Talk to Pediatrician on Child Convulsions

My aunt's child is nearly 1 year old. he recently fell down the stairs and hit his head. after the blow, he now has episodes of convulsions. He first starts crying , then falls back, his eyes roll over and mouth starts foaming. he sometimes sleeps after this episode but other times he doesn't. At first, it only happened after 10-15 days but after Eid it's happening frequently after 1 or 2 days and sometimes it happens 2 times a day.... They have consulted a doctor but they say he is alright. all of his test results came fine. we don't know what is happening to him. all of the family is really worried. please help