A case of idiopathic musical hallucination with increasing repertoire

A musical hallucination is defined as a type of auditory hallucination characterised by the perception of music without an external source.1 Reports in the literature state that musical hallucinations are common in women, and are associated with ageing, deafness,2,3 brain diseases (epilepsy, tumour, stroke, meningitis and neurosyphilis),3,4 psychiatric diseases (schizophrenia and manic depression),3,4 toxic states (alcohol)2 and drugs (antidepressants,1 salicylate,5 quinine and aspirin4). Some authors proposed that, when listening to music, the auditory input is processed by three stages, operating in a hierarchical fashion: perception of individual sounds, perception or imagery of pattern in segmented sound, and encoding or recognition of patterned segmented sound.6 It is supposed that musical hallucinations are caused by abnormal autonomous activity in the auditory brain systems responsible for normal musical imagery.7 It seems reasonable to say that, in acquired peripheral deafness, there is impoverished auditory input that allows spontaneous activity between perception or imagery and encoding or recognition of pattern in segmented sound.6 Regarding lesions in the central nervous system, these lesions may alter the threshold of spontaneous activity within the network for the perception and imagery of music.6 We describe a patient with musical hallucination who experienced an increase in the repertoire of musical hallucinations as she sang various songs, and discuss some of the undetermined problems related to cognitive processing of music: melody, accompaniment and timbre. In July 2002, a 75-year-old, right-handed woman was visiting a hospital on a daily …