Pseudobulbar affect (PBA), or emotional incontinence, is a type of emotional disturbance characterized by uncontrollable episodes of crying, laughing, anger or other emotional displays. PBA occurs secondary to a neurologic disorder or brain injury. Patients may find themselves crying uncontrollably at something that is only moderately sad, being unable to stop themselves for several minutes. Episodes may also be mood-incongruent: a patient may laugh uncontrollably when angry or frustrated, for example. Sometimes, the episodes may switch between emotional states, resulting in the patient crying uncontrollably before dissolving into fits of laughter. The pseudobulbar affect, also referred to as emotional lability, should not be confused with labile mood or labile emotions that stem from emotional instability – affective dysregulation – commonly seen in mental illnesses and certain personality disorders. Signs and symptoms
The cardinal feature of the disorder is a pathologically lowered threshold for exhibiting the behavioral response of laughter, crying, anger or all of the above. An affected individual exhibits episodes of laughter, crying, anger or a combination of these without an apparent motivating stimulus or in response to stimuli that would not have elicited such an emotional response before the onset of their underlying neurologic disorder. In some patients, the emotional response is exaggerated in intensity but is provoked by a stimulus with an emotional valence congruent with the character of the emotional display. For example, a sad stimulus provokes a pathologically exaggerated weeping response instead of a sigh, which the patient normally would have exhibited in that particular instance.
PBA is most commonly observed in people with neurologic injuries such as traumatic brain injury (TBI) and stroke, and neurologic diseases such as dementias including Alzheimers disease, attention deficit/hyperactivity disorder (ADHD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), and Parkinsons disease (PD). It has been reported as a symptom of hyperthyroidism, Graves disease, or hypothyroidism in combination with depression.PBA has also been observed in association with a variety of other brain disorders, including brain tumors, Wilsons disease, syphilitic pseudobulbar palsy, and various encephalitides. Rarer conditions associated with PBA include gelastic epilepsy, dacrystic epilepsy, central pontine myelinolysis, olivopontinocerebellar atrophy, lipid storage diseases, chemical exposure (e.g., nitrous oxide and insecticides), fou rire prodromique, and Angelman syndrome. It is hypothesized that these primary neurologic injuries and diseases affect chemical signaling in the brain, which in turn disrupts the neurologic pathways that control emotional expression. Stroke
PBA is one of the most frequently reported post-stroke behavioral disorders, with a range of reported prevalence rates from 28% to 52%. The higher prevalence rates tend to be reported in stroke patients who are older or who have a history of prior stroke. The relationship between post-stroke depression and PBA is complicated, because the depressive syndrome also occurs with high frequency in stroke survivors. Post-stroke patients with PBA are more depressed than post-stroke patients without PBA, and the presence of a depressive syndrome may exacerbate the weeping side of PBA symptoms. Multiple sclerosis
Recent studies suggest that approximately 10% of patients with multiple sclerosis (MS) will experience at least one episode of emotional lability.