Pseudobulbar affect (PBA) is “a disorder resulting from neurologic damage manifesting as sudden, stereotyped affective outbursts that are not reflective of internal emotion.”1 It has been reported in numerous neurologic conditions, including amyotrophic lateral sclerosis (ALS), Parkinson’s disease (PD), multiple sclerosis (MS), Alzheimer’s disease (AD) and other dementias, stroke, traumatic brain injuries (TBI), nervous system tumors, neurogenetic syndromes, viral cerebellitis, neurosyphilis, and progressive supranuclear palsy.1,2
It is difficult to calculate the prevalence of PBA because of the wide range of conditions associated with it, but it is estimated to affect approximately 1.5 to 2 million people in the United States.3 One study of PBA in AD, ALS, MS, PD, stroke, and TBI estimated the overall prevalence as between 10% and 38%.4
Mood and Affect in PBA
PBA has been referred to by an array of names, including pathologic crying or laughing, emotional incontinence, emotional lability, emotional instability, compulsive laughing or crying, and organic mood disorder.1
The nomenclature has made identification of PBA difficult, according to David Crumpacker, MD, former assistant chief of psychiatry at Baylor University Medical Center at Dallas, who is now in private practice. “Many psychiatrists have never heard of PBA,” he told Psychiatry Advisor. “But when I say ‘organic mood disorder,’ they know exactly what I am referring to.”
Crumpacker distinguished between affect and mood, noting that these terms are often confused. Affect is the behavioral manifestation of mood. “There is nothing ‘pseudo’ about the affect itself,” he said. “The problem in PBA is that the affect does not accurately reflect mood.”
Pathophysiology of PBA
The pathophysiology of PBA is “best conceptualized as a focal or diffuse disruption in the complex neurocircuitry…involved in the inhibition of emotional expression.”1 Lesions in cerebro-pontocerebellar circuitry have been implicated.
“PBA might be compared to having a wiring problem,” Crumpacker explained. The connection between the area of the brain associated with emotions and the area associated with affect is disrupted.
Identifying and Diagnosing PBA
“When a patient consults you about spontaneous crying, PBA should be included in your differential diagnosis,” according to George Alexopoulos, MD, founder and director of the Weill Cornell Institute of Geriatric Psychiatry in New York City. Because PBA is associated with such a wide range of conditions, it is frequently misdiagnosed.
|Proposed Diagnostic Criteria for PBA|
|Source: Cummings, 2007.9|