About TSC

Epilepsy/Seizure Disorders

Seizures remain one of the most common neurological features of TSC, occurring in 85% of individuals with TSC. Some infants will be diagnosed with TSC after they begin having a type of seizure called infantile spasms. Older children and adults may develop multiple types of seizures including generalized, complex partial and other focal seizures. More than 50% of individuals with TSC who have epilepsy will not respond to standard anti-seizure medications and have intractable epilepsy. Techniques can be used to identify the specific area where the seizures begin (called seizure focus) and improved neurosurgical techniques used to remove that specific area of the brain.

Although not all individuals with TSC who undergo brain surgery for epilepsy are seizure-free, many cases result in a significant improvement in seizure frequency and/or severity.

You may find it helpful to keep a diary of seizure activity, such as the free one provided by our friends at Seizure Tracker®.

Types of Seizures in TSC*

Seizure type What it looks like What it is not
Simple partial seizures The major distinction between Simple Partial and Complex Partial (see Next Type) is that there is no alteration in consciousness in individuals with Simple Partial seizures. They may not be obvious to an onlooker. Simple Partial seizures have a diverse range of presentations that include but are not limited to:

  1. involuntary jerking of one part of the body (“focal motor” signs)
  2. involuntary jerking of one part of the body (“focal motor” signs)
  3. behaving out of character because they are hearing or seeing things that are not there; feeling unexplained fear, sadness, or joy; feeling tingling sensations; feeling nauseous; or looking pale and sweating; or appear to be “drugged” because of pupillary dilatation. Jerking may begin in one area of body, arm, leg, or face. Can’t be stopped, but person stays awake and aware. Jerking may proceed from one area of the body to another and sometimes spreads to become a convulsive seizure.
Acting out, bizarre behavior.


Mental illness.

Psychosomatic illness.

Parapsychological or mystical experience.

Complex partial seizures Usually starts with blank stare, followed by chewing (or lip smacking, swallowing), then random activity. Person appears unaware of surroundings. May seem dazed and mumble. Unresponsive. Actions clumsy, not directed. May pick at clothing, pick up objects, try to take clothes off. May run, appear afraid. May struggle or flail at restraint. Once pattern established, same set of actions usually occur with each seizure. Lasts a few minutes, but post-seizure confusion can last substantially longer. No memory of what happened during seizure period. Drunkenness.

Intoxication on drugs.

Mental illness.

Disorderly conduct.

Secondarily generalized seizures


Onset may either be a simple partial or complex partial eizure as described above, which then evolves to a generalized seizure (commonly tonic-clonic as described below). Heart attack.


Diabetic condition.

Tonic clonic seizures Stiffening (tonic) of limbs/body, and often a cry (caused by air forced through contracted vocal cord). Limbs may be extended, flexed, or each in succession. This phase is followed by muscle jerks, shallow breathing or temporarily suspended breathing, bluish skin, possible loss of bladder or bowel control, usually lasts a couple of minutes. There may be deviation of the eyes or head to one side. There may be drooling or foaming resulting from lack of swallowing and excessive salivation. There may also be biting of the tongue, cheek, or lip causing bleeding. Normal breathing then starts again. There may be some confusion and/or fatigue lasting minutes to hours followed by return to full consciousness. Heart attack.


Diabetic condition.

Tonic seizures Prolonged stiffening of both upper and/or lower limbs; often occurs during sleep usually lasting seconds. There may be deviation of the head and/or eyes to one side. Lips may turn bluish; breathing may be irregular. Loss of bladder or bowel control may occur. Heart attack.


Atonic seizures A child or adult suddenly loses postural tone, which may result in a head nod or jaw drops (milder form), or falling to the ground (stronger form). Consciousness is usually impaired. The individual usually recovers after a few seconds to a minute. Clumsiness.

Normal childhood “stage.” In a child, lack of good walking skills.

In an adult, drunkenness, acute illness.


Myoclonic seizures A sudden, involuntary, brief shock-like muscle contraction that usually involves both sides of the body, with synchronous jerks most often affecting the neck, shoulders, upper arms, body, and upper legs. May cause person to spill what they were holding or fall off a chair. Clumsiness.

Poor coordination.

Nervous tics.



Atypical absence Stare may begin and end gradually, usually lasts 5-30 seconds, and is not generally provoked by hyperventilation. Child may be partially responsive during episode.

Eye-blinking or slight twitching movements of the lips may be seen. Children with this type of seizure often have global cognitive impairment and therefore it may be difficult to distinguish a seizure between the child’s usual behavior


Lack of attention.

Child deliberately ignores adult instructions.

Children with TSC may have mixed seizures such as atypical absence, tonic and tonic clonic, myoclonic, or atonic seizures. This condition is called Lennox-Gastaut syndrome (LGS) and many of these patients may have a history of infantile spasms and later transition into this syndrome.

Due to increased interest, the TSC Alliance also has a Position Statement on Medical Cannabis you can review.

*New Terms for Seizure Classifications

The International League Against Epilepsy has approved a new way of organizing seizures that reflects recent advances in our understanding of the brain and seizures. This new system will make diagnosis and classification of seizures easier and more accurate.  Learn more from our friends at the Epilepsy Foundation.


  • The Treatment of Epilepsy: Principles and Practice, Ed. Wyllie E, Ed. Malvern, PA: Lea & Febiger, 1993
  • Pediatric Epilepsy Diagnosis and Therapy, 2nd Edition. Pellock JM, Dodson WE, Bourgeois BF Eds. New York, NY: Demos, 2001.

Reviewed and updated by Elizabeth Thiele, MD, PhD, and Martina Bebin, MD, March 2011. Reviewed and updated by W. Donald Shields, MD, October 2013. Revised August 2016.