German musician who lost nearly all memory after contracting herpes encephalitis can learn new pieces of music

A professional cellist who lost nearly all of his memory after a virus destroyed parts of his brain has astonished doctors with his remarkable recall of music.

The 71-year-old, known only as PM, had played with a major German orchestra before contracting the infection that devastated his brain's memory centres in 2005.

The illness left the musician with such profound amnesia he could remember almost nothing of his past and was unable to plan for the future. The only people he recognised were his brother and a care worker.

"He can hardly remember a thing. He has no memory of any personal or professional events," Carsten Finke, a neurologist at Charité university hospital in Berlin, told the Guardian. "He is living in the moment, more or less. He has lost his whole life."

Doctors made their discovery when they tested PM's ability to recall musical information and found he could identify the scales, rhythms and intervals of pieces they played him. The man went on to score normally on a standard test for musical memory.

But it was later tests that surprised doctors most, when the cellist showed he could learn new pieces of music, even though he failed to remember simple information, such as the layout of his flat, who his doctors were and what medicines he should take.

Neighbours said the man still played the cello in his apartment, but he refused to play in front of doctors, perhaps because he felt he was no longer any good, Finke said.

PM was struck down by a rare herpes encephalitis infection that leaves many patients with brain damage even if they receive urgent treatment.

The infection occurs when the virus – which is responsible for cold sores – travels along nerves that lead to the brain. The condition affects around one in half a million people each year.

In PM's case, the virus wiped out large parts of the brain's medial temporal lobes, which are important for remembering events and facts. Details of the case were described at the Society for Neuroscience meeting in Washington DC on Sunday.

Finke decided to investigate PM's memory for music three years ago after a standard test revealed the musician had very severe amnesia.

"This was a unique chance to investigate musical memory, because we knew what sort of music he knew before he got ill," Finke said.

Working with professional musicians, the doctors created a battery of tests to probe PM's memory in more detail. In one, the doctors took well-known pieces of music composed before the cellist fell ill, such as Vivaldi's Four Seasons, and paired them with similar sounding pieces composed after 2005. When PM was asked to say which he knew better, he named the older scores 93% of the time.

In a later test, PM recognised 77% of pieces he had been played earlier in the day, suggesting he had some capacity to learn new music.

"It's easy to explain why he developed severe amnesia, but what is remarkable about this case is that he has intact musical memory," Finke said. "Given his severe amnesia, it is really astonishing that he could learn new musical material."

The case could help doctors understand how different kinds of memories are stored in the brain. Finke cites another patient who in 1996 lost all comprehension for music after having surgery that damaged his superior temporal gyrus.

"Musical memory seems to be stored independently, at least partially, of other types of memory," Finke said.

"If you contrast these two cases, you could argue the superior temporal gyrus, which is intact on the righthand side in our patient, could be the relevant structure that he uses to remember music."

Doctors now hope that PM's ability to learn music can be used to improve his rehabilitation. One idea is to use musical notes to signify people and various tasks, such as taking medicine or calling someone.

"He cannot remember most of the things we will tell him, but musical aspects he can learn and remember, so it might be a gateway to reach this patient and allow him to learn new things," Finke said.

Professor Alan Baddeley, who studies human memory at the University of York, said the case was similar to that of Clive Wearing, the British conductor and musician who became deeply amnesiac after contracting herpes encephalitis in 1985. Wearing can still play and conduct a choir despite having no recollection of his musical training, or much of his life before 1985.

"Dramatic cases like this make a point that memory isn't unitary. Musical memory is a skill, like riding a bicycle," Baddeley said.