IEED is a distinct neurologic disorder characterized by involuntary episodes of motor expression of emotion, such as crying, laughing, or related facial features that are discordant with or disproportionate to the patient’s actual mood.^{Arciniegas DB, Topkoff J} IEED is also commonly known as pseudobulbar affect, emotional lability, pathological laughing and crying, and emotional incontinence.^{Arciniegas DB, Topkoff J}  

IEED is surprisingly prevalent, impacting millions of patients and caregivers in the United States alone.^{Starstein SE, Migliorelli R, Teson A, et al; Moore SR, Gresham LS, Bromberg MB, et al; Caroscio JT, Mulvihill MN, Sterling R, et al; Gubbay SS, Kahana E, Zilber N, et al; Zeilig G, Drubach DA, Katz-Zeilig M, et al; Tang WK, Chan SSM, Chiu HFK, et al; Minden SL, Schiffer RB; Kim JS, Choi S, Kwon SU, et al}  

IEED occurs secondary to neurologic disorders such as multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), Parkinson’s disease, dementias including Alzheimer’s disease, and neurologic injuries such as stroke and traumatic brain injury.^{Arciniegas DB, Topkoff J; Kaschka WP, Meyer A, Schier KR, et al}

IEED is a disorder of affect (emotional displays of relatively short duration) and should not be confused with mood disorders (the patient’s sustained emotional state over time), such as depression and bipolar disorder.^{Arciniegas DB, Topkoff J} 

IEED can significantly impact patients and caregivers.^{Gubbay SS, Kahana E, Zilbert N, et al}