Download Nerves injuries

Nerves injuries
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The nerves injuries represent revision to all nerves of the upper limbs .
Then we will review the nerves and talk about nerves injuries and their results .
Brachial plexus injuries :
- We remember that the brachial plexus has roots , trunks , divisions and cords
- The roots locate between two muscles : anterior scalene and middle scalene
- The trunks locate in the posterior triangle of the neck
- the posterior triangle neck is a liable place for stab wounds )‫(جروح ناتجة من الطعنات‬
If two people start to fight and somebody stab the other by knife , then the trunks of Br. Plexus may be injured .
- The trunks : upper , lower and middle
- The upper and lower trunks are more liable to injuries than the middle trunk .
- The upper and lower trunks may be injured in delivery .. especially when the arms of the baby get out
firstly and the doctor pull the arms outward … and because the arms of the baby are soft and the nerves
are newly composed , then there is a fraction happened in the upper limbs … maybe in the upper trunk or
in the lower trunk and that is one of the injuries that happened in delivery .
- The cords are located in the axilla : lateral , medial and posterior cords .
- The lateral cord consist of the unite of the anterior divisions of the upper and middle trunks
- The medial cord consist of the continuation of the anterior division of the lower trunk
- The posterior division consist of the unite of the posterior divisions of the all trunks .
The lesion may injure the roots or individual nerves divided by stab wounds
Now , let’s talk about some common injuries in the nerves :
1. Upper Lesions of the Brachial Plexus(Erb-Duchenne Palsy) , which means the
lesion of the upper trunk (C5 , C6)
The upper trunk gives : suprascapular nerve and nerve to subclavius ( here the doctor make a mistake and said
subscapular nerve instead of nerve to subclavius )
The axillary nerve come from C5 and C6
- Erb-Duchenne Palsy : the discoverer of the upper trunk lesion
- Upper lesions of the brachial plexus are injuries resulting from excessive displacement of the head to the
opposite side and depression of the shoulder on the same side
- Note : the divisions of the br .plexus locate behind the clavicle
- This causes excessive traction or even tearing of C5 and 6 roots of the plexus
- Tearing = injury
- It occurs in infants during a difficult delivery or in adults after a blow to or fall on the shoulder.
- All of the above are reasons for the upper trunk lesion and in some books its called : Erb-Duchenne
syndrome
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What are the nerves which will be injured in this lesion ??
Suprascapular nerve ( supplies (supra and infra)spinatus muscles )
Nerve to subclavius ( supplies subclavius muscle)
Musclocutenous nerve : (C5 and C6 ) from the lateral cord (supplies the biceps , coracobrchialis and the
medial half of brachialis muscles )
Thus the functions of all precedent muscle will be affected and there will be a lose of function in each one .
4. Axillary nerve from the posterior cord ( C5 and C6 ) also involved in injury , after travel from the axilla It
pass throw the Quadrangular Space and supplies the deltoid and teres minor muscles and give cutaneous
branches to the skin over the deltoid ..
Then when we talk about axillary we mean motor(to muscles ) and sensory(lose of sensation in injury)
In any injury to any nerve we should concentrate on two important points :
1. Motor 2. Sensory
Then the doctor read from slides :
• The suprascapular nerve, the nerve to the subclavius, and the musculocutaneous and axillary nerves all
possess nerve fibers derived from C5 and 6 roots and will therefore be functionless
• The following muscles will consequently be paralyzed: the supraspinatus (abductor of the shoulder “
initiation of the abduction 0 -15 “ ) and infraspinatus (lateral rotator and extender of the shoulder) , and
these muscles will lose their functions , so that instead of the lateral rotation , there will be medial rotation
and instead of abduction , there will be adduction
• the subclavius (depresses the clavicle)
And if we don’t treat the fibers and sizes of these muscles by Physical Therapy, it will be atrophied
- The biceps brachii do powerful flextion and supinition in spite of supinator of the forearm
‫ ما زالت شغالة‬but the supinator in extention do supinition and flexor of the elbow
and weak flexor of the shoulder the greater part of the brachialis (medial half )
paralyze and coracobrachialis and about the deltoid
the deltoid muscle is divided to three fibers 1.ant 2.med 3.post :
- the medial do abduction from 15 to 90 … if axillary nerve injurie abduction.
- The ant fibers do flextion and medial rotation
- and post fibers do extention and lateral rotation .
- the limb will hang limply by the side, medially rotated by the unopposed
sternocostal part of the pectoralis major. that mean the pectoralis major do
flextion and meadial rotation of limb take the power .in spite of we have the
part of deltoid has loss function that make flextion and meadial rotation but
the deltoid here take the power action then do meadial rotation adduction .
as the result of injuries of the upper trunk (Erb-Duchenne Palsy) :
1_ upper limb rotated medial and adducted
2_the hand will be pronated
and this stance called police man deformete
- The position of the upper limb in this condition has been likened to that of a porter or waiter hinting for a tip
In addition, there will be a loss of sensation down the lateral side of the arm.
All of the muscle which call them become opposite function
that mean :
* abduction become adduction
* lateral rotation become medial rotation
* supination become pronation
- the axillary nerve give sensation over deltoid and musculocutaneous give sensation of the lateral side of the
forearm .
- then we will have loss of sensation of the lateral side of the arm and forearm and maybe to hand but mainly to
arm and forearm
2 . Lower Lesions of the Brachial Plexus (Klumpke Palsy or klumke paralyze)
Which mean lower trunk lesions
Lower trunk originated from C8 and T1 , C8 and T1 compete in the root of two imp. Nerves (Ulnar &median nerve
- Lower lesions of the brachial plexus are usually traction injuries caused by excessive abduction of the arm, as
occurs in the case of a person falling from a height clutching at an object to save himself or herself
(sudden abduction do injury to lower trunk)
And in labor if it frank what mean (the baby start down with the hand or leg not strat with the head usually 90%
start down with head and it is a normal delivery ) but if is dowm frank by hand because any demonetizing will be
lower trunk injury (plus abduction )
- The first thoracic nerve is usually torn which injury T1 and maybe T2 injury with T1
- Take first T1 only :
The nerve fibers from this segment run in the ulnar and median nerves to supply all the small muscles of the
hand (20 muscles,15 from ulnar and 5 from median )
Thenar and hypthenar and interossei palmer & dorsal and lumbrecals all of these muscle became paralyze
- The root value of ulnar and median both are T1 & C8
- When T1 Get injured , the hand will be like a frozen wood ; so hard , without any soft tissue , just bones in visual
appearance because of Paralysis and Atrophy of the muscles of the hand .
- Accordingly , there will be loss in function of hand . ex. Writing Position of the hand ( Flexion of the MCP Joints
and Extension of IP Joints ) . So When T1 is Injured the Opposite of the writing position will occur ( Extension of the
MCP Joints and Flexion of IP Joints ) , this is called a Claw Hand ! So the Claw hand is opposite to the writing
position !
Note : We are here talking about the injury of T1 . When we talk about the injuries of the median or ulnar nerve as
a whole, it’s totally different !
Important : When T1 is Injured , the ulnar and median nerves will be affected and the result is a claw hand .
-The Hand has clawed appearance caused by : hyper extension of MCP Joints and Flexion of IP Joints . ( Refer to
the Image in the Slide )
Motor Effect of Claw Hand :
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The Extensor Digitorum ,is unopposed by Lumbricals and Interossei, Extends the MCP Joint . The Extensor
Digitorum as we learned helps in the condition of the Claw Hand !
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Flexor Digitorum Superficialis and Profundus are unopposed by Lumbricals and Interossei and Flex the
middle and terminal phalanges , respectively . So theses muscles help in the condition of Claw hand (
Flexion of Proximal and Distal IP Joints.)
Sensation ( Sensory) Effect :
- Loss of sensation will Occur along the medial side of the arm in case of T1 Damage.
Note From Dermatomes : (C8) gives skin sensation of the ulnar side of the little finger and hand until the elbow .
(T1) comes after the elbow and gives skin sensation to the medial side of the Arm .
If the 8th Cervical Nerve gets damaged , the extend of anesthesia will be greater and will involve the
medial side of the forearm , hand and medial two fingers ! Don’t forget that T1 is already injured and the
medial side of the hand has also lost sensation ( Revise the Dermatomes to ease things out. )
Lower Lesion of Brachial Plexus can also be produced by :
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Presence of cervical rib.
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The simplest one of the conditions is if the cervical rib was a Bone ! Because it can be diagnosed easily by
Doing X-Ray , and know that this rib is doing all the damage and problems (Pressing on C8 and T1) in the
patient.
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This extra rib must be removed by surgery , otherwise it will keep the pressure on C8 and T1 and life of
that poor patient will be Hell .
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It is better to do the surgery before the atrophy of the muscles of the hand , because if atrophy happened
, an extra problem will evolve ! After the surgery the motor and sensory functions of C8 and T1 Will come
back .
Malignant metastasis from the lungs in the lower deep cervical lymph nodes .
The First Cause : Presence of cervical rib :So , what is the Cervical Rib ?!
Note : Remember the the 1st Rib originates posteriorly from (T1) or First Thoracic vertebrae , then it turns anterior
.
- Usually or in normal conditions there is no extra rib above the first rib . But sometimes we find a cervical
rib that has an origin from (C7) . This rib can be a bone , cartilage or membrane ( Different sets ) .
The Second cause : Metastasis from the lung can affect the deep cervical lymph nodes , and if theses lymph nodes
enlarged , there will be pressure on the Lower Trunk .
Long Thoracic Nerve Injury :
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Long thoracic nerve originates from C5 , C6 and C7 from the roots of Brachial Plexus and this nerve
innervates the Serratus Anterior Muscle .
- The Serratus Anterior :
Origin : from the Upper 8 Ribs
Insertion : on the medial border of Scapula Ventrally
The Main Action of Serratus Anterior : Protraction of the medial border of Scapula towards the ribs , and it assists
the Trapezium muscle in rotating the scapula above the 90 degrees in order to put the hand over the head .
- the long thoracic nerve come from C5 , 6 , 7 and goes to serratus anterior
- the long thoracic nerve can be injured by blows to or pressure on the posterior triangle of the neck or during the
surgical procedure of radical mastectomy and the most case that lead to paralysis to the long thoracic nerve is the
radical mastectomy which means “ breast cancer “
- the Dr. here mentioned some infromations about the cancer breast …. It has 4 stages ( and in some books 5
stages ) … and if the cancer was discovered in the 1st and 2nd stages , it can be treatment without mastectomy
(mastectomy : surgical removal of the breast ) .. but if it was in the the 3rd or 4th stage , they do the “ radical
mastectomy “ … and there is kinds of mastectomy :
-simple mastectomy : very simple and they keep the breast
- subtotal mastectomy : they remove some of the breast but not all of it ( for cosmetic ‫تجميلي‬
- radical mastectomy : they remove all the breast and all the lymph nodes , but the dangerous thing here that
when the surgery is trying to remove all the lymph nodes , he may injure the long thoracic nerve .. and this leads
to paralysis to serrratus anterior muscle
- another example for the causes of long thoracic nerve injuries happened with the “porters ‫حمالين‬
( these days porters usually use ‫ ) عرباية لجر االغراض‬but before 30 years , ‫كانو يربطون حبال حول رأسهم ويمر الحبل اسفل‬
‫االبط ويحتك بمكان مرور العصب الن العصب سطحي‬
( the long thoracic nerve is external ! )
- Paralysis of the serratus anterior results in the inability to rotate the scapula during the movement of
abduction of the arm above a right angle ( above 90 degree ) .. so there is difficulty or sometimes impossibility
to put the hand above the head
- The vertebral border and inferior angle of the scapula will no longer be kept closely applied to the chest wall
and will protrude posteriorly, a condition known as winged scapula
- The most easiest thing for a doctor is to Diagnosis the long thoracic nerve injury of winged scapula , he just ask
the patient to put his hands on the wall and push it .. and here the scapula will not stay retracted ( attached to the
ribs ) because the nerve injury , and the medial border will be away from the ribs , and even the doctor can put his
hand between the medial border and the ribs ..and this is called winged scapula .. and also if the patient was asked
to put his hand over his head he will find it sooo difficultly …
- The Axillary nerve :
- is a branch from the posterior cord of brachil plexus , which is made by the unite of all the posterior divisions of
the trunks ..
- the root value for axillary nerve is : C5 , C6 .. so it’s with the upper trunk lision
- can be injured by the pressure of a badly adjusted crutch ‫ عكاز‬pressing upward into the armpit
- so the people who use a crutch for a long time , which leads to a pressure on the surgical neck where the axillary
nerve pass , may have a nerve injury
- The passage of the axillary nerve backward from the axilla through the quadrangular space makes it particularly
vulnerable here to downward displacement of the humeral head in shoulder ( if there is a displacement the
shoulder joint will go downward and may cause a nerve injury ) dislocations or fractures of the surgical neck of the
humerus.
- The axillry nerve supplies two muscles : teres minor and deltoid
* teres minor is not that important because there is other muscles do the same action of it ( like infraspinatus )
* deltoid musle is the important one
- the axillary nerve also give sensation to the upper lateral side over the deltoid muscle ( lower lateral is supplied
by the Radial nerve )
- paralysis of deltoid :
* the middle fibers we know that is make abduction from 15 to 90 .. and if there was a nerve injuries for the
axillary nerve , the patient can make initiation but can’t continue except if he used his other hand to push the
injured hand to 90 !
* and there will be loss of sensation in the skin over the deltoid muscle
- The paralyzed deltoid wastes rapidly, and the underlying greater tuberosity can be readily palpated…
- The human body is symmetrical. When the axillary nerve is injured, after a some time, when a patient
is standing in the erect anatomical position, the shoulder regions are not symmetrical, since the deltoid
muscle has undergone atrophy. ‫ضمور والعظام تطلع للخارج بشكل غير جميل‬
The greater tuberosity of the head of the humerus can be easily palpated.
Moreover, the acromial and coracoid process can be seen.
When this happens, the supraspinatous is the only abductor of the glenohumeral joint,
therefore abduction can only take place until 15º, which becomes impairment to the
function.
The paralysis of the teres minor is unrecognizable since the infraspinatous replaces its roll.
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The Radial Nerve
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The radial nerve is the largest and most distributed nerve among it and the median and ulnar. It
innervates both muscle and the skin.
It gives off branches in the axilla, spiral groove, supracondylar ridge over the lateral epicondyle
and the forearm.
It originates from the posterior cord, and its root value is C5,6,7,8 and T1.
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In the elbow joint, the nerve divides in the cubital fossa into the deep(interosseous) and
superficial branches(RECALL: the deep branch goes around the radial neck, which may lead to an
injury if the the radius dislocates or fractures).
Axilla
Spiral groove
Supracondylar ridge of Deep
the lateral epicondyle branch
posterior
cutaneous
nerve of arm
lower lateral
nerve to the
cutaneous nerve of brachialis(lateral half)
arm
nerve to the
long and
medial heads
of the triceps
posterior
nerve to the
cutaneous nerve of brachioradialis
forearm
Superficial branch
ma
cutaneous nerve to the lateral
7aka
2/3‘s of the dorsum of hand
ishi! :S and the dorsum of the 3.5
proximal phalanxes
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nerve to the lateral nerve to the extensor
and medial heads carpi radialis
of the triceps
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nerve to anconeus -
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The dislocation of the shoulder joint may injure the radial nerve. Moreover, the miss use of
the crutch may injure both the axillary and radial nerve( another example is the Saturday
night paralysis, when a patient gets drunk and holds their hand on the chairs arm for
whole night, it may also injure the radial nerve).