jerry tarkanian , five , was taken to the hospital at 4 am on friday after complaining about pain in his legs .
he was given a ct scan , could n't move the left side of his body and was having trouble answering questions , mom amy tarkanian said .
parents danny and amy tarkanian say he 's showing signs of improvement .
elder jerry tarkanian , a hall of fame coach , died in february , aged 84 .