Current treatment of vestibular, ocular motor disorders and nystagmus

Falls at advanced age - The importance to search for benign paroxysmal positional vertigo (BPPV)

INTRODUCTION

One of the most important geriatric syndromes is dizziness in conjunction with gait disorder and consequent falls. There are various differential diagnoses for dizziness, one of them is benign paroxysmal positional vertigo (BPPV).

OBJECTIVES

A targeted diagnostic work-up and treatment of BPPV can prevent subsequent falls and a decline in the patients' quality of life, prolonged hospitalization with unnecessary examinations and medication.

DESIGN

Prospective examination of patients with a positive medical history of BPPV.

SETTING AND PARTICIPANTS

All patients treated within the Department of Geriatrics between 05/2015 and 03/2018 were included. A total of n = 5166 patients were screened (n = 2651 geriatrics; n = 2515 controls).

METHODS

All patients from other wards subjected to a neurological examination due to vertigo served as controls. Patients with typical hints in the medical history for a BPPV were subjected to the diagnostic Dix-Hallpike maneuver and, if positive, subsequent canalith repositioning maneuvers. The percentage of successful positional treatments was determined in both groups.

RESULTS

N = 254 patients (4.9 %) had indications in the medical history for a BPPV. For 71 of n = 254 patients (28 %; in total 1.4 %; mean age: 78.4 ± 12.3 years) the diagnosis of BPPV was proven by a positive Dix-Hallpike maneuver. N = 39 (54.9 %) patients belong to the geriatric group (mean age 82 years) and n = 32 (45.1 %) to the control group (mean age 73.9 years). The frequency of BPPV was similar in both groups (1.3-1.5 %). In 91.9 % of patients the BPPV was localized in the posterior semicircular canal. Up to 93 % were asymptomatic after one or repeated canalith repositioning maneuvers.

CONCLUSIONS AND IMPLICATIONS

The BPPV should be considered as an important differential diagnosis for geriatric patients with dizziness and falls. After therapeutic repositioning maneuvers most of the patients are asymptomatic. Therefore, targeted screening and therapy ("theragnostic") of BPPV at an advanced age increases diagnostic accuracy and prevents unnecessary examinations, medications and future falls.

Paraneoplastic Neuropathies: What's New Since the 2004 Recommended Diagnostic Criteria

The diagnostic criteria published by the PNS (Paraneoplastic Neurological Syndromes) Euronetwork in 2004 provided a useful classification of PNS, including paraneoplastic neuropathies. Subacute sensory neuronopathy (SSN) was the most frequently observed peripheral PNS, whereas other forms of neuropathy, as sensory polyneuropathy, sensorimotor polyneuropathy, demyelinating neuropathies, autonomic neuropathies, and focal nerve or plexus lesions, were less frequent. At the time of publication, the main focus was on onconeural antibodies, but knowledge regarding the mechanisms has since expanded. The antibodies associated with PNS are commonly classified as onconeural (intracellular) and neuronal surface antibodies (NSAbs). Since 2004, the number of antibodies and the associated tumors has increased. Knowledge has grown on the mechanisms underlying the neuropathies observed in lymphoma, paraproteinemia, and multiple myeloma. Moreover, other unrevealed mechanisms underpin sensorimotor neuropathies and late-stage neuropathies, where patients in advanced stages of cancer—often associated with weight loss—experience some mild sensorimotor neuropathy, without concomitant use of neurotoxic drugs. The spectrum of paraneoplastic neuropathies has increased to encompass motor neuropathies, small fiber neuropathies, and autonomic and nerve hyperexcitability syndromes. In addition, also focal neuropathies, as cranial nerves, plexopathies, and mononeuropathies, are considered in some cases to be of paraneoplastic origin. A key differential diagnosis for paraneoplastic neuropathy, during the course of cancer disease (the rare occurrence of a PNS), is chemotherapy-induced peripheral neuropathy (CIPN). Today, novel complications that also involve the peripheral nervous system are emerging from novel anti-cancer therapies, as targeted and immune checkpoint inhibitor (ICH) treatment. Therapeutic options are categorized into causal and symptomatic. Causal treatments anecdotally mention tumor removal. Immunomodulation is sometimes performed for immune-mediated conditions but is still far from constituting evidence. Symptomatic treatment must always be considered, consisting of both drug therapy (e.g., pain) and attempts to treat disability and neuropathic pain.

Understanding the Pathophysiology of Congenital Vestibular Disorders: Current Challenges and Future Directions

In congenital vestibular disorders (CVDs), children develop an abnormal inner ear before birth and face postnatal challenges to maintain posture, balance, walking, eye-hand coordination, eye tracking, or reading. Only limited information on inner ear pathology is acquired from clinical imaging of the temporal bone or studying histological slides of the temporal bone. A more comprehensive and precise assessment and determination of the underlying mechanisms necessitate analyses of the disorders at the cellular level, which can be achieved using animal models. Two main criteria for a suitable animal model are first, a pathology that mirrors the human disorder, and second, a reproducible experimental outcome leading to statistical power. With over 40 genes that affect inner ear development, the phenotypic abnormalities resulting from congenital vestibular disorders (CVDs) are highly variable. Nonetheless, there is a large subset of CVDs that form a common phenotype of a sac-like inner ear with the semicircular canals missing or dysplastic, and discrete abnormalities in the vestibular sensory organs. We have focused the review on this subset, but to advance research on CVDs we have added other CVDs not forming a sac-like inner ear. We have included examples of animal models used to study these CVDs. Presently, little is known about the central pathology resulting from CVDs at the cellular level in the central vestibular neural network, except for preliminary studies on a chick model that show significant loss of second-order, vestibular reflex projection neurons.

Breaking a dogma: acute anti-inflammatory treatment alters both post-lesional functional recovery and endogenous adaptive plasticity mechanisms in a rodent model of acute peripheral vestibulopathy

BACKGROUND

Due to their anti-inflammatory action, corticosteroids are the reference treatment for brain injuries and many inflammatory diseases. However, the benefits of acute corticotherapy are now being questioned, particularly in the case of acute peripheral vestibulopathies (APV), characterized by a vestibular syndrome composed of sustained spinning vertigo, spontaneous ocular nystagmus and oscillopsia, perceptual-cognitive, posturo-locomotor, and vegetative disorders. We assessed the effectiveness of acute corticotherapy, and the functional role of acute inflammation observed after sudden unilateral vestibular loss.

METHODS

We used the rodent model of unilateral vestibular neurectomy, mimicking the syndrome observed in patients with APV. We treated the animals during the acute phase of the vestibular syndrome, either with placebo or methylprednisolone, an anti-inflammatory corticosteroid. At the cellular level, impacts of methylprednisolone on endogenous plasticity mechanisms were assessed through analysis of cell proliferation and survival, glial reactions, neuron's membrane excitability, and stress marker. At the behavioral level, vestibular and posturo-locomotor functions' recovery were assessed with appropriate qualitative and quantitative evaluations.

RESULTS

We observed that acute treatment with methylprednisolone significantly decreases glial reactions, cell proliferation and survival. In addition, stress and excitability markers were significantly impacted by the treatment. Besides, vestibular syndrome's intensity was enhanced, and vestibular compensation delayed under acute methylprednisolone treatment.

CONCLUSIONS

We show here, for the first time, that acute anti-inflammatory treatment alters the expression of the adaptive plasticity mechanisms in the deafferented vestibular nuclei and generates enhanced and prolonged vestibular and postural deficits. These results strongly suggest a beneficial role for acute endogenous neuroinflammation in vestibular compensation. They open the way to a change in dogma for the treatment and therapeutic management of vestibular patients.

Predictors of treatment response to pharmacotherapy in patients with persistent postural-perceptual dizziness

The study aimed to identify the predictors of response to selective serotonin reuptake inhibitors (SSRIs) for 12 weeks in patients with persistent postural-perceptual dizziness (PPPD). Short-term treatment responses were studied in 197 outpatients [127 (64.5%) women, mean age ± SD = 51.7 ± 15.9] diagnosed with PPPD. Clinical and self-rated assessments were analyzed at the baseline and at the end of pharmacotherapy for 12 weeks. Multivariable logistic regression analysis was used to determine the following variables as the potential predictors of treatment response as measured by scoring in clinical global impression-improvement scale (CGI-I) scores: age, sex, comorbidity, baseline CGI-S score, Beck Depression Inventory-II score, State-Trait Anxiety Inventory score, Dizziness Handicap Inventory score at the baseline, and prescribed doses of antidepressants or benzodiazepines. The overall response rate to pharmacotherapy was 65.0% (128/197). Female sex and greater disease severity at the baseline (higher CGI-S score) were associated with a better response to the pharmacotherapy. Subgroup analyses by sex identified younger age and lower anxiety as the indicators for better outcomes in men, and absence of comorbidities in women. During the initial assessment, the severity of PPPD was associated with depressive symptoms and subjective functional handicap due to dizziness. The response to pharmacotherapy is favorable in PPPD. Sex, age and initial disease severity are the predictors of the response to SSRIs in patients with PPPD.

[Vestibular vertigo]

Vestibular vertigo is most often caused by benign paroxysmal positional vertigo (BPPV), Meniere's disease, vestibular neuritis, vestibular migraine or stroke. Features, diagnosis and treatment of vestibular vertigo in patients with these diseases are discussed. The authors analyze common diagnostic errors based on the data of 700 outpatients (205 men and 495 women, aged 25-88 years, mean age 55 years). It is noted that the cause of vertigo is often misdiagnosed with vertebral-basilar insufficiency, discirculatory encephalopathy, cervical spine pathology; at the same time, BPPV, Meniere's disease, vestibular neuritis or vestibular migraine is diagnosed less often. This fact reflects the lack of awareness of physicians about these diseases. BPPV, Meniere's disease and migraine are effectively treated and therefore their diagnosis and adequate treatment are of great importance.

Long-term vertigo control after cochlear implantation in patients with end-stage Menière's disease : A retrospective questionnaire-based cross-sectional study

Background

Menière’s disease (MD) is a symptom complex which is characterized by episodes of vertigo, tinnitus and fluctuating sensorineural hearing loss, which worsens during the course of the disease.

Objective

Vertigo attacks (MD functional level scale) before compared to after cochlear implantation in patients with end-stage MD.

Design and patients

In this questionnaire-based cross-sectional study eight patients with end-stage MD, who received a cochlear implant (CI) were analyzed.

Main outcome measure

The effect of the CI on vertigo was measured preoperatively and postoperatively with the Menière’s disease functional level scale and the Menière’s disease outcome questionnaire. The primary outcome parameter influence of vertigo attacks on daily living was analyzed using the non-parametric Wilcoxon signed rank test before and after CI.

Setting

Department of otolaryngology of a medical university.

Results

The primary outcome measure influence of vertigo attacks on daily living as measured by the MD functional level scale improved significantly after CI.

Conclusion

A CI can be an adequate treatment for vertigo attacks in patients with end-stage MD; however, due to the small sample size additional (multicenter) trials are necessary to confirm the findings.

The Vestibular System and Ageing

The world's population is ageing due to increased hygiene and improved medical care. Dizziness and imbalance frequently affect the elderly and is most common among individuals over the age of 60. In this age group approximately 30% of the population experience these debilitating symptoms at some point. They contribute to falls and frailty, which often result in hospitalization causing tremendous cost for the health care systems, and increased mortality. To make the matters worse balance disorders are often complex. Physicians face the difficulty of diagnosing the patient with the exact disorder especially since each disorder may manifest differently in each patient. In addition, several treatment options exist, however, with a low level of evidence. This chapter summarizes the underlying degenerative processes of the peripheral as well as the central vestibular system, diagnostic tools, the most common balance disorders in the elderly, and possible treatment options of these disorders.

Health care utilization, prognosis and outcomes of vestibular disease in primary care settings: systematic review

Vertigo and dizziness are frequent complaints in primary care that lead to extensive health care utilization. The objective of this systematic review was to examine health care of patients with vertigo and dizziness in primary care settings. Specifically, we wanted to characterize health care utilization, therapeutic and referral behaviour and to examine the outcomes associated with this. A search of the MEDLINE and EMBASE databases was carried out in May 2015 using the search terms ‘vertigo’ or ‘dizziness’ or ‘vestibular and primary care’ to identify suitable studies. We included all studies that were published in the last 10 years in English with the primary diagnoses of vertigo, dizziness and/or vestibular disease. We excluded drug evaluation studies and reports of adverse drug reactions. Data were extracted and appraised by two independent reviewers; 16 studies with a total of 2828 patients were included. Mean age of patients ranged from 45 to 79 with five studies in older adults aged 65 or older. There were considerable variations in diagnostic criteria, referral and therapy while the included studies failed to show significant improvement of patient-reported outcomes. Studies are needed to investigate current practice of care across countries and health systems in a systematic way and to test primary care-based education and training interventions that improve outcomes.

An overview of vestibular rehabilitation

Data related to the efficacy of vestibular rehabilitation and its evolution as an intervention are provided. Concepts and various treatment strategies are described, with explanations of why people with uncompensated peripheral and central vestibular disorders might improve with rehabilitation. Various tests and measures are described that are commonly used to examine patients and determine their level of ability to participate in their environment. Factors that affect recovery, both positively and negatively, are described in order to better prognosticate recovery. A case utilizing many of the principles discussed is included to provide insight into how to utilize vestibular rehabilitation with a person with an uncompensated peripheral vestibular loss.

Effectiveness of a Vestibular Rehabilitation Protocol to Improve the Health-Related Quality of Life and Postural Balance in Patients with Vertigo

Introduction Dizziness can be characterized as a balance disorder that causes discomfort, leading to several functional limitations. Currently, vestibular rehabilitation has been highlighted as a possible treatment. Objective Analyze the effects of completing a vestibular rehabilitation treatment protocol on quality of life and postural balance in patients with vestibular complaints, as well as to compare these effects between the patients taking or not taking antivertigo drugs. Methods A nonrandomized controlled trial was performed with 20 patients previously diagnosed with vestibular diseases. Information regarding vertigo symptoms, quality of life as assessed through the Dizziness Handicap Inventory, visual analog scale of dizziness, and stabilometry using force platform was collected. Patients were treated for 12 weeks by a custom protocol. The sample was divided into two groups according to the use (medicated group, n = 9) or not (control group, n = 11) of antivertigo drugs. Results There was improvement in quality of life (p < 0.001) and intensity of dizziness (p = 0.003) with the intervention. An improvement of postural balance was observed through functional tests. However, no statistically significant difference was noted in stabilometry. When both groups were compared, no statistically significant differences between the variations of the variables analyzed were found in the re-evaluation session. Conclusion Quality of life and postural balance are improved with intervention. However, this improvement is not associated with pharmacologic treatment.

Altered Actions of Memantine and NMDA-Induced Currents in a New Grid2-Deleted Mouse Line

Memantine is a non-competitive antagonist of the N-methyl-d-aspartate (NMDA) receptor, and is an approved drug for the treatment of moderate-to-severe Alzheimer’s disease. We identified a mouse strain with a naturally occurring mutation and an ataxic phenotype that presents with severe leg cramps. To investigate the phenotypes of these mutant mice, we screened several phenotype-modulating drugs and found that memantine (10 mg/kg) disrupted the sense of balance in the mutants. Moreover, the mutant mice showed an attenuated optokinetic response (OKR) and impaired OKR learning, which was also observed in wild-type mice treated with memantine. Microsatellite analyses indicated that the Grid2 gene-deletion is responsible for these phenotypes. Patch-clamp analysis showed a relatively small change in NMDA-dependent current in cultured granule cells from Grid2 gene-deleted mice, suggesting that GRID2 is important for correct NMDA receptor function. In general, NMDA receptors are activated after the activation of non-NMDA receptors, such as AMPA receptors, and AMPA receptor dysregulation also occurs in Grid2 mutant mice. Indeed, the AMPA treatment enhanced memantine susceptibility in wild-type mice, which was indicated by balance sense and OKR impairments. The present study explores a new role for GRID2 and highlights the adverse effects of memantine in different genetic backgrounds.

Betahistine exacerbates amikacin ototoxicity

OBJECTIVE

Betahistine augments cochlear blood flow and is currently used as an efficient therapeutic agent. Amikacin is used in a wide range of areas, but its ototoxic effect continues to be problematic. This study investigates the effect of betahistine on amikacin-induced ototoxicity.

METHODS

Thirty-two healthy rats were randomized to 4 groups of 8 rats in each group (amikacin, amikacin+betahistine, betahistine, and no treatment). Amikacin was administered intramuscularly to groups 1 and 2 for 14 days. Betahistine was delivered by oral gavage to groups 2 and 3 for 21 days. Distortion-product otoacoustic emissions (DPOAE) and auditory brainstem response (ABR) tests were conducted on all rats.

RESULTS

There were significant decreases in the DPOAE levels and significant increases in the ABR thresholds of the amikacin and amikacin+betahistine groups on the 7th, 14th, and 21st days, as compared to their basal values. The DPOAE levels of the amikacin+betahistine group significantly decreased on days 7, 14, and 21, and the ABR thresholds significantly increased on the same days, as compared to the amikacin group.

CONCLUSION

Our study implies that amikacin's ototoxic effects are augmented by the concurrent use of betahistine. Experimental and clinical research, supported by histopathological studies, is needed to affirm our findings.

Health services utilization of patients with vertigo in primary care: a retrospective cohort study

Vertigo and dizziness count among the most frequent symptoms in outpatient practices. Although most vestibular disorders are manageable, they are often under- and misdiagnosed in primary care. This may result in prolonged absence from work, increased resource use and, potentially, in chronification. Reliable information on health services utilization of patients with vertigo in primary care is scarce. Retrospective cohort study in patients referred to a tertiary care balance clinic. Included patients had a confirmed diagnosis of benign paroxysmal positional vertigo (BPPV), Menière's disease (MD), vestibular paroxysmia (VP), bilateral vestibulopathy (BVP), vestibular migraine (VM), or psychogenic vertigo (PSY). All previous diagnostic and therapeutic measures prior to the first visit to the clinic were recorded. 2,374 patients were included (19.7 % BPPV, 12.7 % MD, 5.8 % VP, 7.2 % BVP, 14.1 % VM, 40.6 % PSY), 61.3 % with more than two consultations. Most frequent diagnostic measures were magnetic resonance imaging (MRI, 76.2 %, 71 % in BPPV) and electrocardiography (53.5 %). Most frequent therapies were medication (61.0 %) and physical therapy (41.3 %). 37.3 % had received homoeopathic medication (39 % in BPPV), and 25.9 % were treated with betahistine (20 % in BPPV). Patients had undergone on average 3.2 (median 3.0, maximum 6) diagnostic measures, had received 1.8 (median 2.0, maximum 8) therapies and 1.8 (median 1.0, maximum 17) different drugs. Diagnostic subgroups differed significantly regarding number of diagnostic measures, therapies and drugs. The results emphasize the need for establishing systematic training to improve oto-neurological skills in primary care services not specialized on the treatment of dizzy patients.

4-aminopyridine does not enhance flocculus function in tottering, a mouse model of vestibulocerebellar dysfunction and ataxia

The potassium channel antagonist 4-aminopyridine (4-AP) improves a variety of motor abnormalities associated with disorders of the cerebellum. The most rigorous quantitative data relate to 4-AP's ability to improve eye movement deficits in humans referable to dysfunction of the cerebellar flocculus. Largely based on work in the ataxic mouse mutant tottering (which carries a mutation of the Cacna1a gene of the P/Q voltage-activated calcium channel), 4-AP is hypothesized to function by enhancing excitability or rhythmicity of floccular Purkinje cells. We tested this hypothesis by determining whether systemic or intrafloccular administration of 4-AP would ameliorate the eye movement deficits in tottering that are attributable to flocculus dysfunction, including the reductions in amplitude of the yaw-axis vestibulo-ocular reflex (VOR) and vision-enhanced vestibulo-ocular reflex (VVOR), and the optokinetic reflex (OKR) about yaw and roll axes. Because tottering's deficits increase with age, both young and elderly mutants were tested to detect any age-dependent 4-AP effects. 4-AP failed to improve VOR, VVOR, and OKR gains during sinusoidal stimuli, although it may have reduced the tendency of the mutants' responses to VOR and VVOR to decline over the course of a one-hour recording session. For constant-velocity optokinetic stimuli, 4-AP generated some enhancement of yaw OKR and upward-directed roll OKR, but the effects were also seen in normal C57BL/6 controls, and thus do not represent a specific reversal of the electrophysiological consequences of the tottering mutation. Data support a possible extra-floccular locus for the effects of 4-AP on habituation and roll OKR. Unilateral intrafloccular 4-AP injections did not affect ocular motility, except to generate mild eye elevations, consistent with reduced floccular output. Because 4-AP did not produce the effects expected if it normalized outputs of floccular Purkinje cells, there is a need for further studies to elucidate the drug's mechanism of action on cerebellar motor dysfunction.

Referral and final diagnoses of patients assessed in an academic vertigo center

Objective: To identify under-diagnosed neuro-otological disorders and to evaluate whether under-diagnosing depends on the age of the patient. Materials and methods: Retrospective analysis of medical charts from 951 consecutive patients (685 under and 266 above the age of 65 years) who entered diagnostic procedures at the Interdisciplinary Center for Vertigo and Balance Disorders, University Hospital Zurich, Switzerland. Final diagnoses were compared to referral diagnoses. Results: Relative to referral diagnoses, the proportion of patients finally diagnosed with benign paroxysmal positional vertigo (BPPV) almost doubled both in younger (<65 year from 12.7 to 25.1%) and older patients (from 20.7 to 37.6%). Striking relative increases were found for the diagnoses multisensory dizziness in older patients (from 20.7 to 37.6%) and vestibular migraine in younger patients (1.8 to 20.2%). In both age groups, the proportion of patients with undetermined diagnoses was reduced by about 60% (younger: 69.8 to 9.8%; older: 69.2 to 12.4%) by the diagnostic procedures in the vertigo center. These changes were all significant (p < 0.05) in McNemar tests with continuity correction (2 × 2 tables: focused diagnosis vs. other diagnoses, referral vs. final). Conclusion: Significant changes of diagnoses can be expected by a specialized neuro-otological work-up. In particular, BPPV, multisensory dizziness, and vestibular migraine are under-diagnosed by referring physicians. This finding calls for better education of primary care takers in the field of neuro-otology.

A review of the burden of vertigo

AIM AND OBJECTIVES

To provide an overview of vertigo and its management and identify its impact on individuals to offer strategies for managing the condition.

BACKGROUND

Dizziness and vertigo are symptoms common to many pathologies/dysfunctions ranging from the benign to the potentially serious; many are poorly understood. Although rarely life-threatening, vertigo is debilitating and significantly affects quality of life; it may be as disabling as paralysis or loss of a limb. Although 40-80% of cases remain unexplained, referral for specific investigation is rare.

DESIGN

A narrative literature review including descriptive, theoretical and empirical material reliant on the keywords 'dizziness' and 'vertigo' and the phrase 'vestibular disorders'. This provided diverse information that was used to address the research questions.

RESULTS

Vertigo is a widespread and potentially distressing symptom that may arise at any age and be acute or chronic. For most, it resolves spontaneously; for others, dizziness persists, causing significant distress. Its management is challenging, especially when the underlying cause is unclear. Pharmacological interventions, physiotherapy, psychotherapy or, rarely, surgery can be used in its management. Few nursing studies are available, suggesting that nursing knowledge may be limited.

RELEVANCE TO CLINICAL PRACTICE

Although nurses may frequently encounter patients with vertigo, there are few relevant nursing studies in this area; few consider appropriate nursing interventions or approaches to patient care. The information provided reveals that understanding the full impact of the condition and identification of patients' needs are essential to effective care. Some strategies to help affected patients are outlined.

CONCLUSIONS

Vertigo, a widespread, often intractable condition, affects significant numbers of people; diagnosis and management can be challenging. Treatment, care and support must be selected on an individual basis taking individuals into account. The primary goals are to maintain physical status, psychosocial interaction and quality of life.

Saccades and smooth pursuit eye movements in central vertigo

In order to analyze the diagnostic efficiency of saccadic and pursuit eye movements compared to findings from brain magnetic resonance imaging in patients with central vertigo, 108 patients were selected from 580 dizzy patients as cases of suspected central origin; the saccadic and pursuit eye movements were evaluated by electronystagmography and findings were compared to information from magnetic resonance imaging. The study of oculomotor movements in patients suspected of having a central lesion revealed a 83.3% sensitivity and 21.2% specificity. Restricting consideration to severe alterations in eye movements as indicative of a central origin, this test gives a 71.4% sensitivity and 50.0% specificity. In conclusion, the study of alterations in oculomotor movements, in patients with suspected central lesions, proved to be a test with good sensitivity also compared with results of magnetic resonance imaging.

Which medication do I need to manage dizzy patients?

Vertigo and dizziness are not independent disease entities, but instead symptoms of various diseases. Accordingly, a variety of treatment approaches are required. Here we review the most relevant drugs for managing dizziness, vertigo, and nystagmus syndromes. It is important to differentiate symptomatic treatment of nausea and vomiting with, for example, dimenhydrinate and benzodiazepines, and prophylactic treatment of motion sickness with scopolamine from a causal therapy of the underlying disorders. Examples of such causal therapy include aminopyridines for downbeat nystagmus and episodic ataxia type 2; carbamazepine for vestibular paroxysmia, paroxsymal dysarthria and ataxia in multiple sclerosis, and superior oblique myokymia; betahistine, dexamethasone, and gentamicin for Menière's disease; gabapentin and memantine for different forms of acquired and congenital nystagmus; corticosteroids for acute vestibular neuritis and Cogan's syndrome; metoprolol and topiramate for vestibular migraine; and selective serotonin reuptake inhibitors such as paroxetine for phobic postural vertigo. The clinical entities are briefly described, the various medications are discussed in alphabetical order, and dosage, major side effects, contraindications, and alternative medications of each drug are displayed in boxes for easy reference.

GNL-HybELS: an algorithm to classify and identify VOR responses simultaneously

The Vestibulo-Ocular Reflex (VOR) stabilizes the images of the world on the retinae when the head is in motion. Basic daily activities such as walking or driving depend on the proper functioning of this reflex. For several decades, scientists have developed methods to model and identify this system mathematically. However, traditional methods cannot analyze VOR data comprehensively because they disregard pieces of data (fast phases) which biases estimated reflex dynamics. Here we propose, for the first time, an automated tool to analyze entire VOR responses (slow and fast phases), without apriori classification of nystagmus segments.