Lecture 1 Flashcards
Nerve injuries:
Neuropraxia, Axonotoemesis, Neurotemesis
Neuropraxia: myelin sheath injury/ischemia. Spared axons and CT.
Axonotomesis: axon and myelin sheath injury. Wallerian degeneration. Spared CT.
Neurotemesis: axon , myelin sheath, and CT injury. No chance of recovery
Entrapment
Quality (achy/pain, lancinating, numbness, tingling
Somatic Distribution
Exacerbated with percussion activity
Nerve Conduction Studies
Shows speed and quantity of electricity reaching destination
Decreasing suggests: demyelinating injury, and axonal damage.
Needle Electromyography
Differentiates between demyelinating vs axonal injury. Severity vs Chronicity
Suprascapular Nerve purpose and innervation
Mixed motor and sensory
supraspinatus and infraspinatus
How is suprascapular nerve injured?
At supra-scapular notch: compressed by transverse ligament. Denervation of IS and SS.
Spinogelnoid Notch: Denervation of IS only.
Managament
PT, surgical ligament, nerve decompression
Axillary Nerve
Teres Minor and deltoid.
Sensation to shoulder and upper arm.
Quadrilateral space with posterior circumflex humeral artery.
Compression of posterior circumflex humeral artery and axillary nerve in space.
worsened by shoulder abduction and ER.
Arm and forearm pain
Deltoid pain and weakness/atroph
Median Nerve
Mixed motor and sensory: pure motor AIN branches at forearm.
Palmar cutaneous nerve branches 5 cm before wrist.
Proximal Entrapment Sites: bicipital aponeurosis.
2 heads of pronator teres (Pronator Teres Syndrome)
AIN syndrome: treatment as pronator teres syndrome.
Distal entrapment sites: carpal tunnel (MC) –> carpal tunnel syndrome.
Thenar eminence sensation spared (branching)
Treatment: PT, night splinting, steroid injections, carpal tunnel release.
Radial Neuropathies:
Mixed motor and sensory
Exists axilla –> branches –> posterior to spiral groove of the humerus –> travels in front of lateral epicondyle at elbow
Ulnar Nerve
mixed motor and sensory
enter elbow at cubital tunnel–> enters wrist at Guyon’s canal
2nd most common entrapment neuropathy. MC at elbow (cubital tunnel syndrome).
Clinical Paresthesia and weakness of 4th and 5th fingers
Neuropathies:
- Benediction hand: hyperextension of MCP and PIP, DIP. unopposed FDP
- Wartenberg Sign: weakness of palmar interossei –> inability to adduct 5 digits
- Froment Sign: flexion of thumb PIP
Radial neuropathies
Each axilla –> gives branches to triceps and anconeous –> moves posterior to spiral groove humerus –> travels in front of lateral epicondyle at elbow.
Femoral Nerve
mixed motor and sensory (L2-L4)
MC entrapment site: under inguinal ligament ( related to trauamtic injuries to ilopsoas compartment)
Clinical presentation of femoral nerve entrapment:
quad, iliopsoas weakness. Absent knee jerk reflex.
Sensory changes in antero-medial thigh, medial knee, leg and foot.
Lateral femoral cutaneous nerve
pure sensory ( L1-L3)
Meralgia paresthetica: Compression at inguinal ligament. Senosry change and paresthesia to anterolateral thigh.
Worse with standing, walking, or hip extension.
No motor signs
Obdurator nerve
Mixed: L2-L4
Divides into anterior and posterior branches.
Entrapment is uncommon: pelvic trauma, GU surgeries, sports related.
Symptoms:
deep ache near adductor origin on pubic bone..
worsened with exercise, subsides with rest, radiates down medial thigh.
muscle changes with denervation.
Sciatic Nerve
L4-S3 roots,
largest nerve on body, multiple divisions
Innervates posterior thigh muscles
entrapment at hip and thigh.
proximal entrapment causes (iatrogenic :total hip arthroplasty), stretching, trauma, compression ( piriformis syndrme, hamstring syndrome)
Piriformis syndrome
Buttock pain while walking
Sitting may decrease pain
posterior thigh and knee rererral
gluteus maximus atrophy
positive FAIR test
Hamstring Syndrome
preceded by hamstring injury
often seen in runner, sprinters and jumping athletes.
Clinical triad: increased pain with sitting, pain with resisted knee flexion (but not in hip extension)
pain with palpation of ischial tuberosity
Piriformis Syndrome
Physical therapy (avoid stretching)
OMT, anti-inflammatories, botulinum toxin injections, image guided corticosteroid injections
Hamstring Syndrome
Physical therapy, OMT, avoid stretching, activity modification, neural mobilizations, iontophoresis
Tibial Nerve
Enters tarsal tunnel –> posterior tibial nerve
Entrapment syndrome:
- tarsal tunnel syndrome: compression from trauma, lesion, foot deformity, systemic disease
Clinical: burning and paresthesia along plantar aspect of foot and toes.
Positive Tinels Sign
- Medial Plantar Neuropathy (Jogger’s Foot): entrapment at tarsal tunnel or henry’s knot
Repetitive trauma to nerve from running with excessive foot pronation and heel valgus.
Clinical: heel and arch pain, + tinel’s sign posterior to navicular tuberosity
medial foot numbness
- Baxter neuropathy: inferior calceneal neuropathy:
medial calcaneal tuberosity.
- Morton Neuroma:
Fibrotic nodule creating entrapment of interdigital nerves between 2nd and 3rd metatarsal.
peroneal nerve
Motor and sensory fibers, ( L4-S2)
Supplies short head of biceps femoris in thigh
divides at fibular neck into
articular branches
SPN: lateral leg
DPN: anterior leg compartment
Common peroneal nerve entrapment
MC mononeuropathy in LE
Fibular neck and peroneus longus muscle
Paresthesia and anesthesia along lateral lower leg and dorsal foot.
ankle dorsiflexion and foot eversion weakness.
steppage gait
foot drop
DPN: entrapment (anterior tarsal tunnel syndrome):
entrapment under extensor retinaculum or at dorsum of foot at 1st tarsometatarsal joints
Prior to tarsal tunnel –> motor and sensory
within or after tarsal tunnel –> motor and sensory
Within or after tarsal tunnel –> sensory
Clinical:
dorsal foot pain radiating to 1st web space.
weakness at hallux extension.
SPN entrapment:
Compression as nerve enters deep fascia deep fascia of the lateral leg component.
Causes: over stretching from inversion or plantar flexion injuries (dancers), contusion.
Clinical: swelling, point tenderness 10-15 cm above lateral malleolus –> different from DBP –> absence of 1st web space involvement
