Reflex epilepsy is the name for a group of epilepsy conditions in which certain external or internal stimuli cause seizures. Triggers may include flashing lights, sounds, visual motor tasks, and nonverbal activities.
Reflex epilepsies are a group of conditions whereby seizures happen due to a trigger event or stimulus. This can be an environmental stimulus or something complex, such as an internal mental process or emotion.
These types of seizures may be prevalent in
This article explains types of reflex epilepsy, potential triggers for seizures, its diagnosis, and how a person can manage their symptoms.
People with reflex epilepsy experience seizures that occur after a certain stimulus. A
Extrinsic reflex epilepsy
Extrinsic reflex epilepsy results from external stimuli that affect sensory-perceptual systems, such as the eyes. Some types of reflex epilepsy in this category
- Photosensitive epilepsy: Certain visual patterns or light frequencies can cause seizures for people with this reflex epilepsy. The Epilepsy Foundation estimates that 3% of people with epilepsy experience this condition. TV and video games are common triggers for seizures.
- Musicogenic epilepsy: In this condition, certain sounds, such as church bells, machinery, or songs, can trigger seizures.
- Reading epilepsy: People with this type of epilepsy may experience reflex seizures after reading, typically when the content they read has increased difficulty or emotional content.
- Hot water or bathing epilepsy: Reflex seizures in this condition can occur after exposure to water. Factors including water temperature, quantity, and where on the body the water contacts can influence the occurrence of seizures.
- Touch-induced epilepsy: Touch-induced reflex seizures can occur following triggers, such as friction against the skin, toothbrushing, and stimulation against certain parts of the body.
Intrinsic reflex epilepsy
The conditions in this category happen due to higher brain functions and cognitive processes. Intrinsic reflex seizures do not involve external sensory triggers.
Thinking epilepsy is an intrinsic reflex epilepsy. Mental activities that cause seizures in this condition can include decision-making, performing calculations, and abstract reasoning.
Nonverbal activities triggering seizures
Praxis-induced seizures are a subset of thinking epilepsy. These can occur when a person thinks about and plans to put an action, or sequence of actions, into practice.
During these seizures, a person experiences rapid muscle jerking and stiffness. They can involve the entire body, including the torso, arms, and legs on both sides of the body.
A person experiencing a tonic-clonic seizure
Other seizure types that may occur in reflex epilepsies include:
- Absence seizures: These seizures cause a lapse in consciousness. A person will stop all activity and stare into space as if they are daydreaming. Eye fluttering or rolling may also occur.
- Myoclonic seizures: These seizures are very short, only lasting around 2 seconds. They may include sudden jerks or twitches that can occur in one or several muscles.
- Focal seizures: These seizures arise from one part of the brain but can progress to involve several areas of the brain or the entire brain. Symptoms can vary depending on the part of the brain experiencing abnormal activity but can include muscle contractions and vision changes.
Reflex seizure triggers vary from one person to the next depending on the type of reflex epilepsy they experience. However, according to a 2018 article, visual stimuli may account for
According to the Epilepsy Foundation, reflex seizure triggers can include:
- certain light frequencies
- sounds, including a person’s voice and some types of music
- thinking about certain topics
- patterns of a moving escalator step
- bathing in hot water
- skin friction
- specific colors
- certain rates of blinking
The Epilepsy Foundation states that experts have not yet identified a gene that causes reflex epilepsies.
However, they highlight that reflex epilepsies may occur alongside other conditions, including:
- Dravet syndrome
- gene mutations, including the MECP2 and LGI1 genes that provide instructions for making certain proteins
- chromosomal and other genetic disorders
If a doctor suspects a person has reflex epilepsy, they may review the person’s medical history and assess their symptoms. They may ask about seizures and what a person was doing in the moments leading up to the seizure.
Imaging tests may also help a doctor diagnose reflex epilepsy. These include:
- an EEG to observe abnormal brain waves
- MRI and CT scans to detect physical abnormalities
- functional MRIs to identify specific areas of malfunction in the brain
A doctor may order a blood test to rule out any underlying medical conditions that could cause seizures.
There are several treatments available to help a person manage the symptoms of epilepsy. However, people with reflex epilepsy may also be able to manage seizures by avoiding the triggers of a seizure, such as flashing lights.
Avoiding triggers and taking prescribed anti-seizure medications may allow people with reflex epilepsy to manage their condition well.
Some types of reflex epilepsy disappear with age, but this is not always the case. The Epilepsy Foundation suggests 75% of people with photosensitive reflex epilepsy continue to have seizures past the age of 25 if they do not receive treatment.
A reflex seizure happens as a result of a stimulus. This could be internal, such as a complex mental process, or external, such as flickering lights.
Reflex seizures can cause different symptoms depending on the type of seizure a person experiences. However, tonic-clonic seizures are the most common. These seizures can affect the whole body.
People with reflex epilepsy may be able to manage their condition by avoiding known triggers and taking anti-seizure medications.