Lewy body dementia is diagnosed from a combination of cognitive decline with fluctuating attention, recurrent detailed visual hallucinations, parkinsonian movement features, and acting out dreams during sleep. The combination is characteristic even though each feature alone is not.
Lewy body dementia is diagnosed from a combination of cognitive decline with fluctuating attention, recurrent detailed visual hallucinations, parkinsonian movement features, and acting out dreams during sleep. The combination is characteristic even though each feature alone is not.
Fluctuating cognition is the one families notice most: markedly good periods and confused periods varying over hours or days rather than a steady decline, which is frequently mistaken for deliberate variation. Recurrent visual hallucinations are typically well formed and detailed, often of people or animals, and often not distressing. Parkinsonian features include slowness, rigidity and a shuffling gait. REM sleep behaviour disorder, physically acting out dreams, frequently precedes everything else by years.
People with Lewy body dementia are frequently severely sensitive to antipsychotic medication, which may be prescribed for the hallucinations before the diagnosis is recognised. Reactions can be serious. This is the clearest example of why distinguishing dementia types is practical rather than academic: the same symptom treated the same way produces very different outcomes depending on the underlying condition. Any new movement problem or marked worsening after starting such a medication should be reported promptly.
From Alzheimer's disease by the fluctuation, the visual hallucinations early in the course, and the movement features. From Parkinson's disease dementia largely by timing, according to whether cognitive or movement symptoms came first. The assessment involves a history from someone close, cognitive and neuropsychological testing, examination for parkinsonian signs, and imaging arranged externally. Neuropsychological testing is available within the practice's memory service. One practical point for families: because attention fluctuates, the person may perform noticeably better at one appointment than another, and a good day can lead to the difficulty being underestimated. Keeping a short written note of what the bad days look like, with dates, gives the clinician something the consultation itself may not show.
Clinical Neurology Specialists has been physician-owned since 1998, when Leo Germin, M.D., FAANEM founded it. Five board-certified neurologists and four advanced practice providers see patients at the Las Vegas and Henderson offices, each with its own AANEM-accredited electrodiagnostic laboratory.
Clinical Neurology Specialists is an adult outpatient neurology practice for patients 18 and older. The practice performs no surgery and operates no imaging suite, infusion suite or interventional pain programme, and provides no emergency or inpatient care.
Physician-reviewed. Reviewed by the physicians of Clinical Neurology Specialists — board-certified neurologists, AANEM-accredited electrodiagnostic laboratories, physician-owned since 1998. Reviewed 1 August 2026. This article is general education for adults 18 and older and is not a substitute for a consultation.
Sources and further reading: MedlinePlus: Alzheimer disease; National Institute on Aging; MedlinePlus: Parkinson's disease.
Adults 18 and older, at the Las Vegas and Henderson offices. Call 702-804-1212 or request an appointment online.