Gelastic Seizures


People having a gelastic seizure (GS) sound like they are laughing or mumbling. This is an uncontrolled reaction caused by unusual electrical activity in the part of the brain that controls these actions.

Gelastic seizures are named after the greek word for laughter, "gelastikos."

GS often occurs in patients with hypothalamic hamartomas (HH). HH is a rare, non-cancerous brain tumor on the hypothalamus.


The most common sign of GS is the patient startling. Patients may also have a look of panic or fear. Other symptoms include:

  • A smile that seems forced
  • Laughing that begins and stops suddenly
  • Grunting
  • Lip smacking
  • Mumbling
  • Fidgeting

Causes and Risk Factors

GS often begins when the patient is an infant. However, the condition is generally diagnosed years later.

GS can be triggered by:

  • Loud noises
  • Fearful responses
  • Excitement
  • Anxiety


The most useful way to diagnose seizures is an electroencephalogram (EEG). This records electrical activity in the brain. The EEG can record unusual spikes or waves in electrical activity patterns. Different types of seizures can be identified with these patterns.

Magnetic resonance imaging (MRI) and computed tomography (CT) scans may be used to look at the cause and the location within the brain. The scans can also show tumors in the brain.


Medication used to treat focal, or partial, seizures can also help control GS. These anti-seizure medications may include:

  • Carbamazepine (Tegretol)
  • Clobazam (Frisium)
  • Lamotrigine (Lamictal)
  • Lacosamide (Vimpat)
  • Levetiracetam (Keppra)
  • Oxcarbazepine (Trileptal)
  • Topiramate (Topamax)

Surgery may be needed if GS is caused by a tumor. One option is laser ablation. If the seizures are caused by a tumor or lesion, the cells may be killed using focused light and heat from a laser. Imaging technology is used to help place the probe that will deliver the laser very precisely so it only reaches the unhealthy brain cells.

In some cases, radiation therapy may be used to shrink the tumor.

© 2000-2022 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.
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