Nociceptive pain

Neuropathic pain

Neuropathic pain

Examples

Sensation

abnormal function of the nervous system causes ongoing pain (ie. postherpetic neuralgia, diabetic peripheral neuropathy)

shooting or burning pain, often accompanied with hyperalgesia and allodynia

severe pain to a normally minimally painful stimulus 

ie. a pinprick causes severe pain

pain to a normally nonpainful stimulus

ie. light touch causes pain

aka nociceptive pain

where pain signals are carried toward the CNS via the peripheral sensory nerves

basic functional unit of the spine

comprises two adjacent vertebral bodies with two posterior facet joints, an intervertebral disk, and the surrounding ligamentous structures

Begins with loss of hydration of the nucleus pulposes

followed by the appearance of circumferential or radial tears within the annulus fibrosis

pain physician

psychologist

PT (of paramount value)/OT

Nurse specialist

genetic background

prior experiences

current psych experiences

sociocultural influences

continuous nociceptive input provokes changes in the chemical milieu of the cord that leads to structural reorganization

ie, dormant receptors activated, new gene transcription, new neurotransmitter release 

-spontaneous neural discharge

-hyperalgesia

-allodynia

leads to activation of NMDA and AMPA receptors, making spinal cord neurons more reactive to all input

(also makes neurons less sensitive to opioids)

-overactive nociceptors

-increased receptive fields

-enhanced synaptic efficiency

-dysfunctional inhibitory modulation of nociceptive signaling

-somatic

-and/or sympathetic

-and/or visceral

-increase ascending signaling to brain

-reduce descending inhibitory signals

-precipitate spontaneous pain

-review medical records

-ask about location, quality, temporal characteristics, radiation, alleviating/worsening factors, associated symptoms

sensory abnormalities. 

60% of pts have paroxysms of pain, d/t small fiber dysfunction

-EMG studies-nerve conduction

-increased sedimentation rate 

pain centered over the lumbar and/or sacral region

most resolve without tx within 3 months

-frequent causes include internal disc disruption, sprain of lumbar spine muscles &/or ligaments, facet joint sprain

-internal disc disruption (herniated disc)--> intense inflammatory reaction --> nerve root pain

-facet joint synovitis--> articular surface degradation--> facet hypertrophy--> intervertebral and central spinal canal narrowing (spinal stenosis)

become paralyzed with rear MVC.

-prevention with early surgical intervention before said car accident

-low back pain, paresthesias, dermatomal numbness

-pain is sharp, shooting, lancinating

-gait disturbances, hypesthesia, decreased muscle strength and reflexes

-discography

-progressive neurologic deficit warrants immediate MRI to r/o compressive lesion

lumbar internal disk disruption

2. sacroiliac joint disease

3. lumbar facet disease

-medications, bed rest, PT, traction

-epidural steroid injections (ie decadron); intradiscal electrothermal therapy (IDET) for disk disease

-percutaneous disc decompression (nucleoplasty)

-Minimally invasive lumbar decompression (MILD), mini laminectomy

-spinal cord stimulation- for failed back pain; mimics descending inhibitory pathways

-intrathecal pumps

opioids: morphine, dilaudid, oxycodone, methadone, tramadol

others....

-uses gate control theory

-epidural needle used

-trial followed by permanent implantation

-indications include failed back surgery syndome, CRPS, neuropathic pain syndromes, chronic limb ischemia, not a surgical candidate

failed back surgery syndrome (prior lumbar surgery and recurrent/persistent low back pain); cancer pain.

-bypasses the BBB, allowing direct access to opioid receptors, and adenosine release into CSF

-morphine, dilaudid, ziconotide (mullusk venom), clonidine, bupivacaine

-low back pain that radiates to the posterior thigh, ending at the knee

-pain with extension or rotation of back

-paraspinal tenderness to palpation

-facet joint block (of the medial branch)

facet joint injections: may last 3-6 months

-thermal radiofrequency, trying to disrupt two levels of dorsal nerve roots

sacrolicial joint syndrome

2....

causes include: degenerative arthritis, pregnancy, leg length discrepancy, angulospindulitis

dx: medial buttock, posterior hips, groin, post thigh, and sometimes below knee; point tenderness of SI joint, decreased joint mobility, LA injection; imaging less useful

5% of back and leg pain

buttock pain +/- radiation to the leg

-pain aggravated by prolonged sitting, getting up from seated position

-  +Lasegues sign

tx: PT, steriod or botox injection, LA injection, analgesics, NSAIDS

regional pain syndrome...

dx: sore neck, palpation of the trigger point by digital pressure elicits a twitch response, spontaneous electrical activity in the taut band via EMG, painful limitation to full passive ROM

-cold spray over the trigger points, gentle trigger point massage, stretching of affected muscle

-LA injection/ dry needling of the trigger point

-PT

-botox injections

-the prototypical widespread chronic pain disorder

-due to amplified ...

-no discrete tissue injury

1. hx of widespread body pain for > or = 3 months

2. allodynia to digital pressure at > or= 11 out of 18 ...

in 2010-

1. widespread pain index score- 19 body regions

2. symptom severity scale: fatigure, waking unrefreshed, cognitive issues,... 

SNRIs, tramadol, gabapentin, pregabalin

-opioids not effective

-low intensive exercise, Cognitive behavioral therapy

-causes by varicella zoster virus

-damages small, unmyelinated C fibers

-dermatomal pain prodrome --> skin eruption

-pain usually subsides with rash healing

-10-15% will develop PHN; pain persisting >3 months after rash resolved

acute stage: antivirals, steroids, epidural steroids w/ bupiv & methylprednisolone (may help to prevent PHN)

-intrathecal lido & methylpred

-10-15% of pts develop PHN, w/ pain lasting >3 months after rash resolution

-antiviral drugs & vaccination are helping to decerease the incidence of PHN

-opioids, anticonvulsants, antidepressants

-spinal cord stimulation

-viremia (rigors), pain, rash

-rash progresses from macules to vesicles to pustules to scabbing over

-single strips of blisters wrapping around either side of torso

-does not cross midline

acute stage: epidural methylpred & bupiv

-antidepressants>opioids>tramadol> anticonvulsants

-lidocaine patch for allodynia

-intrathecal methypred & lido

-ethyl alcohol burning of spinal nerves

present in 65% of IDDM pts

-related to glycemic control

-damage to small, unmyelinated nerve fibers

-usually develops after persistent hyperglycemia

-d/t chronc nerve ischemia

-described as aching

-.......

-tricyclics>SSRIs

-anticonvulsants

-....

-first described during the civil war by silas mitchell

-occurs in a subset of pts w/ peripheral nerve injury

-risk factors: trauma, nerve injury, surgery, female sex

-inciting injury, which may be minor, or a cause of immobilization, usually to an extremity

as the traumatized area heals, pts are left w/ persistent neuropathic pain...

-pain is continuous

type 1: (RSD)- no identifiable nerve injury, majority of cases

type 2: ...

1. at least one symptom in each category: sensory, vasomotor, sudomotor-fluid balance, motor

2. at least one sign in > or = to 2 of the following categories: sensory, vasomotor (edema), sudomotor-fluid balance, motor

sensory: burning pain

vasomotor: temp abnormalities/skin color changes

sudomotor-fluid balance- sweating abnormalities/ edema

motor- decreased ROM, weakness, tremor, or body part neglect

-irreversible skin and bone changes

-pain is relentless

must be multidisciplinary

-PT, TENS, tactile desensitization, graded motor imagery, mirror box therapy

-LAs (stellate ganglion & lumbar sympathetic blocks, bier blocks)

-meds: anticonvulsants, antidepressants

-opioids & alpha blocks

-last resort: sympathectomy, amputation

good if tx within 3 months

with delay, can spread to entire limb

-77% have spread to other sites in body

-will not "burn itself out" but can go into remission; resurfacing is probable

-intermittent

-80% of amputees experience pain beginning only days after surgery

-incidence may be decreased with epidural LA

...

-seen in 25% of HIV + pts

-mono/polyneuropathy- sensory/motor

-usually affects extremities, but may involve ...

-significant pain is present in 25% of cancer pts, 90% in advanced disease

responsive to nerve blocks, such as celiac plexus block (pancreatic cancer block), superior hypogastric plexus block, and ganglion impar block

-alcohol block to deserve nerves for 3 months (good for terminal cancer pain relief)

lidocaine patch 5%, used for PHN, myofascial pain, low back pain, DPN, osteoarthritis

-efficacious...

-discography

-spinal cord stimulation, peripheral nerve stimulation

-intrathecal pumps

-intradiscal electrothermal therapy (IDET)

-perc disc decompression 

....