Brachial plexus injuries and its management

Ppt on brachial plexus injury and it’s management

1. BRACHIAL PLEXUS INJURIES

OBJECTIVES

ANATOMY

ETIOLOGY

MECHANISM OF INJURY

CLASSIFICATION Dr. CH ADITYA
CLINICAL FEATURES DNB RESIDENT

INVESTIGATIONS Care hospitals, Hyderabad
MANAGEMENT

3. ANATOMY

it is a network of nerves passing through the cervico-axillary canal
to reach axilla and innervates brachium (upper arm), antebrachium
(forearm) and hand.

Brachial plexus is a somatic nerve plexus formed by the union of
anterior rami of C5,C6,C7,C8 and T1.

The formation of brachial plexus begins just distal to the scalenus
muscles.

Function:

The brachial plexus is responsible for cutaneous and muscular
innervation of the entire upper limb, with two exceptions: the
trapezius muscle innervated by the spinal accessory nerve (CN XI)
and an area of skin near the axilla innervated by the
intercostobrachial nerve.

4. Cords‘, Divisions \ Trunks; Roots

\ \ 1
C5

\\ Dorsal scapular nerve \

Suprascapular nerve
c6
Nerve to subclavius

(oy 4
Lateral pectoral nerve c8
T1

Musc ulocutaneous nerve

Axillary nerve Long thoracic nerve

Upper subscapular nerve

Medial pectoral nerve

Thoraco dorsal nerve
Median nerve
Lower subscapular nerve

Ulnar nerve Radial nerve

Wied culaneous nerve:ct'theSirearm. Medial cutaneous nerve of the arm

5. CLINICAL ANATOMY

The plexus consists of roots, trunks, divisions, cords and
branches.

+ Roots : Lower 4 cervical (C5-8) and the 1st thoracic.

> Situated between the scalenus anterior and medius muscle
deep to sternocleidomastoid muscle.

> The origin of the plexus may shift one segment either upward
or downward resulting in a PRE FIXED PLEXUS or POST FIXED
PLEXUS respectively.

> Ina prefixed plexus, the contribution by C4 is large and in that
from T2 is often absent. In a post fixed plexus, the

contribution by T1 is large, T2 is always present, C4 is absent,
and C5 is reduced in size.

6. Fig. 1. Pre-fixed brachial plexus, indicating the contribution of C4 to the
brachial plexus. (Adapted from Songcharoen P, Shin AY, Hand Surgery.

Ist ed. [Online]. Philadelphia: Lippincott Williams & Wilkins, 2004. http://
www.msdlatinamerica.com/ebooks/HandSurgery/sid744608.html#F3-57
(accessed 14 January 2015).)

7. Fig. 2. Post-fixed brachial plexus, indicating the contribution of T2 from

the brachial plexus, (Adapted from Songcharoen P Shin AY, Hand Surgery.
Ist ed. [Online]. Philadelphia: Lippincott Williams & Wilkins, 2004. http://
www.msdlatinamerica.com/ebooks/HandSurgery/sid744608.html#F3-57
(accessed 14 January 2015).)

8. * Trunks:
> Derived from roots

> Located in the antero-inferior portion of post triangle of
neck

% C5-6 > ant primary rami unite > upper trunk.
% C8-T1 > ant primary rami unite > lower trunk.
% C7-.ant primary rami continues as > middle trunk.

% Each trunk ends by splitting into 1) Ant. 2) Post -
divisions.

9. CORDS: it forms 3 cords

The Posterior Cord is formed from the three posterior
divisions of the trunks (C5-C8,T1)

The Lateral Cord is the anterior divisions from the
upper and middle trunks (C5-C7)

The Medial Cord is simply a continuation of the
anterior division of the lower trunk (C8,T1)

10. y — Post. primary ramus

Dorsal scapular n.

TRUNKS SUPRACLAVIC LAR

Upper
Middle
Lower

NY - E a „=
N N ón ist ons,
e < CORDS n°
Lateral \

ET R ~ \

T ee

TERMINAL NERVES

SS — Axillary n.
Ÿ e
O o
Musculocutaneous

Med. brachial cut. n. N
Med. antebrachial cut. n.

Radial n.

Ulnar n. Median n.

11. + BRANCHES:

+ Branches of the brachial plexus may be described as
supraclavicular and infraclavicular.

Supraclavicular branches

+ Supraclavicular branches arise from roots or from trunks as
follows:

From roots

+ 1. Dorsal scapular nerve C5

+ 2. Long thoracic nerve C5, 6 (7)
From trunks

+ 1. Nerve to subclavius C5, 6

« 2.Suprascapular nerve C5, 6:

12. Infraclavicular branches

¢ branches come from the cords,
Lateral cord

+ Lateral pectoral C5, 6, 7

+ Musculocutaneous C5, 6 7

+ Lateral root of median C(5), 6, 7

Medial cord

+ Medial pectoral C8, T1

+ Medial cutaneous of forearm C8, T1
+ Medial cutaneous of arm C8, T1

+ Ulnar C(7), 8, T1

Posterior cord

+ Upper subscapular C5, 6
Thoracodorsal C6, 7,8
Lower subscapular C5, 6
Axillary C5, 6

Radial C5, 6, 7, 8, (T1)

13. ETIOLOGY

penetrating wounds
Missiles

Stab wounds

Injuries related to birth

Traction applied to the plexus during
falls

Vehicular accidents
Sports activities and
Radiation

14. In most large series, motorcycle accidents are the most common
cause 70%.

In 20% cases a/w rupture of subclavian or axillary artery.
Spinal cord injury is reported in 2% - 5% cases.

COMMON ASSOCIATED INJURIES

Fractures of the proximal humerus

Scapula fractures

Rib fractures

Clavicle fractures

Fracture of the transverse process of cervical vertebrae

Dislocations of the shoulder, acromioclavicular and sternoclavicular
joints

15. Mechanisms of
Injury to the Brachial Plexus

WoUUED > 9865 y BBL © UOHENSTAT

A. Traction: direct blow to the
shoulder with the neck laterally
flexed toward the unaffected
shoulder (gymnast falls on beam)

B. Direct trauma: direct blow to the
supraclavicular fossa over Erb’s point

C. Compression: Occurs when the
neck is flexed laterally toward the
patient’s affected shoulder,
compressing / irritating the nerves,
resulting in point tenderness over
involved vertebrae of affected
nerve(s)

(Troub, 2001)

17. Mechanisms of
Injury to the Brachial Plexus

18. CLASSIFICATION OF BRACHIAL PLEXUS
INJURIES:

* Classification of injuries

+ The various classifications of brachial plexus injury are as follows:
1. Leffert classification of brachial plexus injury

2. Millesi classification of brachial plexus injury
3 . Classification on anatomical location of injury

1. Leffert classification of brachial plexus injury: It is based on mechanism
and level of injury and is as follows

+ 1 Open (usually from stabbing)
+ 11 Closed (usually from motorcycle accident)
+ Ila Supraclavicular

19. — preganglionic:
+ avulsion of nerve roots, usually from high speed injuries
* no proximal stump, no neuroma formation (neg Tinel's)
+ pseudomeningocele, denervation of neck muscles are common
+ horner's sign (ptosis, miosis, anhydrosis)
— postgangionic:
* roots remain intact;
+ usually from traction injuries;
+ there are proximal stump and neuroma formation (pos Tinel's)

+ deep dorsal neck muscles are intact, and pseudomeningoceles will not
develop;

— Ilb Infraclavicular Lesion:
* usually involves branches from the trunks (supraclavicular);
+ function is affected based on trunk involved;

Ill Radiation induced

IV Obstetric

IVa Erb's (upper root)

IVb Klumpke (lower root)

20. 2. Millesi classification of brachial plexus injury: It is mainly divided into 4

I: supraganglionic/preganglionic.
ll: infraganglionic/postganglionic
Il: trunk.
IV: cord.

3. Classification on anatomical location of injury:

Upper plexus palsy (Erb’s palsy in the OBPI cases) involves C5-C6+/-
C7roots.

Lower plexus palsy (Klumpke’s palsy) involves C8-T1 roots (and sometimes
also C7)

Total plexus lesions involve all nerve roots C5-T1

21. Upper brachial
plexus injuries

Lower brachial
plexus injuries

22. ERB'S PARALYSIS:

Site of injury: The region of the upper trunk of the
brachial plexus is called Erb's point. Injury to the upper
trunk causes Erb's Paralysis.

Causes of injury: Undue separation of the head from
the shoulder, which is commonly encountered in
1)birth injury 2) fall on shoulder, and 3)during
anaesthesia

Nerve roots involved: Mainly C5 and partly C6.

Muscles paralysed: Mainly biceps, deltoid, brachilais
and brachioradialis.Partly supraspinatus, infraspinatus
and supinator

23. Deformity

Arm: Hangs by the side, it is adducted and
medially rotated

Forearm: Extended and pronated

Abduction impossible because of paralysis of
deltoid & supraspinatus m/s.

ER impossible because of paralysis of
infraspinatus & teres minor m/s.

24. + Active flexion
impossible because of
paralysis biceps,
brachialis &
brachioradialis.

« Paralysis of supinator
m/s causes pronation
deformity of forearm.

+ The deformity is known
as "Policeman's tip
hand" or "Porter's tip
hand".

(a) Erb-Duchenne palsy
(waiter's tip)
Copyright © 2005 John Wiley & Sons. Inc. All rights reserved.

25. Upper Brachial Plexus Injury:

+ Appearance: drooping, wasted shoulder; pronated
and extended limb hangs limply (“waiter’s tip palsy”)
+ Loss of innervation to abductors, flexors,& medial
rotators of shoulder and flexors & supinators of
elbow

+ Loss of sensation to lateral aspect of upper
extremity

+ More common; better prognosis

From Bayne & Costas (1990)

GY

From Netter 1997

26. KLUMPKE’S PALSY

Site of injury: Lower trunk of the brachial plexus.

Cause of injury: Undue abduction of the arm, as in clutching
something with the hand after a fall from a height, or sometimes in
birth injury.

Nerve roots involved: Mainly T1 and partly C8.

Muscles paralysed:

Intrinsic muscles of the hand (T1)

Ulnar flexors of the wrist and fingers (C8).

Deformity: (position of the hand): claw hand due to the unopposed
action of the long flexors and extensors of the fingers. in a claw
hand there is hyperextension at the metacarpophalangeal joints
and flexion at the interphalangeal joints.

27. Disability:

Claw hand

Cutaneous anaesthesia and analgesia in a narrow zone along the
ulnar border of the forearm and hand.

Horner's syndrome: ptosis, miosis, anhydrosis, enophthalmos and
loss of ciliospinal reflex- may be associated. This is because of
injury to sympathetic fibres to the head and neck that leave the
spinal cord through nerve T1.

Vasomotor changes: The skin areas with sensory loss is warmer due
to arteriolar dilation. skin is dry due to the absence of sweating as
there is loss of sympathetic activity.

Tropic changes: Long standing case of paralysis leads to dry and
scaly skin.The nails crack easily with atrophy of the pulp of fingers.

28. Lower Brachial Plexus Injury: Klumpke’s Palsy

+ Much rarer than UBPIs and Erb’s Palsy

+ Loss of C8 & T1 results in major motor deficits in
the muscles working the hand: “claw hand”

+ Loss of sensation to medial aspect of upper
extremity

+ Sometimes ptosis or full Horner's syndrome

+ Much rarer (1%) but much poorer prognosis

Anterior view

From Moore & Dalley (1999)

ca

sE

From Netter 1997

29. 4 Normal

—
Intact sensory neuron

Neuron destroyed

Axon disrupted

Intraneural disruption

2 Infraganglionic
injuries
distinguishable
only by
3 exploration
4
Supraganglionic
5 injuries: no
recovery
possible —
6

Possible
2 recovery

Impossible
recovery

Myelographic
appearances

Recent injury with
intrathecal effusion

Rent in dura sealed
off; no meningocele

Traumatic

meningocele

7 Cord distorted by
band tethering it
to meningocele
(Penfield)

Types of Injuries sustained by roots of brachial plexus. (Spinal cord Is viewed from posterior.) Left, Types of Injuries
and prognosis in each at postganglionic (infraganglionic) and preganglionic (supraganglionic) levels. Right, Myelographic appearances
for various injuries. 1, Normal nerve root. 2, Injury in continuity distal to posterior root ganglion. All axons degenerate; axon reflex

30. Clinical features :
History :
> The mechanism of injury should be considered.
> Birth injury : Usually 5th and 6th root.
> Motor cycle accidents.
> Stab and bullet wounds.

Symptoms vary depending upon the type and
location of the injury to the brachial plexus.

The most common symptoms of BPI include:
-Weakness or numbness

-Loss of sensation

-Loss of movement (paralysis)

-Pain

31. CLINICAL FEATURES

+ The pain from brachial plexus injuries results
from injury to the spinal cord where the nerve
rootlets are avulsed from the cord. This pain is
neuropathic in nature. The pain can last for a very
long time.

* Brachial plexus injuries that occur at the level of
the spinal cord often produce greater pain than
injuries more distant from the spinal cord.

* In addition, injuries nearer the spinal cord may
cause a burning numbness, which is called
paresthesias or dysesthesias.

32. Physical examination :

Examination of all nerve groups controlled by the brachial

plexus to identify the specific location of the nerve injury and its

severity.

In addition, some patients display specific signs that help

determine the location of the nerve injury:

U Narrowing of the eye pupils, drooping of the eyelid, and lack

of ability for the face to sweat (Horner's syndrome) is a sign

that the injury is close to the spinal cord.

U A shooting nerve-like pain on taping along the affected
nerves (Tinel sign) suggests an injury farther from the spinal
cord. Over time, if the location of the Tinel sign moves down
the arm toward the hand, it is a sign that the injury is
repairing itself.

During the physical examination, assess the arm and shoulder

for stability and range of motion

33. INVESTIGATIONS

Imaging Studies

Electromyogram

Nerve Conduction Velocity
Intraoperative Nerve Action Potential
Myelography

CT scan for any tumours

MRI

34. Imaging studies :

X-ray of cervical spine :

“+ Fracture of lateral masses of cervical vertebrae are
strongly associated with pre-ganglionic injuries.

Chest x-ray :

« May show ‘st and 2nd rib fracture or an elevated
hemidiaphragm, which denotes phrenic nerve
paralysis and proximal injury to upper plexus.

“+ Fractures of scapula and clavicle and Humerus may
indicate infraclavicular plexus injuries.

35. INVESTIGATIONS

EMG :

< Most important use of EMG studies is for serial evaluation
of injury to search for signs of re innervation.

+ A decreased in number of fibrillation potentials and positive
sharp potentials > typically seen in dennervated
muscles > regenerating axons have reached the motor
end plates.

+ The appearance of prolonged, polyphasic and low-amp
indicated > re-innervation.

+ Seen several weeks before the onset of voluntary muscle
contraction and signify that a further period of
observation is in order.

36. : Fibrillati
Positive sharp waves Rein

38. Proximal stimulation
Site of injury
Distal stimulation

Recording electrode

; —_ Le. [immediately after injury] Ten days after injury
hier fone eee distal simulation distal stimulation
pee (Segment B} (Segment 8)

ie | + 4—
Ny ome

Mosby, Inc. items and derived items copyright © 2003, Mosby, Inc. All rights reserved.

Neuropraxia

Axonotmesis
or
Neurotmesis

39. Intra operative nerve action potential (NAP) :
+ This study is performed during surgical exploration of the
plexus, which is usually done 3-4 months after injury.

“+ If a nerve action potential can be recorded.

“Substantial number of regenerating axons have
traversed the lesion site.

+ Conversely if an action potential cannot be elicited > the
abnormal segment is resected because spontaneous
recovery is likely to be poor.

+ NAP is best for evaluating a neuroma in continuity. If an
NAP can be transmitted across the area of injury, the
patient has 93% chance of useful motor function
will develop in the muscles supplied by that nerve.

40. Direct
Intraoperative
nerve stimulation

No nerve action Nerve action
potentials are potentials are
recorded obtained

Excision and Simple neurolysis
nerve grafting is indicated

41. CT Myelography :

+ If plexus injury is strongly suspected a myelogram and
subsequent CT scan should be obtained 2-3 months
after injury.

“It may be inaccurate early after the injury because clotted

blood may occlude the opening into the pseudomeningocele.

A delay of 6-12 weeks is recommended before myelogram is

advised.

Advantages:

-detect partial root avulsion

-excellent visualization of bony structures

-no CSF flow artifacts and

-multiplanar reconstruction.

Disadvantages:

- high radiation dose

-poor visualization of lower brachial plexus
due to bony artifacts.

43. owec Dy comput

Fig 2. Cervical myelography fc
scanning showing a large pseudomeningocele (PI

omography

44. CT myelogram showing a normal brachial plexus (left) and injured brachial plexus
(right)

45. Nagano et al. classified myelographic findings into six
types; N, A1, A2, A3, D, and M.
N is a normal shadow;

Al is a slightly abnormal root sleeve shadow in which
shadows of roots and rootlets can be recognized but
appear different from those on the unaffected side;

A2 is obliteration of the tip of the root sleeve with the
shadows of roots or rootlets visible;

A3 is obliteration of the tip of the root sleeve with no
shadows of roots or rootlets visible;

D is a defect instead of a root sleeve shadow; and
M is a traumatic meningocele.

46. N is the sign of normality or a postganglionic
lesion.

A1 is observed in either a preganglionic or a
postganglionic lesion; thus, detailed evaluation
with CT myelography is necessary for this kind of
finding.

A2, A3, D, and M are indicative of a preganglionic
lesion.

A traumatic meningocele is a valuable sign of a
preganglionic lesion, although it is not
pathognomonic.

47. CONVENTIONAL MRI

+ MRI provides additional anatomic and
physiologic information on injuries.

1. Signal intensity changes in the spinal cord
2. Enhancement of nerve roots and
3. Enhancement of paraspinal muscles

48. 1. Signal intensity changes in the spinal cord

+ Hyperintense areas on T2-weighted images
suggest edema in the acute phase and
myelomalacia in the chronic phase.

+ Hypointense lesions on T2-weighted images
reflect hemosiderin deposition on account of
hemorrhage .

49. 2. Enhancement of nerve roots

+ Enhancement of intradural nerve roots and
root stumps suggests functional impairment
of nerve roots despite morphologic continuity

« Breakdown of the blood-nerve barrier and
dilatation of radicular veins are postulated as
the mechanisms of intradural nerve root
enhancement.

50. 3. Enhancement of paraspinal muscles

Abnormal enhancement of paraspinal muscles is
an accurate indirect sign of root avulsion injury.
Denervated muscles show enhancement as early
as 24 hours after a nerve is injured.

The presumed mechanisms for muscle
enhancement are

. dilatation of the vascular bed and
. enlargement of the extracellular space.