Neuromodulation of afferent fibers for Postural Orthostatic Trachycardia Syndrome (POTS)

Abstract

Postural Orthostatic Trachycardia Syndrome, or POTS, is characterized by low arterial blood pressure, inappropriate cardiovascular and breathing responses to tilt, dizziness and syncope to sudden standing, and a range of other autonomic signs, including thermoregulatory issues in the periphery and frequent manifestations of migraine pain. Interventions are few, and typically include volume repletion by saline and enhanced fluid intake. In the course of evaluating neuromodulatory procedures for migraine pain (n=62), several subjects showed classic POTS symptoms, many of which spontaneously resolved with the intervention for migraine. Non‐invasive neuromodulation of two different areas, one being the auditory canal containing mandibular nerve V3, cranial nerves VII, IX, and X and cervical nerves C2 and C3; and the other being regional stimulation of V1 and V2, together with C2 and C3 sensory areas, caused significant declines in dizziness, hand cooling, and other POTS symptoms. The neuromodulatory device stimulating the auditory canal consisted of bilateral silicon impressions of the auditory canals, each containing a mechanical vibratory device which reached a range of cranial nerves, and especially the IXth (glossopharyngeal) nerve to the carotid baroreceptors. The other neuromodulatory device applied vibrating signals to the cutaneous surface over areas innervated by V1 and V2. The trials consisted of a 10‐min control period, followed by 25‐min stimulation, and finished with a 10‐min control period. Continuous thoracic wall movement, pulse oximetry, and ECG were collected, and beat‐by‐beat blood pressure values were inferred from the pulse transit time of the cardiac R wave and oximetry signal. All procedures were approved by the UCLA Institutional Review Board. Subjects who began the trial with low blood pressure increased systolic and diastolic pressures. In two subjects, repeated trials benefitted critical signs (hand warming, dizziness, syncope to sudden movement). These findings suggest that repeated activation of afferent input to baroreceptors can elicit both short‐ and long‐term effects on blood pressure control. The means by which this “learning" or adaptation of cardiovascular regulatory systems remain unknown, but raise the possibility that a low‐cost, non‐invasive intervention can provide another means to restore effective blood pressure control in a syndrome with few options for treatment approaches.Support or Funding InformationThis research was supported in part by the Fidelity Charitable Nancy Adams and Scott Schoen Fund and the Kraig and Linda Kupiec Family Trust.