he became fascinated by it and ranked it as a great work. In January 1932 he premiered it in Vienna to instant acclaim, and performed it in Paris with Ravel conducting the following year. The critic Henry Prunières wrote, "From the opening measures, we are plunged into a world in which Ravel has but rarely introduced us." The Piano Concerto in G major was completed a year later. After the premiere in January 1932 there was high praise for the soloist, Marguerite Long, and for Ravel's score, though not for his conducting. Long, the dedicatee, played the concerto in more than twenty European cities, with the composer conducting; they planned to record it together, but at the sessions Ravel confined himself to supervising proceedings and Pedro de Freitas Branco conducted. In October 1932 Ravel suffered a blow to the head in a taxi accident. The injury was not thought serious at the time, but in a study for the British Medical Journal in 1988 the neurologist R. A. Henson concludes that it may have exacerbated an existing cerebral condition. As early as 1927 close friends had been concerned at Ravel's growing absent-mindedness, and within a year of the accident he started to experience symptoms suggesting aphasia. Before the accident he had begun work on music for a film, Don Quixote (1933), but he was unable to meet the production schedule, and Jacques Ibert wrote most of the score. Ravel completed three songs for baritone and orchestra intended for the film; they were published as Don Quichotte à Dulcinée. The manuscript orchestral score is in Ravel's hand, but Lucien Garban and Manuel Rosenthal helped in transcription. Ravel composed no more after this. The exact nature of his illness is unknown. Experts have ruled out the possibility of a tumour, and have variously suggested frontotemporal dementia, Alzheimer's disease and Creutzfeldt–Jakob disease. Though no longer able to write music or perform, Ravel remained physically and socially active until his last months. Henson notes that Ravel preserved most or all his auditory imagery and could still hear music in his head. In 1937 Ravel began to suffer pain from his condition, and was examined by Clovis Vincent, a well-known Paris neurosurgeon. Vincent advised surgical treatment. He thought a tumour unlikely, and expected to find ventricular dilatation that surgery might prevent from progressing. Ravel's brother Edouard accepted this advice; as Henson comments, the patient was