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Flashcards in Peripheral Neuropathies 2 Deck (30)
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dermatome: definition

area of skin supplied w/ afferent n. fibers by a single posterior spinal root


myotome: definition

group of mm. innervated from a single spinal segment


sclerotome: definition

area of a bone innervated from a single spinal segment


injury to a peripheral n. can lead to ??

- osteoporosis
- fibrosis or ankylosis of the innervated bones, joints and periarticular tissues


lumbar and sacral radiculopathies

- aka "sciatica"
- normally it's an S1 radiculopathy; a true sciatic n. injury is rare - it's most often a pinched n.
- caused by bony abnormalities, herniated disc, trauma, inflammatory, tumor, DM, vasculitis, infection


Do herniations affect the n.: coming out above or below the herniation?

herniations affect the n. coming out below it i.e. an L4/5 herniation will affect the L5 n.


disc herniations: general info

- nucleus pulposus penetrates the annulus fibrosis
- bulging, extruded, sequestered
- usually herniation is in a dorsolateral direction but it could be laterally or centrally
- large disc herniations will involve multiple n. roots = cauda equina syndrome or spinal stenosis


disc herniations: clinical features

- pain aggravated by valsalva maneuver or sneezing
- radiating pain and paresthesias
- + SLR (straight leg raise) test
- pt bent forward and lumbar curve flattened
- paraspinal mm. spasms
- most commonly involves L5 & S1 roots


common spinal root compressions and corresponding disc herniations causing them

1. L4 root compression = L3/4 disc or laterally extruded L4/5 disc
2. L5 root = L4/5 disc or laterally extruded L5/S1 disc
3. S1 root = L5/S1 disc


best imaging for a herniated disc?

today you would mostly use MRI; could use a myelogram also



- can be acquired or hereditary
- caused by degenerative arthritis involving facet joints
- hypertrophy and osteophyte formation are possible
- involved discs become flattened and narrowed
- subluxation of the facet joints



slippage of one vertebra over another
basically you took spondylosis a step further


clinical features of bony changes

- multiple root involvement
- widespread arthritic changes --> more in older pts
- long standing LBP (low back pain)


In a 30yo pt, would you more likely see a disc herniation or spondylosis?

herniations happen more in younger pts = <40
spondylosis seen in older pts = 50+


cauda equina syndrome

- central disc herniation at L4/5 level usually
- involves multiple roots L5-S3
- intermittent neurogenic claudicaiton


what is the difference b/w vascular and neurogenic (i.e. cauda equina syndrome) claudication?

vascular = pain in legs when you exercise b/c mm. not getting enough blood flow, like a lactic acid burn; during your PE you will find diminished pulses due to ischemia of mm.
neurogenic = pt w/ bony changes that crowd the canal containing the nn. roots; when you walk the vessels swell and compete for the space and the nn. get pinched = pain w/ walking; pts usually hunched over, normal pulses, could have reflex changes



- thick, scarred arachnoid adhering to the pia and dura
- caused usually by contrast dye and surgery


possible causes of arachnoiditis

1. intrathecal agents = dye, anesthetic drugs, steroids, amphotericin B, methotrexate
2. infections = TB, Cryptococcus, syphilis, viral
3. trauma = spinal surgery, vertebral injuries, disc herniations
4. spinal subarachnoid hemorrhage


arachnoiditis: dx and tx

- dx = H&P, EMG w/ NCS, imaging
- tx: conservative = OMT, PT, bed rest, meds (prednisone, NSAIDs, analgesics); chemonucleolysis (chymopapain) - usually not used b/c of allergic rxn
can also tx w/ surgery


cervical radiculopathy: symptoms for the different levels and tx for all

- disc disease or spondylosis
- C5 = shoulder pain/numbness
- C6 = pain/numbness of thumb and index fingers
- C7 = pain/numb middle finger; pectoral and upper back pain
- C8 = pain/numb 4th and 5th digits and medial forearm
*the level of herniation is the same as the n. root
- tx = same as lumbar disc disease = cervical collar


ddx for C5 or C6 radiculopathy

- carpal tunnel
- brachial plexopathy
- mononeuropathy --> radial, musculocutaneous, or suprascapular


ddx for C7 radiculopathy

- carpal tunnel
- radial mononeuropathy
- brachial plexopathy


ddx for C8 radiculopathy

- brachial plexopathy
- ulnar mononeuropathy


Raynaud's disease: general info

- episodic blanching of fingers precipitated by cold or emotion (red, white, blue phases)
- idiopathic
- can be symptomatic of a disease or medication (beta blockers)


Raynaud's disease: pathogenesis, causes, tx

- pathogenesis = increased arterial constriction and decrease in intraluminal distending pressure
- causes = arterial obstruction, connective tissue disease, trauma, medication
- tx = tx underlying cause, eliminate precipitating factors, sympathectomy is usually ineffective


Name 2 complex regional pain syndromes.

1. causalgia
2. reflex sympathetic dystrophy



- caused by trauma to a n. resulting in injury to sympathetic fibers
- happens in 2-5% of cases
- persistent, severe, burning, dysesthetic pain
- associated sudomotor, vasomotor and atrophic changes
- tx = procaine block or regional sympathectomy


reflex sympathetic dystrophy: general info

- caused by blunt trauma to soft tissue and bone
- other causes = CVA, MI, angina, degenerative joint disease
- believed to be secondary to autonomic dysfunction


stages of reflex sympathetic dystrophy

Stage I = Acute
increased: temp, hair/nail growth, blood flow, rubor, edema; decreased ROM; may last up to 3 months
Stage II = Dystrophic
hyperesthesia, cold intolerance, decreased: temp, hair growth; brittle nails, pale limbs, cyanotic, demineralized bone
Stage III = atrophic
decreased pain, hyperesthesia, smooth and glossy skin, m. wasting, contractures
**want to tx in stage I; prognosis very poor if pt progresses to stage II before tx


dx and tx of reflex sympathetic dystrophy

- dx by H&P, bone scan, thermography, x-rays
- tx options:
sympathetic block - surgical or chemical
regional IV meds
psychological care
PT, TENS unit for pain modulation
- possible meds to use = NSAIDs, propranolol, nifedipine, reserpine, guanethidine, prednisone, antidepressants, antiarrhythmics, anticonvulsants, phenothiazines, gabapentin