Migrainous Vertigo

Migraine management for the otolaryngologist

Objective

To characterize migraine pathophysiology, presentation, and current treatment strategies, specifically in regard to vestibulocochlear manifestations of migraine.

Methods

Narrative review of available literature.

Results

Migraine disorder can be described as a spectrum of otologic manifestations, with vestibular migraine now recognized with fully-fledged diagnostic criteria. Otologic manifestations are theorized to be due, in part, to trigeminal innervation of the inner ear structures and calcitonin gene-related peptide (CGRP) expression within the labyrinth. Patients can experience vertigo, aural fullness, enhanced tinnitus, and hearing loss without the characteristic migraine headache, leading to under recognition of these symptoms as migraine-related. Meniere's disease, mal de débarquement syndrome, persistent postural perceptual dizziness, and recurrent benign paroxysmal positional vertigo have close associations to migraine and may exist on the migraine spectrum. Migraine treatment consists of two goals: halting acute attacks (abortive therapy) and preventing attacks (prophylactic therapy). Abortive medications include triptans, corticosteroids, anti-histamines, and anti-emetics. Pharmacologic prophylaxis in conjunction with lifestyle modifications can decrease frequency and severity of symptoms and include tricyclic antidepressants, calcium channel blockers, anti-epileptic medications, selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, beta-blockers, gepants, and monoclonal antibodies to CGRP. Promising evidence is emerging regarding the ability of migraine medications to positively treat the various otologic symptoms of migraine.

Conclusion

Migraine disorder manifesting with primarily cochleovestibular symptoms can be challenging to diagnose and manage for practicing clinicians. Patients with various vestibulopathies that are closely related to migraine may benefit from migraine treatment. Lifestyle choices and prophylactic medications are key to satisfactorily preventing acute migrainous attacks and improve function.

Management of Migraine-Associated Vestibulocochlear Disorders

Migraine is a chronic neurological disorder that frequently coexists with different vestibular and cochlear symptoms (sudden hearing loss, tinnitus, otalgia, aural fullness, hyperacusis, dizziness, imbalance, and vertigo) and disorders (recurrent benign positional vertigo, persistent postural perceptual dizziness, mal de debarquement, and Menière's disease). Despite evidence of an epidemiological association and similar pathophysiology between migraine and these vestibulocochlear disorders, patients suffering from migraine-related symptoms are usually underdiagnosed and undertreated. Current migraine treatment options have shown success in treating vestibulocochlear symptoms. Lifestyle and dietary modifications (reducing stress, restful sleep, avoiding migraine dietary triggers, and avoiding starvation and dehydration) and supplements (vitamin B2 and magnesium) offer effective first-line treatments. Treatment with migraine prophylactic medications such as tricyclic antidepressants (e.g., nortriptyline), anticonvulsants (e.g., topiramate), and calcium channel blockers (e.g., verapamil) is implemented when lifestyle and dietary modifications are not sufficient in improving a patient's symptoms. We have included an algorithm that outlines a suggested approach for addressing these symptoms, taking into account our clinical observations. Greater recognition and understanding of migraine and its related vestibular and cochlear symptoms are needed to ensure the appropriate diagnosis and treatment of affected patients.

Impairments to the multisensory integration brain regions during migraine chronification: correlation with the vestibular dysfunction

Objectives

Migraine is often combined with vestibular dysfunction, particularly in patients with chronic migraine (CM). However, the pathogenesis of migraine chronification leading to vestibular dysfunction is not fully understood. The current study investigated whether structural or functional impairments to the brain during migraine chronification could be associated with vestibular dysfunction development.

Methods

The eligible participants underwent clinical assessment and magnetic resonance imaging (MRI) scans. Voxel-based morphometry (VBM) determined structural impairment by evaluating alterations in gray matter volume (GMV). Functional impairment was assessed by the mean amplitude of low-frequency fluctuation (mALFF). Furthermore, the resting-state functional connectivity (rsFC) of regions possessing impairment was examined with a seed-based approach. We also analyzed the correlations between altered neuroimaging features with clinical variables and performed multiple linear regression.

Results

Eighteen CM patients, 18 episodic migraine (EM) patients, and 18 healthy controls (HCs) were included in this study. A one-way ANOVA indicated the group differences in mALFF. These were located within right supramarginal gyrus (SMG), left angular gyrus (AG), middle frontal gyrus (MFG), left middle occipital gyrus (MOG), right rolandic operculum (Rol) and left superior parietal gyrus (SPG). During rsFC analysis, the CM group had more enhanced rsFC of left SPG with left MOG than the EM and HC groups. The EM group revealed enhanced rsFC of left SPG with left AG than the CM and HC groups. In multiple linear regression, after controlling for age, body mass index (BMI) and disease duration, the rsFC of left SPG with left MOG (β = 48.896, p = 0.021) was found to predict the total Dizziness Handicap Inventory (DHI) score with an explained variance of 25.1%. Moreover, the rsFC of left SPG with left MOG (β = 1.253, p = 0.003) and right SMG (β = -1.571, p = 0.049) were significant predictors of migraine frequency, accounting for a total explained variance of 73.8%.

Conclusion

The functional impairments due to migraine chronification are primarily concentrated in the multisensory integration-related brain regions. Additionally, the rsFC of SPG with MOG can predict the frequency of migraine and the degree of vestibular dysfunction. Therefore, these neuroimaging features could be potential mechanisms and therapeutic targets for developing vestibular dysfunction in migraine.

Physical therapy and migraine: musculoskeletal and balance dysfunctions and their relevance for clinical practice

BACKGROUND

Migraine is a primary headache with high levels of associated disability that can be related to a variety of symptoms and comorbidities. The role of physical therapy in the management of migraine is largely unknown. Therefore, the aim of this review is to highlight and critically discuss the current literature and evidence for physical therapy interventions in individuals with migraines.

METHODS

A narrative review of the literature was performed.

RESULTS

Physical therapists assessing and treating patients with migraine should focus on two primary aspects: (1) musculoskeletal dysfunctions, and (2) vestibular symptoms/postural control impairment. Signs and symptoms of musculoskeletal and/or vestibular dysfunctions are prevalent among individuals with migraines and different disability levels can be observed depending on the presence of aura or increment of the migraine attacks.

CONCLUSION

A proper physical examination and interview of the patients will lead to a tailored treatment plan. The primary aim regarding musculoskeletal dysfunctions is to reduce pain and sensitization, and physical therapy interventions may include a combination of manual therapy, exercise therapy, and education. The aim regarding postural control impairment is to optimize function and reduce vestibular symptoms, and interventions should include balance exercises and vestibular rehabilitation. However, consistent evidence of benefits is still lacking due to the lack of and therefore need for tailored and pragmatic clinical trials with high methodological quality.

Presence of vestibular symptoms and related disability in migraine with and without aura and chronic migraine

Objective

To assess the presence and handicap due to vestibular symptoms in three subgroups of patients with migraine and controls.

Methods

Women between 18–55 years old were diagnosed by headache specialists and stratified as migraine with aura (n = 60), migraine without aura (n = 60), chronic migraine (n = 60) and controls (n = 60). Information regarding demographics, headache and vestibular symptoms were collected in this cross-sectional study. The self-perceived handicap related to vestibular symptoms was assessed through the Dizziness Handicap Inventory questionnaire.

Results

A total of 85% of women with migraine with aura and chronic migraine had vestibular symptoms contrasted to 70% of the migraine without aura group ( p < 0.05), and 12% of the control group reported symptoms ( p < 0.0001). Patients with migraine exhibited greater Dizziness Handicap Inventory scores than controls ( p < 0.001); and migraine with aura and chronic migraine groups reached greater scores than migraine without aura ( p < 0.01). Presence of migraine is associated with a greater risk of vestibular symptoms (migraine without aura: 5.20, migraine with aura: 6.60, chronic migraine:6.20, p < 0.0003) and with a greater risk of moderate-to-severe handicap (migraine without aura: 20.0, migraine with aura: 40.0, chronic migraine: 40.0, p < 0.0003). The presence of aura and greater migraine frequency adds to the risk of any handicap (migraine with aura: 1.9, chronic migraine: 1.7, p < 0.04) and to the risk of moderate-to-severe handicap (migraine with aura: 2.0, chronic migraine: 2.0, p < 0.0003). Migraine aura, intensity and frequency predict 36% of the dizziness handicap.

Conclusion

The prevalence of vestibular symptoms is increased in migraine during and between headache attacks, particularly in migraine with aura and chronic migraine along with an increased handicap due to those symptoms. Vestibular symptoms among subgroups of migraine should be considered when evaluating the functional impact of migraine.

Vestibular migraine in an otolaryngology clinic: prevalence, associated symptoms, and prophylactic medication effectiveness

OBJECTIVE

To assess the prevalence of vestibular migraine (VM) in patients consulting to an otolaryngology clinic, the neuro-otological associated symptoms, and the effect of prophylactic antimigrainous medication on VM symptom improvement.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary referral otolaryngology clinic.

SUBJECTS AND METHODS

We used the diagnostic criteria from the Bárány Society and the International Headache Society to allocate patients to a subgroup: VM, possible VM, and atypical VM.

MAIN OUTCOME MEASURE

The prevalence of VM, percentages of associated neurotological symptoms, and percentages of effectiveness of prophylactic medication.

RESULTS

Sixty-five (16%) patients were selected from the total patient population (n = 407) from which 4.2% were assigned to the definite VM group, 5.7% to the probable VM group, and 6.1% to the atypical VM group. We found a significantly different distribution between the groups for photophobia (p = 0.035), ear pressure (p = 0.023), and scotoma (p = 0.015). Thirty patients were administered with flunarizine and 68% responded with an improvement in VM symptoms (p < 0.001). For propranolol, 31 patients were treated and there was an improvement of symptoms in 73% (p < 0.001). Remarkable was the fact that these percentages were not significantly different between the subgroups.

CONCLUSION

VM is a common disorder presenting in a dizziness clinic, and detailed history taking is important to assess VM-associated symptoms and thus to prevent underdiagnosis. The latter is very important because our study shows that the majority of patients, regardless of VM subtype, can benefit from a prophylactic treatment, but further prospective studies are necessary.

Vestibular functioning and migraine: pilot study comparing those with and without vertigo

Background:

The current study compared a migrainous vertigo group with a migraine without vertigo group. It was hypothesised that those with migrainous vertigo would have more abnormal test results during a non-migrainous period than those who suffer from migraine without vertigo.

Methods:

Both groups, comprising 10 participants each, were tested using: the gaze stabilisation test, dynamic visual acuity test, sensory organisation test, head shake sensory organisation test and functional gait assessment.

Results:

Eighteen females and 2 males aged 18–53 years participated. There were no significant differences between the two groups for the dynamic visual acuity test, sensory organisation test or head shake sensory organisation test. However, mean dynamic visual acuity loss was greater in both groups than in a normal population, and the head shake sensory organisation (sway) test was well below the normal mean. The functional gait assessment showed a significant difference (p = 0.0025) between the two groups.

Conclusion:

Both groups showed abnormalities in vestibular functioning compared with norms, suggesting that both had some degree of vestibular dysfunction. However, vestibular dysfunction was greater in the migrainous vertigo group than in the migraine without vertigo group, as evidenced by differences in functional gait assessment.

Vestibular functioning and migraine: comparing those with and without vertigo to a normal population

Objective:

This study compared vestibular functioning in a migrainous vertigo group, a migraine without vertigo group and a control group. It was hypothesised that the migrainous vertigo group would perform worse in tests of vestibular function and gait than the other groups during a non-migrainous period.

Methods:

Sixty-six participants (22 per group) were assessed using the head shake sensory organisation test, the gaze stabilisation test, the dynamic visual acuity test and the functional gait assessment. Separate analyses of variance and planned pair-wise comparisons (alpha = 0.05) were performed.

Results:

There was a difference between the results of the non-migraine group and the two migraine groups for the gaze stabilisation pitch test (p < 0.003), in which the control group showed faster head movement. There were also group differences in functional gait (p < 0.0001); the control group scored highest and the migrainous vertigo group scored lowest. There were no differences in the vestibular spinal reflex and balance tests.

Conclusion:

These findings indicate underlying differences in the vestibular ocular reflexes and function of migraine sufferers compared with those who do not suffer migraines, but the difference is most pronounced for those with migrainous vertigo. This suggests that vestibular rehabilitation for migrainous vertigo should focus on vestibular ocular reflexes and functional retraining.

Impairment of habituation of the auditory brain stem response in migrainous vertigo

OBJECTIVES

We evaluated the auditory brain stem response (ABR) in migrainous vertigo (MV).

METHODS

Four subjects who met clinical criteria for definite MV and 4 subjects with non-vertiginous migraine (NVM) underwent ABR testing while asymptomatic and within 16 hours of a symptomatic episode. Four control subjects were also tested. A set of 4 consecutive 750-click series was administered at 50-, 60-, and 70-dB intensities. We compared the groups in terms of habituation of the amplitude of wave IV-V (habituation of IV-V) from the first through fourth series for each set.

RESULTS

The habituation of IV-V amplitude to 50-dB stimuli was significantly less (p = 0.047) in the symptomatic MV group (5.08% +/- 22.32%) than in the symptomatic NVM group (-21.44% +/- 13.50%) or the control group (-26.06% +/- 9.76%). The habituation of IV-V amplitude to 70-dB stimuli in the MV group was significantly less (p = 0.031) during symptomatic testing (-3.43% +/- 8.89%) than during asymptomatic testing (-21.23% +/- 6.41%).

CONCLUSIONS

The habituation of IV-V amplitude is reduced during MV attacks. This finding suggests impaired brain stem inhibition at the level of the inferior colliculus, which shares serotonergic connections with the dorsal raphe nucleus, an area hyperactive in migraine.

Does Ménière's Disease in the Elderly Present Some Peculiar Features?

Object. Aim of our study was to establish some peculiar features of Ménière's Disease (MD) in a group of elderly MD patients, in which the first vertigo spell happened when over 65 years old. Material and Methods. We analyzed a group of 73 younger than 65-years-old and a group of 30 elderly MD patients. All patients underwent a neurotological evaluation, an anamnestic evaluation including a lifetime history of migraine, and blood withdrawal for autoantibody screening. Results. Some differences were found between elderly and younger MD patients. Elderly MD patients presented a higher prevalence of Tumarkin attacks and a lower prevalence of lifetime history of migraine; moreover, they presented a faster develop of hearing loss and vertigo spells than a subgroup of 32 younger patients matched for the duration of illness. Conclusions. Some clinical features of MD in elderly have been pointed out. Particularly, the lower rate of migrainous history and positivity for autoantibodies often associated with MD, in our opinion, support the hypothesis of a vascular disorder acting as a predisposing factor for MD in elderly.

Migraine-associated vertigo: a review of the pathophysiology and differential diagnosis

The clinical diagnosis of migraine-associated vertigo may be difficult because it shares features with some other clinical conditions. This communication presents a systematic review on the epidemiology and theories of pathophysiology of migraine-associated vertigo and its distinguishing features from peripheral vestibular disorders. We searched the Cochrane Library, MEDLINE, and Google scholar for all the studies on migraine-associated vertigo published in English language between 1966 and 2010. Their references were also reviewed for completion. Data from the studies were independently extracted and assessed by the three authors using standardized data forms. There was consensus between the authors on the studies in this review that met the criteria. Forty-five studies were identified and independently assessed based on the objectives of the study by the authors. All the studies discussed on the epidemiology of the migraine-associated vertigo, six discussed on the pathophysiology, while differential diagnosis were documented in thirty-two studies. In conclusion, migraine-associated vertigo is a global distinct disease entity that can be clinically distinguished from peripheral vestibular disorders. Abstinence from trigger factors remains imperative in the control, whereas some medications have been found useful in the management.

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.

Genetic investigations of Meniere's disease

Meniere's disease remains a disorder of unknown origin despite the collective efforts to determine the pathogenesis, although experts have long recognized that disease development likely has some heritable component. Although genetic studies of Meniere's disease have been inconclusive, increasing knowledge of human genetic structure and mutation and investigative techniques have potential to further understanding of this disorder.

Vestibular migraine

Vestibular migraine is a chameleon among the episodic vertigo syndromes because considerable variation characterizes its clinical manifestation. The attacks may last from seconds to days. About one-third of patients presents with monosymptomatic attacks of vertigo or dizziness without headache or other migrainous symptoms. During attacks most patients show spontaneous or positional nystagmus and in the attack-free interval minor ocular motor and vestibular deficits. Women are significantly more often affected than men. Symptoms may begin at any time in life, with the highest prevalence in young adults and between the ages of 60 and 70. Over the last 10 years vestibular migraine has evolved into a medical entity in dizziness units. It is the most common cause of spontaneous recurrent episodic vertigo and accounts for approximately 10% of patients with vertigo and dizziness. Its broad spectrum poses a diagnostic problem of how to rule out Menière's disease or vestibular paroxysmia. Vestibular migraine should be included in the International Headache Classification of Headache Disorders (ICHD) as a subcategory of migraine. It should, however, be kept separate and distinct from basilar-type migraine and benign paroxysmal vertigo of childhood. We prefer the term "vestibular migraine" to "migrainous vertigo," because the latter may also refer to various vestibular and non-vestibular symptoms. Antimigrainous medication to treat the single attack and to prevent recurring attacks appears to be effective, but the published evidence is weak. A randomized, double-blind, placebo-controlled study is required to evaluate medical treatment of this condition.

Dizziness, migrainous vertigo and psychiatric disorders

OBJECTIVES

This study sought to establish the prevalence of vestibular disorders, migraine and definite migrainous vertigo in patients with psychiatric disorders who were referred for treatment of dizziness, without a lifetime history of vertigo.

STUDY DESIGN

Retrospective study.

SETTING

Out-patients in a university hospital.

MATERIALS AND METHODS

Fifty-two dizzy patients with panic disorders and agoraphobia, 30 with panic disorders without agoraphobia, and 20 with depressive disorders underwent otoneurological screening with bithermal caloric stimulation. The prevalence of migraine and migrainous vertigo was assessed. The level of dizziness was evaluated using the Dizziness Handicap Inventory.

RESULTS

Dizzy patients with panic disorders and agoraphobia had a significantly p = 0.05 regarding the prevalence of peripheral vestibular abnormalities in the group of subjects with PD and agoraphobia and in those with depressive disorders. Migraine was equally represented in the three groups, but panic disorder patients had a higher prevalence of migrainous vertigo definite migrainous vertigo. Almost all patients with a peripheral vestibular disorder had a final diagnosis of definite migrainous vertigo according to Neuhauser criteria. These patients had higher Dizziness Handicap Inventory scores. The Dizziness Handicap Inventory total score was higher in the subgroup of patients with panic disorders with agoraphobia also presenting unilateral reduced caloric responses or definite migrainous vertigo, compared with the subgroup of remaining subjects with panic disorders with agoraphobia (p < 0.001).

CONCLUSIONS

Our data support the hypothesis that, in patients with panic disorders (and especially those with additional agoraphobia), dizziness may be linked to malfunction of the vestibular system. However, the data are not inconsistent with the hypothesis that migrainous vertigo is the most common pathophysiological mechanism for vestibular disorders.

[Vertigo treatment according to their mechanisms]

Vertigo is an illusion of rotatory or linear movement that demonstrates a functional or lesional disturbance of the vestibular system, from periphery to central connections. According to the ANAES report (1997), benign paroxysmal positional vertical vertigo, vestibular neuronitis and Ménière's disease account for 40-50% of all mixed vertigo etiologies. Central etiologies may account for 20-40% of causes and 10-40% remain more difficult to classify, and are usually classified under the term of "peripheral vestibulopathy." These include vertigo due to neurovascular compression syndrome of the VIIIth nerve. Clinical manifestations, differential diagnosis, and treatment of the main etiologies of vertigo will be developed in this chapter. A specific section will discuss the subject of neurovascular compression syndrome of the VIIIth nerve. Even though some publications should be challenged, it appears that neurovascular compression syndrome of the VIIIth nerve might explain some cases of vertigo or chronic instability, with or without cochlear signs. The diagnosis is difficult and must be established on multiple clinical, electrophysiological and radiological arguments. A therapeutic test with antiepileptic drugs is helpful. The treatment includes these drugs as a first option but may require a neurosurgical approach if medical treatment fails.

Migraine associated with auditory-vestibular dysfunction

The association between hearing and balance disorders with migraine is known since the times of the ancient Greeks, when Aretaeus from Cappadocia in 131 B.C, made an accurate and detailed description of this occurrence during a migraine episode. We present a broad review of migraine neurotological manifestations, using the most recent publications associated with epidemiology, clinical presentation, pathophysiology, diagnostic methods and treatment for this syndrome.

AIM

To describe the clinical entity: "Migraine associated with auditory-vestibular dysfunction" in order to help otorhinolaryngologists and neurologists in the diagnosis and management of such disorder.

FINAL REMARKS

There is a strong association between neurotological symptoms and migraine, and the auditory-vestibular dysfunction-associated migraine is the most common cause of spontaneous episodic vertigo (non-positional). Symptoms may vary broadly among patients, making it a diagnostic challenge to the otorhinolaryngologist. This entity usually presents with positional or spontaneous vertigo spells, lasting for seconds or days, associated with migraine symptoms. A better understanding of the relationship between central vestibular mechanisms and migraine mechanisms, besides the discovery of ionic channel disorders in some cases of migraine, ataxia and vertigo, may lead to a better understanding of migraine pathophysiology associated with audio-vestibular disorder.

Enxaqueca associada a disfunção auditivo-vestibular

A associação de distúrbios da audição e equilíbrio com enxaqueca é reconhecida desde a Grécia antiga quando Aretaeus da Capadócia em 131 a.C., fez uma descrição precisa e com detalhes desta ocorrência durante uma crise de enxaqueca. Uma revisão ampla das manifestações otoneurológicas da enxaqueca é apresentada, usando as mais recentes publicações com respeito à epidemiologia, apresentação clínica, fisiopatologia, métodos diagnósticos e manejo desta síndrome. OBJETIVO: Descrever a entidade clínica "Enxaqueca associada a Disfunção Auditivo-vestibular" no intuito de ajudar médicos otorrinolaringologistas e neurologistas no diagnóstico e no manejo clínico dessa doença. COMENTÁRIOS FINAIS: Uma forte associação existe entre sintomas otoneurológicos e enxaqueca, sendo a enxaqueca associada a disfunção auditivo-vestibular a causa mais comum de vertigem episódica espontânea (não-posicional). Os sintomas podem variar bastante entre pacientes tornando um desafio diagnóstico para o otorrinolaringologista. Esta entidade geralmente se apresenta com ataques de vertigem espontâneos ou posicionais, durando de segundos a dias com sintomas de enxaqueca associados. Uma melhor elucidação da ligação entre os mecanismos vestibulares centrais e os mecanismos da enxaqueca em si, além da descoberta de defeitos em canais iônicos em algumas causas de enxaqueca, ataxia e vertigem, podem levar a um entendimento maior da fisiopatologia da enxaqueca associada a disfunção auditivo-vestibular.

Vertigo, dizziness and imbalance in the elderly

Objective:

The aim of this retrospective analysis was to evaluate the diagnosis of vertigo, dizziness and imbalance in elderly patients in two tertiary neurotology clinics.

Design and setting:

Six hundred and seventy-seven patients aged over 65 years were assessed by the same senior author, and 601 patients were enrolled in the study.

Results:

The most frequent diagnoses were benign paroxysmal positional vertigo (42.43 per cent), idiopathic vestibulopathy (20.29 per cent), migraine vestibulopathy (13.15 per cent), Ménière's disease (12.47 per cent) and acute vestibular attack (6.49 per cent).

Conclusion and significance:

This retrospective study showed that 93.5 per cent of the elderly patients studied had been diagnosed with peripheral vertigo. The majority of patients had been classified as having benign paroxysmal positional vertigo, idiopathic vestibulopathy or migraine vestibulopathy.

Episodic ataxia type 2

Episodic ataxia type 2 (EA 2) is a rare neurological disorder of autosomal dominant inheritance resulting from dysfunction of a voltage-gated calcium channel. It manifests with recurrent disabling attacks of imbalance, vertigo, and ataxia, and can be provoked by physical exertion or emotional stress. In the spell-free interval, patients present with central ocular motor dysfunction, mainly downbeat nystagmus. A slow progression of cerebellar signs accompanied by a slight atrophy of midline cerebellar structures is commonly observed during the course of the disease. EA 2 is caused most often by the loss of function mutations of the calcium channel gene CACNA1A, which encodes the Ca(v)2.1 subunit of the P/Q-type calcium channel and is primarily expressed in Purkinje cells. To date, more than 30 mutations have been described. Two effective treatment options have been established for EA 2: acetazolamide (ACTZ), which probably changes the intracellular pH and thereby the transmembraneous potential, and 4-aminopyridine (4-AP), a potassium channel blocker. Approximately 70% of all patients respond to treatment with ACTZ, but the effect is often only transient. In an open trial, 4-AP prevented attacks in five of six patients with EA 2, most likely by increasing the resting activity and excitability of the Purkinje cells. These findings were confirmed by experiments in animal models of EA 2. Many aspects of the pathophysiology (e.g., induction of the attacks) and treatment of EA 2 (e.g., mode of action of ACTZ and 4-AP) still remain unclear and need to be addressed in further animal and clinical studies.