A 10-day-old baby with "lightning-like" myoclonic limb jerks during sleep: a case report

Abstract

Background: Benign neonatal sleep myoclonus (BNSM) is a condition commonly mistaken for seizures. It is characterized by self-limiting "lightning-like" myoclonic limb jerks that occur primarily during sleep in the newborn phase but are not associated with epilepsy that suddenly stops when the infant is agitated. This condition is potentially resolved between the ages of 2 and 6 months.  The incidence of BNSM per 1,000 births is 0.8 to 3 cases. This case report aims to explain the findings of a neonate with multiple episodes of abnormal jerks affecting the entire limb, only during sleep.Case Report: We reported a 40-day-old baby boy with multiple episodes of abnormal jerks affecting the entire limb since 10-day-old only during sleep. The jerky body movements appeared six until nine times a day with approximately an hour interval between movements. The patient did not have any neurologic deficits, pathologic reflexes and vital signs abnormalities. Electroencephalogram (EEG) revealed the normal result. We diagnosed the patient with BNSM.Conclusion: The BNSM is a self-limiting disorder. For neonatal seizures or even neonatal status epilepticus, BNSM can be misinterpreted, recognizing childhood benign sleep myoclonus is important to prevent unnecessary diagnostic studies and treatments. The prognosis was good and the patient didn't need any medication and long-term follow-up.