About this Video

• Video Title: 345 ‒ Chronic pain: pathways, treatment, and the path to physical and psychological recovery
• Channel: Peter Attia MD
• Speakers: Peter Attia MD, Sean Mackey
• Duration: 3:15:36

Introduction

This podcast discusses chronic pain, its biological and psychological mechanisms, and treatment approaches. The speakers explore the evolution of pain understanding, biological pathways of pain perception, the role of consciousness, different types of pain, the use of fMRI in pain research, and various treatment options including pharmacology (NSAIDs, COX-2 inhibitors, acetaminophen, muscle relaxants, antidepressants, opioids), alternative therapies (acupuncture, cannabis), and low-dose naltrexone (LDN). Personal experiences with chronic pain are shared, highlighting the importance of physical rehabilitation and psychological recovery.

Key Takeaways

1. Evolved Understanding of Pain: The understanding of pain has evolved from a simplistic model to a nuanced biopsychosocial model, recognizing the interplay of biological, psychological, and social factors.
2. Biological Mechanisms: Pain involves nociceptors converting various forms of energy into electrochemical impulses transmitted via A-delta (fast, sharp) and C-fibers (slow, burning) to the brain. A conscious brain is necessary for the experience of pain.
3. Brain's Role in Pain: The brain actively processes and modulates pain signals. Descending control systems from the brain can regulate pain perception through mechanisms like the gate control theory. Emotional, cognitive, and sleep factors influence pain experience.
4. Treatment Approaches: Multiple treatment approaches are discussed, emphasizing a personalized and multi-faceted strategy combining pharmacological interventions (with nuanced considerations for opioids), alternative therapies, and psychological support with physical rehabilitation. The importance of identifying the underlying cause of pain and individual variability in response to treatment is highlighted.
5. Chronic Pain Definition and Management: Chronic pain is defined as pain persisting beyond the expected time of tissue healing, emphasizing context specificity. Management strategies focus on breaking pain cycles, improving function, and addressing psychological aspects such as catastrophizing.
6. LDN and its Potential: Low-dose naltrexone (LDN) is presented as a potentially beneficial treatment for chronic pain and other conditions due to its ability to modulate the microglia.

The gate control theory proposes that the spinal cord acts like a gate, modulating incoming pain signals. A-delta and C-fibers (nociceptive fibers) carry pain signals from the periphery to the spinal cord. However, the spinal cord doesn't simply relay these signals; it also receives input from A-beta fibers (touch and pressure fibers). Activation of A-beta fibers can inhibit the transmission of pain signals from A-delta and C-fibers, essentially "closing the gate" and reducing pain perception.

TENS (transcutaneous electrical nerve stimulation) utilizes this principle. TENS units deliver electrical stimulation to the skin, activating A-beta fibers. This activation, in turn, inhibits the transmission of pain signals in the spinal cord, providing pain relief.

The podcast describes four types of pain:

1. Nociceptive pain: This is pain caused by the activation of primary nociceptors (pain receptors) in response to tissue injury. It's typically well-localized, has a specific intensity, and is often time-limited. It tends to respond well to standard analgesics such as acetaminophen, NSAIDs, COX-2 inhibitors, and opioids.

2. Visceral pain: This arises from the activation of nociceptors in internal organs (viscera). It's often diffuse and poorly localized, and the perceived location may not directly correspond to the source. Treatment often focuses on identifying and addressing the underlying cause, as standard analgesics may be less effective.

3. Neuropathic pain: This results from damage or dysfunction of the peripheral or central nervous system. It's characterized by burning, sharp, lancinating, stabbing, or shock-like sensations. Standard analgesics are often less effective, and treatment often involves anti-neuropathic medications (e.g., anticonvulsants, antidepressants).

4. Nociplastic pain: This category describes pain caused by dysfunction in the central pain processing system, even in the absence of identifiable peripheral causes. Conditions like fibromyalgia are associated with nociplastic pain. Treatment may involve addressing central sensitization and psychological factors along with medications.