A 4-year-old boy is brought to the physician for a 2-month history of abnormal eye and bodily movements reported by his mother. He has no past medical history. Physical examination shows a slight violaceous appearance of the eyelids and rapid, involuntary movements of both eyes. There are sudden brief muscle jerks of the left arm and right leg. A midline abdominal mass is palpated. Blood pressure is elevated. EEG shows no abnormalities. Which of the following is the most likely diagnosis?
Dermatomyositis
Lupus
Neuroblastoma
Pheochromocytoma
West syndrome (infantile spasms)
