CM: Headache, Back Pain, & Management

Question 1

What is nociceptive vs.neuropathic pain?

Answer 1

nociception = transmission of nerve impulses along certain pathways in response to application of potentially tissue-damaging stimuli
neuropathic = sharp, burning, gnawing, aching, shooting, lancinating, often persists w/o application of stimulus, poorly responsive to Rx

Question 2

What does the term “pain” encompass that nociception does not?

Answer 2

emotional responses to having pain

serves a protective role

Question 3

What is peripheral sensitization?

Answer 3

inflammatory soup accompanies painful stimulus and lowers threshold for pain generation from peripheral nociceptors
can lead to central sensitization

Question 4

What is hyperalgesia and allodynia?

Answer 4

allodynia: normally innocuous stimuli produce sensation of pain when applied to peripherally sensitized tissues
hyperalgesia: normally painful stimuli provoke exaggerated responses

Question 5

What is the physiological basis for central sensitization?

Answer 5

wind-up: progressive build up of amp of response of dorsal horn neurons during repetitive stimuli to C fibers = C fiber dependent
peripheral sensitization and structural changes (increase in nerve fiber density)
decreased inhibition

Question 6

What are the three types of axons for peripheral nociception?

Answer 6

alpha-delta: finely myelinated, slow conducting, small diameter - pricking, sharpness, achy feelings, do what C fibers do with more gusto
C: unmyelinated, very slow, very small, employ substance P - burning sensation

Question 7

What is substance P?

Answer 7

peripherally: dilates cutaneous vessels, releases histamine from mast cells, chemoattractant for leukocytes - result in increased hypersensitive area
centrally: nociceptive transmitter in dorsal horn - excites relay neurons involved in pain transmission

Question 8

When is substance P released?

Answer 8

when normally propagating AP rebounds antidromically through other axonal branches, which activates other C fibers to release it

Question 9

What are the pathophysiological correlates to neuropathic pain?

Answer 9

damage to larger, more myelinated fibers –> loss of vibration and proprioception = weakness, not as painful
damage to small, myelinated fibers –> loss of pain, light touch, and temp = pinprick, more painful

Question 10

What different fiber types are involved in polyneuropathies?

Answer 10

small fiber = painful, no EMG findings necessarily

large fiber = can be painful, sensory ataxia, should have EMG findings

Question 11

What is a brief ddx of polyneuropathies?

Answer 11

DIABETES!

Question 12

What are different ways that neuropathies are classified?

Answer 12

fiber type
etiology
pathophysiology (axonal, demyelinating, mixed) - demyelinating has weakness earlier and more severe than axonal

Question 13

How can polyneuropathies be evaluated?

Answer 13

labs, CXR, EMG, hemoccult stools x3, skeletal survey, repeat labs 6-12 mos, ANS testing, Ab testing

Question 14

What are characteristics of referred pain?

Answer 14

deep, achy, intensity similar to that of local
upper lumbar –> flank, hip, groin, ant thigh
lower lumbar –> buttock, sciatica

Question 15

What are characteristics of radicular pain?

Answer 15

similar to referred but more severe, radiates distally, in a nerve root distribution
increases with valvalva maneuvers, straight leg raising
sharp, intense superimposed on dull, achy referred
often has numbing and tingling

Question 16

What are characteristics of pain from muscle spasm?

Answer 16

local, dull, crampy
can see or feel muscle
stiffness, limited movement, numbness/tingling, weakness, bowel/bladder incontinence
characteristic postural adjustments: knees and hips flexed, fetal position
prolonged sitting and standing from sitting is painful

Question 17

What is cauda equina syndrome?

Answer 17

LMN findings only, intense low back pain, bilateral sciatic distribution, decreased perianal sensation = saddle anesthesia, loss of both ankle jerks, asymmetric LE weakness, radicular symptoms, may have urinary retention or impotence

Question 18

What is conus medullaris syndrome?

Answer 18

mixed UMN and LMN findings, bowel bladder and sexual dysfunction early, poor rectal tone, perianal sensory chages = saddle anesthesia, sometimes lower extremity weakness, less severe radicular pain

Question 19

What are alarm signs suggestive of a secondary cause of acute headache?

Answer 19

worse headache ever
first headache >50
change in headache pattern (esp accelerating)
apocalyptic onset (rapid progression to max intensity)
onset w exertion (cough, sneeze, sex)
subacute that worsens
headache w systemic illness
associated w abnormal neurological symptoms or physical findings

Question 20

What are alarm signs suggestive of a secondary cause of chronic headache?

Answer 20

increasing frequency
dyscoordination
hx of localized signs
awakened BY (not with) headache
occipitonuchal location

Question 21

How can a tension type headache be recognized?

Answer 21

can cause chronic daily headache
dull ache, located posteriorly/occiptionuchally
“band around head”, tightness, pressure
no nausea/vomiting, not increased by physical activity, no sonophobia/light sensitivity*
tight stiff neck, neck movement causes radiation
chronic - lightheadedness, dizziness, fatigue
not everyone has evidence of muscle overactivity

Question 22

How can a rebound headache be recognized?

Answer 22

= medication overuse

only in migraine pts, hard to treat

Question 23

What are sinus headaches?

Answer 23

usually not - mostly migraines (including TTH)

lack any other sinus symptoms

Question 24

How can migraine with aura be recognized?

Answer 24

unilateral, pulsing/throbbing, usually in frontal, temporal, orbital or overlapping
worsened by physical exertion
lasts 4-72 hrs
uncontrolled bouts of dysautonomia

Question 25

What are the four phases to a migraine attack?

Answer 25

prodrome (hrs-days before)
aura (immediately proceeding): mostly visual, can be sensory or motor, see bright moving lights, can have tingling/numbness/weakness, don’t return to normal before headache
headache pain (<72 hrs)
postdrome (hrs-days after): poor concentration, tired, refreshed or euphoric, anorexic or food cravings

Question 26

How can cluster headaches be recognized?

Answer 26

adult men
severe unilateral orbitotemporal/retroorbital headache with no crescendo for pain <1 hr
associated w Horners
2 aspects: headache is time-locked in circadian pattern, occurs for weeks to months then remits then recurs often with spring and fall
*purse physical activity, unlike migraines (pacing, rocking, hitting head)
alcohol can provoke