Clinical and electrographic findings in epileptic vertigo and dizziness: a systematic review

Clinical features and outcome of 10 dogs with suspected idiopathic vestibular epilepsy

BACKGROUND

In humans, vestibular epilepsy (VE) is described as focal seizures with transient signs of vestibular disease. In dogs, 2 cases of vestibular episodes, called vestibular paroxysmia, are reported.

HYPOTHESIS/OBJECTIVES

The objective of this study was to define the clinical features, phenotypical manifestation, and outcome of suspected VE in dogs.

ANIMALS

Ten dogs with recurrent vestibular episodes.

METHODS

Retrospective study. Medical records between 2009 and 2023 were reviewed, and dogs with a normal neurological examination, a history of transient signs of vestibular disease, absence of abnormalities detected on blood exams and brain magnetic resonance imaging (MRI) or computed tomography (CT), besides a minimum 10-month follow-up were included. Clinical improvement was defined as a ≥50% reduction in frequency or the cessation of clinical signs after the onset of antiseizure medications (ASMs).

RESULTS

Pugs were the most prevalent breed (5/10; 50%). In 2 cases, additional generalized tonic-clonic (GTC) seizures were reported. MRI exam was performed in most cases (9/10; 90%), whereas 1 dog underwent a CT scan (1/10; 10%). Electroencephalography (EEG) was carried out in 3 dogs that showed interictal spikes in the fronto-temporal and fronto-parietal areas. All cases received ASMs, with clinical improvement in 10/10 dogs (100%).

CONCLUSION AND CLINICAL IMPORTANCE

The presence of GTC seizures, EEG interictal spikes, and responsiveness to ASMs supported the hypothesis of an epileptic origin of vestibular episodes and thus the existence of VE in these dogs, with a presumed idiopathic cause and apparent favorable outcome.

Electrical stimulation of the peripheral and central vestibular system

PURPOSE OF REVIEW

Electrical stimulation of the peripheral and central vestibular system using noninvasive (galvanic vestibular stimulation, GVS) or invasive (intracranial electrical brain stimulation, iEBS) approaches have a long history of use in studying self-motion perception and balance control. The aim of this review is to summarize recent electrophysiological studies of the effects of GVS, and functional mapping of the central vestibular system using iEBS in awake patients.

RECENT FINDINGS

The use of GVS has become increasingly common in the assessment and treatment of a wide range of clinical disorders including vestibulopathy and Parkinson's disease. The results of recent single unit recording studies have provided new insight into the neural mechanisms underlying GVS-evoked improvements in perceptual and motor responses. Furthermore, the application of iEBS in patients with epilepsy or during awake brain surgery has provided causal evidence of vestibular information processing in mostly the middle cingulate cortex, posterior insula, inferior parietal lobule, amygdala, precuneus, and superior temporal gyrus.

SUMMARY

Recent studies have established that GVS evokes robust and parallel activation of both canal and otolith afferents that is significantly different from that evoked by natural head motion stimulation. Furthermore, there is evidence that GVS can induce beneficial neural plasticity in the central pathways of patients with vestibular loss. In addition, iEBS studies highlighted an underestimated contribution of areas in the medial part of the cerebral hemispheres to the cortical vestibular network.

Unilateral non-lesional temporal lobe epilepsy presenting as isolated ictal vertigo: a case report

Temporal lobe epilepsy is the most common focal epilepsy syndrome and has a broad spectrum of presentations. Nevertheless, isolated vestibular symptoms without other symptoms typical of temporal lobe seizures are relatively rare. Here, we report one female patient who suffered from chronic refractory vertigo and had inappropriate pharmacotherapy for several years. Eventually, epileptic vertigo and dizziness (ictal vertigo) were accurately diagnosed by detailed history taking and serial examinations assisted by sphenoid electroencephalography. Awareness of this unique syndrome is important in the diagnosis of patients with epileptic vertigo and dizziness.

Cervical and ocular vestibular evoked myogenic potentials in epileptic patients

Background

Vertigo and dizziness are very common complaints that may be related to epilepsy. The purpose of this study was to assess vestibulo-spinal and linear vestibulo-ocular function in epileptic patients in the inter ictal period. The current observational study was carried out in audio-vestibular unit Menoufia University. Subjects in the current study were divided into two groups: The control group included 30 normal individuals not complaining from any dizzy symptoms and the epileptic cases group included 30 epileptic patients. All subjects in the study were submitted to cervical and ocular vestibular evoked myogenic potential.

Results

There was no significant difference between the control and epileptic group regarding the age and sex distribution. Sixty-seven percent of epileptic cases had dizzy symptoms. There was statistically significant difference in the latency and amplitude of c and o VEMP between the control and the epileptic group, 39/60 ears (65%) in the study group had cVEMP abnormalities, 32/60 ears (53%) had oVEMP abnormalities. Abnormal c and o VEMP were reported in 28/60 ears (46.7%). There was statistically significant relationship between VEMP abnormalities and duration of seizures, frequency of epileptic attacks, and type of therapy.

Conclusion

Vestibular abnormalities were frequently reported in epileptic patients in the current study which may be related to the severity and control of epilepsy.

[Neurophysiological and functional neuroimaging methods in the assessment of migraines and epilepsy with vertigo]

A review of the current literature shows that the combined use of neurophysiological and structural-functional neuroimaging methods has significantly expanded the understanding of the mechanisms of migraine with vestibular dysfunction: functional and structural disorders were found in brain regions involved in multisensory vestibular control and Central vestibular processing. Analysis of numerous studies shows that epilepsy can also cause vestibular symptoms, they can occur both without epileptic markers, and in combination with epileptic paroxysms. In isolated epileptic vertigo, according to studies widely presented in the literature, epileptic activity was most often detected by EEG data in the temporal regions, to a lesser extent in the parietal regions. In these studies, neuroimaging findings of foci of reduced substance density were found, which could be a consequence of deafferentation, as well as violations of connections with the focus of neuronal activity. In the absence of structural abnormalities, numerous studies have shown using magnetic resonance spectroscopy, diffusion MRI, and PET that the physiological basis for impaired neuronal metabolism was a decrease in synaptic activity, a violation of maintaining the difference in membrane potentials on the surface of the hippocampus, or changes in neighboring tracts of the white matter of the brain.

Vestibular disorders in children: A retrospective analysis of vestibular function test findings

OBJECTIVE

This study was designed to describe the most common vestibular disorders in children and their associated findings on vestibular function testing.

METHOD

Data from 203 children with a mean age of 11.16 ± 3.87 (range, 1-17) years were collected from among 3400 patients who underwent vestibular assessment at a vertigo center in a tertiary hospital over a 3-year period. A retrospective data analysis was performed for 203 children.

RESULTS

Vestibular disorders were diagnosed in 78.3% (n = 159) of 203 children among 3400 patients, which revealed a 3-year incidence of 4.67% in our study. Benign paroxysmal positional vertigo (BPPV) was the most common diagnosis in our group of children (49%; n = 100), which involved both primary BPPV, and secondary BPPV that was associated with other vestibular pathologies. Vestibular migraine (VM) was the second most common diagnosis (41%; n = 83) followed by benign paroxysmal vertigo of childhood (BPVC; 4.5%, n = 9), vestibular neuritis (VN; 4.5%, n = 9), and psychogenic vertigo (4.5%, n = 9). Our study showed that Meniere's Disease (MD; 1.5%, n = 3) and central vertigo (1.5%, n = 3) were less commonly diagnosed in children. Perilymphatic fistula (PLF) was diagnosed and surgically confirmed in only one child.

CONCLUSION

BPPV and VM were the most common pediatric vestibular disorders in our study. Clinicians should be aware of the prevalence, signs, and symptoms of the most common vestibular disorders in children to enable diagnosis, treatment, and rehabilitation. Vestibular function testing with age-appropriate adaptations results in improved differential diagnosis, which guides medical treatment and rehabilitation.

Reliability of additional reported seizure manifestations to identify dissociative seizures

PURPOSE

Descriptions of seizure manifestations (SM), or semiology, can help localize the symptomatogenic zone and subsequently included brain regions involved in epileptic seizures, as well as identify patients with dissociative seizures (DS). Patients and witnesses are not trained observers, so these descriptions may vary from expert review of seizure video recordings of seizures. To better understand how reported factors can help identify patients with DS or epileptic seizures (ES), we evaluated the associations between more than 30 SMs and diagnosis using standardized interviews.

METHODS

Based on patient- and observer-reported data from 490 patients with diagnoses documented by video-electoencephalography, we compared the rate of each SM in five mutually exclusive groups: epileptic seizures (ES), DS, physiologic seizure-like events (PSLE), mixed DS and ES, and inconclusive testing.

RESULTS

In addition to SMs that we described in a prior manuscript, the following were associated with DS: light triggers, emotional stress trigger, pre-ictal and post-ictal headache, post-ictal muscle soreness, and ictal sensory symptoms. The following were associated with ES: triggered by missing medication, aura of déjà vu, and leftward eye deviation. There were numerous manifestations separately associated with mixed ES and DS.

CONCLUSIONS

Reported SM can help identify patients with DS, but no manifestation is pathognomonic for either ES or DS. Patients with mixed ES and DS reported factors divergent from both ES-alone and DS-alone.

Clinical and demographic characteristics of children and adolescents with acute vertigo symptoms: A cross-sectional study

Background/aim

Vertigo is one of the rarely diagnosed disorders during childhood due to insufficient description of the children regarding their experiences to the physicians. The clinical features of children and adolescents admitted by acute vertigo symptoms were investigated to elaborate the subject retrospectively.

Materials and methods

Between January 2017–July 2019, records of cases admitted with acute vertigo complaints to pediatric neurology were retrospectively examined.

Results

Of 761 patients, mean age was 13.8 years, 64% (n = 487) were women, 22.6% (n = 172) of which were children (1–11 years). A total of 37.3% of the cases (n = 284) had unknown etiology of acute vertigo symptoms, 39.6% (n = 301) had acute vertigo, and 23.1% (n = 176) were considered with no organicity problems but a group of the families stopped cooperating to the full extent in the study. Among all the patients, 25.6% (195/761) had paroxymal vertigo, 6.8% (52/761) had migraine-associated vertigo, 4.5% (34/761) had psychogenic vertigo, and 2.6% (20/761) had epileptic vertigo. Epileptic vertigo was significantly higher in younger children (mean age = 10.6, F(3) = 8874, P < .001), and the ratio of its occurence was also higher among children (60%, χ2 (3) = 20.347, P < .001).

Conclusion

Vertigo complaints are 1.7 times more common among the girls. Epileptic vertigo is significantly higher among the children. Among younger children, it seems important to consider epilepsy when vertigo emerged.

Non-convulsive seizure clustering misdiagnosed as vertebrobasilar insufficiency

Diagnosing non-convulsive seizures (NCSs) is a great challenge for most clinicians due to a wide spectrum of clinical presentations. The complexity of the disease course usually results in a delayed diagnosis or misdiagnosis so that timely and appropriate treatment is not given. Herein, we report a case with NCSs misdiagnosed as vertebrobasilar insufficiency (VBI), in which the patient suffered from episodes of prominent dizziness, vertigo, becoming transfixed, and worsening response within a day. Brain magnetic resonance image findings were unremarkable, however electroencephalography (EEG) showed rhythmic epileptiform discharges that appeared to originate from the right frontal area with ipsilateral hemispheric involvement. We prescribed intravenous valproate and the seizures ceased. Few studies have reported a patient with NCS misdiagnosed with VBI, a very different entity. It is thus important that clinicians should be aware of the trivial symptoms of NCSs, and to consider implementing early EEG studies and anti-epileptic drug therapy.

A Practical Approach to Vertigo: A Synthesis of the Emerging Evidence

Vestibular presentations represent a large financial and symptomatic burden of disease^1,2 , while remaining one of the most elusive presentations to accurately and confidently diagnose. A primary cause for this is that the same symptom can be the end-product of numerous aetiologies, and uncertainties can lead to unnecessary investigations and associated increased cost and delays in diagnosis. An effective method to narrow the diagnosis is firstly to determine, from a limited list, which type of vestibular syndrome the patient possesses, and then apply a focussed history and examination to define the most likely aetiology within that syndrome. This review provides a diagnostic approach to the vertiginous patient, outlining the underlying pathophysiology that accounts for the clinical symptoms and signs. With this approach, physicians should be able to diagnose the majority of common vestibular presentations and know when to refer the urgent, complex, or rare cases to sub-specialist neuro-otologists for prompt and appropriate management. This article is protected by copyright. All rights reserved.

Episodic Vestibular Symptoms in Children With a Congenital Cytomegalovirus Infection: A Case Series

OBJECTIVE

Congenital cytomegalovirus (cCMV) infection is the most common non-genetic cause of sensorineural hearing loss in children. Although cCMV-induced vestibular loss is demonstrated in several studies, the occurrence of vertigo has been described in only two cases to date. The aim of this paper is to discuss the underlying pathophysiology of recurrent vestibular symptoms in children with cCMV, based on five cases investigated in our center and an extensive research of the literature.

STUDY DESIGN

Retrospective case series.

SETTING

Tertiary referral center.

PATIENTS

This case series describes five pediatric cCMV-patients (three boys, two girls). Four of them were symptomatic at birth, one was asymptomatic. Three patients underwent cochlear implantation. The age of onset of the vestibular symptoms varied from 2;0 to 7;3 years of age.

INTERVENTION

None.

MAIN OUTCOME MEASURES

Details regarding the patient history and results of cranial imaging, audiological, vestibular, and neurological assessments were collected retrospectively.

RESULTS

The selected cases suffered from recurrent vestibular symptoms. All patients had delayed onset, fluctuating, and/or progressive hearing loss. In all cases, the attacks were accompanied with nausea and vomiting and occurred without clear-cut trigger. Migraine and epilepsy often were proposed as first diagnosis, although they could not be confirmed eventually. Four out of five patients were diagnosed with a peripheral vestibular deficit.

CONCLUSIONS

Diagnosis of vestibular symptoms in children with cCMV is complex, given the multiple morbidities than can occur. Peripheral vestibular causes should be considered in the diagnosis, as important vestibular deficits are demonstrated in this population.

Severe presentation of antibody-negative, postinfectious steroid-responsive encephalitis and atonic bladder after herpes simplex encephalitis

A 75-year-old woman presented with new onset of confusion, intense episodic dizziness and formed visual hallucinations. Herpes simplex encephalitis and non-convulsive temporal lobe seizures were confirmed with cerebrospinal fluid (CSF) and electroencephalography testing. In addition, her hospital course was complicated by syndrome of inappropriate antidiuretic hormone secretion and atonic bladder contributing to an episode of urinary tract infection. After completing 3 weeks of acyclovir treatment, the patient became obtunded with right arm choreiform movements and persistent inflammatory CSF findings not attributable to persistent herpes simplex virus infection or other confounding factors. The patient responded to steroid treatment. Repeated autoimmune and paraneoplastic evaluations were negative. Both clinical (cognitive testing and atonic bladder) and CSF inflammatory finding improved in the follow-up period.

Genes important for otoneurological diagnostic purposes - current status and future prospects

SUMMARY

This review focuses on the current knowledge of the genes responsible for non-syndromic hearing loss that can be useful for otoneurological diagnostic purposes. From among a large number of genes that have been associated with non-syndromic hearing impairment, we selected several best-known genes, including the COCH gene, GJB2, GJB6 and SLC26A4, and we describe their role and effects of mutations and prevalence of mutations in various populations. Next, we focus on genes associated with tinnitus. Important areas for further research include assessment of genes potentially involved in pathophysiology of tinnitus and vertigo, which have traditionally been considered as being of otological aetiology, while advances in neuroimaging techniques have increasingly shifted studies toward neurological correlations.

Vestibular Function in Adults With Epilepsy of Unknown Etiology

OBJECTIVE

This study aimed to evaluate vestibular function in adults with chronic epilepsy of unknown etiology in the inter-ictal period.

BACKGROUND

Epilepsy is a chronic medical disorder. Life-long therapy may be required in one-third of patients. Epilepsy is associated with comorbid somatic conditions which impairs patients' quality of life.

METHODS

This cross-sectional study included 28 with generalized tonic clonic (GTC) convulsions and 14 and 3 with temporal (TLE) and frontal lobe (FLE) epilepsies with secondary generalization (all were on regular carbamazepine therapy) and 40 healthy control subjects. The patients' mean age was 34.97 ± 7.35 years and the duration of illness was 18.75 ± 7.99 years. All underwent videonystagmography (VNG).

RESULTS

Compared with controls, patients had frequent vestibular symptoms including dizziness (62.22%) (p = 0.0001) and sense of imbalance (44.44%) (p = 0.0001). Eleven patients (24.44%) had central vestibular dysfunction (p = 0.0001); 9 (20%) had mixed vestibular dysfunction and one (2.22%) had peripheral vestibular dysfunction (p = 0.0001). Abnormalities were observed in saccadic (44.4%) and pursuit (42.2%) eye movements, optokinetic nystagmus (42.2%) and positioning/positional (11.11%) and caloric (13.33%) testing. TLE and FLE were associated with more VNG abnormalities than GTC. No significant differences were observed in the demographic and clinical characteristics between patients with and without VNG abnormalities.

CONCLUSION

Vestibular manifestations are frequent in patients with epilepsy. This may be a result of the permanent damaging effect of chronic epilepsy on the vestibular cortical areas and/or a toxic effect from prolonged carbamazepine therapy on the peripheral and central vestibular systems.

Vestibular paroxysmia: Diagnostic criteria

This paper describes the diagnostic criteria for vestibular paroxysmia (VP) as defined by the Classification Committee of the Bárány Society. The diagnosis of VP is mainly based on the patient history and requires: A) at least ten attacks of spontaneous spinning or non-spinning vertigo; B) duration less than 1 minute; C) stereotyped phenomenology in a particular patient; D) response to a treatment with carbamazepine/oxcarbazepine; and F) not better accounted for by another diagnosis. Probable VP is defined as follows: A) at least five attacks of spinning or non-spinning vertigo; B) duration less than 5 minutes; C) spontaneous occurrence or provoked by certain head-movements; D) stereotyped phenomenology in a particular patient; E) not better accounted for by another diagnosis.

Ephaptic discharges in the proximal part of the 8th cranial nerve, which is covered by oligodendrocytes, are the assumed mechanism. Important differential diagnoses are Menière’s disease, vestibular migraine, benign paroxysmal positional vertigo, epileptic vestibular aura, paroxysmal brainstem attacks (in multiple sclerosis or after brainstem stroke), superior canal dehiscence syndrome, perilymph fistula, transient ischemic attacks and panic attacks. Current areas of uncertainty in the diagnosis of VP are: a) MRI findings of vascular compression which are not diagnostic of the disease or predictive for the affected side because they are also observed in about 30% of healthy asymptomatic subjects; and b) response to treatment with carbamazepine/oxcarbazepine supports the diagnosis but there are so far no randomized controlled trials for treatment of VP.

[Metavestibular disorders and disorders of higher vestibular function]

Vertigo, instability, oscillopsia and concomitant autonomic disorders are classical and well-known symptoms of vestibular disorders. At the same time, recent studies suggest that there are more complicated vestibular dysfunctions caused by the cortical projections of the vestibular system. The central vestibular system includes parietal temporal cortex and insular, anterior intraparietal sulcus, posterior parietal and medial parts of the superior temporal gyrus, singular gyrus retrosplenial cortex, hippocampus and parahippocampal area. The central part of the vestibular system closely interacts with other afferent systems forming a multisensory structure of higher brain functions. Dysfunctions of higher vestibular function play an important role in the development of clinical syndromes including pusher syndrome, room tilt illusion, unilateral spatial neglect syndrome, impairment of spatial memory and navigation. These syndromes can develop due to the direct damage of the cortical vestibular system or as a result of disconnection between the vestibular cortex and other parts of the sensory cortex.

Novel clinical features of nonconvulsive status epilepticus

Nonconvulsive status epilepticus (NCSE) has rapidly expanded from classical features such as staring, repetitive blinking, chewing, swallowing, and automatism to include coma, prolonged apnea, cardiac arrest, dementia, and higher brain dysfunction, which were demonstrated mainly after the 2000s by us and other groups. This review details novel clinical features of NCSE as a manifestation of epilepsy, but one that is underdiagnosed, with the best available evidence. Also, we describe the new concept of epilepsy-related organ dysfunction (Epi-ROD) and a novel electrode and headset which enables prompt electroencephalography.

Incidence and localizing value of vertigo and dizziness in patients with epilepsy: Video-EEG monitoring study

Vertigo and dizziness are common neurological complaints that have long been associated with epilepsy. However, studies of patients with epileptic vertigo or dizziness with concurrent EEG monitoring are scarce. We performed the present study to investigate the incidence and localizing value of vertigo and dizziness in patients with epilepsy who had confirmation of EEG changes via video-EEG monitoring. Data of aura and clinical seizure episodes of 831 consecutive patients who underwent video-EEG monitoring were analyzed retrospectively. Out of 831 patients, 40 patients (4.8%) experienced vertigo or dizziness as aura (mean age, 32.8±11.8years), all of whom had partial seizures. Eight had mesial temporal, 20 had lateral temporal, four had frontal, one had parietal, and seven had occipital lobe onset seizures. An intracranial EEG with cortical stimulation study was performed in seven patients, and the area of stimulation-induced vertigo or dizziness coincided with the ictal onset area in only one patient. Our study showed that vertigo or dizziness is a common aura in patients with epilepsy, and that the temporal lobe is the most frequent ictal onset area in these patients. However, it can be suggested that the symptomatogenic area in patients with epileptic vertigo and dizziness may not coincide with the ictal onset area.