Involuntary emotional expression disorder in postural tachycardia syndrome

Area of Science:

• Neurology
• Autonomic Dysfunction
• Psychiatry

Background:

• Postural Orthostatic Tachycardia Syndrome (PoTS) is a condition affecting autonomic nervous system regulation.
• Involuntary Emotional Expression Disorder (IEED) is characterized by frequent, uncontrollable episodes of crying or laughing.
• The prevalence and triggers of IEED in PoTS are not well understood.

Purpose of the Study:

• To determine the frequency of latent and overt IEED in patients with PoTS.
• To compare IEED occurrence in PoTS patients with those with Neurally Mediated Hypotension (NMH) and healthy controls.
• To identify potential triggers and underlying mechanisms of IEED in PoTS.

Main Methods:

• A cohort of 51 PoTS patients, 15 NMH patients, and 12 controls were assessed.
• Latent IEED was evaluated using the Center for Neurologic Study-Lability Scale (CNS-LS).
• Overt IEED was observed during head-up tilt (HUT) testing; depression was screened using PHQ-9.

Main Results:

• Overt IEED occurred during HUT in 22% of PoTS patients, but not in NMH or controls.
• Latent IEED was identified in 45% of PoTS patients and 33% of NMH patients.
• PoTS patients showed elevated tearfulness (CNS-LS subscale) and depression scores (PHQ-9) compared to controls.

Conclusions:

• Latent IEED is frequent in PoTS and NMH, while overt IEED is triggered by HUT specifically in PoTS.
• Depression is a common comorbidity in PoTS.
• Cerebral blood flow changes, autonomic arousal, and neurohumoral alterations during orthostatic stress may underlie IEED in PoTS.