Identifying Pseudobulbar Affect in Alzheimer’s Disease and Dementia

Abstract

Pseudobulbar affect (PBA) can be challenging to differentiate from the symptoms of various neurological diseases with which it is associated. In patients with Alzheimer’s disease (AD) and dementia such a diagnosis can be particularly difficult as illustrated by a case of an elderly male with sudden tearful outbursts, which is reported and discussed here. PBA attacks are often incorrectly attributed to emotion or distress in response to memory loss or a result of depression or dementia. PBA is common, affecting between 10–40 % of people with AD but is frequently not detected or is misdiagnosed. Multiple authors have published clinical criteria for identifying PBA; in sum, it is described as a condition affecting the brain with episodes of laughing or crying that are sudden and unpredictable, occur without warning and are excessive, exaggerated, or not appropriate to the stimuli and are involuntary and difficult to control. Differentiating PBA from depression and other behavioral disturbances in AD and dementia is helpful to patients by identifying a specific cause of their symptoms and enabling appropriate management. Various different approaches have been taken in the treatment of PBA. A combination of dextromethorphan and quinidine has been shown in well-controlled trials and in clinical use to control the symptoms of PBA associated with several neurological diseases including AD and to reduce the burden on patients and their caregivers.