28 September 2026
: Case report 
Coexisting Postural Orthostatic Tachycardia Syndrome on Autonomic Reflex Testing in Functional Neurologic Disorder
Unusual clinical course, Challenging differential diagnosis
Sushmita Das
AEF 1, Sri Rama Narayana Yerraballa AEF 1, Priyanka Shekhawat AEF 1*
DOI: 10.12659/AJCR.953323
Am J Case Rep 2026; 27:e953323
Figure 2 Beat-to-beat heart rate and blood pressure during the Valsalva maneuver demonstrating normal late phase II blood pressure recovery, indicating preserved sympathetic vasoconstrictor function. Phase IV blood pressure overshoot is mildly delayed, suggesting subtle slowing of adrenergic baroreflex recovery without evidence of significant adrenergic failure. The Valsalva ratio is 2.64 (5th percentile 1.46), consistent with preserved cardiovagal function. Red tracings denote systolic and diastolic blood pressure, and the green tracing denotes heart rate. Vertical green lines indicate onset and release of strain during the Valsalva maneuver.