Intrinsic reflex epilepsy is when someone develops seizures in response to a specific mental process or sensation. These processes include decision-making, spatial thinking, and feeling startled.

Epilepsy is a condition that causes seizures. Reflex epilepsy is a rare condition that occurs when someone develops seizures in response to specific stimuli.

For instance, some people experience seizures in response to flashing lights. This is a form of extrinsic reflex epilepsy because the trigger is an external stimulus.

Contrastingly, intrinsic reflex epilepsy involves seizures in response to internal activities or processes. In this form of epilepsy, external stimuli play only a limited role, if any at all.

This article explains the symptoms, causes, and triggers of intrinsic reflex epilepsy. It also discusses the risk factors for this condition as well as the diagnosis, treatment, and outlook.

A green and white cube -2.Share on Pinterest
Nur Ariyansah/Getty Images

Intrinsic reflex epilepsy causes seizures in response to internal stimuli. Seizures can present in the following ways:

Individuals may have issues concentrating or with memory after a seizure.

Researchers are unsure about what causes the development of intrinsic reflex epilepsy.

There is some evidence that genetics can play a role in reflex epilepsies. This is because individuals can inherit reflex epilepsies from their biological parents.

However, further research is necessary to understand the exact role of genetics and other factors that might cause intrinsic reflex epilepsy.


According to a 2021 article, the following triggers could cause seizures in people with intrinsic reflex epilepsy:

  • Thinking: Noogenic epilepsy, also known as thinking epilepsy, is when certain cognitive tasks trigger seizures. These include decision-making, calculations, and abstract reasoning.
  • Praxis: Praxis-induced seizures can occur after tasks that involve spatial thinking or thinking about bodily movements. Seizure triggers can include drawing, solving Rubik’s cubes, or playing with board games.
  • Proprioception: Some people experience seizures during movement itself or due to posture changes.
  • Startle: In some people, being startled can cause seizures. Triggers can include sudden noises, although other sensory experiences can have the same effect. For certain people, startling triggers include abrupt visual or tactile changes.

Risk factors for intrinsic reflex epilepsy increase the risk of having or developing this condition. However, more research is necessary on this topic.

Reflex epilepsy involves recurrent seizures in response to the same stimulus. Certain types of epilepsy, such as Dravet syndrome, are among the major risk factors for reflex epilepsy. In these cases, people may have several seizure types in addition to reflex seizures.

According to the same 2021 review, the genetic condition nonketotic hyperglycemia is a risk factor for proprioception-induced seizures.

Startle-induced seizures usually develop during infancy. Healthcare professionals associate them with metabolic disorders or genetic conditions that affect brain development, often with other symptoms, such as weakness on one side of the body.

According to the Epilepsy Foundation, doctors diagnose reflex epilepsies using the following techniques:

  • analyzing a person’s symptoms and medical history
  • a physical examination
  • blood tests and tests for metabolic disorders
  • an EEG, which can pick up on seizure or seizure-like brain activity
  • MRI scans

In many cases of intrinsic reflex epilepsy, avoiding triggers is either impossible or undesirable. However, some treatment options can help someone manage this condition effectively.

For thinking epilepsy and praxis epilepsy, doctors may prescribe antiseizure medications (ASMs) such as valproic acid.

If proprioception epilepsy is due to an area of damage in the brain, doctors may use anticonvulsants, such as carbamazepine (Tegretol) and clobazam (Frisium, Onfi).

If proprioception epilepsy is due to nonketotic hyperglycemia, glucose control is a cornerstone of treatment.

Startle-induced seizures do not respond very well to treatments. ASMs seem to have little effect on the condition, although some anticonvulsants may help.

According to a 2018 review, intrinsic reflex epilepsies are extremely variable in their outlook. It all depends on how a person responds to treatment and the nature of any underlying causes.

Additionally, some people may grow out of intrinsic reflex epilepsy seizures.

If an individual believes they have experienced an intrinsic reflex seizure, they need to seek immediate medical attention. Doing so can help doctors either rule out intrinsic reflex epilepsy or diagnose it.

A prompt diagnosis of intrinsic reflex epilepsy allows individuals to receive the best possible treatment.

Epilepsy resources

Visit our dedicated hub for more research-backed information and in-depth resources on epilepsy and seizures.

Was this helpful?

Intrinsic reflex epilepsy is when someone experiences seizures due to internal triggers, such as certain mental processes. Researchers do not know the exact cause of reflex epilepsies, although genetics may play a role.

Some people may also develop intrinsic reflex epilepsies due to brain injury or underlying conditions.

Triggers for seizures may include abstract or practical thinking, startling due to sudden noise or visuals, and proprioception. Because avoiding these triggers is difficult, doctors usually treat intrinsic reflex epilepsy with medications.