Musical hallucinations (also known as auditory hallucinations, auditory Charles Bonnet Syndrome, and Oliver Sacks' syndrome) describes a neurological disorder in which the patient will hallucinate songs, tunes, instruments and melodies. These hallucinations are not correlated with psychotic illness. A majority of patients who have symptoms of musical hallucinations are older and have onset conditions predisposing them to the disease. While there is no set form of treatment, research has discovered medications and alternative therapies to be successful in alleviating the hallucinations.
Description In 73 individual cases reviewed by Evers and Ellger, 57 patients heard tunes that were familiar, while 5 heard unfamiliar tunes. Keshavan found that a consistent feature of musical hallucinations was that they represented a personal memory trace. Memory traces refer to anything that may seem familiar to the patient. Tunes ranged from religious pieces to childhood favorites and popular songs from the radio. Vocal and instrumental forms of classical music were also identified in most patients. An 84 year old in one case described her symptoms as pleasant, but also sought treatment because she felt distracted. The music she heard was similar to the hymns and songs sung at her wedding. She had been widowed for a while and had no signs of psychiatric disorders. However, she did have hypertension, hyperthyroidism, and osteoporosis, and it was theorized that the distress from these illnesses manifested the hallucinations. Researchers found that due to the unexpected origin of the hallucinations, there was no clear diagnosis or recommendation for treatment. Another case, which studies a 74-year-old woman, described her symptoms as music that would play in short verses of patriotic and children's songs. These symptoms would occur when the patient was alone and much more frequently when driving. Researchers suspected her hearing loss as a factor for developing the hallucinations. Moreover, through further analysis the patient was found to have a medical history of hypertension, hyperlipidemia, and atrial fibrillations. Cases are commonly found in the elderly, but in one case a 29-year-old woman reported hearing music for one week. Prior to her hallucinations, the patient had undergone surgery for intraventricular and intracranial hemorrhages. Following her recovery, she mentioned the onset of hallucinations followed by headaches. Doctors found no neurological impairments through scans. They prescribed her with quetiapine, which she responded well to. Her symptoms therefore only lasted a year.
Causes Musical hallucinations can occur in people who are physically and mentally healthy, and for them, there is no known cause. Most people find their musical hallucinations obtrusive, and wish to be rid of them, while others welcome them. In addition, investigators have pointed to factors that are associated with musical hallucinations. Evers and Ellgers compiled a significant portion of musical hallucination articles, case studies etc. and were able to categorize five major etiologies:
Hypoacusis Psychiatric disorders Focal brain lesion Epilepsy Intoxication
Hypoacusis Hypoacusis is defined as impairment in hearing or deafness. It was the most common of the five etiologies in the case studies reviewed by Evers and Ellgers. According to Sanchez et al. 2011, there have been suggestions that pontine lesions could alter the central auditory system's function, causing hypoacusis and musical hallucinations.
Psychiatric disorders A case study by Janakiraman et al. 2006, revealed a 93‑year‑old woman with major depressive disorder who experienced musical hallucinations while treated with electroconvulsive therapy (ECT). Investigators found that the patient's depression symptoms were inversely related to her hallucinations and primarily stemmed from the ECT treatment. The patient had no known abnormalities in hearing, suggesting that musical hallucinations could arise from a variety of sources including psychiatric illnesses. After a complete course of ECT, her hallucinations dissipated, also suggesting that they can be acute. According to Evers and Ellgers, some other major psychiatric disorders that contribute to musical hallucinations include schizophrenia and depression. Some patients who have schizophrenia experience musical hallucinations due to their ongoing psychosis, but there are some cases that do so without psychosis. There are also a very small percentage of musical hallucination cases due to obsessive-compulsive disorder (OCD). Several different types of psychiatric disorders can be precursors for Musical Hallucinations. according to Blom and Coebergh, Bipolar Disorder and personality disorders can increase the chances of musical hallucinations. Likewise, cocaine dependence can elevate the symptoms.
Focal brain lesions Among the handful of cases that Evers and Ellgers studied, major lesion sites included the temporal cortex; however, the specific location and laterality (left vs. right temporal cortex) was variable. Many cases of focal brain lesions had comorbidity with hearing impairment (see hypoacusis), epileptic activity and intoxication. There have also been several findings of acute musical hallucinations in patients with dorsal pons lesions post-stroke and encephalitis potentially due to disruption of connections between the sensory cortex and reticular formation. Also, any kind of traumatic lesion imposed on the brain can be a risk factor for Musical Hallucinations.
Epilepsy Epileptic brain activity in musical hallucinations originates in the left or right temporal lobe. In a specific case studied by Williams et al. 2008, a patient who received a left temporal lobectomy in order to treat epilepsy was diagnosed with musical hallucinations post-surgery. The patient also had multiple additional risk factors that could have accounted for the hallucinations including mild neuropsychiatric dysfunction and tinnitus. The causation of hallucination through epilepsy is linked to seizure episodes. Through experiments, researchers have found that patients with epilepsy and hallucinations will respond to antiepileptics and surgery.
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