Diagnosing and Managing Lewy Body Dementia

Overview

This comprehensive guide for healthcare professionals, provided by the Lewy Body Dementia Association, covers the diagnosis and management of Lewy body dementia (LBD). LBD includes two related disorders: dementia with Lewy bodies (DLB), in which dementia is the early disabling symptom, and Parkinson's disease dementia (PDD), in which dementia develops in the setting of established Parkinson's disease. Both are linked to aggregates of alpha-synuclein. DLB is the second most common degenerative dementia after Alzheimer's disease, yet it is often misdiagnosed.

Clinical features

Typical features include early problems with attention, executive function and visuospatial skills, fluctuating cognition and alertness, recurrent detailed visual hallucinations, parkinsonism and REM sleep behavior disorder, which may appear years before other symptoms. Autonomic dysfunction, loss of smell, delusions, apathy, anxiety and depression are common. Many patients react severely to antipsychotic drugs.

Diagnosis

Assessment should include a neurological examination, orthostatic blood pressure at every visit, a brief cognitive test sensitive to non-amnestic deficits, and evaluation of motor, psychiatric, sleep and autonomic symptoms. Reversible causes of dementia should be excluded and structural brain imaging performed; dopamine transporter imaging can help distinguish LBD from Alzheimer's disease. The guide summarizes the 2017 DLB Consortium criteria, based on core clinical features and indicative biomarkers, and the Movement Disorder Society criteria for PDD. The diagnosis should be clearly documented because of medication sensitivities.

Treatment

Palliative, goal-oriented care should begin at diagnosis. Cholinesterase inhibitors are the standard treatment for cognitive and psychiatric symptoms. Parkinsonism may be treated cautiously with the lowest effective dopaminergic therapy, since these drugs can provoke psychosis. Behavioral symptoms should first be managed without drugs, by looking for triggers such as infection or pain and stopping anticholinergic medications. Typical antipsychotics must be avoided because of the risk of severe reactions, including neuroleptic malignant syndrome; if an antipsychotic is unavoidable, only selected atypical agents should be used, with great caution and after discussing the risks. Sleep and autonomic symptoms have their own management strategies.

Referral and caregivers

A team approach involving neurology, neuropsychology and psychiatry is recommended, together with early advance care planning. Caregiver burden in LBD is high, so caregivers need education, access to support services and monitoring for depression and burnout.