How to Assess Auditory Hallucinations in Dementia With Lewy Bodies
How should clinicians assess auditory hallucinations in patients with probable dementia with Lewy bodies?
Patients with dementia with Lewy bodies often present with hallucinations that increase caregiver burden, but auditory hallucinations may be missed if clinicians ask only about visual phenomena. This guide applies to the clinical evaluation of probable dementia with Lewy bodies when a clinician needs to determine whether true auditory hallucinations are present and what form they take.
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Interview a reliable primary caregiver with the Neuropsychiatric Inventory
Assess neuropsychiatric symptoms through a semiquantitative interview with the primary caregiver using the Neuropsychiatric Inventory. In the study, symptoms were rated for the month before the interview, and the NPI assessment was performed within a month of the first visit.
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Screen specifically for hearing voices or sounds
Use the hallucinations subdomain question that asks whether the patient claims to hear voices and sounds or acts as if hearing voices and sounds. Classify the patient as having auditory hallucinations when this item is endorsed. Do not count a patient as having auditory hallucinations if the only positive response is that the patient talks to people who are not there, because that can occur with visual hallucinations alone.
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Assess visual hallucinations in parallel
Ask whether the patient describes seeing things not seen by others or behaves as if seeing things not seen by others, such as people, animals, or lights. This parallel assessment matters because 90.9% of patients with auditory hallucinations in the study also had visual hallucinations, and pure auditory hallucinations were uncommon.
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Rate recent frequency and severity
If hallucinations are present, rate NPI frequency from 1 for less than once per week to 4 for at least once per day, and rate severity from 1 for mild to 3 for severe. Calculate the domain score as frequency multiplied by severity, with a maximum score of 12.
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Clarify the phenomenology directly with the patient when possible
After caregiver screening identifies hallucinations, question the patient about the details of the experience. In the study, senior neuropsychiatrists routinely asked about the content of hallucinations, which were mostly human voices and often functioned like a soundtrack to the visual scene.
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Document whether the voices accompany a visual scene
Ask whether the figures the patient sees are speaking to each other or speaking to the patient. Among patients with verbal auditory hallucinations, 90% heard the visual hallucinations speak, and 61% reported that the visual hallucinations spoke directly to them.
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Record content and emotional valence
Note whether the auditory hallucinations are human voices, nonverbal sounds, or unspecified sounds, and document whether they are bad, pleasant, or neutral. In the study, 41 of 44 patients reported human voices, 29 of 41 patients with voices described them as bad or unpleasant, and 4 reported command content such as being told to get up early.
Clinical Considerations
- Auditory hallucinations in dementia cannot be directly quantified easily because recollection may be incomplete and caregiver reports may emphasize the most memorable or behaviorally disruptive experiences.
- The study's procedure may have underestimated the prevalence of auditory hallucinations because patients were excluded when the only positive finding was talking to people who were not there.
- The findings come from patients with probable dementia with Lewy bodies diagnosed clinically at a dementia referral center, so applicability to other settings or pathologically confirmed cases may be limited.
Bottom Line
In dementia with Lewy bodies, assess auditory hallucinations by asking specifically about hearing voices or sounds, not just talking to unseen people, and then determine whether the voices accompany visual hallucinations as a verbal soundtrack.
