Easy way to learn Brachial Plexus pathology?

[FadingPromise]

Hey guys,

Was just reviewing material from MSK section of FA, and felt pretty stuck on hand deformity due to brachial plexus damage. My anatomy lesson was two years ago, since which I have never bothered to review this material. If there is any web-sites/easy break down material that I could learn from, some tips about info would be helpful. I tried reading down FA but I am feeling that (from overall experience of FA) I can't learn the material, even as review, if I don't at least read through something once that spells out the steps of pathophys/anatomy. Thanks again.

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[1nycdoc8]

Hey guys,

Was just reviewing material from MSK section of FA, and felt pretty stuck on hand deformity due to brachial plexus damage. My anatomy lesson was two years ago, since which I have never bothered to review this material. If there is any web-sites/easy break down material that I could learn from, some tips about info would be helpful. I tried reading down FA but I am feeling that (from overall experience of FA) I can't learn the material, even as review, if I don't at least read through something once that spells out the steps of pathophys/anatomy. Thanks again.

I always liked BRS anatomy for anything anatomy related including the brach plexus, is there anything we can help with in particular?

 

[phospho]

can't you just memorize it fom BRS?

Also, this helps me sometimes because it's weird and dirty: My Aunt Raped My Uncle

musc. n.--->axillary n.---->radial n.---->median n.---->ulnar n.

 

[RaraBovis]

can't you just memorize it fom BRS?

Also, this helps me sometimes because it's weird and dirty: My Aunt Raped My Uncle

musc. n.--->axillary n.---->radial n.---->median n.---->ulnar n.

How does this help?

 

[Aphtalyfe]

BRS is good.

Here is a basic rundown of how I remember brachial plexus pathologies.

First be able to draw the entire brachial plexus. If you can do that, the following will make more sense:

Musculocutaneous (lateral cord) - C5+C6 = Arm Flexors
Axillary Nerve (posterior cord) - C5+C6 = Abduction
Radial (posterior cord) - C6+C7 (mostly) = Extensors (forearm and arm)
Ulnar Nerve - C8+T1 (medial cord) = Intrinsic hand muscles
Median Nerve - Medial + Lateral cords = forearm flexion, thumb usage (opposition)
Suprascapular nerve comes off C5+C6 also.

So if I have an upper trunk lesion (erbs palsy) I will mostly see pathology related to Abduction(suprascapular + axillary) and Arm flexion(musculocutaneous), as well as forearm extension. My arm will be adducted, internally rotated (biceps brachii is a strong supinator and is innervated by musculocutaneous) and my forearm will be flexed. I will also be unable to flex my arm. Waiter's tip hand.

If I have a lower trunk injury (klumpkies) I will mostly see pathology related to Ulnar nerve. So I will have intrinsic hand muscle problems. I will also have numbness over the medial 1.5 fingers. Claw hand

If I have median nerve injury such as in carpel tunnel. I will be unable to do opposition of my thumb. If I have median nerve injury proximal to the elbow joint, I will most likely have inability to flex the forearm. Ape hand or hand of benediction

If I have radial nerve injury I will have problems extending my forearm/arm depending on where the lesion is.

Also remember that the suprascapular nerve innervates the suprascapular muscle which is how you initiate abduction for the first 15degrees. Axillary takes over with the deltoid beyond that.

So an injury to the suprascapular nerve will cause the inability to initate abduction of the arm. Injury to the axillary nerve will cause the inability to abduct the arm beyond 15degrees.

Hope that helps.

 

[aashkab]

BRS is good.

Here is a basic rundown of how I remember brachial plexus pathologies.

First be able to draw the entire brachial plexus. If you can do that, the following will make more sense:

Musculocutaneous (lateral cord) - C5+C6 = Arm Flexors
Axillary Nerve (posterior cord) - C5+C6 = Abduction
Radial (posterior cord) - C6+C7 (mostly) = Extensors (forearm and arm)
Ulnar Nerve - C8+T1 (medial cord) = Intrinsic hand muscles
Median Nerve - Medial + Lateral cords = forearm flexion, thumb usage (opposition)

So if I have an upper trunk lesion (erbs palsy) I will mostly see pathology related to Abduction and Arm flexion, as well as forearm extension. My arm will be adducted, internally rotated (biceps brachii is a strong supinator and is innervated by musculocutaneous) and my forearm will be flexed. I will also be unable to flex my arm. Waiter's tip hand.

If I have a lower trunk injury (klumpkies) I will mostly see pathology related to Ulnar nerve. So I will have intrinsic hand muscle problems. I will also have numbness over the medial 1.5 fingers. Claw hand

If I have median nerve injury such as in carpel tunnel. I will be unable to do opposition of my thumb. If I have median nerve injury proximal to the elbow joint, I will most likely have inability to flex the forearm. Ape hand or hand of benediction

If I have radial nerve injury I will have problems extending my forearm/arm depending on where the lesion is.

Also remember that the suprascapular nerve innervates the suprascapular muscle which is how you initiate abduction for the first 15degrees. Axillary takes over with the deltoid beyond that.

So an injury to the suprascapular nerve will cause the inability to initate abduction of the arm. Injury to the axillary nerve will cause the inability to abduct the arm beyond 15degrees.

Hope that helps.

i had a question about this. have they ever asked what the actual "cords" are or "roots" because there is a lot of overlap when it comes to what root it is atleast

 

[Aphtalyfe]

i had a question about this. have they ever asked what the actual "cords" are or "roots" because there is a lot of overlap when it comes to what root it is atleast

I have yet to take the step, so I can't answer that definitively.

However, I would probably memorize what the cords are and what they do, the roots are probably less important since there is considerable overlap like you said.

 

[Tourterm]

This classic may be helpful too.

 

[phospho]

How does this help?

the branches in order from top to bottom

 

[doc29]

what about nerve innervation of lower extremity?

 

[aashkab]

yeah i've heard several people say the sacral plexus was on the test and that ...is...scary

 

[PokerDoc]

yeah i've heard several people say the sacral plexus was on the test and that ...is...scary

I had six-seven questions... but theyre not hard.. you just need to know what innervates what.. its nothing ground breaking and certainly not more involved than the brachial plexus

the extent of the question will be "Patient complains of pain radiating down the back of her leg into the bottom of her foot, what nerve root is most likely compressed?"

L3
L4
L5
S1
S2

thats it..

 

[aashkab]

s2?

the other problem is that there are like 500 different variations of dermatome maps out there ... i don't know which one is the "GOLD standard"