. As a result of chronic injury, the palate and nose are deformed in a very complex way and the vascularity of the remaining local tissues may be compromised or inadequate for flap harvesting. Palatal and nasal reconstructions are very delicate operations and should be addressed separately to maximize the predictability of the result.

Heterologous Materials Are Really Better than Autologous in Tympanoplasty Mastoid Obliteration? A Systematic Review with Meta-Analysis.

The aim is to analyze Literature concerning mastoid obliteration in adults with either autologous or heterologous grafts in the last 10 years. Data Source: Databases such as NIH PubMed, Bookshelf, NLM Catalog, Cochrane Library, and Embase were consulted. Thirty-seven studies were selected (22 concerning autologous materials, 15 about heterologous ones). Only studies with more than 12 months of follow-up were considered. A statistical analysis with random-effects models was performed to allow the true effect sizes to differ from study to study. The present literature review and meta-analysis does not allow to establish the supremacy of one technique over the other, but underlines the advantages of each reconstructive choice and the importance of mastoid obliteration in cholesteatoma surgery. The total number of obliterated ears was 2882. Overall otorrhea rate was 5% (5.2% for heterologous grafts; 4.9% for autologous materials; P < .05). Recurrent and residual cholesteatoma rate was 4.5% (3.4% in heterologous materials; 5.2% in autologous grafts; P < .05). Recurrent cholesteatoma rate was 1.8% (1.6% when using heterologous grafts, 1.9% with autologous; P < .05). Residual cholesteatoma rate was 1.5% (1.6% with heterologous materials, 1.5% with autologous; P < .05). TM (tympanic membrane) retraction pockets rate was 5.3% (3.6% with heterologous materials; P >.05; 7% with autologous materials; P < .05). TM perforations rate was 2.9% (4.3% with heterologous materials, 2.5% with autologous; P < .05). Infection rate was 2.3% (2.3% with heterologous materials, 2.2% with autologous; P < .05). Heterologous materials are associated with significantly lower rates of recurrent and residual cholesteatoma and retraction pockets development, although they are associated with higher rates of otorrhea and TM perforation.

rTMS of the auditory association cortex improves speech intelligibility in patients with sensorineural hearing loss.

OBJECTIVE: Sensorineural hearing-loss (SHL) is accompanied by changes in the entire ear-brain pathway and its connected regions. While hearing-aid (HA) partially compensates for SHL, speech perception abilities often continue to remain poor, resulting in consequences in everyday activities. Repetitive transcranial magnetic stimulation (rTMS) promotes cortical network plasticity and may enhance language comprehension in SHL patients. METHODS: 27 patients using HA and with SHL were randomly assigned to a treatment protocol consisting of five consecutive days of either real (Active group: 13 patients) or placebo rTMS (Sham group: 14 patients). The stimulation parameters were as follows: 2-second trains at 10 Hz, 4-second inter-train-interval, and 1800 pulses. Neuronavigated rTMS was applied over the left superior temporal sulcus. Audiological tests were administered before (T0), immediately after (T1), and one week following treatment completion (T2) to evaluate the speech reception threshold (SRT) and the Pure Tone Average (PTA). RESULTS: In the context of a general improvement likely due to learning, the treatment with real rTMS induced significant reduction of the SRT and PTA at T1 and T2 versus placebo. CONCLUSIONS: The long-lasting effects on SRT and PTA observed in the Active group indicates that rTMS administered over the auditory cortex could promote sustained neuromodulatory-induced changes in the brain, improving the perception of complex sentences and pure tones reception skills. SIGNIFICANCE: Five days of rTMS treatment enhances overall speech intelligibility and PTA in SHL patients.

Multi-Magnet Cochlear Implant Technology and Magnetic Resonance Imaging: The Safety Issue.

Despite the spread of novel-generation cochlear-implant (CI) magnetic systems, access to magnetic resonance imaging (MRI) for CI recipients is still limited due to safety concerns. The aim of this study is to assess and record the experiences of Hires Ultra 3D (Advanced Bionics) recipients who underwent an MRI examination. A multicentric European survey about this topic was conducted focusing on safety issues, and the results were compared with the current literature. We collected a total of 65 MRI scans performed in 9 otologic referral centers for a total of 47 Hires Ultra 3D recipients, including, for the first time, 2 children and 3 teenagers. Preventive measures were represented by scanning time and sedation for children. Head wrapping was used in eight cases, and six of the eight cases received local anesthesia, even if both measures were not needed. Only three patients complained of pain (3/65 examinations, 4.6%) due to the tight head bandage, and one of the three cases required MRI scan interruption. No other adverse events were reported. We believe that these results should encourage MRI execution in accordance with manufacturer recommendations for Ultra 3D recipients.

Clinical course of two Italian siblings with ataxia-telangiectasia-like disorder.

Ataxia-telangiectasia-like disorder (ATLD) due to mutations in the MRE11 gene is a very rare autosomal recessive disease, described so far in only 20 patients. Little is known about the onset of the first symptoms or the clinical course of the disease. The present report contributes to the diagnosis of ATLD and its prognosis at onset. We report 30 years of clinical and ophthalmic observations and the results of quantitative magnetic resonance (MR), MR spectroscopy (proton magnetic resonance spectroscopic imaging) and neuropsychological assessment in the first Italian siblings identified with ATLD. Although the disease had early onset and the clinical picture was initially severe, suggesting ataxia-telangiectasia, neurological impairment, ocular motor apraxia and neuropsychological tests showed very slow deterioration in adult age. The patients developed eye and head motor strategies to compensate ocular motor apraxia. MR measurements and MR spectroscopy disclosed widespread neuronal and axonal involvement. ATLD should be considered in patients with ocular apraxia and ataxia in infancy. The long follow-up provided insights into clinical outcome, with functional neuroimaging studies shedding light on the pathogenetic mechanisms of this rare disease.

Hyperventilation-induced nystagmus in vestibular schwannoma and unilateral sensorineural hearing loss.

We evaluated the incidence and characteristics of hyperventilation-induced nystagmus (HVN) in 49 patients with gadolinium-enhanced magnetic resonance imaging evidence of vestibular schwannoma and 53 patients with idiopathic unilateral sensorineural hearing loss and normal radiological findings. The sensitivity and specificity of the hyperventilation test were compared with other audio-vestibular diagnostic tests (bedside examination of eye movements, caloric test, auditory brainstem responses) in the two groups of patients. The hyperventilation test scored the highest diagnostic efficiency (sensitivity 65.3 %; specificity 98.1 %) of the four tests in the differential diagnosis of vestibular schwannoma and idiopathic unilateral sensorineural hearing loss. Small tumors with a normal caloric response or caloric paresis were associated with ipsilateral HVN and larger tumors and severe caloric deficits with contralateral HVN. These results confirm that the hyperventilation test is a useful diagnostic test for predicting vestibular schwannoma in patients with unilateral sensorineural hearing loss.

Development of a Magnetoresistive-Based Wearable Eye-Tracking System for Oculomotor Assessment in Neurological and Otoneurological Research-Preliminary In Vivo Tests.

Over the past 20 years, several eye-tracking technologies have been developed. This article aims to present a new type of eye tracker capable of producing detailed information on eye and head movements using an array of magnetoresistive detectors fixed on the patient's head and a small magnet inserted into a contact lens, adapted to the curvature of the cornea of the subject. The software used for data analysis can combine or compare eye and head movements and can represent them as 2D or 3D images. Preliminary data involve an initial patient who was asked to perform several tasks to establish the accuracy, reliability, and tolerance of the magnetic eye tracker and software. The tasks included assessment of saccadic eye movements and pursuit, "drawing" alphabetic shapes or letters, and reading. Finally, a Head Impulse Test (HIT) was performed to estimate the VOR gain, comparing the standard deviation established via vHIT with that established via this magnetic eye tracker (mHIT). This prototypical device is minimally invasive, lightweight, relatively cheap, and tolerable, with a high degree of reliability and precision. All these characteristics could lead to the future use of the magnetic eye tracker in neurological and otoneurological fields.

The Semont-Plus Maneuver or the Epley Maneuver in Posterior Canal Benign Paroxysmal Positional Vertigo: A Randomized Clinical Study.

Importance: Questions remain concerning treatment efficacy for the common condition of benign paroxysmal positional vertigo (BPPV). Objective: To compare the effectiveness of the Semont-plus maneuver (SM-plus) and the Epley maneuver (EM) for treatment of posterior canal benign paroxysmal positional vertigo (pcBPPV) canalolithiasis. Design, Setting, and Participants: This prospective randomized clinical trial was performed at 3 national referral centers (in Munich, Germany; Siena, Italy; and Bruges, Belgium) over 2 years, with a follow-up to 4 weeks after the initial examination. Recruitment took place from June 1, 2020, until March 10, 2022. Patients were selected randomly during routine outpatient care after being referred to 1 of the 3 centers. Two hundred fifty-three patients were assessed for eligibility. After consideration of the exclusion criteria as well as informed consent, 56 patients were excluded and 2 declined to participate, with 195 participants included in the final analysis. The analysis was prespecified and per-protocol. Interventions: After being randomized to the SM-plus or the EM group, patients received 1 initial maneuver from a physician, then subsequently performed self-maneuvers at home 3 times in the morning, 3 times at noon, and 3 times in the evening. Main Outcome and Measures: Patients had to document whether they could provoke positional vertigo every morning. The primary end point was the number of days until no positional vertigo could be induced on 3 consecutive mornings. The secondary end point was the effect of the single maneuver performed by the physician. Results: Of the 195 participants included in the analysis, the mean (SD) age was 62.6 (13.9) years, and 125 (64.1%) were women. The mean (SD) time until no positional vertigo attacks could be induced in the SM-plus group was 2.0 (1.6) days (median, 1 [range, 1-8] day; 95% CI, 1.64-2.28 days); in the EM group, 3.3 (3.6) days (median, 2 [range, 1-20] days; 95% CI, 2.62-4.06 days) (P = .01; α = .05, 2-tailed Mann-Whitney test). For the secondary end point (effect of a single maneuver), no significant difference was detected (67 of 98 [68.4%] vs 61 of 97 [62.9%]; P = .42; α = .05). No serious adverse event was detected with both maneuvers. Nineteen patients (19.6%) in the EM group and 24 (24.5%) in the SM-plus group experienced relevant nausea. Conclusions and Relevance: The SM-plus self-maneuver is superior to the EM self-maneuver in terms of the number of days until recovery in pcBPPV. Trial Registration: ClinicalTrials.gov Identifier: NCT05853328.

Treating benign paroxysmal positional vertigo of the lateral semicircular canal with a shortened forced position.

Benign paroxysmal positional vertigo (BPPV) is the peripheral vestibular disorder that is most frequently encountered in routine neuro-otological practice. Among the three semicircular canals, the lateral semicircular canal (LSC) is the second most frequently interested in the pathological process. In most cases, LSC BPPV is attributable to a canalithiasis or cupulolithiasis mechanism. The clinical picture of LSC BPPV is that of positional nystagmus and vertigo evoked by turning the head from the supine to the side lateral position. With such a movement, a horizontal positional (and often also paroxysmal) direction-changing nystagmus is generated. Depending on whether the pathogenetic mechanism is that of canalithiasis or cupulolithiasis and depending on where the dense particles are located, LSC BPPV direction-changing positional nystagmus is geotropic or apogeotropic on both lateral sides. Due to its mechanical nature, BPPV is effectively treated by means of physical therapy. In the case of a LSC BPPV, one of the most effective therapies is the forced prolonged position (FPP), in which the patient is invited to lie for 12 h on the lateral side on which vertigo and nystagmus are less intense, to move the canaliths out from the canal (or to shift them inside of the canal from one tract to another) exploiting the force of gravity. Despite its efficacy, FPP is not always well tolerated by every patient, and it cannot be done during the diagnostic session because of its duration. The present study aimed to verify the efficacy of a different forced position, shortened forced position (SFP), with respect to the original FPP. SFP treatment would allow patients to more easily bear the forced position and physicians to control the outcome almost immediately, possibly enabling them to dismiss patients without vertigo. After 1 h of lying on the side where vertigo and nystagmus are the less intense, 38 out of 53 (71.7%) patients treated with SFP were either healed or improved. Although the outcomes are not as satisfying as those of the original FPP, SFP should be considered as a therapeutic prospect, especially by those physicians who work in collaboration with emergency departments or otherwise encounter acute patients to cure them of vertigo as soon as possible.

A Wearable Wireless Magnetic Eye-Tracker, In-Vitro and In-Vivo Tests.

A wireless, wearable magnetic eye tracker is described and characterized. The proposed instrumentation enables simultaneous evaluation of eye and head angular displacements. Such a system can be used to determine the absolute gaze direction as well as to analyze spontaneous eye re-orientation in response to stimuli consisting in head rotations. The latter feature has implications to analyze the vestibulo-ocular reflex and constitutes an interesting opportunity to develop medical (oto-neurological) diagnostics. Details of data analysis are reported together with some results obtained in-vivo or with simple mechanical simulators that enable measurements under controlled conditions.

Frequency-dependent tuning of the human vestibular "sixth sense" by transcranial oscillatory currents.

OBJECTIVE: The vestibular cortex is a multisensory associative region that, in neuroimaging investigations, is activated by slow-frequency (1-2 Hz) galvanic stimulation of peripheral receptors. We aimed to directly activate the vestibular cortex with biophysically modeled transcranial oscillatory current stimulation (tACS) in the same frequency range. METHODS: Thirty healthy subjects and one rare patient with chronic bilateral vestibular deafferentation underwent, in a randomized, double-blind, controlled trial, to tACS at slow (1 or 2 Hz) or higher (10 Hz) frequency and sham stimulations, over the Parieto-Insular Vestibular Cortex (PIVC), while standing on a stabilometric platform. Subjective symptoms of motion sickness were scored by Simulator Sickness Questionnaire and subjects' postural sways were monitored on the platform. RESULTS: tACS at 1 and 2 Hz induced symptoms of motion sickness, oscillopsia and postural instability, that were supported by posturographic sway recordings. Both 10 Hz-tACS and sham stimulation on the vestibular cortex did not affect vestibular function. As these effects persisted in a rare patient with bilateral peripheral vestibular areflexia documented by the absence of the Vestibular-Ocular Reflex, the possibility of a current spread toward peripheral afferents is unlikely. Conversely, the 10 Hz-tACS significantly reduced his chronic vestibular symptoms in this patient. CONCLUSIONS: Weak electrical oscillations in a frequency range corresponding to the physiological cortical activity of the vestibular system may generate motion sickness and postural sways, both in healthy subjects and in the case of bilateral vestibular deafferentation. SIGNIFICANCE: This should be taken into account as a new side effect of tACS in future studies addressing cognitive functions. Higher frequencies of stimulation applied to the vestibular cortex may represent a new interventional option to reduce motion sickness in different scenarios.

Frequency-Dependent Reduction of Cybersickness in Virtual Reality by Transcranial Oscillatory Stimulation of the Vestibular Cortex.

Virtual reality (VR) applications are pervasive of everyday life, as in working, medical, and entertainment scenarios. There is yet no solution to cybersickness (CS), a disabling vestibular syndrome with nausea, dizziness, and general discomfort that most of VR users undergo, which results from an integration mismatch among visual, proprioceptive, and vestibular information. In a double-blind, controlled trial, we propose an innovative treatment for CS, consisting of online oscillatory imperceptible neuromodulation with transcranial alternating current stimulation (tACS) at 10 Hz, biophysically modelled to reach the vestibular cortex bilaterally. tACS significantly reduced CS nausea in 37 healthy subjects during a VR rollercoaster experience. The effect was frequency-dependent and placebo-insensitive. Subjective benefits were paralleled by galvanic skin response modulation in 25 subjects, addressing neurovegetative activity. Besides confirming the role of transcranially delivered oscillations in physiologically tuning the vestibular system function (and dysfunction), results open a new way to facilitate the use of VR in different scenarios and possibly to help treating also other vestibular dysfunctions.