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EMG pathology Flashcards

1
Q

____ is a pathologic process affecting the nerves at a root level.

A

Radiculopathy

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2
Q

Radiculopathy most commonly presents as: (3, in descending order)

A
  1. pure sensory complaints
  2. sensorimotor
  3. pure motor complaints

(this is due to the larger size of sensory fibers, rendering them more prone to injury)

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3
Q

Most common cause of radiculopathy?

  1. in adults <50yoa?
  2. in adults >50yoa?
A
  1. Herniated nucleus pulposis
  2. Spinal Stensosis
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4
Q

Name the 7 uncommon causes of radiculopathy:

A

“Hi Madam”

H - herpes zoster

I - inflammatory (TB, Lyme disease, HIV, syphilis, cryptococcus, and sarcoidosis)

M - Metastasis

A - Arachnoiditis

D - DM

A- Abscess

M - Mass: meningioma, neurofibroma, leukemia, lipoma, cyst, hematoma

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5
Q

Clinical presentation of Radiculopathy: Name 1. reflex reduced 2. Weakness 3. Numbness/parasthesia

C5

A

Reduced reflex: Biceps brachii

Weakness: Elbow flexion

Numbness/parasthesia: Lateral arm

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6
Q

Clinical presentation of Radiculopathy: Name 1. reflex reduced 2. Weakness 3. Numbness/parasthesia

C6

A

Reduced Reflex: Brachioradialis

Weakness: Elbow Flexion

Numbness/Parasthesis: Lateral forearm

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7
Q

Clinical presentation of Radiculopathy: Name 1. reflex reduced 2. Weakness 3. Numbness/parasthesia

C7

A
  1. reduced reflex: Triceps brachii
  2. Weakness: elbow extension
  3. Numbness/parasthesias: middle finger
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8
Q

Clinical presentation of Radiculopathy: Name 1. reflex reduced 2. Weakness 3. Numbness/parasthesia

C8

A
  1. Reduced reflex: none
  2. Weakness Finger flexion
  3. Numbness/parasthesias: Medial forearm
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9
Q

Clinical presentation of Radiculopathy: Name 1. reflex reduced 2. Weakness 3. Numbness/parasthesia

T1

A

Reduced reflex: none

Weakness: Finger adduction

Numbness/parasthesia: medial elbow

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10
Q

Clinical presentation of Radiculopathy: Name 1. reflex reduced 2. Weakness 3. Numbness/parasthesia

L4

A

Reflex reduced: patella tendon

Weakness: knee extension

Numbness/Parasthesias: Medial ankle

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11
Q

Clinical presentation of Radiculopathy: Name 1. reflex reduced 2. Weakness 3. Numbness/parasthesia

L5

A

Reduced reflex: Lateral hamstring

Weakness: Hall extension

Numbness/parasthesias: Dorsal foot

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12
Q

Clinical presentation of Radiculopathy: Name 1. reflex reduced 2. Weakness 3. Numbness/parasthesia

S1

A

Reduced reflex: Achilles tendon

Weakness: plantar flexion

Numbness/parasthesias: Lateral ankle.

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13
Q

In Radiculopathies:

SNAP:

CMAP:

A

SNAP: normal if lesion is located proximal to dorsal root ganglgion

CMAP: normal or reduced amplitude. This lesion is distal to the motor neuron cell body. It can be normal if the injury is purely demyelinating, incomplete, or reinnervation has occurred.

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14
Q

C2-3 C3-4 radiculopathy is a ____ diagnosis

A

clinical

No discrete myotomal patterns

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15
Q

C3 and C4

C2/3, C3/4 HNP

radiculopathy:

  1. Innervates:
  2. Patient may complain of:
  3. C2 and C3 nerve becomes:
A
  1. posterior and lateral scalp
  2. headaches
  3. greater and lesser occipital nerve
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16
Q

C5 (C4-5 HNP) myotome: 9

A

Rhomboids

Deltoid (5/6)

Biceps (5/6)

Supraspinatus (5/6)

Infraspinatus (5/6)

Brachialis (5 only)

BR (5/6)

Supinator (5/6)

Paraspinals (5-8)

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17
Q

C6 (C5-6 HNP) myotome: 10

A

Deltoid (5/6)

Biceps (5/6)

BR (5/6)

Supraspinatus (5/6)

Infraspinatus (5/6)

Supinator (5/6)

PT (6/7)

FCR (6/7)

EDC (6/7)

Paraspinals (5-8)

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18
Q

C7

C6-7 HNP

Myotome: 5

A

PT (6/7)

FCR (6/7)

EDC (6/7)

Triceps (7/8)

Paraspinals (5-8)

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19
Q

C8

C7-T1 HNP

Myotome: 8

A

Triceps (7/8)

FCU

FDP

ADM

FDI

PQ

APB

Paraspinals

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20
Q

L2/3/4 roots

L1/2, L2/3, L3/4 HNP

Myotome: 7

A

Iliopsoas

Iliacus

Gracilis

adductor longus

vastus medialis

TA

paraspinals (all)

Difficult to distiguish between radiculopathy and alternate lesions due to only two peripheral nerves

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21
Q

Root: L5

Posterolateral L4/5 HNP

Myotome: 9

A

gluteus maximus

gluteus medius

TFL

TA (2-5)

medial hamstring

TP

PL

Paraspinals

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22
Q

Root: S1

Posterolateral L5/S1 HNP

Myotome: 8

A

gluteus maximus (L5/S1)

gluteus medius (L5/S1)

TFL (L5/S1)

MG (L5/S1)

Medial hamstring(L5/S1)

PL (L5/S1)

TP (L5/S1)

Paraspinals

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23
Q

Root: S2/3/4

Etiology: iatrogenic, cauda equina, spinal stenosis

Myotome: 2

needle exam of:

Other reflexes: 4

A

Myotome: Abductor Hallucis, ADQ

Needle exam: external anal sphincter

Reflexes: bulbocavernosus reflex, anal wink, external sphincter tone, bowel and bladder function

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24
Q

Name the 8 dual innervated muscles and their innervation.

A
  1. Pectoralis major: Medial pectoral, lateral pectoral n
  2. Brachialis: musculocutaneous n, radial n
  3. FDP: Median n (AIN), Ulnar
  4. Lumbricals: Median, ulnar
  5. Flexor pollicis brevis: median, ulnar
  6. Pectineus: Femoral Nerve, Obturator Nerve
  7. Adductor magnus: Sciatic (tibial portion), Obturator
  8. Biceps femoris: Sciatic (tibial portion), Sciatic (peroneal)
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25
Q

Chronology of findings: radiculopathy:

O days: 4

4 days:

1 week:

2 weeks:

3 weeks:

5-6 weeks:

6months-1yr:

A

0 days: decreased recruitment, decreased recruitment interval, prolonged F-wave, Abnormal H-reflex (S1 radiculopathy)

4 days: Decreased CMAP amplitude (~50% compared to opposite side)

1 week: abnormal spontaneous activity if occurs first in the paraspinals. They can be normal if they become reinnervated or if the posterior prinary rami are spared (they can be the only abnormal finding 10-30% of the time)

2 weeks: abnormal spontaneous activity beginning in the limbs

3 weeks: abnormal activity present in paraspinals and limbs

5-6 weeks: reinnervation

6months-1yr: increased amplitude from reinnervated motor unit.

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26
Q

_____ is the pathologic process typically occurring distal to the DRG and proximal to the peripheral nerves. Abnormalities can appear diffuse and will not follow any particular dermatomal or myotomal distribution.

A

plexopathy

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27
Q

3 etiologies of plexopathy

A
  1. trauma (traction, transection, obstetrical injuries, compression, hemorrhage)
  2. cancer (tumor, radiation therapy)
  3. idiopathic (neuralgic amyotrophy)
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28
Q

Electrodiagnostic findings of plexopathy:

  1. NCS:

2 Late Response: (a) F-wave (b) H-reflex

  1. EMG:
A
  1. NCS - abnormal SNAPs and CMAPs corresponding to the site of plexus injury. Can have specific injury patterns.
  2. Late response: both possibly useful
  3. Abnormal activity in the peripheral muscles in distribution of nerve injury but with normal paraspinal activity
29
Q

Draw the brachial plexus

30
Q

Erbs palsy/upper truck bracial plexopathy/”stinger”

  1. INvolves:
  2. Etology (3)
  3. Clinical presentation:
A
  1. C5/6 nerve roots or the upper trunk
  2. :
    a. nerve traction/compression from an obstetrical injury
    b. sports related (stinger)

c involves C5-C6 n roots or upper trunk

  1. Waiter’s tip position. Arm is adducted (deltoid/supraspinatus weakness), internally rotated (teres minor and infraspinatus), extended (bicep and brachioradialis weakness), pronated (supinator and brachioradialis weakness), with wrist flexed (extensor carpi radialis longus and brevis weakness)

Has anesthesia of anterior portion of arm.

31
Q

Electrodiagnosis pearl for erbs palsy/upper truck brachial plexopathy/”stinger” - how to access erbs point

A

Stimulate at the tip of the C6 transverse process over the trunks of the brachial plexus ot assess erb’s point.

32
Q

treatment of erbs palsy, upper trunk brachial plexopathy, “stinger”

A

1 rehab

  1. intermittent splinting
  2. activity restriction
33
Q

Klumpki palsy

AKA:

Involves:

etiology:

Presents:

A
  1. lower trunk brachial plexopathy
  2. C8/T1 nerve roots or lower trunk
  3. obstetrical traction injury
  4. wasting of the small hand muscles and claw hand deformity (lumbrical weakness). Shoulder girdle muscle function is preserved
34
Q

musculocutaneous by nerve root

A

C5-6 biceps/brachialis

C5/6/7 coracobrachialis

35
Q

axillary muscles per nerve root

A

C5/6 deltoid, teres minor

36
Q

radial nerve muscles per nerve root

A

C5/6 - supinator

C5/6/7 - brachioradialis

C6/7/8 - ECR longus, Triceps

C7/8 - ECR breavis, Extensor digitorum, EIP, EDM, ECU, abd poll longus, ext poll brevis, ext poll longus

C7/8/T1 - anconeus

37
Q

Median nerve muscles by root

A

C6/7 - pronator teres, FCR

C7/8 - Palmaris longus

C7/8/T1 FDS 4 muscles

C8/T1 - FDP (2 muscles), FPL, pronator quadratus, lumbricals (2 muscles), opponens pollicis brevis, flexor pollicis brevis 1/2

38
Q

ulnar nerve muscles by root

A

C7/8 - FCU

C8/T1 - FDP (2 muscles), Dorsal interossei (4 muscles), palmar interossei (3 muscles), lumbricals (2 muscles) adductor pollicus (1 muscle), flexor pollicus brevis (1/2 muscle), hypothenar muscles (opponen digiti minimi, abductor digiti minimi, flexor digit minimi), palmaris brevis

39
Q

VASCULAR Thoracic outlet syndrome

  1. Affects:
  2. etiology:
  3. Clinical presentation
A
  1. subclavian artery, subclavian vein, axillary vein
  2. pathology results from arterial or venous compromise
  3. arterial involvement: limb ischemia, necrosis, vague pain, fatigue, wiht decreased color or temp. Vein: bluish swollen achy limb
40
Q

NEUROGENIC thoracic outlet syndrome

  1. involves:
  2. etiology
  3. presentation
A
  1. rare, may actually be seen in only 1 of 1 million patients
  2. compression of lower trunk of brachial plexus between a fibrous band, between the first cervical rib and clavical (costoclavicular syndrome), muscular entrapment by the scalenes (anterior and middle scalene syndromes) or pectoralis minor muscles (pectoralis minor syndrome)
  3. pain and numbness along the medial aspect of the forearm and hand which increases with overhead activity.

Hand muscle wasting may also be noted (median thenar > ulnar intrinsics).

41
Q

What is Adsons test?

A

a maneuver to assess the neurovascular bundle

performed by abduction, extending and externally rotating the patient’s arm. While monitoring the radial pulse, have the patient rotate the head toward the arm (side of the lesion). A decrease or loss of pulse may be releated to compression of teh subclavian arter, indicating compromise to the complex.

42
Q

In Klumpke’s palsy, preservation of SNAP potential may indicate: ______.

These may be associated with this injury specifically due to lack of protective support at C8 and T1 roots.

A

nerve root avulsion

43
Q

In Klumpkes palsy _____ sensory response will be reduced or absent

A

medial antibrachial cutaneous sensory response

44
Q

for thoracic outlet syndrome:

  1. Median CMAP
  2. Ulnar SNAP/CMAP
  3. medial antebrachial cutaneous studies
  4. Median SNAP
  5. spontaneous activity over median and ulnar hand muscles (C8-T1 myotomes)
A
  1. decreased amplitude
  2. same
  3. Same
  4. spared
  5. abnormal
45
Q

treatment of thoracic outlet syndrome

  1. Rehab focuses on:
  2. surgery?
A
  1. ROM

stretching of appropriate muscles (anterior/middle scalenes, pectoralis minor, trapezius and levator scapulae)

strengthening of scapular stabilizers (upper/middle trapezius and rhomboids)

postural mechanics to address possible entrapment syndromes against the 1st rib

  1. can be indicated for 1st rib or fibrous band resection
46
Q

____ is an injury which can include varius nerves of the brachial plexus.

Other names?

A

Neuralgic Amyotrophy

Parsonage-Turner syndrome, brachial neuritis, brachial neuropathy, idiopathic brachial plexopathy, shoulder-girdle neuritis, paralytic brachial neuritis

47
Q

etiology of neuralgic amyotrophy?

48
Q

presentation of neuralgic amyotrophy

exacerbated by:

recovery can take

A

patient may complain of acute onset symptoms of intense pain and weakness at or about the shoulder girdle region. IT can be exacerbated by abduction and rotation. Two-thirds may present bilaterally with recovery taking up to 2-3 years

49
Q

treatment of neuralgic amyotrophy?

A

rehab to prevent contractures. It can resolve spontaneously (up to 2-3 years in bilateral cases)

50
Q

A primary plexus tumor can arise from: (3)

a secondary plexus tumor can arise from

______ can cause neural fibrosis and constrictio of the vasa nervorum, leading ot destruction of the axon and Schwann cells.

A
  1. schwannomas, neuromas, neurofibromas
  2. pancoast tumor from lung or breast
  3. radiation therapy - can occur months or years postradiation treatment

causing plexopathy

51
Q

Neoplastic vs radiation plexopathy:

  1. Radiation
  2. tumor
    - site of injury
    - clinical presentation
    - sensation
A
  1. radiation - upper trunk, myokymia, painless
  2. lower trunk, horner’s syndrome, painful
52
Q

____ nerve roots are most common site of tearing fromthe spinal cord attachments (nerve root avulsion)

A

C8 and T1 - less protection

53
Q

____ presents as patient complaints of absent sensation or muscle contraction from the muscles innervated by roots involved. May manifest as flail shoulder

A

nerve root avulsion

54
Q

Nerve root avulsion

  1. CMAP
  2. SNAP
  3. needle emg:
A
  1. absent
  2. normal
  3. absent recruitment and abnormal sponatneous activity in myotomic distribution, including paraspinals
55
Q

Nerve fibers from the ______ roots form the lumbar plexus.

Nerve fibers from the _____ roots form the sacral plexus.

A

L1, L2, L3, and L4

L4, L5, S1, S2, S3, and S4 roots

56
Q

Lumbar plexus:

  • anterior division
  • posterior division

Sacral plexus:

  • Anterior division
  • posterior division
A

Lumbar plexus:

A: Obturator N

P: Femoral N and lateral femoral cutaneous n

Sacral plexus:

A: Tibial N

P: Common peroneal N

57
Q

5 methods of obtaining lumbosacral plexopathy

A
  1. neuralgic amotyrophy - similar to brachial plexus pathology
  2. neoplastic vs radiation plexopathy - similar to brach
  3. Retroperitoneal bleed - hematoma formation in psoas muscle
  4. hip dislocation
  5. obstetric injuries/cephalopaelvic disproportion - presents as postpartum foot drop
58
Q

EDX - lumbar plexus abnormality:

  1. SNAP:
  2. CMAP:
  3. EMG:

sacral plexus abnormaltiy:

  1. SNAP:
  2. CMAP:
  3. EMG:
A

Lumbar

  1. saphenous or lateral femoral cutaneous
  2. femoral innervated muscles
  3. femoral, obturator, iliopsoas (paraspinals)

Sacral:

  1. sural
  2. Tibial, peroneal innervated muscles
  3. peroneal, tibial, gluteal (paraspinals)
59
Q

Femoral nerve muscles by root (L1-4)

A

L2/3 - sartorius, iliacus, pectinius

L2/3/4 - quadriceps femoris (vastus medialis, intermedius, lateralis, rectus femoris

60
Q

nerve roots for lateral femoral cutaneous n

61
Q

Superior gluteal nerve muscles by root

A

L4/5 - TFL

L4/L5/S1 - gluteus medius, gluteus minimus

62
Q

Inferior gluteal nerve muscles by root

A

L5/S1/2 - gluteus maximus

63
Q

Obturator nerve muscles by root

A

L2/3 Pectinius - may receive a branch from the obturator n; gracilis

L3/4 obturator externus

L2/3/4 - adductor brevis, longus

Adductor magnus

64
Q

Sciatic Nerve divisions with muscles and nerve root

A
  1. peroneal division

Biceps femoris (short head L5/S1S2)

  1. Tibial division

L5/S1/S2 - semimembranosus, semitendinosus, biceps femoris (long head)

L4 - adductor magnus (shares with obturator)

65
Q

Common peroneal nerve with muscles per root

A

Deep peroneal nerve

  • L4/L5: Tib Ant
  • L4/S1: Extensor digitorum longus, extensor hallucis longus, peroneus tertius, ED

Superficial peroneal nerve

  • L5/S1 - peroneus longus, peroneus brevis
66
Q

Tibial nerve muscles per root:

Not including posterior tib, medial plantar n, or lateral plantar n

A

L4/5/S1 - popliteus

S1/S2 Gastrocnemius (medial and lateral heads), plantaris, soleus

67
Q

Posterior tibial nerve muscles with roots

A
  1. Posterior tibial nerve:

L4/5 - tibialis posterior (four digits)

S2/3 - Flexor digitorum longus, flexor hallicus longus

  1. Medial plantar nerve

S2/3 - flexor digitorum brevis, abductor hallucis, flexor hallucis brevis, first lumbrical

  1. Lateral plantar nerve

S2/S3 - abductor digiti minimi, quadratus plantae, flexor digit minimi brevis, 2-4 lumbricals (3 muscles), dorsal interossei (four muscles), plantar interossei (3 muscles), adductor hallucis

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