There's no single cause. Forming memories requires many parts of the brain. Injury to or illness in any one of them can cause anteretrograde amnesia.
It's like asking "what makes a person unable to walk?" Arthritis, paralysis, muscle wasting, MS, Parkinson's, a broken bone, an amputated foot... some are temporary, some are permanent.
Walking is hard, even though most of us can do it. Forming memories is similarly hard.
It's like asking "what makes a person unable to walk?" Arthritis, paralysis, muscle wasting, MS, Parkinson's, a broken bone, an amputated foot... some are temporary, some are permanent.
Walking is hard, even though most of us can do it. Forming memories is similarly hard.