It is also known as sleep myoclonus as it occurs only during NREM or deep sleep. The muscle twitching is short-lived and occurs in clusters of 4-5 jerks per second during sleep and abruptly stops when the child wakes up.
Diagnosis is usually clinical. An EEG done during the myoclonus shows no abnormal activity in the brain. Additional workup to rule out other causes may include a metabolic panel and screening for toxins. Rocking the baby back and forth while the baby sleeps can bring about sleep myoclonus. That helps differentiate it from epilepsy or a pathologic seizure. No treatment is needed for sleep myoclonus as it resolves spontaneously within 6-8months of age.