Auditory hallucinations in cognitive neurology

Different types and localisations of neurological lesions can produce tinnitus and verbal or musical hallucinations (VMH).

These symptoms were screened for in 1,000 outpatients at a cognitive neurology clinic, and epidemiological and neuroimaging data were recorded.

Tinnitus was present in 6.9% of the total and VMH in 0.9%. The paracusia group was predominantly female but the difference was not statistically significant. Patients with tinnitus were younger and those with VMH were older than the rest of the sample (mean ages). Hearing loss was more prevalent in the paracusia group (difference was significant in VMH subgroup). There were no intergroup differences in the prevalence of psychotic and obsessive-compulsive disorders, or of leukoaraiosis. Treatment with acetylsalicylic acid was more frequent in the VMH group, whereas other non-opioid analgesics and benzodiazepines were more commonly prescribed to patients with tinnitus. The suspected cause of VMH was dementia with Lewy bodies (n=2, one with vascular disease), Alzheimer disease (n=2, one with vascular disease), isolated cerebrovascular disease (n=3), traumatic brain injury (n=1), and surgical brainstem lesion (n=1). All VMH cases displayed an underlying factor that might prompt this symptom, eg, hearing loss (n=6), a predisposing drug (n=9), and polypharmacy (n=9).

Treatment with benzodiazepines and non-opioid analgesics was more frequent in the tinnitus group, whereas the VMH group showed a higher prevalence of hearing loss and treatment with acetylsalicylic acid. The causes of VMH were dementia with Lewy bodies, Alzheimer disease, and focal lesions in the mesencephalon, pons, left temporal lobe, or left claustrum.