Peripheral Neuropathies 2 Flashcards
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
- L4 root compression = L3/4 disc or laterally extruded L4/5 disc
- L5 root = L4/5 disc or laterally extruded L5/S1 disc
- S1 root = L5/S1 disc
best imaging for a herniated disc?
today you would mostly use MRI; could use a myelogram also
spondylosis
- 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
spondylolisthesis
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
arachnoiditis
- thick, scarred arachnoid adhering to the pia and dura
- caused usually by contrast dye and surgery
possible causes of arachnoiditis
- intrathecal agents = dye, anesthetic drugs, steroids, amphotericin B, methotrexate
- infections = TB, Cryptococcus, syphilis, viral
- trauma = spinal surgery, vertebral injuries, disc herniations
- 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)
