Entrapment Neuropathy
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Transcript of Entrapment Neuropathy
Entrapment neuropathy
Surat Tanprawate, MD, FRCP(T)Northern Neuroscience Center
Chiangmai University
Concept
• All of confusing problem come form plexus
• Entrapment level: root, plexus, nerve
• Concept to be remembered: muscle– Same nerve: different root– Same root: different nerve
• Step to remember– Muscle: nerve innervation– Muscle: root innervation
• Step approach1. Clarify symptom:
where’s drop?2. What’s muscle affected?3. What’s nerve and root
innervated that muscle?4. Test key muscle: muscle
innervated by : same nerve, different root : same root, different nerve
Musculocutaneous n.
5 6 7 8T1
5 6 78
Median n.
Ulnar n.
Axillary n. Radial n.
Proximal forearm
• Musculocutaneous nerve– Muscle: Bicep m.– Cutaneous: lateral
cutaneous of forearm
• Axillary nerve– Pass under axillar– Supply: deltoid m.
Radial nerve
• Radial n:– Run around radial
groove
• Form:– Posterior interosseous n. – Superficial radial n.
• Special test– Out stretch arm test
Tricep
Brachioradialis
ExtensorCarpi
ExtensorDigitorum
PollicisIndices
Median nerve
• Median n:– Run median of arm
• Form:• Median n.• Anterior interosseous n.• Special test
– Finger pinch or O.K. test: งอ distal ไม่�ได้�
– Benediction’s sign– Tinel’s and Phalen’s test
for CTS
Flexor carpi radialis
Flexor digitorum superficialis
Flexor digitorum profundus 1,2
Flexor Pollicis longus
LOAF
Pronator quadratus
Median nerve syndrome
• Carpal tunnel syndrome
Pronator teres syndrome
• Signs:
Ulnar nerve
• Ulnar n:– Run ulnar of arm
• Most intrinsic hand except LOAF
• Special test– Open your hand:
• Ulnar claw hand
– Prayer test
Flexor carpi ulnaris
Flexor digitorum profundus 3,4
Intrinsic hand muscle except
LOAF
Ulnar n syndrome
• Cubital tunnel syndrome• wrist
Entrapment of upper extremities
• Clinical approach– Proximal arm weakness– Wrist drop– Hand atrophy
Proximal arm weakness
• Proximal arm muscle: key muscle– Deltoid:C5,6- axillary n.– Bicep: C5, 6-
musculocutaneous n.– Tricep: C7,8- radial n.– Brachioradialis: C5, 6-
radial n.
• Pattern involved– Deltoid alone
• axillary n. lesion
– Deltoid, bicep, brachioradialis involved(spare tricep)• C5,6 root
– Involve alls muscle• Brachial plexus• Cord
Wrist drop
• Wrist drop– Extexsor carpi radialis
longus(C5, C6 and radial nerve)
– Extensor carpi ulnarlis( C7, C8 and posterior interosseous branch of radial nerve)
Key muscle: nerve, root
• Key muscle: radial distribution– Radial n: tricep,
brachioradialis– P.I.N: extensor
digitorum, extensor carpi ulnaris
• Key muscle: C5,6– Deltoid: axiallary n– Bicep:
musculocutaneous n.– Tricep: radial n.(C6,7,8)– FCR: median n.(C6,7)
Interprete
• Generalized weakness: esp. weakness of deltoid, tricep, wrist ext, finger ext.– UMN: corticospinal tract
lesion
• Selected weakness– C7,C8 root or plexus– Radial nerve lesion– Posterior interosseous
nerve lesion
Out stretch arm test
Tricep Brachioradialis
Wrist extension
Finger extension
Finger flexion
PIN lesion(finger drop with radial deviation)
Normal Normal Normal (radial
diviation)
Weak Normal
C7,8 or brachial
plexus lesion
Weak Normal Radial diviation
Weak Weak
Radial nerve lesion(radial
groove)(wrist drop)
Normal Weak Weak Weak Normal
C5,6 orBrachial plexus
Mild Weak
Weak Weak Normal Normal
Hand atrophy(wast hand)
Muscle of hand
Median nerve Ulnar nerve
LOAF Others than LOAF
APB ADM and 1 DI
Hand atrophy
• Muscle of hand– LOAF(median n.), other
than LOAF(ulnar n.)– Key muscle: 3 muscle
• APB(for LOAF), ADM and 1 DI(for other than LOAF)
• Root innervation– APB: C8 T1– 1DI: C8, T1– ADM: C8, T1
• Pattern of weakness– Only APB: median n.
lesion-test other flexor m. group
– Only ADM and 1DI: ulnar n. lesion
– Weak all 3 muscle: many causes
Weak all 3 key muscle
• 3 muscle plus finger extensor, tricep, finger flexor– C7,8,T1 root
• Fail arm+ all sensation– Brachial plexus
• Fail arm and cape distribution sensory loss– Spinal cord
• Generalized– MND– Polyneuropathy
C8 radiculopathy Brachial plexus,lower trunk
Brachial plexus, medial cord
Ulnar neuropathy
Wrist flexion Weak Weak Weak Weak
Finger flexion Normal Weak Weak Normal
Thumb flexion, opposision
Normal Weak Weak Normal
Interossei weakness, atrophy
Yes Yes Yes Yes(esp. atrophy of 1 dorsal interossei
Senseory loss Same as ulnar+ulnar aspect of forearm
Similar to medial cord
Same as ulnar+palmar aspect of hand and digit1-4
Ulnar aspect of hand, 5 digit and half of 4
Tricep reflex Partial No Partial No
Hand shape Either Simian hand Simian hand Claw hand
Horner syndrome Can occur Can occur Never Never
Causes Compression by cervical disc
Traumatic injury at birth
Traumatic, tumor, neuritis
Compression, ulnar groove
Lower extremities
• Lumbosacral plexus• Proximal– Anterior: obturator n., femoral n.– Posterior: gluteal n., sciatic n(hamstring m.)
• Distal – Anterior: peroneal nerve(deep VS superficial)– Posterior: tibial nerve
Entrapment neuropathy of lower extremities
L1 L2 L3 L4 L5 S1 S2
Femoral nerve- Iliopsoas(L1,2,3)- Quadricep(L2,3,4)Obturator nerve- Adductor group(L2,3,4)
Femoral n. Obturator n.
Entrapment neuropathy of lower extremities
L1 L2 L3 L4 L5 S1 S2
Glureal n.Superior gluteal nInferior gluteal n
Sciatic n.
Gluteal n.
Tibial n.TP. m.(L4,5)Gastroc m(S1,2) Deep peroneal n.
TA. M(L4,5)EHL m.(L5, S1)
Proximal weakness of legs
• Key muscle– Iliopsoas m: L1, 2-
femoral n.– Quadricep m: L2,3-
femoral n.– Adductor m: L3,4-
obturator n.– Hamstring m: L5, S1,2-
sciatic n.– Gluteus maximus m: L5,
S1,2- inferior gluteal n
• Weak • Iliopsoas+quadricep– Femoral n. lesion
• Iliopsoas+quadricep+ hip adduction– L2,3, 4 lesion
Foot drop
• Due to weakness of tibialis anterior• Key muscle– Tibialis anterior m: L4,5-DPN– EHL: L5, S1- DPN– Peroneus m: L5, S1- SPN– Tibialis posterior m: L4,5 - tibial n.– Gastrocnemius m: S1,2 - tibial n.
Pattern of foot drop
• weakness of• Dorsiflex+eversion+EHL– Common peroneal n.
lesion
• Dorsiflex+inversion+ hip abduction– L4, 5 root or plexus
lesion
• Alls movement of foot– Peripheral neuropathy– Sciatic n. lesion– Plexus lesion– Cauda equina lesion– Anterior horn cell
disease
Differential diagnosis of foot drop
L5 radiculopathy Lumbar plexopathy
Sciatic neuropathy
Peroneal neuropathy
Ankle inversion W W N or mildly weak N
Toe flexion W W N or mildly weak N
Plantar flexion N N N or mildly weak N
Ankle jerk N N or depress N or depress N
Sensory loss Big toe L5 dermatome Entire lateral leg and dorsum of foot
Distal 2/3 of lateral leg, dorsum of foot
Pain Rare, deep pain Radicular pain Can be severe Radicular pain
Causes Disc herniation Prolong labor, pelvic fracture
Hip surgery Compression
Good luck