The causes, clinical manifestations, and evolution of gelastic seizures (GS) were studied, using video-EEG and MRI, in 9 patients observed between 1986 and 1997 at the Epilepsy Center, Federico II University, Naples, Italy. Seizures were frequent (several/day) and characterized by laughing attacks, sometimes with facial flushing, and rarely with loss of contact. Age at onset was less than a year in 3, and < 12 years in 8. All older patients reported feelings of embarrassment, and attempts to conceal the seizure (eg. by feigning a sneeze); no feeling of amusement accompanied the laughter. Of 5 patients with symptomatic, localization-related epilepsy, 4 had hypothalamic hamartoma (HH) and 1 had tuberous sclerosis (TS). In 4 patients with cryptogenic gelastic seizures, the MRI was negative but seizures and EEG showed focal characteristics. Seizures were drug resistant in the HH cases, the TS patient responded to vigabatrin, and cryptogenic GS showed a variable outcome with partial seizure control. Two HH cases (ages 3 yrs and 28 yrs) showed complete or partial benefit following total surgical removal. Precocious puberty and cognitive deterioration, well recognized complications of the gelastic epilepsy-hypothalamic hamartoma syndrome of childhood, were not encountered in this series of patients. Cryptogenic cases of GS were usually more benign than the symptomatic HH cases. [1]

COMMENT. The childhood epileptic syndrome of early-onset gelastic seizures (GS; from the Greek ’gelos’ meaning mirth), hypothalamic hamartoma (HH), and precocious puberty (PP) is relatively rare but important in diagnosis and management. Frequent recurrent attacks of laughter, especially when accompanied by facial flushing, in a young infant or child may represent a recognized form of epilepsy and should prompt an MRI and EEG. The prognosis is usually poor, the GS evolving into symptomatic generalized epilepsy and leading to cognitive deterioration, but early recognition and surgical ablation of the hamartoma may occasionally result in control of drug refractory seizures and prevention of mental retardation.

The authors in this relatively large series of cases of gelastic epilepsy, including GS that are symptomatic of hamartomas and an equal number of cryptogenic cases, allude to the absence of precocious puberty, usually considered a classic sign of the syndrome, a later onset of seizures in some, and the relatively benign outcome of non-hamartoma cases.

Previous reports of gelastic epilepsy have usually involved only isolated cases. In 3 cases studied at Johns Hopkins University, GS originated in the anterior cingulate or fusiform gyri, and seizures were controlled following surgical removal of a cavernous hemangioma in one [2]. Infantile spasms are often associated with attacks of paroxysmal laughter [3]. The classic epilepsy monographs of Turner WA (1907) and Lennox WG (1960;pp280-l) have references to compulsive laughter as a manifestation of epilepsy. Reference to GS is surprisingly absent from Penfield’s monograph (1954). (See Progress in Pediatric Neurology II, Chicago, PNB Publishers, 1994;pp41-42, for reports and commentary on gelastic epilepsy).