Musicogenic seizures can arise from multiple temporal lobe foci: intracranial EEG analyses of three patients

Musicogenic seizures in temporal lobe epilepsy: Case reports based on ictal source localization analysis

Musicogenic epilepsy is a rare form of reflex epilepsy in which seizures are provoked by music. Different musicogenic stimuli have been identified: pleasant/unpleasant music or specific musical patterns. Several etiologies have been uncovered, such as focal cortical dysplasia, autoimmune encephalitis, tumors, or unspecific gliosis. In this article, we report two patients with musicogenic seizures. The first patient was diagnosed with structural temporal lobe epilepsy. Her seizures were elicited by music that she liked. Interictal and ictal video-electroencephalography (video-EEG) and signal analysis using independent component analysis revealed the right temporal lobe seizure onset extending over the neocortical regions. The patient underwent right temporal lobectomy (including the amygdala, the head, and the body of the hippocampus) and faced an Engel IA outcome 3 years post-surgery. The second patient was diagnosed with autoimmune temporal lobe epilepsy (GAD-65 antibodies). Her seizures were triggered by contemporary hit radio songs without any personal emotional significance. Interictal and ictal video-electroencephalography (video-EEG) and independent component analysis highlighted the left temporal lobe seizure onset extending over the neocortical regions. Intravenous immunoglobulin therapy was initiated, and the patient became seizure-free at 1 year. In conclusion, musicogenic seizures may be elicited by various auditory stimuli, the presence or absence of an emotional component offering an additional clue for the underlying network pathophysiology. Furthermore, in such cases, the use of independent component analysis of the scalp EEG signals proves useful in revealing the location of the seizure generator, and our findings point toward the temporal lobe, both mesial and neocortical regions.

Wired for sound: The effect of sound on the epileptic brain

Sound waves are all around us resonating at audible and inaudible frequencies. Our ability to hear is crucial in providing information and enabling interaction with our environment. The human brain generates neural oscillations or brainwaves through synchronised electrical impulses. In epilepsy these brainwaves can change and form rhythmic bursts of abnormal activity outwardly appearing as seizures. When two waveforms meet, they can superimpose onto one another forming constructive, destructive or mixed interference. The effects of audible soundwaves on epileptic brainwaves has been largely explored with music. The Mozart Sonata for Two Pianos in D major, K. 448 has been examined in a number of studies where significant clinical and methodological heterogeneity exists. These studies report variable reductions in seizures and interictal epileptiform discharges. Treatment effects of Mozart Piano Sonata in C Major, K.545 and other composer interventions have been examined with some musical exposures, for example Hayden's Symphony No. 94 appearing pro-epileptic. The underlying anti-epileptic mechanism of Mozart music is currently unknown, but interesting research is moving away from dopamine reward system theories to computational analysis of specific auditory parameters. In the last decade several studies have examined inaudible low intensity focused ultrasound as a neuro-modulatory intervention in focal epilepsy. Whilst acute and chronic epilepsy rodent model studies have consistently demonstrated an anti-epileptic treatment effect this is yet to be reported within large scale human trials. Inaudible infrasound is of concern since at present there are no reported studies on the effects of exposure to infrasound on epilepsy. Understanding the impact of infrasound on epilepsy is critical in an era where sustainable energies are likely to increase exposure.

Laser ablative treatment of musicogenic epilepsy arising from dominant mesial temporal lobe: illustrative case

BACKGROUND

Musicogenic epilepsy (ME) is a rare reflex epilepsy in which seizures are triggered by musical stimuli. Prior descriptions of ME have suggested localization to the nondominant temporal lobe, primarily in neocortex. Although resection has been described as a treatment for ME, other surgical modalities, such as laser ablation, may effectively disrupt seizure networks in ME while incurring comparatively lower risks of morbidity. The authors described the use of laser ablation to treat ME arising from the dominant mesial temporal structures.

OBSERVATIONS

A 37-year-old woman with a 15-year history of drug-resistant ME was referred for surgical evaluation. Her seizures were triggered by specific musical content and involved behavioral arrest, repetitive swallowing motions, and word incomprehension. Diagnostic studies, including magnetic resonance imaging, single-photon emission computed tomography, magnetoencephalography, Wada testing, and stereoelectroencephalography, indicated seizure onset in the left (dominant) mesial temporal lobe. Laser interstitial thermal therapy was used to ablate the left mesial seizure onset zone. The patient was discharged on postoperative day two. At 18-month follow-up, she was seizure-free with no posttreatment neurological deficits.

LESSONS

Laser ablation can be an effective treatment option for well-localized forms of ME, particularly when seizures originate from the dominant mesial temporal lobe.

Where words are powerless to express: Use of music in paediatric neurology

Music is an art form that strongly affects people and can elicit many different emotions at the same time, including happiness, anxiety, sadness, and even ecstasy. What is it about music that causes such a strong reaction from each of us? Music engages many senses, which in turn can produce a multiplicity of responses and help create more extensive neuronal connections, as well as influence behaviour through structural and functional changes in the brain. Music-based interventions as a therapeutic tool in rehabilitation are becoming more common. It is said that the impact of music on the human body is positive. However, what impact does music have on the young nervous system, especially the affected one? This review presents the advantages and disadvantages of the use of music in paediatric neurology to treat dyslexia, cerebral palsy, and stroke, among others. Potential negative impacts such as musicogenic epilepsy and hallucinations will be discussed.

Musicogenic reflex seizure with positive antiglutamic decarboxylase antibody: A case report

The association of musicogenic epilepsy (ME) with antibodies against glutamic decarboxylase (GAD) supports autoimmune workups for these patients. No appropriate treatment has been established for ME; therefore, immunotherapy should be considered for patients who become drug-resistant. The connection between neurological manifestations and antibodies against GAD, a rate-limiting enzyme that helps create the inhibitory neurotransmitter gamma-aminobutyric acid, has been well established. Furthermore, a strong correlation has been found between ME and the temporal lobe. However, its connection with anti-GAD antibodies is still unclear. This paper reports on a 50-year-old right-handed female who has had ME symptoms for 14 years and been found to be anti-GAD antibody-positive. Therefore, we will elaborate on the relation between ME and anti-GAD antibodies.

A Case of Musicogenic Epilepsy

Musicogenic epilepsy is a relatively rare form of epilepsy characterized by seizures triggered by specific music experiences, with an estimated prevalence of 1/10,000,000 population. In this article, we reported a case of 12-year-old boy patient with a history of recent onset focal seizures associated with an aura of formed visual hallucinations, feeling of familiarity (déjà vu), and impending fear lasting for seconds to a minute followed by eye blinking, oral automatisms, and unresponsiveness for almost 15 minutes. These episodes, most often, were provoked by music. Video electroencephalogram (EEG) done in our institute was suggestive of reflex musicogenic epilepsy arising from the left anterior temporal lobe. Magnetic resonance imaging of the brain 3T with epilepsy protocol confirmed video EEG findings, with an abnormal signal intensity in the left hippocampal and mesial temporal lobe. Treatment included lifestyle modification and antiepileptic drugs.

Interictal and Ictal MEG in presurgical evaluation for epilepsy surgery

Although presurgical evaluation of patients with pharamacoresistent focal epilepsies provides essential information for successful epilepsy surgery, there is still a need for further improvement. Developments of noninvasive electrophysiological recording and analysis techniques offer additional information based on interictal and ictal epileptic activities. In this review, we provide an overview on the application of ictal magnetoencephalography (MEG). The results of a literature research for published interictal/ictal MEG findings and experiences with own cases are demonstrated and discussed. Ictal MEG may provide added value in comparison to interictal recordings. The results may be more focal and closer to the invasively determined seizure onset zone. In some patients without clear interictal findings, ictal MEG could provide correct localization. Novel recording and analysis techniques facilitate ictal recordings. However, extended recording durations, movement and artifacts still represent practical limitations. Ictal MEG may provide added value regarding the localization of the seizure onset zone but depends on the selection of patients and the application of optimal analysis techniques.

Spatio-temporal dynamics of interictal activity in musicogenic epilepsy: Two case reports and a systematic review of the literature

OBJECTIVE

To explore neurophysiological features of musicogenic epilepsy (ME), discussing experimental findings in the framework of a systematic review on ME.

METHODS

Two patients with ME underwent high-density-electroencephalography (hd-EEG) while listening to ictogenic songs. In one case, musicogenic seizures were elicited. Independent component analysis (ICA) was applied to hd-EEG, and components hosting interictal and ictal elements were identified and localized. Finally, the temporal dynamics of spike-density was studied relative to seizures. All findings were compared against the results of a systematic review on ME, collecting 131 cases.

RESULTS

Interictal spikes appeared isolated in specific fronto-temporal independent components, whose cortical generators were located in the anterior temporal and inferior frontal lobe. In the patient undergoing seizure, ictal discharge relied in the same component, with the interictal spike-density decreasing before the seizure onset.

CONCLUSION

Our study shows how ICA can isolate neurophysiological features of ictal and interictal discharges in ME, highlighting a fronto-temporal localization and a suppression of spike-density preceding the seizure onset.

SIGNIFICANCE

While the localization of ME activity could indicate which aspect within the musical stimulus might trigger musicogenic seizures for each patient, the study of ME dynamics could contribute to the development of models for seizure-prediction and their validation.

Reflex epileptic features in patients with focal epilepsy of unknown cause

OBJECTIVES

There is a gap of knowledge regarding reflex seizures in patients with focal epilepsy of unknown cause (FEUC). We aimed to evaluate the prevalence, demographic and clinical characteristics of reflex seizures in patients with FEUC to provide an insight to the underlying ictogenic mechanisms and to draw attention to this important but under-investigated topic.

PATIENTS AND METHODS

After carefully questioning for reflex triggers, 186 patients diagnosed according to ILAE criteria and followed-up for a minimum of 5 years were included. The demographic and clinical properties as well as electrophysiological and neuroimaging data of these patients were reevaluated and compared to the patients without reflex seizures.

RESULTS

The reflex seizure rate was 6.5 % in patients with FEUC. Patients with reflex features had lower monotherapy rates (p = 0.005) and higher major depression rates (p = 0.001) than patients without reflex features. The distribution of the patients according to their reflex triggers were as follows: hot-water induced (n = 3, 25 %), photosensitive (n = 2, 16.7 %), eating- induced (n = 2, 16.7 %), musicogenic (n = 2, 16.7 %), startle induced (n = 2, 16.7 %) and both musicogenic and startle type (n = 1, 8.3 %) respectively. The drug resistance rate of patients with reflex seizures was 25 % (n = 3). One patient with drug resistant reflex seizures showed benefit from epilepsy surgery and became seizure-free during last 3 years of follow-up.

CONCLUSION

A careful and thoroughly history taking specifically questioning and focusing on seizure inducing factors in patients with FEUC is needed to confirm the presence of reflex seizures in patients with FEUC, who had higher rates of polytherapy and major depression. Elaborative evaluation of reflex features in FEUC might contribute to effective seizure control, ensure new therapeutic approaches, enlighten the obscurity and the resulting anxiety of having a diagnosis of FEUC in epilepsy patients.

Musicogenic epilepsy: A Stereo-electroencephalography study

Musicogenic epilepsy is rare focal epilepsy in which seizures are triggered by music. Both spontaneous and reflexes seizures may occur. To date there are limited data about this epilepsy, particularly about its etiopathogenesis. We report the clinical, neurophysiological and imaging data about musicogenic epilepsy in a patient who underwent Stereo-electroencephalography (SEEG) study. A 27 year-old right-handed woman suffering from drug-resistant epilepsy since the age of 17 years, was evaluated for surgery. She had weekly seizures characterized by an unpleasant ascending gastric sensation, tachycardia, occasionally late oro-alimentary automatisms, déjà-vu and vomiting. Only during longer seizures a partial loss of awareness was reported. Interestingly, familiar songs triggered seizures. Rarely, she had spontaneous seizures with the same features. The ictal EEG onset appeared to be right temporal, but there was seizure propagation to suprasylvian areas. Brain MRI was negative. A SEEG implantation was performed to study the right temporo-perisylvian regions. SEEG data clearly indicated the antero-mesial temporal regions as origin of the seizures, without any spread to other close or distant cortical areas. Right temporal antero-mesial resection was performed 24 months ago and the patient is seizure-free since surgery. Neuropathology was uninformative. SEEG data highlighted the hypothesis regarding a temporo-mesial emotional-mnesic network triggered by particular music with an affective component for the patient. The primary auditory cortex and lateral mid-posterior temporal and extratemporal cortices were not involved. Different triggers as mentally singing and hearing the music can induce seizure as well as electrical stimulation in the mesial temporal structures.

Correlation of vocals and lyrics with left temporal musicogenic epilepsy

Whether the cognitive processing of music and speech relies on shared or distinct neuronal mechanisms remains unclear. Music and language processing in the brain are right and left temporal functions, respectively. We studied patients with musicogenic epilepsy (ME) that was specifically triggered by popular songs to analyze brain hyperexcitability triggered by specific stimuli. The study included two men and one woman (all right-handed, aged 35-55 years). The patients had sound-triggered left temporal ME in response to popular songs with vocals, but not to instrumental, classical, or nonvocal piano solo versions of the same song. Sentimental lyrics, high-pitched singing, specificity/familiarity, and singing in the native language were the most significant triggering factors. We found that recognition of the human voice and analysis of lyrics are important causal factors in left temporal ME and provide observational evidence that sounds with speech structure are predominantly processed in the left temporal lobe. A literature review indicated that language-associated stimuli triggered ME in the left temporal epileptogenic zone at a nearly twofold higher rate compared with the right temporal region. Further research on ME may enhance understanding of the cognitive neuroscience of music.

Localization of musicogenic epilepsy to Heschl's gyrus and superior temporal plane: case report

Musicogenic epilepsy (ME) is an extremely rare form of the disorder that is provoked by listening to or playing music, and it has been localized to the temporal lobe. The number of reported cases of ME in which intracranial electroencephalography (iEEG) has been used for seizure focus localization is extremely small, especially with coverage of the superior temporal plane (STP) and specifically, Heschl's gyrus (HG). The authors describe the case of a 17-year-old boy with a history of medically intractable ME who underwent iEEG monitoring that involved significant frontotemporal coverage as well as coverage of the STP with an HG depth electrode anteriorly and a planum temporale depth electrode posteriorly. Five seizures occurred during the monitoring period, and a seizure onset zone was localized to HG and the STP. The patient subsequently underwent right temporal neocortical resection, involving the STP and including HG, with preservation of the mesial temporal structures. The patient remains seizure free 1 year postoperatively. To the authors' knowledge, this is the first reported case of ME in which the seizure focus has been localized to HG and the STP with iEEG monitoring. The authors review the literature on iEEG findings in ME, explain their approach to HG depth electrode placement, and discuss the utility of STP depth electrodes in temporal lobe epilepsy.

Musicogenic Epilepsy and Treatment of Affective Disorders: Case Report and Review of Pathogenesis

Musicogenic epilepsy is a rare syndrome in which music triggers seizures. Affective network processing appears to play a key role in epileptogenesis. Many people with epilepsy suffer from comorbid affective disorders, the shared basis of which involves similar pathophysiologies, including deficiencies of serotonergic and noradrenergic function. Seizures and mood disorders may thus have reciprocal effects on one another, particularly in emotionally precipitated syndromes such as musicogenic epilepsy. I report a man with long-standing depression and anxiety who developed focal epilepsy that evolved into musicogenic seizures. His case suggests a pathophysiologic basis for this shared phenomenon.

Multimodal effective connectivity analysis reveals seizure focus and propagation in musicogenic epilepsy

Dynamic causal modeling (DCM) is a method to non-invasively assess effective connectivity between brain regions. 'Musicogenic epilepsy' is a rare reflex epilepsy syndrome in which seizures can be elicited by musical stimuli and thus represents a unique possibility to investigate complex human brain networks and test connectivity analysis tools. We investigated effective connectivity in a case of musicogenic epilepsy using DCM for fMRI, high-density (hd-) EEG and MEG and validated results with intracranial EEG recordings. A patient with musicogenic seizures was examined using hd-EEG/fMRI and simultaneous '256-channel hd-EEG'/'whole head MEG' to characterize the epileptogenic focus and propagation effects using source analysis techniques and DCM. Results were validated with invasive EEG recordings. We recorded one seizure with hd-EEG/fMRI and four auras with hd-EEG/MEG. During the seizures, increases of activity could be observed in the right mesial temporal region as well as bilateral mesial frontal regions. Effective connectivity analysis of fMRI and hd-EEG/MEG indicated that right mesial temporal neuronal activity drives changes in the frontal areas consistently in all three modalities, which was confirmed by the results of invasive EEG recordings. Seizures thus seem to originate in the right mesial temporal lobe and propagate to mesial frontal regions. Using DCM for fMRI, hd-EEG and MEG we were able to correctly localize focus and propagation of epileptic activity and thereby characterize the underlying epileptic network in a patient with musicogenic epilepsy. The concordance between all three functional modalities validated by invasive monitoring is noteworthy, both for epileptic activity spread as well as for effective connectivity analysis in general.

Musicogenic epilepsy

Musicogenic epilepsy, which is a form of reflex epilepsy, is characterized by the triggering of epileptic seizures by specific music experiences. Individuals with musicogenic epilepsy differ in the music trigger, but may have similar seizures. Typically, these seizures are focal dyscognitive and have a temporal-lobe origin with a limbic system distribution. As such, the music trigger is likely related to either an emotional or memory aspect of music perception. Investigations into musicogenic epilepsy may lead to a better understanding of seizure propagation within the brain and of neurologic aspects of the music experience. Successful treatment of medication-resistant musicogenic epilepsy has been achieved with anterior temporal-lobe resection.

Do reflex seizures and spontaneous seizures form a continuum? - triggering factors and possible common mechanisms

Recent changes in the understanding and classification of reflex seizures have fuelled a debate on triggering mechanisms of seizures and their conceptual organization. Previous studies and patient reports have listed extrinsic and intrinsic triggers, albeit their multifactorial and dynamic nature is poorly understood. This paper aims to review literature on extrinsic and intrinsic seizure triggers and to discuss common mechanisms among them. Among self-reported seizure triggers, emotional stress is most frequently named. Reflex seizures are typically associated with extrinsic sensory triggers; however, intrinsic cognitive or proprioceptive triggers have also been assessed. The identification of a trigger underlying a seizure may be more difficult if it is intrinsic and complex, and if triggering mechanisms are multifactorial. Therefore, since observability of triggers varies and triggers are also found in non-reflex seizures, the present concept of reflex seizures may be questioned. We suggest the possibility of a conceptual continuum between reflex and spontaneous seizures rather than a dichotomy and discuss evidence to the notion that to some extent most seizures might be triggered.

Generalized versus partial reflex seizures: a review

In this review we assess our currently available knowledge about reflex seizures with special emphasis on the difference between "generalized" reflex seizures induced by visual stimuli, thinking, praxis and language tasks, and "focal" seizures induced by startle, eating, music, hot water, somatosensory stimuli and orgasm. We discuss in particular evidence from animal, clinical, neurophysiological and neuroimaging studies supporting the concept that "generalized" reflex seizures, usually occurring in the setting of IGE, should be considered as focal seizures with quick secondary generalization. We also review recent advances in genetic and therapeutic approach of reflex seizures.

Music and epilepsy: a critical review

The effect of music on patients with epileptic seizures is complex and at present poorly understood. Clinical studies suggest that the processing of music within the human brain involves numerous cortical areas, extending beyond Heschl's gyrus and working within connected networks. These networks could be recruited during a seizure manifesting as musical phenomena. Similarly, if certain areas within the network are hyperexcitable, then there is a potential that particular sounds or certain music could act as epileptogenic triggers. This occurs in the case of musicogenic epilepsy, whereby seizures are triggered by music. Although it appears that this condition is rare, the exact prevalence is unknown, as often patients do not implicate music as an epileptogenic trigger and routine electroencephalography does not use sound in seizure provocation. Music therapy for refractory epilepsy remains controversial, and further research is needed to explore the potential anticonvulsant role of music. Dopaminergic system modulation and the ambivalent action of cognitive and sensory input in ictogenesis may provide possible theories for the dichotomous proconvulsant and anticonvulsant role of music in epilepsy. The effect of antiepileptic drugs and surgery on musicality should not be underestimated. Altered pitch perception in relation to carbamazepine is rare, but health care professionals should discuss this risk or consider alternative medication particularly if the patient is a professional musician or native-born Japanese. Studies observing the effect of epilepsy surgery on musicality suggest a risk with right temporal lobectomy, although the extent of this risk and correlation to size and area of resection need further delineation. This potential risk may bring into question whether tests on musical perception and memory should form part of the preoperative neuropsychological workup for patients embarking on surgery, particularly that of the right temporal lobe.

Reflex seizures and reflex epilepsies: old models for understanding mechanisms of epileptogenesis

Reflex seizures and epilepsies represent an ancient human model to understand basic mechanisms of epilepsy. The increase of light stimulation makes this issue extremely actual and interesting. In addition, a lot of observations show the frequent occurrence of provoked seizures in malformations of cortical development and in recently defined conditions such as familial or sporadic lateral temporal epilepsy. Advances in morphological and functional neuroimaging techniques, and the possibility of their fusion with EEG (e.g., fMRI-EEG co-registration) offer a unique non-invasive opportunity to investigate cortical areas and brain networks involved in cerebral functions and in epileptic discharges.

Surgical treatment for musicogenic epilepsy

We report a patient with medically intractable musicogenic epilepsy (ME) who was treated with surgery. Using the non-invasive methods of ictal and interictal electroencephalography (EEG), MRI, interictal single photon emission computed tomography and clinical manifestations, we first localized the musicogenic seizures (MS). The ictal onset zone was then further localized using intracranial EEG to the middle part of the left superior temporal gyrus. Surgical resection of the epileptogenic zone was then performed. The patient had two seizures within 2 weeks post-operatively, but has then had no seizures during the following year (Engel class II). The results suggest that patients who have medically intractable ME combined with unilateral ictal onset zones should be considered for the surgical treatment of epilepsy.

Seizure propagation in a patient with musicogenic epilepsy

Musicogenic epilepsy (ME) is a condition in which seizures are triggered by music. We describe a novel investigation of the mechanisms of ME using noninvasive (ictal 2-flurodeoxyglucose (2-FDG) positron emission tomography (PET)) and invasive (subdural arrays and depth electrodes) methodology in one patient with ME. Ictal PET defined onsets in the right mesial temporal lobe. This was confirmed by intracranial electrode recordings, where there was onset in the right mesial temporal lobe, followed by sequential spread to the lateral temporal cortex, Heschel's gyrus, insula, and frontal lobes. Right temporal lobectomy resulted in Engel class 1 outcome.

Combined EEG/fMRI recording in musicogenic epilepsy

Seizures induced by musical stimulation are usually correlated to temporal epilepsy, although the precise localization of their epileptogenic networks are not well characterized. Brain imaging studies show that regional cerebral blood flow (rCBF) recorded during musicogenic seizures is increased in putative epileptogenic foci, as well as in other brain regions not directly related to seizure activity. These studies, however, afford only a virtual temporal relation between ictal discharges and rCBF changes, given that brain images are correlated with off-line EEG recordings. To obviate this problem, the simultaneous multimodal recording of the episode of musicogenic epilepsy is mandatory. The present study describes the EEG-fMRI co-recording of musicogenic elicited seizures in a case of simple partial epilepsy. Our results show that EEG features recorded in epileptogenic areas are largely coupled with rCBF increase. Furthermore, rCBF modifications in other regions suggest that additional aspects of musical processing are also elicited during musicogenic seizures.

Videopolygraphic and functional MRI study of musicogenic epilepsy. A case report and literature review

A 36-year-old right-handed man, who had experienced partial seizures since the age of 24 every time he played or listened to music with a strong emotional charge, underwent videopolygraphic recording, including autonomic variables, and brain fMRI study during which he listened to both "neutral" and "emotionally charged" music. Three right temporal seizures recorded during videopolygraphic monitoring were elicited by listening to the triggering song. The fMRI study disclosed activation in right acoustic areas during "neutral music," whereas an "emotionally charged melody" provoked widespread activation over the right fronto-temporo-occipital area before seizure onset. The literature review disclosed 110 published cases of musicogenic epilepsy that seemed to suggest a right-sided predominance of the epileptogenic zone. Our results support the role of the right temporal lobe in musicogenic epilepsy and demonstrate that the cerebral areas activated during the period of strong emotion leading to the seizures encompass the auditory cortex activated by neutral music.