CHAPTER 2 CLASSIFICATION OF PAIN Robert A. Duarte, MD, Charles E. Argoff, MD 1. List the bases for the most widely used classifications of pain Pain is a subjective experience that does not lend itself to the usual classifications. On a practical basis, pain classifications depend on the following: Inferred pathophysiology (nociceptive vs. nonnociceptive) Time course (acute vs. chronic) Location (painful region) Etiology (e.g., cancer, arthritis) 2. What is the neurophysiologic classification of pain? The neurophysiologic classification is based on the inferred mechanism for pain. There are essentially two types: (1) nociceptive, which is due to injury in pain-sensitive structures, and (2) nonnociceptive, which is neuropathic and psychogenic. Nociceptive pain can be subdivided into somatic and visceral (depending on which set of nociceptors is activated). Neuropathic pain can be subdivided into peripheral and central (depending on the site of injury in the nervous system believed responsible for maintaining the pain). 3. What is nociceptive pain? Nociceptive pain results from the activation of nociceptors (A-delta fibers and C fibers) by noxious stimuli that may be mechanical, thermal, or chemical. Nociceptors may be sensitized by endogenous chemical stimuli (algogenic substances) such as serotonin, substance P, bradykinin, prostaglandin, and histamine. Somatic pain is transmitted along sensory fibers. Visceral pain, in comparison, is transmitted along autonomic fibers; the nervous system is intact and perceives noxious stimuli appropriately. 4. How do patients describe pain of somatic nociceptive origin? Somatic nociceptive pain may be sharp or dull and is often aching in nature. It is a type of pain that is familiar to the patient, much like a toothache. It may be exacerbated by movement (incident pain) and relieved upon rest. It is well localized and consonant with the underlying lesion. Examples of somatic nociceptive pain include metastatic bone pain, postsurgical pain, musculoskeletal pain, and arthritic pain. These pains tend to respond well to the primary analgesics, such as nonsteroidal antiinflammatory drugs (NSAIDs) and opioids. 5. How do patients describe pain of visceral nociceptive origin? Visceral nociceptive pain arises from distention of a hollow organ. This type of pain is usually poorly localized, deep, squeezing, and crampy. It is often associated with autonomic sensations including nausea, vomiting, and diaphoresis. There are often cutaneous referral sites (e.g., heart to the shoulder or jaw, gallbladder to the scapula, and pancreas to the back). Examples of visceral nociceptive pain include pancreatic cancer, intestinal obstruction, and intraperitoneal metastasis. 6. How do patients describe pain of neuropathic origin? Patients often have difficulty describing pain of neuropathic origin because it is an unfamiliar sensation. Words used include burning, electrical, and numbing. Innocuous stimuli may be perceived as painful (allodynia). Patients often complain of paroxysms of electrical sensations (lancinating or lightning pains). Examples of neuropathic pain include trigeminal neuralgia, postherpetic neuralgia, and painful peripheral neuropathy. 7. Clinically, how do you distinguish between paresthesia and dysesthesia? Paresthesia is described simply as a nonpainful altered sensation, e.g., numbness. Dysesthesia is an altered sensation that is painful, e.g., painful numbness. 8. What are examples of deafferentation pain? Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Neuroimaging in the Patient with Pain Pharmacologic Management Postoperative Pain Management Sympathetic Neural Blockade Cancer Pain Syndromes Temporary Neural Blockade Stay updated, free articles. Join our Telegram channel Join Tags: Pain Management Secrets Jun 14, 2016 | Posted by admin in PAIN MEDICINE | Comments Off on Classification of Pain Full access? Get Clinical Tree
CHAPTER 2 CLASSIFICATION OF PAIN Robert A. Duarte, MD, Charles E. Argoff, MD 1. List the bases for the most widely used classifications of pain Pain is a subjective experience that does not lend itself to the usual classifications. On a practical basis, pain classifications depend on the following: Inferred pathophysiology (nociceptive vs. nonnociceptive) Time course (acute vs. chronic) Location (painful region) Etiology (e.g., cancer, arthritis) 2. What is the neurophysiologic classification of pain? The neurophysiologic classification is based on the inferred mechanism for pain. There are essentially two types: (1) nociceptive, which is due to injury in pain-sensitive structures, and (2) nonnociceptive, which is neuropathic and psychogenic. Nociceptive pain can be subdivided into somatic and visceral (depending on which set of nociceptors is activated). Neuropathic pain can be subdivided into peripheral and central (depending on the site of injury in the nervous system believed responsible for maintaining the pain). 3. What is nociceptive pain? Nociceptive pain results from the activation of nociceptors (A-delta fibers and C fibers) by noxious stimuli that may be mechanical, thermal, or chemical. Nociceptors may be sensitized by endogenous chemical stimuli (algogenic substances) such as serotonin, substance P, bradykinin, prostaglandin, and histamine. Somatic pain is transmitted along sensory fibers. Visceral pain, in comparison, is transmitted along autonomic fibers; the nervous system is intact and perceives noxious stimuli appropriately. 4. How do patients describe pain of somatic nociceptive origin? Somatic nociceptive pain may be sharp or dull and is often aching in nature. It is a type of pain that is familiar to the patient, much like a toothache. It may be exacerbated by movement (incident pain) and relieved upon rest. It is well localized and consonant with the underlying lesion. Examples of somatic nociceptive pain include metastatic bone pain, postsurgical pain, musculoskeletal pain, and arthritic pain. These pains tend to respond well to the primary analgesics, such as nonsteroidal antiinflammatory drugs (NSAIDs) and opioids. 5. How do patients describe pain of visceral nociceptive origin? Visceral nociceptive pain arises from distention of a hollow organ. This type of pain is usually poorly localized, deep, squeezing, and crampy. It is often associated with autonomic sensations including nausea, vomiting, and diaphoresis. There are often cutaneous referral sites (e.g., heart to the shoulder or jaw, gallbladder to the scapula, and pancreas to the back). Examples of visceral nociceptive pain include pancreatic cancer, intestinal obstruction, and intraperitoneal metastasis. 6. How do patients describe pain of neuropathic origin? Patients often have difficulty describing pain of neuropathic origin because it is an unfamiliar sensation. Words used include burning, electrical, and numbing. Innocuous stimuli may be perceived as painful (allodynia). Patients often complain of paroxysms of electrical sensations (lancinating or lightning pains). Examples of neuropathic pain include trigeminal neuralgia, postherpetic neuralgia, and painful peripheral neuropathy. 7. Clinically, how do you distinguish between paresthesia and dysesthesia? Paresthesia is described simply as a nonpainful altered sensation, e.g., numbness. Dysesthesia is an altered sensation that is painful, e.g., painful numbness. 8. What are examples of deafferentation pain? Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Neuroimaging in the Patient with Pain Pharmacologic Management Postoperative Pain Management Sympathetic Neural Blockade Cancer Pain Syndromes Temporary Neural Blockade Stay updated, free articles. Join our Telegram channel Join Tags: Pain Management Secrets Jun 14, 2016 | Posted by admin in PAIN MEDICINE | Comments Off on Classification of Pain Full access? Get Clinical Tree
