Trip to dentist leaves man with 90-min memory

LONDON: In a 'never-before-seen case', reminiscent of the film "Momento", a man in the UK has been left with just 90-minutes of memory after a root-canal treatment at a dentist, researchers say. 

The incident left the 38-year-old man stuck in an endless loop of waking up and thinking he has a routine dental appointment. The amnesia patient suffered memory loss similar to that featured in movies such as "Groundhog Day" and "Memento". 

The patient was referred to Dr Gerald Burgess, a clinical psychologist from University of Leicester, a decade ago. 

"One of our reasons for writing up this individual's case was that we had never seen anything like this before in our assessment clinics, and we do not know what to make of it, but felt an honest reporting of the facts as we assessed them was warranted, that perhaps there will be other cases, or people who know more than we do about what might have caused the patient's amnesia," said Burgess. 

"Our experience was that none of our colleagues in neurology, psychiatry, and clinical neuropsychology could explain this case, or had seen anything like it themselves before," said Burgess, who collaborated with Bhanu Chadalavada, Consultant Psychiatrist at Northamptonshire Healthcare Foundation NHS Trust. The man had gone to a dentist for a routine procedure and lost the ability to create new memories. Since the one-hour root-canal treatment, during which he was given a local anaesthetic, the individual cannot remember anything beyond 90 minutes. 

He is fully aware of his identity and his personality did not change - but every day the man thinks it is the day of his dental appointment. He has to manage his life through an electronic diary and access to prompts. 

His symptoms are similar to patients suffering from anterograde amnesia. This is when damage to the bilateral hippocampal or diencephalon regions in the brain cause short spans of awareness as well as complete and rapid memory loss. Typically it is brought on by a specific event or trauma. He can remember his childhood, relationships and his children, up to the year 2005, but can't remember what happened more than an hour and a half ago.