From the Guidelines
Pain processing in the nervous system involves a complex pathway that begins when specialized nerve endings called nociceptors detect potentially harmful stimuli, and the most recent evidence suggests that this process is highly influenced by the biopsychosocial factors that affect pain perception 1. The process of pain transmission is regulated by descending pathways originating in the brainstem and in other cerebral structures, which modulate the nociceptive information at the spinal dorsal horn mainly by reducing the release of neurotransmitters from primary afferent neurons or by inhibiting projection neurons and excitatory interneurons. Some key points to consider in the processing of pain include:
- The role of nociceptors in detecting potentially harmful stimuli and converting them into electrical signals that travel through peripheral nerves to the spinal cord 1
- The importance of the dorsal horn of the spinal cord, where signals synapse with second-order neurons that cross to the opposite side and ascend to the brain via pathways like the spinothalamic tract 1
- The distribution of signals to various brain regions, including the somatosensory cortex, limbic system, and prefrontal cortex, which are responsible for different aspects of pain perception, such as location, intensity, and emotional response 1
- The modulation of pain signals through descending pathways that release neurotransmitters like endorphins, serotonin, and norepinephrine, which can inhibit pain transmission and are influenced by factors like stress, attention, and expectations 1 The most recent and highest quality study on this topic, published in 2022, highlights the complex interactions between the nervous system, pain perception, and biopsychosocial factors, and emphasizes the importance of considering these factors in the management of chronic pain 1.
From the Research
Nervous System Processing of Pain
The nervous system processes pain through a complex interplay of messages sent from the periphery to the central nervous system and vice versa, with specific pathways playing a vital role in carrying these messages and modulating their downstream effects 2.
Key Pathways and Physiology
- Pain involves the activation of nociceptors, which send signals to the spinal cord and brain, where they are processed and interpreted 3.
- The neuromatrix theory suggests that pain is a multidimensional experience produced by multiple influences, including genetic and sensory factors, and influences from within the body and other areas of the brain 3.
- Cognitive, emotional, and behavioral factors also play a central role in the pain experience, highlighting the importance of a biopsychosocial perspective in understanding and treating pain 4.
Treatment and Management
- Pharmacologic management of acute pain should be tailored to each patient, with first-line treatment options including acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) 5.
- Fixed-dose combinations of ibuprofen and acetaminophen may be an effective alternative to opioids for managing acute pain, with benefits including reduced need for rescue opioid medication and fewer adverse events 6.
- A comprehensive approach to pain management should consider the complex interplay of biological, psychological, and social factors that contribute to the pain experience, and incorporate a range of treatment strategies to address these factors 4.