Three patients with small hypothalamic hamartomas and a recurrent “pressure to laugh,” often without actual laughter, are reported from the University of Melbourne, Australia, and McGill University, Canada. Giggling attacks began in infancy, at age 4 years, and at 10 years. Complex partial seizures occurred in 2 patients with onset at 14 and 25 years, and focal clonic seizures in 1 beginning at 2 years. EEGs and IQ tests were normal, and pressure-to-laugh sensations were not controlled by anticonvulsants. MRIs revealed the small hypothalamic hamartomas. [1]

COMMENT. The childhood epileptic syndrome of early-onset gelastic seizures, hypothalamic hamartoma, and precocious puberty is usually associated with a poor prognosis, leading to cognitive deterioration, but in a recent report of 9 cases, 4 were cryptogenic and the outcome was more benign (see Ped Neur Briefs March 1999;13:19-20). The present authors consider their syndrome as a mild form of gelastic epilepsy.

Gelastic seizures with a frontal lobe focus [2]. A 5-year-old boy had daily episodes of forced laughter, without feelings of mirth, and with loss of contact, automatisms, facial flushing, and right facial jerking. Ictal EEG showed right frontal spikes and slowing that spread to the temporal region. MRI was normal, but interictal SPECT showed hypoperfusion in the right frontal lobe. Seizures were controlled with sodium valproate. Gelastic seizures originating in the frontal lobe are unusual, the more common locus being the diencephalon or temporal lobe.