Actor Mohanlal's mother, Santhakumari, passed away on Tuesday at her home in Ernakulam. She was 90. The actor, who was shooting in the city at the time, immediately headed back after being informed of her demise.Santhakumari had been battling health issues for several years. About a decade ago, she suffered a stroke that resulted in paralysis and confined her to bed. Following this, she was shifted to Ernakulam so that she could undergo specialised treatment at a multi-specialty hospital.