Neural Entrapment Flashcards
Wallerian degeneration
Axons degenerate distal to the lesion to protect the nerve cell bodies.
Nerve cell bodies can regenerate axon but cannot regenerate the cell bodies
Layers of nerve damaged vs severity
Epinerum damage = high severity
Endoneruium = low severity
Perineruium = moderate severity
Reticolapathy
Damage to a nerve right when it comes out to form a root/ trunk.
Most severe damage
Plexus apathy
Damage to a nerve once it is in a plexus (i.e not a root/trunk)
Mononeruopathy vis polyneruopathy
Mono = one peripheral nerve is affected
Poly = multiple nerves are affected
Myotomes
C5: abduction of shoulder and elbow flexion
C6: flexion of elbow, wrist extension and abduction of shoulder
C7: elbow and fingers extension, wrist flexion, abduction of shoulder
C8: elbow extension and finger flexion
T1: finger abduction and abduction
Muscle strength testing scale
0: no contraction at all
1: weak contraction that is palpable
2: full ROM when gravity is eliminated
3: full ROM against gravity
4: full ROM against gravity and mild resistance
5: full ROM against gravity and maximal resistance
Dermatome
C5: lateral shoulder
C6: thenar eminence
C7: index finger (variable)
C8: hypothenar eminance
T1: medial forearm
T2: axilla
Cutaneous sensation of peripheral nerves
Axillary: Lateral deltoid/ shoulder
Musculocutaneous: Lateral forearm
Radial: dorsal webbing between thenar eminance and index finger
Ulnar: tip of hypothenar eminance
Median: tip of index finger
Reflex ratings
0: no response
1: slight by depressed response
2: normal response
3: very brisk response
4: clonus response (repeating)
Erb- duchenne palsy
Upper root nerve plexus damage (C5-C6)
Klumpke paralysis
Lower root brachial plexus injury ( C8-T1)
Also produces Horners syndrome (T1) in eyes
- contraction of pupil, drooping eyelid and sunken eyeball
Musculocutaneous nerve sensory branches
Lateral antebrachial cutaneous
- Elbow sensation and forearm sensation only*
- upper arm motor function only*
Common ways of damage to the axillary nerve
Anterior dislocation of GH joint
Crutch usage
Fracture of the surgical head of the humerus
Improper IM injections
Places of radial nerve damage
Axilla or proximal arm (Saturday nights palsy)
Radial groove fracture
Wrist fracture (posterior interosseous syndrome)
locations of median nerve damage
Elbow via supracondyler fracture or pronator hypertonicity
Forearm: anterior interosseous syndrome
Wrist: carpel tunnel MOST COMMON
Pronator Syndrome (median nerve palsy)
Flexion of PIP in 1-3 digits affected
Flexion of MIP in 2-3 digits affected
Sign of benediction and simian hand
Abnormal pinch sign (cant make ok sign and cant hold paper)
Can’t pronate
Locations of ulnar nerve damage
Elbow: posterior to medial epicondyle of humerus
Cubital tunnel (funny bone) MOST COMMON
Wrist (handlebar neuropathy)
Hand (hook of hamate fracture)
Difference between guyons canal syndrome and elbow neuropathys of the ulnar nerve
Elbow location = lose of sensation of medial palm and 4th/5th digits
- froments sign is key (cant use pads of fibers to grasp something, must use tips.)
- cant flex 4th and 5th digits
Guyons canal = ulnar claw w/ no radial deviation and can still flex fingers.
Difference between simian hand and sign of benediction
Simian hand = passive sign of distal (usually wrist) Medial neuropathies
Sign of benediction = active sign of proximal medial neuropathies
Myotome for L2-L4
Hip flexion and adduction
Knee extension
Myotome for L4 and L5
Dorsiflexion of foot
hip abduction( has S1 also)
Myotome for S1
Plantar flexion and hip abduction
Hip abduction also includes L4-5
Myotome for L4-S2
Knee flexion
Dermatome of lower leg
L2: upper lateral thigh
L3: Medial knee
L4: Medial malleolus
L5: medial foot
S1: heel of foot
S2: medial popliteal fossa
Lower leg reflexes
Quads = L4
Achilles = S1
Femoral neuropathy signs
Causes:
- primarily by prolonged external rotation of hip and flexion of knee (like giving birth position)
- also when using the saphenous vein for harvesting, femoral nerve may be knicked
Sings:
- diminished quadriceps reflex
- leg drags and buckling of the knee, instability of the knee as well.
- loss of sensation of anterior medial thigh
Lateral femoral neuropathy
Causes
- obesity, diabetic, pregnant, tight clothes (especially in lateral thigh)
- often trapped between ASIS and inguinal ligament if it is entrapped
Signs:
- numbness on lateral thigh that gets worse at night and when hip is extended
- use tinels test to determine
Superior gluteal neuropathy
Causes:
- injury, trauma, fracture/dislocation of greater trochanter
- improper IM technique
Signs:
- pelvic sag via (+) trendleberg
- cant abduct or internally rotate hip well
Sciatic neuropathy
Causes:
- piriformis Syndrome (hypertrophy of overuse)
- trauma
- athletes that utilize gluteal muscles a lot
- improper IM technique
Signs:
- complete paralysis of all ankle movement and knee flexion
- cant feel lower leg and foot
Where on the butt and thigh should you inject into in order to avoid damage to the sciatic or gluteal nerves
Von hochstetter triangle
- place palm on greater trochanter
- place index finer on ASIS
- place the middle finger on the iliac tubercle
- between the fingers = OK
Common fibular nerve neuropathy
MOST COMMON LOWER LEG NEUROPATHY
Causes:
- trauma (especially around fibular head) , overcrossed legs, bed ridden patients, rapid weight loss
Signs:
- weak in dorsiflexion, ankle eversion and toe extension
- often say “ feel like i am tripping over my toes”
- loss of sensation in the anteriolateral leg and dorsiflexion of foot
Superficial fibular neuropathy
Causes:
- compartment syndrome of lateral compartment and chronic ankle sprains
Signs:
- atrophy of the lateral compartment leg muscles
- loss of sensation in dorsum of foot (except for webbing between 1st and 2nd toes
- weakness in ankle eversion
How do you distinguish the the difference between superifical and deep neuropathies?
Sensory of webbing between the 1st and 2nd digits =deep
Entire rest of the dorsum of the foot = superficial
Deep fibular neuropathy
Causes: tight shoe wear and braces of ankles
- “ski-boot” neuropathy can occur dismally and results similarly
Signs:
- atrophy
- loss of sensation of webbing between 1st and 2nd digits
What kind of injection is corticosteroids?
IM but paraneural NOT intranerual
Signs to consider aggressive/surgical treatment over conservative
Atrophy in affected area
Active damage on a EMG
Doesn’t respond at all to conservative treatments
Most common nerve used for nerve grafting
Sural nerve
