Chronic pain and Chronic pain syndromes Flashcards
What is chronic pain?
Chronic pain is any pain lasting longer than three months. It can be persistent, transient, or recurrent, and may require long-term medical management.
What are the three categories of chronic pain syndromes based on pathophysiology
Chronic pain syndromes are categorized as:
Nociceptive pain (e.g., osteoarthritis).
Neuropathic pain (e.g., complex regional pain syndrome).
Nociplastic pain (e.g., fibromyalgia).
What is nociceptive pain?
Nociceptive pain is pain that arises from tissue damage or inflammation, such as in osteoarthritis. It is often described as aching or throbbing and is typically well-localized
What are common examples of nociceptive pain?
Examples of nociceptive pain include pain from arthritis, burns, fractures, and muscle injuries.
What is neuropathic pain?
Neuropathic pain results from a lesion or disease within the somatosensory system, such as nerve damage, and often occurs spontaneously without external stimuli. It is commonly described as burning, shooting, or electric-like pain.
What is nociplastic pain?
Nociplastic pain involves sensory alterations in nociception without any detectable lesion or nociceptive source, such as in fibromyalgia syndrome. It is characterized by pain sensitivity, widespread pain, and associated symptoms like fatigue and sleep disturbances.
How can chronic pain be classified based on its duration?
Chronic pain can be classified as persistent (lasting continuously), transient (comes and goes), or recurrent (repeated episodes).
What are examples of chronic pain syndromes ?
Examples include neuropathic pain, headaches, musculoskeletal pain (e.g., osteoarthritis, low-back pain), irritable bowel syndrome (IBS), burning mouth syndrome, and temporomandibular disorder (TMD).
Where can neuropathic pain originate?
Neuropathic pain can originate from lesions in either the central nervous system (brain or spinal cord) or peripheral nerves
What are the major causes of peripheral neuropathic pain?
Peripheral neuropathic pain can be caused by demyelination (loss of the myelin sheath), axotomy (cutting the nerve), or inflammation of peripheral nerves.
What happens during axotomy
During axotomy, the cut nerve forms an end bulb, loses myelin, and sends out new sprouts. If the gap is too large, sprouts form a tangled knot called a neuroma, which generates ectopic potentials causing pain
What is the ectopic firing hypothesis of neuropathic pain?
The ectopic firing hypothesis suggests that pain results from hyperexcitability at sites where myelin is lost, leading to spontaneous or evoked action potentials due to an accumulation of sodium channels and a decrease in potassium channels.
How do A-delta and C-fibers differ in ectopic firing?
A-delta fibers exhibit rhythmic firing at higher frequencies (15-30 Hz), whereas C fibers fire at lower, irregular frequencies (1-10 Hz). Both types can be affected by external stimuli, causing after-discharges.
What do thermal stimuli play in ectopia?
Cooling enhances ectopia in C fibers but reduces it in A -delta fibers, while warming has the opposite effect. This difference can be used therapeutically to manage neuropathic pain.
How do adrenergic hormones affect ectopic firing?
Adrenaline and noradrenaline increase ectopic firing by enhancing neuroma sensitivity to adrenergic mediators, leading to heightened pain sensitivity. This effect can contribute to the persistence of neuropathic pain.
Where else can ectopic firing occur besides the injury site?
Ectopic firing can also occur in the dorsal root ganglion (DRG) cell bodies of affected nerve fibers, which can contribute to shooting pain, altered pain behaviors, and spontaneous pain
How does ectopia contribute to dorsal horn sensitisation?
Ectopic activity drives sensitization of dorsal horn neurons within minutes of nerve injury, leading to heightened pain processing and increased pain perception.
What are common symptoms of neuropathic pain?
Symptoms include burning, searing, tearing pain, hyperalgesia (increased pain response), allodynia (pain from non-painful stimuli), tingling (pins and needles), dysesthesia (unpleasant sensations), decreased muscle tone (hypotonia), and motor incoordination (apraxia).
What is peripheral neuropathy?
Peripheral neuropathy is a condition involving damage to peripheral nerves, leading to numbness, spontaneous pain, impaired sleep, drowsiness, fatigue, and other associated symptoms.
What are the main types of peripheral neuropathy?
Peripheral neuropathy can be metabolic (e.g., diabetes), hereditary (e.g., Fabry’s disease), inflammatory (e.g., Guillain-Barré syndrome), nutritional (e.g., beriberi), or infectious (e.g., HIV)
What is diabetic polyneuropathy
Diabetic polyneuropathy is a common complication of diabetes, where high sugar levels damage small nerve fibers and vascular tissues, leading to numbness, tingling, spontaneous deep aching pain, and foot ulcers
How does diabetic polyneuropathy develop?
High blood sugar levels cause damage to small nerve fibers in distal areas like the feet. Damage to blood vessels also causes local anoxia (low oxygen), worsening the condition and contributing to ulcers.
What is Fabry’s disease
Fabry’s disease is a hereditary polyneuropathy due to a deficiency in the enzyme alpha-galactosidase, causing accumulation of lipids and leading to burning pain in hands and feet. It primarily affects males, though it can affect females later in life.
What is Guillain-Barre syndrome?
Guillain-Barré syndrome is an inflammatory demyelinating polyneuropathy caused by the Epstein-Barr virus, leading to early pain, motor weakness, demyelination of nerve roots, and possible need for ventilatory support.
What is nutritional neuropathy (beriberi)?
Beriberi is caused by a deficiency of vitamin B1 (thiamine), leading to nerve degeneration, burning or lancinating pain in feet, and can be treated with B1 supplementation.
What is HIV-associated neuropathy?
HIV-associated neuropathy affects about 30% of patients with AIDS, leading to burning pain, allodynia, and hypoesthesia due to vascular deficiencies and demyelination, which may be caused by HIV or antiretroviral drugs.
What is low-back pain and its classifications?
Low-back pain affects the lumbar region and can be classified as:
Axial pain - related to trauma or repetitive motion.
Radicular pain - caused by compression of a nerve root (e.g., sciatica).
Referred pain - resulting from degenerative disc disease, which may cause pain in areas like the hips or thighs.
How is low-back pain categorised based on duration?
Low-back pain is categorized as:
Acute: Lasting less than 6 weeks.
Subacute: Lasting between 6-12 weeks.
Chronic: Lasting more than 12 weeks.
What are the risk factors for developing low-back pain?
Risk factors for low-back pain include obesity, smoking, sedentary lifestyle, physically demanding jobs, trauma, and psychological factors like anxiety and depression.
How is low-back pain treated
Treatments include patient education, remaining active, using heat, topical analgesia, NSAIDs, and muscle relaxants. Chronic cases may require multidisciplinary treatment involving medical, psychological, physical, and interventional approaches.
What are “red flags” and “yellow flags” in low-back pain?
Red flags are signs of serious underlying issues needing further evaluation (e.g., fractures, tumors), while yellow flags are psychosocial factors that increase the risk of chronic pain, such as anxiety, depression, fear avoidance behaviors, and catastrophizing.
What is Complex Regional Pain Syndrome
CRPS is a type of neuropathic pain involving severe, persistent pain often following an injury. It includes symptoms such as swelling, skin color changes, temperature sensitivity, and decreased mobility of the affected limb.
What are the phases of central sensitisation in neuropathic pain?
Central sensitization involves an initial phase where wide-dynamic range neurons are activated (wind-up), followed by long-term potentiation that prolongs neuron excitability and sensitization, leading to increased pain perception.
How can chronic pain affect psychological well-being?
Chronic pain can lead to anxiety, depression, sleep disturbances, reduced quality of life, social withdrawal, and increased dependency on medications, requiring comprehensive pain management strategies.
What is the role of cognitive behavioural therapy, CBT in chronic pain management?
CBT helps patients manage chronic pain by addressing negative thought patterns, promoting coping strategies, reducing anxiety and depression, and encouraging active participation in daily activities.
What is the significance of patient education in managing chronic pain?
Patient education is crucial in managing chronic pain as it helps patients understand their condition, set realistic goals, adopt effective coping strategies, and improve adherence to treatment plans.
How does physical therapy help in managing chronic pain?
Physical therapy helps improve mobility, strengthen muscles, reduce stiffness, and alleviate pain, thereby enhancing overall physical function and quality of life in
What is failed-back surgery syndrome (FBSS)?
Failed-back surgery syndrome is a condition where patients continue to experience low back pain after one or more technically successful spinal surgeries. Symptoms include shooting, burning pain, and frequent allodynia.
What are some risk factors for developing failed-back surgery syndrome?
Risk factors for failed-back surgery syndrome include preoperative anxiety, depression, poor coping strategies, pursuing litigation or workers’ compensation, poor surgical technique, and postoperative complications like epidural fibrosis and new instability.
