Authorities are asking for help in locating two men who are missing and believed to be at risk, with one disappearing in San Jose on Friday and the other in Cupertino on Monday.

Hipolito Canseco, 54, walked away from a Vine Street residence around 3:30 p.m. Friday. Canseco had a traumatic brain injury and his family said he has the mental capacity of a 5-year-old, according to San Jose police. He also has a history of seizures but had been taking his medication.

Canseco is Hispanic, 5-foot-8 and 140 pounds, with brown eyes, black hair and a dark complexion. He was last seen wearing a black jacket, white T-shirt, black pants and sandals. He uses a cane and walks with a limp.

Anyone with information about his whereabouts is asked to call San Jose police at 408-277-8990.

Dennis Brooks, 60, vanished from his Meteor Place residence after 1 p.m. Monday, according to the Santa Clara County Sheriff's Office. He is considered at-risk because he has dementia.

Brooks is black with a very light complexion, 5-foot-11 and 150 pounds with short black hair. He was last seen wearing a white and blue Hawaiian polo shirt, blue jeans and gray shoes. He may also be wearing a gray sweatshirt.

Anyone with information about Brooks is asked to call the Sheriff's Office at 408-299-2311.

Contact Eric Kurhi at 408-920-5852. Follow him at Twitter.com/erickurhi.