Utility of early single photon emission computed tomography (SPECT) in neonatal gelastic epilepsy associated with hypothalamic hamartoma.

Gelastic epilepsy, or laughing seizures, is a rare seizure manifestation often associated with hypothalamic hamartoma. This seizure type is well described in older children and adults, but has only rarely been reported in neonates, oftentimes recognized in retrospect when the children are older. We report a child diagnosed at 3 months of age with a large hypothalamic mass after evaluation for spells occurring since birth. The spells were characterized by bursts of hyperpnea, followed by repeated "cooing" respirations, giggling, and smiling. These spells were recognized soon after birth in the delivery room, and occurred at 15-20 minute intervals. They did not interrupt feeding and occurred during sleep. On referral to our center, the patient was noted to be thriving, with normal medical and neurologic examinations except for his spells. The laboratory evaluation was normal, as were endocrine and ophthalmologic evaluations. Neuroimaging was performed, with magnetic resonance imaging demonstrating a large 2.8-cm isodense, nonenhancing hypothalamic mass. Electroencephalogram was abnormal, demonstrating bi-frontal sharp and spike-wave discharges. Video-EEG did not demonstrate ictal discharges associated with the patient's spells. Single photon emission computed tomography (SPECT) demonstrated dramatic ictal uptake in the area of the tumor, with normalization during the interictal phase. Partial excision of hamartomatous tissue has minimally improved the spells. In conclusion, this patient manifested an unusual, early presentation of a rare seizure type. SPECT scanning confirmed the intrinsic epileptogenesis of the hamartoma, further justifying a surgical approach to such patients. Early surgical intervention is probably indicated in an attempt to minimize or prevent the cognitive and behavioral sequelae commonly seen with this seizure type.

Rare interstitial deletion (2)(p11.2p13) in a child with pericentric inversion (2)(p11.2q13) of paternal origin.

An unbalanced 46,XY,der(2)del(2)(p11.2p13) inv(2)(p11.2q13) karyotype was found in a phenotypically abnormal child with a de novo interstitial deletion of band 2p12 associated with an inv(2)(p11.2q13) inherited from the father. The inv(2) is generally considered a benign familial variant without significant reproductive consequences. However, our findings led us to consider a previously proposed mechanism of unequal meiotic crossing over at the base of a parental inversion loop, which could lead to either a deletion or duplication of a segment adjacent to the inverted region in the offspring. This phenomenon has been reported in other inversions of chromosomes 1, 7, 13, 15, and 17 and may explain the origin of the deletion in our patient. Although repetitive sequences might be present around such inversions, which could predispose to de novo deletions independently of the inversion, current evidence including this case favors a proposed causal relationship between the parental inversion and the deletion in the child. Our review and results suggest there could be a small risk for a related imbalance to couples with an inv(2)(p11.2q13). For del(2)(p11.2p13), which is rare, a more distinct phenotype has been proposed herein. Our patient shared several findings with the three previously published cases, namely the broad nasal bridge, abnormal ears, high-arched palate, psychomotor retardation, and micrognathia. However, our patient also had sensorineural hearing loss and significant hypotonia, which have not been previously reported, thereby expanding our understanding of this rare deletion. Am. J. Med. Genet. 87:139-142, 1999. Published 1999 Wiley-Liss, Inc.