The epidemiology and pathophysiology of pseudobulbar affect and its association with neurodegeneration.

Pseudobulbar affect is a disorder resulting from neurologic damage manifesting as sudden, stereotyped affective outbursts that are not reflective of internal emotion. A literature review was completed to examine the current understanding of the epidemiology, characterization, diagnosis, pathophysiology, and treatment of pseudobulbar affect. This review revealed that it is common in neurodegenerative disorders but is poorly recognized, placing significant impacts on patients and their families. The disorder appears to result from a disruption of the cortico-limbic-subcortical-thalamic-pontocerebellar network involved in emotional expression and regulation with resulting disruptions of neurotransmitter systems. Effective treatment is available with agents such as selective serotonin reuptake inhibitors and dextromethorphan combined with quinidine, but further well-designed comparative studies are needed. Advances in technology such as neuroimaging may enhance knowledge about the pathophysiology of this disorder, and help guide future interventions.