Musical hallucinations are a rare phenomenon in clinical practice. The purpose of this study was to analyze the clinical spectrum of musical hallucinations.

We analysed demographic and clinical features of cases published in English, Italian, French or Spanish between 1991 and 2006 registered in MEDLINE, including three of our own cases. The cases were separated into four groups according to their main diagnoses (hearing impairment; psychiatric disorder; neurological disorder; toxic or metabolic disorder).

115 patients with musical hallucinations were included, of which 63.5% were female. The mean age was 57,25 years. Main diagnoses were: psychiatric disorder (46.1%; schizophrenia 30.4%), neurological disorder (21,7%), hearing impairment (17,4%), toxic or metabolic disorder (12.2%) and 2.6% other diagnoses.

61.7% patients presented simple diagnoses while 36.5% presented two or more diagnoses. 2.1% of patients didn't receive any diagnoses. 35.7% of patients and 60.9% of non psychiatric patients presented hearing impairment.

Both instrumental and vocal were the more frequent musical hallucinations and most of the patients had insight about the abnormality of their perceptions. Another kind of hallucinations was present in 40.9% of patients, auditory hallucinations being the most common. Also, 38,3% of the global sample had abnormalities in brain structural image (MRI, CT).

Musical hallucinations are a heterogeneous phenomenon in clinical practice. published cases describe them as more common in women and in psychiatric and neurological patients. Hearing impairment seem to be an important risk factor in the development of musical hallucinations.