Musicogenic seizure, also known as music-induced seizure, is a rare type of seizure, with an estimated prevalence of 1 in 10,000,000 individuals, that arises from disorganized or abnormal brain electrical activity when a person hears or is exposed to a specific type of sound or musical stimuli. There are challenges when diagnosing a music-induced seizure due to the broad scope of triggers, and time delay between a stimulus and seizure. In addition, the causes of musicogenic seizures are not well-established as solely limited cases and research have been discovered and conducted respectively. Nevertheless, the current understanding of the mechanism behind musicogenic seizure is that music triggers the part of the brain that is responsible for evoking an emotion associated with that music. Dysfunction in this system leads to an abnormal release of dopamine, eventually inducing seizure.
Currently, there are diverse intervention strategies that patients can choose from depending on their situations. They can have surgery to remove the region of the brain that generates a seizure. Behavioral therapy is also available; patients are trained to gain emotional control to reduce the frequency of seizure. Medications like carbamazepine and phenytoin (medication for general seizure) also suggest effectiveness to mitigate music-induced seizures.
Signs & symptoms
While the signs and symptoms of musicogenic seizures are similar to that of other focal seizures, one unique distinction is the variation in the time interval between the stimulus and seizure among different patients. Unlike most focal seizures, the duration between the triggering musical stimulus and seizure varies among patients; some patients encounter the seizure imminently after the trigger, while some experience a wide time gap between the stimulus and seizure. During this latent prolonged time lapse, the symptoms experienced are autonomic responses. Patients may encounter changes in respiratory rate, blood pressure, and heart rate such as tachycardia, leading them to feel distressed and agitated.
Furthermore, hallucinations are often experienced when encountering a seizure triggered by a musical stimulus. For example, musical release hallucinations and synesthetic experiences are the most common hallucinations associated with music-induced seizures. Musical auditory hallucinations may also develop due to epilepsy in the temporal lobe, which is found to be affected in 75% cases of musicogenic seizures.
Causes
Musicogenic seizures are generally defined as a focal seizure, as the lateral and mesial temporal, and orbitofrontal areas of the brain are affected. Musicogenic seizures have complex stimuli due to the broad scope of possibilities of triggers.
A wide spectrum of triggers has been noted to stimulate musicogenic seizures and musicogenic epilepsy as the type of music and method of perceiving music varies from one patient to another. It has been reported that 17% of music-evoked seizures are induced solely by music, while 53% are induced by miscellaneous musical stimuli. Examples of musical triggers not only include listening to noise, sound, volume, pure words, genre, singer, song, and anthem, but also playing, thinking and dreaming of music. Among these triggers, most patients tend to be triggered by a specific tune, song or singer. Musical characteristics such as cadence, frequency, and timbre are possible reasoning behind the musical stimuli. Hence, this proposes that a particular rhythmic activity or pattern induces a seizure.
Mechanism
Although the understanding of the exact causes of musicogenic seizures is currently not fully known, a commonly understood mechanism is that this epilepsy is associated with emotional responses to music rather than the music itself. Specifically, music creates an emotional response that is activated by the limbic areas. This emotional effect of the music then triggers the increase of dopamine in the different parts of the brain, eventually leading to hyperexcitation, which is an abnormal excitation of neurons, and generation of seizures in those areas when there is a dysfunction in this system.
This notion is supported by many functional imaging studies like fMRI, PET scan, and clinical studies which suggested that patients of the musicogenic seizure often express emotional feelings before the onset of the seizure.