Chronic Pain and the TENS Unit

Project Sync / Status Update Summary

Podcast Episode Overview

• The host discussed Transcutaneous Electrical Nerve Stimulation (TENS) as a recurring pain board topic and reviewed mechanisms, efficacy, and clinical considerations.

• Emphasis that TENS appears on pain boards annually and is a foundational topic from early podcast episodes.

• Board Prep and NRAP Community at PainExam.com or NRAPpain.org
• ABA ABPM ABIPP FIPP Pain Management Board prep, Question Banks, and Virtual Pain Fellowship

Educational Offerings and Events

• Training and Courses:

• Monthly ultrasound courses in New York and upcoming courses in Detroit covering ultrasound-guided regional anesthesia and chronic pain.

• Ultrasound Guided Acute and Chronic Pain course in November near Hollywood/Fort Lauderdale with venue pending confirmation.

• Multiple instructors to offer diverse perspectives; registration via the CME calendar at nrappain.org.

• Conferences and Teaching:

• New York–New Jersey Pain Conference in November (hosted by Soudir Duwan).

• ISPN conference in London next week, with ultrasound teaching participation by the host.

• Community and Coaching:

• Private coaching and shadowing opportunities available; contact via newsletter replies.

• Access to the NRAP community forum upon signup at nrappain.org for discussions on neuromodulation, regional anesthesia, and pain.

TENS: Mechanisms and Parameters

• Device and Parameters:

• TENS delivers adjustable pulse frequency and intensity; configurations include low (<10 Hz), high (>50–100+ Hz), and mixed frequencies.

• Mechanisms of Analgesia:

• Activation of large-diameter, non-noxious A-beta afferent fibers in the periphery, driving descending inhibitory pathways and reducing hyperalgesia.

• Board-relevant point: selective activation of A-beta fibers is frequently tested.

• Central effects:

• Reduces central excitability and nociceptive dorsal horn neuron activity in uninjured and injured models.

• Frequency-dependent opioid receptor mediation:

• High-frequency analgesia blocked by delta receptor antagonists.

• Low-frequency analgesia blocked by mu receptor antagonists (spinal cord and rostral ventral medulla).

• Additional receptor involvement: muscarinic M1/M3, GABA-A, and cannabinoid (CB1) receptors; blockade reduces or prevents TENS analgesia depending on frequency.

• Peripheral effects:

• High-frequency TENS reduces injury-related increases in substance P in DRG neurons.

• Blockade of peripheral opioid and CB1 receptors can prevent analgesia from both low- and high-frequency TENS.

• Clinical dosing considerations:

• Adequate dosing (timing, frequency of use, intensity achieving strong but non-painful paresthesia) influences efficacy.

• Analgesia has rapid onset/offset and may require repeated administration throughout