ABNS Boards > Peripheral Nerve > Flashcards

Peripheral Nerve Flashcards

(103 cards)

Study These Flashcards
1
Q

Idiopathic brachial plexopathy

AKA

A

Parsonage-Turner Syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Winged scapula associated with Parsonage-Turner Syndrome is often caused by inflammation to which nerve?

A

Long thoracic nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Long thoracic nerve innervates which muscle?

A

Serratus anterior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is recommended treatment for Parsonage-Turner Syndrome?

A

Physical therapy

Approximately 80% of people have goof recovery of function.

Steroids may be used empirically but no good evidence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the name of a condition that causes burning paresthesias and numbness in the lateral thigh and groin?

A

Meralgia paresthetica

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What nerve affected in meralgia paresthetica?

A

Lateral femoral cutaneous nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where is the incision made for decompression of lateral femoral cutaneous nerve?

A

Transverse and just medical to ASIS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Lateral femoral cutaneous nerve is located above which muscle?

A

Sartorius

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Bilateral hand atrophy at the interossei in combination with normal sensation and UMN/LMN findings may be a sign of …

A

ALS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Gilliatt-Sumner hand leads to both thenar and hypothenar atrophy. Why does this occur and what is the common casue?

A

Compression of lower trunk of brachial plexus, often due to neurogenic thoracic outlet syndrome or a pancoast tumor which leads to compression of this structure between clavicle and first rib

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Radial nerve innervates what muscles, generally?

A

Extensors

E.g. triceps, extensor carpi radialis longus/brevis, extensor carpi ulnaris, extensor digitorum, extensor digiti minimi, extensor pollicus longus/brevis, and extensor indicis

Also: brachioradialis, supinator, and abductor pollicis longus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Finger drop, radial deviation on wrist extension, and no cutaneous sensory loss due to …

A

Posterior interosseus neuropathy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Arcade of Frohse is a site of entrapment of which nerve?

A

Posterior interosseous nerve (branch of radial nerve)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Wrist and finger drop is a sign of ….

A

Radial nerve palsy, often at spiral groove

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Winging of the scapula occurs with muscular dysfunction?

A

Serratus anterior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are common nerves affected in isolation or combination in Parsonagfe-Turner Syndrome?

A

Long thoracic
Suprascapular
Axillary
AIN
PIN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

In patients presenting with pain and weakness in an extremity consistent with a peripheral nerve issue, what questions on history can help cement the diagnosis?

A

Any recent illness, trauma, or vaccinations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Upper trunk injuries to brachial plexus (C5 and C6) lead to what palsy? What does this look like and clinically what muscles involved?

A

Waiter’s tip posture

No shoulder abduction, no elbow flexion, arm internally rotated, good extension and grip

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Obese patient with lateral thigh dysesthesias is often due to …

A

Meralgia paresthetica (lateral femoral cutaneous nerve)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Distinguish common peroneal nerve injury from L5 radiculopathy

A

Common peroneal nerve:
- Weak DF and weak EVERSION
- Tinel’s at knee
- Pain usually from knee

L5
- Weak DF and weak INVERSION
- Positive straight leg raise
- Pain from back radiating down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are causes (or how do they arise) of malignant peripheral nerve sheath tumors?

A

Spontaneous
NF related
Post-radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

True/False

A patient with a benign nerve sheath tumor usually presents with a mass and relatively mild neurologic symptoms and few (if any) neurologic findings

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

If suspecting a MPNST, what surgical approach would you recommend?

A

Biopsy first to confirm diagnosis to then formulate a multi-disciplinary plan

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Closed peripheral nerve injuries and GSWs may benefit from surgery when no evidence of clinical or electrical recovery after what period of time?

A

3 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are the two common entrapment sites for the median nerve?
Transverse carpal ligament/Carpal tunnel (wrist) Pronator teres (upper forearm)
26
What nerves make up the median nerve? What cords supply it?
C5-T1 Medial and Lateral Cords
27
Where does the median nerve branch off into AIN?
Upon entering forearm
28
Is the anterior interosseus nerve motor or sensory?
Motor
29
What muscles does the median nerve supply?
LOAF Lumbricals (1st and 2nd) Opponens pollicus Abductor pollicis brevis Flexor pollicis brevis
30
Is sensation to the base of the thenar eminence often involved in classic carpal tunnel syndrome? Why?
No Palmar cutaneous branch which provides sensation to this area branches proximal to the transverse carpal ligament
31
Paresthesias in hand, worse at night and with hands elevated Decreased pinprick sensation to digits 1-3.5 Diagnosis?
Carpal tunnel syndrome
32
What are positive exam findings seen in carpal tunnel syndrome?
Tinel's sign (tapping at wrist produces pain) ~ 60% Phelan's sign (wrist flexion produces pain) ~ 80%
33
On exam, your patient has pain at the base of the thumb when you palpate in an abducted position. Diagnosis?
De Quervain's Tenosynovitis
34
If a young patient presents with paresthesias in hand consistent with carpal tunnel but they don't have a history of repetitive hand movements what is on your differential and how do you work it up?
Myxedema (TSH/T3 and T4) Uremia (BUN/Cr) Diabetes (BG) Multiple myeloma (SPEP/UPEP)
35
What are nonoperative considerations in patients with carpal tunnel syndrome?
Neutral position splints Steroid injections
36
Walk me through a carpal tunnel release
-Surgical timeout and confirm sidedness -MAC anesthesia and local -Incision slightly towards ulnar side of thenar crease (b/w 3rd and 4th digit), extending to base of thumb - Sharp incision until identify TCL, then protect nerve and snip to totally release both proximal and distal
37
Abnormal pinch sign is associated with what peripheral neuropathy?
Anterior Interosseous Neuropathy
38
What nerves supply the ulnar?
C7 and T1
39
Where are the four compression sites of the ulnar nerve?
(i) Above elbow: Arcade of Struther's (ii) At elbow: Retroepicondylar groove (iii) Forearm: b/w heads of flexor carpi ulnaris (iv) Wrist: Guyon's canal
40
What are the motor findings of ulnar neuropathy?
Interossei wasting Wartenberg's sign: pinky abduction d/t 3rd interosseus denervation Froment's prehensile thumb sign (when gripping sheet of paper) Claw deformity (extension at MCP, flexion at distal phalyngeal joint, most prominent in digits 4 and 5)
41
What is the presentation of ulnar cubital tunnel syndrome?
Pain and paresthesias in 4th and 5th digits with possible early motor signs
42
Describe surgery for ulnar cubital tunnel decompression
Surgical timeout and confirm correct side Lazy S incision over medial epicondyle and carried 6 cm proximal and distal Decompress nerve at cubital tunnel retinaculum, flexor carpi ulnaris heads, and arcade of struther's Decompression with or without transposition of nerve
43
Besides MRI, what imaging modality can be helpful to evaluate peripheral nerve pathology?
Ultrasound
44
If concerned for a neuroma-in-continuity, how does the nerve action potential help guide what you do?
If there is a potential across the neuroma then it means it is healing then neurolysis alone If there is no potential across the neuroma then may need to excise and cable graft with sural nerve or other types
45
For cable grafting of peripheral nerves, how many 'cables' are often necessary?
Several, especially if going to a large nerve with a relatively small nerve harvested (i.e. sural)
46
Are nascent units on an EMG good or bad? What are they?
Signs of muscle activation/regeneration, generally a good sign when looking at nerve healing
47
Are fibrillations on EMG good or bad? What do they represent?
Bad Denervation
48
What are differences between fasiculations and fibrillations? Are they more associated with UMN or LMN diseases?
LMN diseases Fasiculations are coarse muscle contractions that can be seen in muscles by naked eye Fibrillations are not visually detectable and require an EMG
49
Serratus anterior Function Nerve roots Nerve
Forward shoulder thrust C5-C6 Long thoracic
50
Infraspinatus Function Nerve roots Trunks/Cords Nerve
External humerus rotation C5-C6 Superior trunk Suprascapular nerve
51
Deltoid Function Nerve roots Trunks/Cords Nerve
Abduct arm (30-90 deg) C5-C6 Superior trunk Posterior cord Axillary nerve
52
Biceps brachii Function Nerve roots Trunks/Cords Nerve
Flex forearm (w/ hand supinated) & supinate forearm C5-C6 Superior trunk Lateral cord Musculocutaneous nerve
53
Flexor carpi ulnaris Function Nerve roots Trunks/Cords Nerve
Ulnar flexion of wrist C7-T1 (C8 main) Middle/Inferior Trunk Medial cord Ulnar nerve
54
Flexor digitorum profundus III and IV Function Nerve roots Trunks/Cords Nerve
Flex distal phalanx of digit 4 & 5 C7-T1 (C8 main) Middle/Inferior Trunk Medial Cord Ulnar nerve
55
Interossei Function Nerve roots Trunks/Cords Nerve
Flex proximal phalanx, extend 2 distal phalanges, abduct or adduct fingers C8-T1 (T1 Main) Inferior Trunk Medial Cord Ulnar nerve
56
Pronator teres Function Nerve roots Trunks/Cords Nerve
Forearm pronation C6-C7 Superior, Middle Trunk Lateral cord Median nerve
57
Flexor carpi radialis Function Nerve roots Trunks/Cords Nerve
Radial flexion of wrist C6-C7 Superior, Middle Trunk Lateral Cord Median nerve
58
Flexor digitorum superficialis Function Nerve roots Trunks/Cords Nerve
Flexion middle phalanx dig 2-5, flex wrist C7-T1 (C8 main) Middle and Inferior trunk Medial cord Median nerve
59
Abductor pollicis brevis Function Nerve roots Trunks/Cords Nerve
Abduct thumb metacarpal C8-T1 (T1 main) Inferior trunk Medial cord Median nerve
60
Opponens pollicis Function Nerve roots Trunks/Cords Nerve
Oppose thumb C8-T1 (T1 main) Inferior trunk Medial cord Median nerve
61
Triceps brachii Function Nerve roots Trunks/Cords Nerve
Forearm extension C6-C8 (C7 main) All trunks Posterior cord Radial nerve
62
Brachioradialis Function Nerve roots Trunks/Cords Nerve
Forearm flexion in mid-prone position (thumbs up) C5-C6 (C6 main) Superior trunk Posterior cord Radial nerve
63
Extensor carpi radialis Function Nerve roots Trunks/Cords Nerve
Radial wrist extension C5-C6 (C6 main) Superior/Middle trunk Posterior cord Radial nerve
64
Supinator Function Nerve roots Trunks/Cords Nerve
Forearm supination C6-C7 Superior trunk Posterior cord Radial nerve
65
Extensor digitorum Function Nerve roots Trunks/Cords Nerve
Extension of wrist and phalanxes dig 2-5 C7-C8 (C7 main) Middle/Inferior trunkis Posterior cords Posterior Interosseous nerve (PIN)
66
Abductor pollicis longus Function Nerve roots Trunks/Cords Nerve
Abduction thumb metacarpal and radial wrist extension C7-C8 (C7 main) Middle/Inferior trunkis Posterior cords Posterior Interosseous nerve (PIN)
67
How many different nerves control thumb movement and what are they?
Median N.: abduction, flexion, opposition Radial N.: extension Ulnar N.: adduction
68
Iliopsoas Function Nerve roots Nerve
Hip flexion L1-L3 (L1-2 Major) Femoral
69
70
Quadricep femoris Function Nerve roots Nerve
Knee extension L2-L4 (L3-L4 main) Femoral nerve
71
Adductor longus Function Nerve roots Nerve
Thigh adduction L2-L4 (L2-3 main) Obturator
72
Gluteus medius/minimus Function Nerve roots Nerve
Thigh abduction and medial rotation L4-S1 (L4-L5 main) Superior gluteal nerve
73
Gluteus maximus Function Nerve roots Nerve
Thigh abduction (when prone) L5-S1 Inferior gluteal nerve
74
Hamstrings (biceps femoris, semitendinosus, semimembranosus) Function Nerve roots Nerve
Leg/knee flexion and thigh extension L5-S1 (S1 main) Sciatic
75
Tibialis Anterior Function Nerve roots Nerve
Foot dorsiflexion L5 main Deep peroneal nerve
76
Extensor hallucis longus Function Nerve roots Nerve
Great toe extension L5 main Deep peroneal nerve
77
Posterior tibialis Function Nerve roots Nerve
Inversion & plantar flex supinated foot L4-L5 Tibial nerve *This is why L5 radic causes foot inversion weakness but not eversion*
78
Gastrocnemius Function Nerve roots Nerve
Knee flexion and ankle plantar flex S1 Tibial nerve
79
What is the benefit of a nerve action potential?
Helps distinguish if healing is occurring across a nerve distal to a lesion-in-continuity. If present, surgical intervention is often not needed
80
After ____ months of denervation, even with attempt at reinnervation most muscles will not regain function
24 months
81
Where is the incision placed for a peroneal nerve decompression?
Linear incision, just slightly posterior to fibular head and extending from fibular head to to fibular neck
82
What fascial structures are released in peroneal nerve decompression?
Biceps femoris fascial bands (proximal) Fibular tunnel (over fibular neck; most common) Peroneus longus fascia (distal)
83
Where is the incision located for cubital tunnel syndrome?
Between medial epicondyle and olecranon moving a total of 3 cm proximal and 3 cm distal
84
What fascial structures are decompressed in cubital tunnel surgery?
Arcade of Struthers/Medial intermuscular septum (proximal) Cubital tunnel (aka Osborne's ligament, most significant) Two heads flexor carpi ulnaris
85
Where is the incision located for carpal tunnel surgery?
Between 3rd and 4th digits and in-line just ulnar to the thenar crease. Spanning from base of thumb to upper wrist
86
What band is released in carpal tunnel surgery?
Transverse carpal ligament
87
Before closure of cubital tunnel release, what is a mandatory step prior?
Perform flexion/extension movements to ensure no kinking of nerve
88
What are other conditions in the differential of patients presenting with carpal tunnel syndrome symptoms?
Acromegaly Amyloid Hypothyroidism Pregnancy MPS Diabetes
89
Increased latency in EMG/NCS suggests ...
Demyelination
90
Decreased amplitude in EMG/NCS suggests ...
Loss of axons
91
When you see both median and ulnar nerve palsies you should consider what diagnosis?
Thoracic outlet syndrome or pancoast tumor
92
For a peripheral nerve schwannoma, what stimulation parameters can be used to determine if non-motor origin?
Stimulation at fascicle level at 1-2 mA or using NAP
93
What are intraneural ganglion cysts histoligically and what is treatment?
The cyst is derived from a neighboring articular joint and transmits via the articular branch. The cyst needs to be decompressed and the connection to the joint excised
94
What is a common location of an intraneural ganglion cyst?
Peroneal nerve, lateral to fibular head
95
Sharp, clean peripheral nerve transections should be managed how?
Urgent/emergent operation for tension free repair. Sometimes a hematoma is present If can get high resolution US or MRI to confirm transection that is helpful
96
A supraclavicular brachial plexus approach is used for evaluation of what trunk? What are the basic steps of this approach?
Upper trunk of brachial plexus -Transverse incision in posterior triangle of neck a few fingerbreadths above the clavicle (ends up posterior to SCM) -Mobilize EJ and divide omohyoid -Interscalene triangle b/w anterior and middle scalene is where brachial plexus will be *If need help identifying nerves, the phrenic nerve is on top of the anterior scalene and can be followed to C5
97
Closed injuries, stretch injuries, or GSWs should be surgically evaluated at what time after injury?
3-6 months
98
Thumb movements and nerve supply Opposition Abduction Adduction Flexion Extension
Opposition: Median Abduction: Median Adduction: Ulnar Flexion: Median Extension: Radial
99
What sensory pattern distinguishes cubital tunnel from Guyon's canal compression and why?
Dorso-ulnar sensation to hand because the nerve supplying this branches 6cm proximal to the wrist, thus it will be numb in cubital tunnel but not in Guyon's canal compression.
100
A hand with both thenar and hypothenar wasting may be suggestive of what entrapment?
Neurogenic thoracic outlet syndrome due to cervical rib or elongated TP affecting lower trunk at C8-T1 with both median and ulnar muscles affected. The hand is called Gilliat-Sumner hand
101
Anterior interosseous nerve is a branch of what nerve and causes what weakness?
Median nerve Flexor pollicis longus, Flexor to index/middle fingers, and pronator quadratus
102
Erb's palsy (waiter's tip posture) is often due to what injury?
Upper trunk brachial plexus, more common in borth trauma
103
ABNS Boards
flashcards
Decks in class (10)
# Cards
Brainscape helps you reach your goals faster, through stronger study habits.
© 2026 Bold Learning Solutions. Terms and Conditions