Uncontrollable Crying or Laughing: What’s Behind Pseudobulbar Affect?

 

“PBA is a syndrome, not a disease, so once you have identified it, you have to initiate a workup to find out what’s causing it,” Alexopoulos told Psychiatry Advisor. “Is there a dementia process or a multi-infarct state in the brain stem and subcortical regions, leading to loss of control of emotions? Or it may be a silent stroke you have not yet identified, since a limited stroke can present with PBA.”

In a younger patient with PBA, consider stroke, TBI, MS, ALS, brain tumors, or Lyme disease, Alexopoulos advised. In older patients, it is more likely PD, AD or some other dementia.

Patients with executive dysfunctions caused by head trauma, brain tumors, CNS insults, or dementia who become disinhibited and do inappropriate things, such as engaging in indecent exposure or exploding in rage, may also be experiencing episodes of PBA, Crumpacker noted.

The workup should include history, screening for functional impairment, psychosocial impact and comorbidities, physical exam, and imaging or lab work, depending on the potential underlying disorder.¹ Validated screening scales include the Center for Neurologic Study-lability Scale (CNS-LS) and the Pathological Laughter and Crying Scale (PLACS).¹

Common Comorbidities

Misdiagnosis of PBA as depression does not preclude the possibility that depression can occur comorbidly, said Alexopoulos.

“Following an outburst of tears, a patient with PBA may say, ‘I thought of my young granddaughter and cried, but I’m not sad,’” he added. “The crying would stop and there would be no lingering depression. But a depressed patient with PBA would experience sadness, even after the crying stopped.”

Patients with a history of trauma may experience comorbid post-traumatic stress disorder (PTSD) and PBA, Crumpacker added. “For example, patients who have been abused and sustained head injuries may be experiencing tardive PDA and PTSD.”

Table 2
Differential Diagnosis of PBA
Illness/Condition	Overlapping Behavior	Difference
Depression	Affective lability Tearfulness	Affect incongruent with mood
Bipolar disorder	Affective lability Rapid affective cycling	Affect incongruent with mood
Anxiety disorders, PTSD	Episodic displays of affect Autonomic reactivity	No internal sense of anxiety
Psychotic Disorders	Incongruent/odd affect	Absence of hallucinations, delusions, disorganized behavior
Borderline personality disorder	Sudden/shifting affect	Affect incongruent with mood
Alcohol/psychoactive substance intoxication	Inappropriate affective displays	Affect incongruent with mood
King, 2013.1