Peripheral Nerve Injury Flashcards
Wall layer that covers a nerve fascicles
Perineurium
Wall layer that covers a nerve fiber
Endoneurium
Wall layer that covers a spinal nerve
Epineurium
Three classifications under Seddon
Neuropraxia, Axonotmesis, Neurotmesis
Seddon: (+) Wallerian Degeneration
Axonotmesis and Neurotmesis
Seddon: (+) Complete transaction of neuron
Neurotmesis
Good rate of nerve regeneration
1-2 mm per day
Seddon: (+) Conduction block
Neuropraxia
Healing time of Neuropraxia
1-2 months (3-4 weeks)
Seddon: (+) Axonal injury
Axonotmesis
Seddon: (+) Compression
Neuropraxia
Sunderland V
Axon + Endo + Peri + Epi
Seddon: (+) Gunshot wound
Neurotmesis
Sunderland: Axon + Endoneurium
III
Sunderland: IV
Axon + Endo + Peri
Nerves commonly affected in Neuropraxia
Thick myelinated motor nerve
Sunderland: Conduction Block
I
Nerves commonly affected in Neurotmesis
Any
Seddon: (+) Severe compression
Axonotmesis
Prognosis of Axonotmesis
Good
True or False: There is a (+) atrophy with Neuropraxia injuries
False
Sunderland II
Axon
Nerves commonly affected in Axonotmesis
Myelinated motor and sensory nerve
True or False: Surrounding structures are affected in Axonotmesis
False
Brachial Plexus comes from what nerve roots?
ANTERIOR rami of C5-T1 (VEMDAS)
Nerve Innervation: Serratus Anterior
Long Thoracic Nerve (C5-7)
Nerve Innervation: Supraspinatus and Infraspinatus
Suprascapular Nerve (Upper Trunk)
Largest nerve in the brachial plexus
Radial Nerve
Medial Pectoral Nerve innervates what muscles?
Pectoralis Major and Minor
Nerve Innervation: Subscapularis Muscle
Upper and Lower Subscapular Nerve (Posterior Cord)
Lower Subscapular Nerve innervates what muscles?
Subscapularis and Teres Major
Nerve root of Axillary Nerve
C5-6
Nerve Innervation: Rhomboids
Dorsal Scapular Nerve
“External Respiratory Nerve of Bell”
Long Thoracic Nerve
Nerve Innervation: Pectoralis Major Muscle
Lateral Pectoral Nerve (Lateral Cord)
Musculocutaneous Nerve innervates what muscles?
BiCoBra: Biceps Brachii, Coracobrahialis, Brachioradialis
Nerve root of Levator Scapulae
C3-4
Sensory Innervation: Posterior forearm
Musculocutaneous, Radial and Medial Cutaneous of FA
Sensory Innervation: Superolateral Arm
Axillary Nerve
Sensory Innervation: Medial arm
Medial Cutaneous of Arm Nerve
Sensory Innervation: Lateral FA
Musculocutaneous Nerve
Sensory Innervation: Posterior Arm
Radial Nerve
Cause of Musculocutaneous nerve injury
Fracture and Dislocation
What atrophy happens if there is a (+) entrapment of the musculocutaneous nerve at the arm?
Flatness of Anterior arm
What weakness can be observed if there is a (+) entrapment of the musculocutaneous nerve at the arm?
BiCoBra: Weakness of Shoulder and Elbow flexion + FA supination
What area usually has a diminished sensation if there is a (+) entrapment of the musculocutaneous nerve at the arm?
Lateral FA sensory affectation
Two causes of musculocutaneous nerve entrapment in the forearm
Musculocutaneous nerve tunnel syndrome and Hyperextension of elbow
Musculocutaneous nerve tunnel syndrome is secondary to what structure?
Distal biceps tendon
What kind of sport causes musculocutaneous nerve entrapment in the forearm?
Backhand sports (hyperextension of the elbow)
What kind of neuropathy does musculocutaneous nerve entrapment in the forearm have?
Pure sensory neuropathy
Another name of Axillary Nerve
Circumflex Nerve
Two causes of axillary nerve entrapment
Anterior shoulder dislocation and Proximal Humeral Fracture
Site of Proximal Humeral Fracture
Quadrangular Space
3 clinical manifestations of axillary nerve entrapment
(+) Weakness of Teres Minor & Deltoids, (+) Atrophy, (+) Sensory loss of the superolateral arm
What atrophy happens if there is a (+) entrapment of the axillary nerve?
Square Shoulder Deformity
Two sites of Suprascapular nerve entrapment
Suprascapular ntoch and spinoglenoid notch
If there is a (+) suprascapular notch entrapment, what are the muscles affected?
Supraspinatus and Infraspinatus
If there is a (+) spinoglenoid notch entrapment, what are the muscles affected?
Infraspinatus
What area usually has a diminished sensation if there is a (+) entrapment of the suprascapular nerve?
AC and GH joint
If there is axillary nerve entrapment, what muscles would compensate for the weakness of shoulder ABER?
Supraspinatus and Infraspinatus
“Open Book” Winging
Medial Winging
Winging: Lesion of Dorsal Scapular Nerve
Posterior Winging
“Sliding Door” Winging
Lateral Winging
Synergistic action of SA and Traps
Upward Rotation of Scapula (lateral)
Winging: (+) Radial Neck Dissection
Lateral Winging
The same action of Traps and Rhomboids in the scapula
Retraction
Winging: Middle scalene hypertrophy
Posterior Winging
Winging: (+) Radial Mastectomy
Medial WInging
Winging: (+) Overhead activities
Posterior Winging
Winging: (+) Neck Surgery
Lateral Winging
Winging: (+) Back Pack Palsy
Medial WInging
9 muscles that are innervated by PIN
ECRB, Supinator, Extensor Digitiminimi, Extensor Indicis, Extensor Digitorum, Extensor Pollicis Brevis, Ext Pollicis Longus, Abductor Pollicis Longus
2 branches of radial nerve that branched out under spiral groove
Superficial and Deep Branch
4 sensory branches of radial nerve
Posterior arm, Lateral inferior arm, Posterior forearm and Superficial branch
Two muscles innervated by the radial nerve after its passes through the spiral groove
ECRL and Brachioradialis
The superficial branch of the radial nerve innervates what area of the arm?
Dorsum of the hand
What is the nerve palsy that occurs due to the entrapment of radial nerve in the level of axilla?
Crutch Palsy
The most common site of radial nerve entrapment
Spiral Groove
Site of radial entrapment: (+) Cheralgia Paresthetica
At the wrist
Site of radial entrapment: (+) Saturday night Palsy
Spiral Groove
Site of radial entrapment: (+) Supinator Syndrome
Radial Tunnel
Spared muscles in Spiral Groove Entrapment
Triceps and Anconeus
Pure motor neuropathy of radial nerve
Radial Tunnel Syndrome
Spared muscles in Radial Tunnel Syndrome
Triceps, Anconeus, ECRL, Brachioradialis
Two causes of Radial Tunnel Syndrome
Supinator Syndrome and Vascular Leash of Henry
The most common site of radial entrapment in the radial tunnel
Arcade of Froshe
Pure sensory neuropathy of radial nerve
Cheralgia Paresthetica / Wartenburg disease
Another name of Cheralgia Paresthetica
Wartenburg disease or syndrome
Four causes of Cheralgia Paresthetica
Tight bracelet, Tight wristwatch, scaphoid fracture, handcuff neuropathy
Three muscles innervated by AIN
FDP (lateral 2), Pronator Quadratus, FPL
Four muscles innervated by the Median nerve at the elbow
Pronator Teres, FCR, Palmaris Longus, FDS
Four muscles innervated by the Median nerve at the carpal tunnel
Lumbricals, Opponens Pollicis, Abductor Pollicis, Flexor Pollicis Brevis
A sensory branch of Median Nerve
Superficial Palmar Branch
Area innervated by Superficial Palmar Branch of Median Nerve
Thenar Area
Ligament attached to the medial epicondyle to the supracondylar process of the humerus
Ligament of Struthers
What is the specific site in the supracondylar process where the Ligament of Struthers is attached?
Avian Spur
What is the name of the median entrapment above the elbow?
Supracondylar syndrome
Three causes of median entrapment at the elbow?
Pronator teres syndrome, screwdrivers palsy and bicipital aponeurosis
Does screwdrivers palsy occur due to repetitive movements?
Yes, because. of the repetitive pronation and supination
Other two names of Bicipital Aponeurosis
Lacertus Fibrosus and Grace Dieu Fascia
What is the spared muscle in the median entrapment at the elbow?
Pronator Teres (but weak if loaded)
Pure motor neuropathy of median nerve
AIN/ Kiloh Nevin Syndrome
What is the abnormal muscle formed by FPL?
Gantzer Muscle
Two causes of AIN entrapment at the elbow?
Pronator Teres and Gantzer Muscle
Sign of (+) Kiloh Nevin Syndrome
(-) Ok sign
A special test of AIN neuropathy
Pinch Grip Test
The most common entrapment of the nerve in the shoulder
Axillary Nerve
The most common site of median nerve entrapment
Carpal Tunnel
Four contents of carpal tunnel
4 tendons of FDP, 4 tendons of FDS, 1 tendon of FPL, and 1 median nerve
What is the gender predominantly affected by CTS
Females
True or False: Bilateral hand affectation is more prevalent than unilateral in patients with CTS
True
Four systemic cause of CTS
Pregnancy, Obesity, Arthritis, Endocrine Problem
Four traumatic cause of CTS
Lunate Dislocation, Repetitive Typing, Piano Playing, Usage of vibrating equipments
What is spared in the CTS?
Superficial Palmar Branch (thenar area)
True or False: There is a weakness of finger flexors in CTS
False
Three sensory branches of the ulnar nerve
Palmar Cutaneous, Dorsal Cutaneous, Superficial Branch
What are the two muscles innervated by the ulnar nerve as it passes through the cubital tunnel?
FCU and FDP (median 2)
What are the muscles innervated by the ulnar nerve as it passes through the tunnel of Guyon?
Palmaris Brevis
Seven muscles innervated by a deep branch of the ulnar nerve
Interossei, Lumbricals, Flexor Digitiminimi, Abductor Digitiminimi, Opponens Digitiminimi, Adductor Pollics, Flexor Pollis Brevis
Three dually innervated muscles of the hand
Lumbricals, FDP and Flexor Pollicis Brevis
2 innervations of Flexor Digitorum Profundus
AIN and Deep branch of Ulnar Nerve
The most common site of ulnar nerve entrapment
Cubital Tunnel (at elbow)
Four causes of Cubital Tunnel Syndrome
Trauma on posterior elbow, cubitus valgus, Osborne ligament (FCU), anomalous epitrochelais anconeus muscle
What is the gender predominantly affected by Cubital Tunnel Syndrome?
Male due to old age
Three risk factors of Cubital Tunnel Syndrome
Tardy ulnar palsy, gripping activity, smoking
What activity causes Tardy ulnar palsy?
Elbow Flexion
What are the two muscles spared in the entrapment of the ulnar nerve in the tunnel of Guyon?
FCU and FDP
The tunnel fo Guyon is formed by what structures?
Pisiform, Hamate, and Pisohamate Ligament
Two causes of entrapment of the ulnar nerve in the tunnel of Guyon?
Handlebar’s Palsy and Jackhammer’s Palsy
Who is most likely predisposed in Handlebar’s Palsy?
Bikers, Riders, Cyclist
What area usually has a diminished sensation if there is a (+) entrapment of the ulnar nerve at the tunnel of Guyon?
Palmar Aspect of fingers
Sensory innervation: Lateral palm of the hand
Median Nerve
Sensory innervation: Lateral dorsum of the hand
Radial Nerve
Sensory innervation: Medial aspect of the hand
Ulnar Nerve
Sensory innervation: Lateral tips of the dorsum of the hand
Median Nerve
Two special tests for interossei
Egawa and Wartenburg
Special test for adductor pollicis
Froments
Carpal bone affected in Radial Nerve Entrapment
Scaphoid
Carpal bone affected in Median Nerve Entrapment
Lunate
Carpal bone affected in Ulnar Nerve Entrapment
Pisiform and Hamate
Hand Injury: (+) Active Papal Sign
Median Nerve
Deformity present in Median Injury of the Hand
Ape Hand or Simian Hand
Hand Injury: (+) Guttering stick palsy
Ulnar Nerve
Deformity present in Ulnar Injury of the Hand
Bowler’s Thumb
Hand Injury: (+) Hypothenar Muscle
Ulnar Nerve
Hand Injury: (-) Precision Grips
Median Nerve
Hand Injury: (-) Power Grips
Ulnar Nerve
Hand Injury: (+) Thenar Muscle
Median Nerve
Hand Injury: (+) Passive Papal Sign
Ulnar Nerve
The ligament that causes Median Nerve Entrapment
Ligament of Struthers
The ligament that causes Ulnar Nerve Entrapment
Osborne’s Ligament
The abnormal muscle that causes Median Nerve Entrapment
Gantzer Muscle (FPL)
The abnormal muscle that causes Ulnar Nerve Entrapment
Anomalous epitrochelais anconeus muscle
“Anterior Crural Nerve”
Femoral Nerve
Nerve that is activated during cremasteric reflex
Genitofemoral Nerve (L1-2)
What is the continuation of the external oblique muscles to the inguinal ligament?
External Oblique Aponeurosis
What nerve is usually entrapement due to the External Oblique Aponeurosis?
Ilioinguinal Nerve
What type of sports injury is predominantly causes the Ilioinguinal Nerve entrapment
Hockey Groin Injury
What syndrome occurs due to the LFCN entrapment?
Meralgia Paresthetica
Another name of Meralgia Paresthetica
Bernhardt-Roth Syndrome
5 risk factors of Meralgia Paresthetica
Male, Obese, Tight Clothing, Seatbelt and Pregnancy
What area usually has a diminished sensation if there is a (+) Meralgia Paresthetica?
Lateral Thigh
The largest nerve in the lumbar plexus
Femoral Nerve
The largest nerve in the sacral plexus
Sciatic Nerve
Roots of nerve to piriformis
Posterior S1-2
Sensory Innervation: Posterior Thigh
PFCN
Femoral nerve supplies sensation in what area of the thigh?
Anterior and Inferior Medial part of the thigh
Sensory Innervation: Superior Medial Thigh
Genitofemoral
Sensory Innervation: Anterolateral of leg
SPN
Deep peroneal nerve supplies sensation in what area of the for?
1st web space of the foot
Sensory Innervation: Posteromedial of leg
Saphenous Nerve
Sensory Innervation: Middle Medial Thigh
Obturator Nerve
What are the nerves that provide sensory innervation in the sole of the foot?
Medial and Lateral Plantar Nerve, Sural Nerve, Saphenous Nerve, Calcaneal Nerve
Sensory Innervation: Posterolateral of leg
Sural Nerve
What nerve supplies the outstep of the foot?
Sural Nerve
What nerve supplies the instep of the foot?
Saphenous Nerve
Two pure sensory branches of the sciatic nerve
Sural Nerve and Calcaneal branch of tibial nerve
Muscle innervated by Inferior Gluteal Nerve
Gluteus Maximus
Cause of Inferior Gluteal Nerve entrapment
Posterior Hip Arthroplasty
(+) Gluteus Maximus Gait
Posterior Leaning (Hyperextension)
Muscles innervated by Superior Gluteal Nerve
Gluteus Minimus and Medius + TFL
“Uncompensated” Trendelenburg
Trendelenburg Sign / Pelvic Drop
“Compensated” Trendelenburg
Trendelenburg Gait / Leaning
The direction of Trendelenburg Sign or Pelvic Drop
Contralateral
The direction of Trendelenburg Gait or Leaning
Ipsilateral
3 compensatory mechanism of (+) Trendelenburg
C/L Pelvic Drop, C/L Cane, I/L leaning
Where would you put a briefcase if the patient has (+) Trendelenburg gait
Ipsilateral (not compensatory mechanism)
(+) Right gmed and gmin weakness, where is the location of the pelvic drop?
Left pelvic drop
(+) Right gmed and gmin weakness, where is the location of the trunk lean?
Right trunk lean
Cause of Obturator Nerve entrapment
Obstetric Palsy (Child Birth)
3 causes of Femoral Nerve entrapment
Anterior Hip Dislocation, Hip Fracture, and Child Birth
What muscle is the first to atrophy in femoral nerve entrapment?
Quadriceps muscle
(+) Quadriceps Gait
Forward Lurch
6 muscles innervated by DPN
Peroneus Tertius, TA, EHL, EDL, EHB, EDB
2 muscles innervated by SPN
Peroneus Longus and Brevis
Innervation of Shorthead of Hamstrings
CPN
Innervation of true hamstrings
Tibial Nerve
7 muscles innervated by the tibial nerve
Popliteus, TP, Gastrocs, Soleus, Plantaris, FHL, FDL
4 muscles innervated by MPN
FAF1: Flexor Hallucis Brevis, Abductor Hallucis Brevis, FDB, 1st Lumbricals
5 muscles innervated by LPN
FAIL AQ: Flexor DM, Abductor DM, Interossei, Lumbricals, Adductor Hallucis, Quadratus Plantae
Most common entrapment in the hip region
Sciatic Nerve at Hip
Most common tunnel syndrome in the body
CTS
Most common entrapment in the LE
CPN at Fibular Head
5 causes of sciatic entrapment in the hip
Posterior hip dislocation, Injection palsy, Fat wallet syndrome, toilet seat fracture, piriformis syndrome
What atrophy is seen in sciatic entrapment in the hip?
Spindle Leg atrophy
What are the 2 signs seen in sciatic entrapment in the hip?
Sign of pace and nagel and Sign of Freiberg
Sign: (+) pain and weakness in active ABER of hip
Sign of pace and nagel
Sign: (+) pain in passive IR of extended hip
Sign of Freiberg
7 causes of CPN entrapment at Fibular Head
Crossed-leg sitting, side-lying, leg ER at supine, Indian sitting, Guitarist Posture, Prolonged squatting, Strawberry picker’s palsy
4 gait deviations present in CPN entrapment at Fibular Head
Weak DF: (+) Foot drop (swing), (+) Foot slap (stance), (+) Steppage gait (increase hip and knee flexion), and (-) heel strike
2 causes of DPN entrapment
Fracture or Trauma
Sensory loss present in DPN entrapment
Sensory affectation in the 1st dorsal space
3 syndrome that causes weakness of EDB and EHB
Anterior compartment syndrome, anterior tarsal tunnel, ski boots palsy
Two sites of tibial nerve entrapment
Popliteal fossa and tarsal tunnel
2 causes of tibial nerve entrapment at the popliteal fossa
Baker’s cyst and too long wheelchair seat depth
3 gait deviations present in tibial nerve entrapment at popliteal fossa
Weak PF: (-) push-off, (+) decrease step length of the opposite foot, (+) calcaneal gait
Cause of tibial nerve entrapment at the tarsal tunnel
Lesion at porta pedis
What nerve is affected in tibial nerve entrapment at the tarsal tunnel?
MPN and LPN (foot intrinsics)
2 causes of medial plantar nerve entrapment
Jogger’s foot and runners with flat feet (overpronation of the foot)
The most common site of pain present in medial plantar nerve entrapment
Medial sole
What is the pure sensory neuropathy occurs due to the entrapment of the 3rd-4th metatarsal?
Interdigital neuroma
Other name of interdigital neuroma
Morton’s Neuroma
What is the gender predominantly affected in interdigital neuroma?
Female
Cause of interdigital neuroma
usage of poorly fitting high-heeled shoes
