A Clinical Overview of Pseudobulbar Affect: Part I of II

Wednesday, February 6, 2013 | 0

This week we begin a two-part series about a distressing complication that may arise following a traumatic brain injury—pseudobulbar affect (PBA). Due to minimal awareness and knowledge of PBA in the medical community, PBA is often misdiagnosed as depression or part of the primary neurological disease, when in fact it’s a separate, treatable condition.

What is PBA?

Pseudobulbar affect, also known as pathological laughter and crying, or emotional lability, is characterized by involuntary, unexpected outbursts of inappropriate laughter or crying. The neurological condition is common in multiple sclerosis and amyotrophic lateral sclerosis, and may also occur in other neurological conditions, including traumatic brain injury, stroke, and Alzheimer’s disease. It is a source of embarrassment and can be associated with a reduction in the patient’s quality of life. When compromised by injury or disease, this emotional dysregulation can have a substantial impact on the injured person, his or her family, and the larger community.

Affect Versus Mood

This disorder of emotion is thought to be predominantly dysregulation of affect versus mood. The American Journal of Geriatric Pharmacology has described “mood” as an emotional feeling stated by a patient and “affect” as the emotional appearance of the patient. Mood is often described as denoting an individual’s emotional state over a relatively long period of time (e.g., depression, anxiety and adjustment). Affect, on the other hand, refers to one’s emotional state over a relatively short duration (minutes to hours) that varies from moment to moment and can be superimposed on the prevailing mood.

The disorders of mood are described in considerable detail in the Diagnostic and Statistical Manual of Mental Disorders IV. This diagnostic-based system has, over time, facilitated improved identification and treatment of those disorders in many clinical settings. Unfortunately, the exclusive presentation of mood disorders in that system has unintentionally nearly eliminated the disorders of affect from the minds of many clinicians. Disorders of affect are characterized by impairment of the moment-to-moment regulation of emotion and the sustained/pervasive disturbances of mood are not necessary for the diagnosis and often times are absent. The prototype of an affective disorder is seen in Kluver-Bucy-like syndromes, which present with symptoms such as docility, hyperorality and visual agnosia.

Observing Pseudobulbar Affect

One of the earliest recorded references to what was probably pseudobulbar affect was made by Darwin, who observed in his writings on emotion that, “Certain brain diseases, as hemiplegia, brain-wasting, and senile decay, have a special tendency to induce weeping.” The landmark medical description of the disorder was made in 1924 by S. A. Kinnear Wilson who described pseudobulbar affect as primarily secondary to strokes which enumerated the clinical features of laughter and crying and may evolve into its opposite.

Wilson further pointed out the well-known fact that brain injury affecting descending motor pathways, from the cortex to the brainstem, can impair voluntary activation of facial musculature but leave involuntary facial expression, such as occurs in emotion, intact. This further led Wilson to propose that involuntary pathways allow stimuli with emotional contact to activate the brainstem facial respiratory control center into producing emotion and voluntary centers allowing regulation of brainstem facial respiratory center activation. Unfortunately, there has been little progress in verifying Wilson’s theory on the origins of PBA.

Dr. H. Richard Adams is a medical director for Paradigm Outcomes and a practicing physician and brain injury specialist currently serving as staff physical medicine and rehabilitation specialist at Long Beach Memorial Medical Center in California. This column was reprinted with permission from Paradigm's Outlook on Outcomes blog.</i>