Doose Syndrome (Myoclonic-Atonic Epilepsy)

A 3-year-old previously healthy boy is brought to the pediatric neurology clinic with a 4-week history of sudden-onset seizures. Parents describe brief jerking movements of both arms immediately followed by sudden collapse and falls. EEG shows a normal background with bursts of generalized discharges at 2–5 Hz. The pattern marked **A** in the diagram is consistent with which diagnosis and is associated with which seizure semiology?

A 3-year-old previously normally developing boy presents to the pediatric neurology clinic with a 2-month history of sudden falls during play. His parents describe brief jerking movements of the shoulders and arms immediately followed by loss of muscle tone, causing him to collapse forward onto the floor. He has sustained two facial lacerations from these falls. EEG shows the pattern marked **A** in the diagram. Which of the following best describes the ictal electromyographic (EMG) correlate of this seizure type?