Traumatic Brachial Plexus Injuries

Front 1

Most common mechanism of injury to brachial plexus in trauma?

Back 1

traction injuries, in which the head and neck are moved away violently from the ipsilateral shoulder

Front 2

what is the Narakas rule of "seven seventies "?

Back 2

*
Approximately 70% were motor vehicle accidents (MVAs).
*
Of the MVAs, 70% were motorcycles or bicycles.
*
Of the cycle riders, 70% had multiple injuries.
*
Of the multiple injuries in cycle riders, 70% were supraclavicular injuries.
*
Of the supraclavicular injuries, 70% had at least one root avulsed.
*
Of the avulsed roots, 70% were lower C7, C8, T1.
*
Of the 70% avulsed roots, 70% of those were associated with chronic pain.

Front 3

What is most the crucial prognostic factor?

Back 3

whether the injury is proximal (preganglionic) or distal (postganglionic) to the dorsal root ganglion. A preganglionic root avulsion means that the cell bodies of the sensory nerves are pulled from the cord, whereas postganglionic stretch injuries with cell bodies still in continuity with their axons

Front 4

A lower plexus lesion (C8-T1) predominates when the arm is _____

Back 4

raised / abducted

Front 5

where are preganglionic lesions located?

Back 5

lesions proximal to the dorsal root ganglion, (which is in the spinal canal, and foramen) may be central, at the spinal cord or intradural.

Front 6

Do preganglionic lesions cause wallerian degeneration or neuroma formation?

Back 6

No. Preganglionic lesions do not cause wallerian degeneration or neuroma formation because the axons remain in continuity with the cell bodies in the dorsal root ganglion.

Front 7

where are the postganglionic lesions located?

Back 7

any lesions distal to the spinal ganglion, which are physiologically similar to other peripheral nerve injuries.

Front 8

What do you look for on history?

Back 8

mechanism of injury- possible shoulder girdle injuries, esp MVA
symptoms:
*Pain, esp.neck/ shoulder. Pain over a nerve is common with rupture, as opposed to lack of percussion tenderness with avulsion
*Paresthesias and dysesthesias
*Weakness in the extremity
*Diminished pulses/ vascular injury

Front 9

Physical examination?

Back 9

Standard ATLS protocol
Abrasions to the head, helmet, or tip of the shoulder suggest supraclavicular injury; Horner syndrome suggest a complete lower plexus lesion

Front 10

What are the signs for Horners Syndrome?

Back 10

Ptosis (lid droop), enophthalmos (sinking of the eye into the orbit), anhydrosis (dry eye), and miosis (small pupil)

Front 11

Why does Horners syndrome suggest a lower plexus injury?

Back 11

because the sympathic ganglion for T1 is in close proximity to the lower brachial plexus

Front 12

Diminished or absent pulses suggests?

Back 12

vascular injury, esp. rupture of the subclavian vessels

Front 13

Other things to check for?

Back 13

-swelling about the shoulder
-clavicle fractures may be palpable
-inspection/palpation of the axial skeleton for injuries
-examine each cervical root individually for motor and sensory function,

Front 14

What is the only clue to continuity in a nerve with no motor function or other sensation?

Back 14

Deep pressure sensation. Apply full pinch to the nail base and pull the patient's finger outward. Any burning suggests continuity of the tested nerve. When no burning is elicited, these examination findings are less helpful because a neuropraxia can persist for more than 6 months.

Front 15

Thumb: what is the affected Spinal Nerve, peripheral nerve, and affected cord?

Back 15

C6 spinal nerve; Median nerve; Lateral cord

Front 16

Middle finger. what is the affected Spinal Nerve, peripheral nerve, and affected cord?

Back 16

C7. Median nerve. Lateral cord

Front 17

Little finger. what is the affected Spinal Nerve, peripheral nerve, and affected cord?

Back 17

C8. Ulnar nerve. Medial cord

Front 18

What is a "prefixed cord"?

Back 18

When C4 makes a significant contribution to the plexus, occuring in 60% of people. A prefixed cord can explain recovery in the distribution of a nerve root clinically presumed to be avulsed.

Front 19

assessment of motor function & affected spinal nerves?

Back 19

C5 Shoulder abd, extn, ext rot; some elbow flexion (e.g biceps = flex elbow)
C6 Elbow flexion, forearm pronation and supination, some wrist extension (e.g. wrist ext. = cock up wrist)
C7 Diffuse loss of function in the extremity without complete paralysis of a specific muscle group, elbow extension, consistently supplies the latissimus dorsi (e.g. triceps = extend elbow)
C8 Finger extensors, finger flexors, wrist flexors, hand intrinsics (e.g. Fl. dig. profundus = flex middle distal phalanx)
T1 Hand intrinsics =abduct little finger

Hint 19

For lower limb: L2 flex hip (iliopsoas); L3 flex hip (quadriceps); L4 dorsiflex foot (tibialis anterior); L5 dorsiflex big toe (EHL); S1 plantarflex foot (gastrocnemius)

Front 20

Ix?

Back 20

Xray C spine, CXR, consider CT, EMG, NCS

Front 21

Mx?

Back 21

multidisciplinary - surgeon, OT, physio

Front 22

Prognosis & followup?

Back 22

recovery is slow process requiring significant patient and family education and involvement. Follow-up should be prolonged, as neural recovery time is lengthy, with a regeneration rate of 1 mm per day. Physical therapy and bracing often are used over the prolonged postoperative period to prevent contractures, to keep joints supple, and to reinforce the need for patience

Front 23

complications?

Back 23

Contractures
Deafferentation pain - severe burning