Focal emotional seizures with laughter (gelastic seizures) are usually the initial seizure type, occurring in >95% of individuals. Seizures are typically brief (5-20 seconds), frequent (multiple daily, even multiple per hour), and can be subtle. When they occur with retained awareness (a focal aware emotional seizure with laughter), they are often not recognized as seizures in infants and young children, until after the emergence of other seizure types. Focal impaired awareness seizures are common, seen in 50-60% of individuals, with the impaired awareness typically preceded by the laughter phase.
Focal to bilateral tonic-clonic seizures can occur.
Status epilepticus, including focal status epilepticus, can occur.
CAUTION patients with hypothalamic hamartoma may have a change in their seizure types over time, with the emergence of epileptic spasms or generalized seizure types, such as atypical absence, atonic and tonic seizures. Developmental and cognitive impairments are more common in this group.