Musical hallucination following whiplash injury: case report and literature review

Hallucinations: diagnosis, neurobiology and clinical management

Hallucinations are important diagnostic symptoms in schizophrenia, but also occur in other medical and neuropsychiatric conditions. Not all patients with hallucinations are psychotic. There has been a surge of interest in the topic of hallucinations, as new research data have begun to reveal their neurobiology. Hallucinogenic molecules may also serve as new scaffolds for the development of new psychotropic drugs. We searched and reviewed recent literature, focusing on the refinement of clinical management, which was inspired by new data regarding the neurobiology of hallucination subtypes. We concluded that the successful management of hallucinations depends on accurate differential diagnosis to identify subtypes, which would then determine the most appropriate treatment.

Musical hallucinations: review of treatment effects

BACKGROUND

Despite an increased scientific interest in musical hallucinations over the past 25 years, treatment protocols are still lacking. This may well be due to the fact that musical hallucinations have multiple causes, and that published cases are relatively rare.

OBJECTIVE

To review the effects of published treatment methods for musical hallucinations.

METHODS

A literature search yielded 175 articles discussing a total number of 516 cases, of which 147 articles discussed treatment in 276 individuals. We analyzed the treatment results in relation to the etiological factor considered responsible for the mediation of the musical hallucinations, i.e., idiopathic/hypoacusis, psychiatric disorder, brain lesion, and other pathology, epilepsy or intoxication/pharmacology.

RESULTS

Musical hallucinations can disappear without intervention. When hallucinations are bearable, patients can be reassured without any other treatment. However, in other patients musical hallucinations are so disturbing that treatment is indicated. Distinct etiological groups appear to respond differently to treatment. In the hypoacusis group, treating the hearing impairment can yield significant improvement and coping strategies (e.g., more acoustic stimulation) are frequently helpful. Pharmacological treatment methods can also be successful, with antidepressants being possibly more helpful than antiepileptics (which are still better than antipsychotics). The limited use of acetylcholinesterase inhibitors has looked promising. Musical hallucinations occurring as part of a psychiatric disorder tend to respond well to psychopharmacological treatments targeting the underlying disorder. Musical hallucinations experienced in the context of brain injuries and epilepsy tend to respond well to antiepileptics, but their natural course is often benign, irrespective of any pharmacological treatment. When intoxication/pharmacology is the main etiological factor, it is important to stop or switch the causative substance or medication.

CONCLUSION

Treatments for musical hallucinations tend to yield favorable results when they target the main etiological factor of these phenomena. There is a need to establish the natural course of musical hallucinations, their response to non-pharmacological treatments, and their effects on the patient's quality of life. There is also a need to standardize the assessment of treatment responses, and document long-term follow up.

Monoaural musical hallucinations caused by a thalamocortical auditory radiation infarct: a case report

INTRODUCTION

Musical hallucinations are complex auditory perceptions in the absence of an external acoustic stimulus and are often consistent with previous listening experience. Their causation can be classified as associated with either psychiatric disorders, such as schizophrenia, or organic disorders, such as epilepsy or sensorineural deafness. Non-epileptic musical hallucinosis due to lesions of the central auditory pathway, especially of the thalamocortical auditory radiation, is rare.

CASE PRESENTATION

We describe the case of an 85-year old ethnic Chinese woman with a history of transient ischemic attacks and chronic bilateral hearing impairment, who experienced an acute onset of left unilateral musical hallucinations. Our patient did not experience any psychiatric symptoms and there was no other neurological deficit. Pure tone audiometry revealed bilateral hypacusis and magnetic resonance imaging revealed a right non-dominant hemisphere sublenticular lacunar infarct of the thalamocortical auditory radiation. Our patient was managed expectantly and after three months her symptoms subsided spontaneously.

CONCLUSION

We propose that all patients with monoaural musical hallucinations have brain imaging to rule out a central organic cause, especially within the non-dominant hemisphere, regardless of the presence of a hearing impairment.