LONDON - Frederic Chopin's habit of drifting off and hallucinating at the piano may have been caused by epilepsy, according to a new study of the 19th-century romantic composer.

Chopin's tendency to lapse out of consciousness was interpreted by his partner George Sand, pseudonym of the French novelist Aurore Dudevant, as "the manifestation of a genius full of sentiment and expression." But in the analysis published this week, Spanish doctors say Chopin's hallucinations may have been due to a temporal lobe epilepsy rather than the result of any sweeping artistic tendencies.

Manuel Vazquez Caruncho and Francisco Branas Fernandez of the Complexo Hospitalario Xeral-Calde in Spain analyzed descriptions of Chopin's hallucinations from those close to him. They propose the French-Polish composer suffered from a type of epilepsy that produces conscious hallucinations that last from seconds to minutes. The research was published in the journal Medical Humanities, a specialist publication of the BMJ.

Caruncho and Fernandez cite an extract from Sand's memoir, where she recalls returning to the home she shared with Chopin, along with her son, after a long journey delayed by flooding. The composer had been playing one of his preludes and told Sand he was lulled to sleep while at the piano and saw himself drowned at the bottom of a lake.

Hallucinations are typically seen in patients with severe psychiatric disorders like schizophrenia and bipolar disorder. Other romantic composers such as Robert Schumann, who was committed to an asylum, experienced auditory and visual hallucinations which some believed were the product of his musical genius.

Caruncho and Fernandez say Chopin's hallucinations occurred mostly in the evening or coincided with fever, unlike those linked to psychotic disorders.

While Chopin was plagued by health ailments, like severe headaches and insomnia, there is no record he was diagnosed with any neurological problems. Some historians have suggested the composer's frequently noted melancholic moods may have been due to depression. Experts are split on what ultimately killed him; his death certificate lists tuberculosis as the cause, but others suspect it may have been cystic fibrosis. A request to the Polish government to perform genetic tests on Chopin's heart was denied.

Determining medical conditions and what killed historical figures is extremely difficult without forensic proof. In recent years, scientists have suggested the Austrian composer Wolfgang Amadeus Mozart was killed by strep throat after comparing accounts of his illness with diseases prevalent at his time of death. And after years of computer scans and DNA testing, researchers concluded Egypt's King Tut died of complications from a broken leg and malaria.

Caruncho and Fernandez suggest that because Chopin was able to recall his complex hallucinations in detail, they could have been caused by a temporal lobe epilepsy, though it's not known whether that might have contributed to his death. They acknowledge that without brain imaging or other tests, proving it will be nearly impossible.

"We doubt that another diagnosis ... will help us understand the artistic world of Frederic Chopin," Caruncho and Fernandez wrote. "But we do believe knowing he had (epilepsy) could help to separate romanticized legend from reality."