Man's (un)forgettable dental visit results in bizarre amnesia

Many people dread going to the dentist, but at least they only have to think about it a few times a year. This is not the case for one British man who, due to a bizarre case of amnesia, wakes up every morning thinking it’s the day of his dental appointment.

In a unbelievable scenario reminiscent of “Groundhog Day” or “Momento,” the man, known in recent scientific publications only as “William,” is stuck in a loop; while he can remember everything leading up to the start of his routine root canal in 2005, he can now only store new memories for 90 minutes.

“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 Dr. Gerald Burgess, a University of Leicester clinical psychologist who has been treating the 48-year-old William for 10 years. “His amnesia is the sort that, since onset, he can no longer make ‘new’ memories, but he remembers his personal identity and history up to the point of the root canal procedure beginning.”

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“I remember getting into the chair and the dentist inserting the local anesthetic,” William told the BBC. But that’s the final lasting memory he has. Every morning, his wife prompts him to check his computer, where the family has listed and updated important facts he should be aware of. William can remain generally oriented during the day with continuous access to an online diary and prompts, but is often surprised or bewildered by developments that have taken place over the past 10 years.

The dentist that performed the root canal speculated that William may have fainted during the procedure, as his blood pressure dropped at one point. William was given oxygen and glucose tablets to bolster his blood pressure. However, doctors cannot explain William’s symptoms based upon this incident.

Continue to page two to read what caused William's amnesia...

William’s symptoms are consistent with anterograde amnesia, in which a person struggles to make new memories due to an inability to translate new sensory information into long-term memories. He differs from typical anterograde amnesia patients, however, in that there is no structural damage to his brain or hippocampus. There is nothing in William’s medical history that can explain the bizarre memory loss, as his brain cells do not show any sign of damage.

Anterograde amnesia can also be caused by a specific psychological event or emotional trauma but, in William’s case, there were no noteworthy precipitating events. Although he cannot specifically determine what caused the memory loss, Dr. Burgess cautions against jumping to conclusions regarding William’s dental visit. “I don’t think that at this point the dental anesthetic or root canal can be blamed; it would be unethical and perhaps scaremongering to do so, there is not sufficient evidence.”

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At this point, Dr. Burgess’ best guess is that the amnesia could be caused by a breakdown of protein synthesis in the brain. “An acquired or manifest deficiency of protein synthesis, required for permanent restructuring of synapses in the brain, seemed an intriguing speculation, and one we hope there might be further human research into.”

Dr. Burgess has published the patient’s unusual case study, along with four other similar cases, and is hoping to hear of similar cases from other professionals, in an attempt to gather more information about this unprecedented memory loss.

While the medical mystery is undoubtedly intriguing, the fascination is largely lost on William, who can’t remember what has happened for more than an hour and a half. All he can remember is that he’s got an upcoming dental appointment that he simply can’t miss.