“Pressure to laugh”: An unusual epileptic symptom associated with small hypothalamic hamartomas

Case 1.

This 25-year-old right-handed man completed a high school education and worked as a laborer and musician (table). His prenatal and birth history were unremarkable, developmental milestones were normal, and there was no family history of epilepsy. Puberty occurred at 12 years of age. Giggling attacks lasting a few seconds were noted from infancy but were infrequent after age 7 years. He described a recurrent pressure to laugh, which could be suppressed, from early childhood. At age 14 years, he had two tonic-clonic seizures and was treated with phenytoin. He developed complex partial seizures from age 19 years, which sometimes were preceded by a pressure to laugh. These seizures were relatively well controlled on carbamazepine and lamotrigine, occurring every 2 months on average. The recurrent pressure to laugh continued to occur up to 10 times daily. The feeling was pleasant and made him feel happy; the feeling was nonsexual. In a socially appropriate situation, he would allow the sensation to evolve into laughter, which was similar to his normal laugh. He could suppress the laughter by biting on his lip. Facial reddening and tearing would occur with laughter but not with the pressure to laugh. There have been no further tonic-clonic fits and no atonic seizures. Neurologic examination gave normal results. Neuropsychologic assessment performed this year revealed no focal cognitive deficits, a full scale IQ of 104, and a general memory quotient of 115. MRI brain scan showed a 5-mm diameter hypothalamic hamartoma and otherwise was normal (figure). EEG recorded during episodes of pressure to laugh was normal, as was the interictal EEG.

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Figure. MRI scans of Patients 1, 2, and 3 (A through C). The small hypothalamic hamartomas are indicated with arrows. Scale bar = 1 cm.

Case 2.

This 34-year-old right-handed woman was a university graduate and worked as a contract administrator before becoming a full-time parent. Her prenatal, birth history, and developmental milestones were normal. There was no family history of epilepsy. Puberty occurred at 12 years of age. Giggling attacks were noted from age 4 years, and an EEG performed at age 7 years was normal. The patient described a desire to laugh, “like a tickling inside my head,” which could be suppressed. This was accompanied by elevation of the left side of the mouth or smiling, dilation of the pupils, and reddening of the face.

These events lasted 10 to 15 seconds and occurred 6 to 10 times a day. During these events, there was a slight elevation in the pitch of her voice, detectable by herself and her husband; she gave up singing because of this. The feelings were pleasant and nonsexual. From the age of 25 years, complex partial seizures occurred, manifested by a desire to laugh followed by decreased awareness, staring, and disorientation. These have been treated with carbamazepine and lamotrigine and occur fortnightly. The frequency of the desire to laugh was unchanged by medications. There have been no tonic-clonic or atonic seizures. Results of neurologic examination were normal. Neuropsychologic assessment performed this year showed no focal cognitive deficits, a full scale IQ of 108, and a general memory index of 125. The interictal EEG was normal. MRI brain scan showed a 6-mm diameter hypothalamic hamartoma and otherwise was normal (see figure).

Case 3.

This 18-year-old woman was a high school student. Her prenatal and birth history were unremarkable. Development and pubertal onset were normal. At age 2 years, the patient developed episodes of right facial twitching followed by jerking of the right arm and leg or all limbs. These events lasted 30 seconds and were stopped by carbamazepine, which was discontinued at 4 years of age. At age 10, laughing attacks developed. These were preceded by a pleasant emotional feeling in the chest and a desire to laugh. At times, a pressure to laugh occurred, which was not followed by laughter. These gelastic events occurred up to 15 times a day. She was treated with lamotrigine. There have been no tonic-clonic, atonic, or complex partial events. Results of neurologic examination were normal. There was no evidence of cognitive impairment on examination; however, formal neuropsychological assessment has not been performed. MRI revealed a 5-mm diameter hypothalamic hamartoma and otherwise was normal (see figure).