Small Group Session I

(to view with answers)

Lesions of the Brachial Plexus

Case 1
Your patient is recovering from radiation treatment for her breast cancer. She seems to be
doing fine but you notice she does have some difficulty moving her right arm. She has
difficulty raising her right arm laterally to the side of her head. When you ask her to push
hard against the wall, a protrusion occurs on the right side of her upper back.

1. What nerve do you think was damaged as a result of her radiation treatment?________
__________________________________________________________________________

2. What muscle(s) were damaged as a result of the nerve damage? Was the muscle
paralyzed or just weakened? _________________________________________________
_________________________________________________________________________
_________________________________________________________________________

3. Analyze the mechanism involved in full abduction of the arm to the side of the head.
What muscles are responsible for each component of full abduction? Why was your
patient not able to fully perform this task? ______________________________________
_________________________________________________________________________
_________________________________________________________________________

4. Demonstrate how you would assess scapular movements._______________________
_________________________________________________________________________
_________________________________________________________________________

Case 2
You are examining a patient who fell off a ladder while painting his house, injuring his right
shoulder. The patient complains of pain in the area of the shoulder and he has difficulty
moving his arm. You notice that his acromion is visible and that most of his arm
movements are weak. You test for sensation and find a small area of loss just below the
point of the right shoulder. Movements of the scapula and elbow were normal and you
could detect no additional sensory loss.

1. Would you expect to see any bone fractures on an X- Ray of the shoulder area? If you
do, where would you expect to find the fracture?__________________________________
__________________________________________________________________________
__________________________________________________________________________

2. Do you suspect that nerve damage has occurred? If so, what nerve(s) were injured?
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________

3. What muscle(s) would be affected? __________________________________________
__________________________________________________________________________
__________________________________________________________________________

4. Describe the movement of the shoulder that would be affected and would the movement
be lost or weak? ____________________________________________________________
__________________________________________________________________________
__________________________________________________________________________

Case 3
Your teen-age son comes home from his first date with his high school's prom queen. He
looks nervous and he is rubbing his forearm. You ask him what is wrong and he tells you
they went to a movie. When they came out, his hand was "tingling" and he could not lift
his wrist. You ask him if he had his arm around his date and he replies, somewhat
ashamed, the he did have his arm around herfor most of the movie. You examine him
and find the parasthesia ("tingling" is most noticeable along the radial side of the dorsum
of his wrist. He also has difficulty extending his wrist, especially when his forearm is in
the prone position, and can not make a tight fist. You laugh and tell him he has a classic
case of "Saturday Night Palsy", not to worry and he will be better in the morning.

1. What was the cause of his symptoms? _______________________________________
__________________________________________________________________________
__________________________________________________________________________

2. Was there nerve involvement and, if so, what nerve(s). ___________________________
__________________________________________________________________________
__________________________________________________________________________

3. What muscles were affected? Were they paralyzed or weakened? _________________
__________________________________________________________________________
__________________________________________________________________________

4. Could the son extend his wrist and make a tight fist if his forearm was in the supine
position? Explain your answer. _______________________________________________
__________________________________________________________________________
__________________________________________________________________________

5. Based upon the site of the injury, what other movements of the upper limb would be
affected? __________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________

Case 4
You are called to examine a psychiatric patient who has been hospitalized for 6 months
suffering from depression. You are called to consult because this individual has difficulty
doing routine tasks with his hands. He has difficulty grasping objects between his thumb
and forefinger. He also has difficulty holding his cigarette between his 1st. and 2nd.
fingers. Your examination finds he has reduced sensation along the medial side of his
palm and the 4th. finger. He has weakened wrist flexion, his 3rd. and 4th. fingers are
"clawed" and there is evidence of muscle wasting on the muscle mass on the dorsal side
of his hand between the thumb and first finger.

1. You suspect the symptoms are a result of nerve damage. What nerve would you expect
is involved and where is the most likely site for it to have be damaged? ________________
__________________________________________________________________________
___________________________________________________________________________

2. Explain the sensory and motor symptoms by discussing those muscles that are affected.
Why were the 3rd. and 4th. fingers "clawed" and why could he not hold his cigarette? _____
____________________________________________________________________________
____________________________________________________________________________

3. Why is the wasting of the muscle mass on the dorsum of his hand a clue to the nerve
involved? ____________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________

4. Are any of the muscles acting on the thumb affected? If so, what movement(s) of the
thumb would be involved? ______________________________________________________
____________________________________________________________________________
____________________________________________________________________________

Case 5
You have put on a lot of weight and decide to join a gym and to work out on a regular basis.
Your routine includes weight training, stationary bicycle and using the stair master start.
Visions of a svelte you result in your becoming very enthusiastic about your work out
routines. After about 3 months, you go to you doctor because you notice a tingling
sensation along the palmar surface of your thumb and first 2 fingers. This tingling has
gotten a lot worse in the past few weeks. You also notice your grip is weakening , you
have difficulty flexing your wrist using weights you were used to using, and you have
difficulty performing a percussion grip for any length of time (writing with a pencil). You
have no difficulty supinating your forearm, extending your wrist or flexing the distal phalanx
of your thumb.

1. What does your physician think is the cause of your symptoms? ____________________
____________________________________________________________________________
____________________________________________________________________________

2. Do you think an X-Ray or MRI would reveal anything significant? _____________________
____________________________________________________________________________
____________________________________________________________________________

3. What muscles are involved and how does their involvement explain you symptoms? _____
____________________________________________________________________________
____________________________________________________________________________

4. What can you do to help improve the situation? __________________________________
____________________________________________________________________________
____________________________________________________________________________


Case 6
You notice your young child's left upper limb is not developing normally so you take her to
her doctor. You explain that your child's birth was not an easy one and forceps were used
in her delivery. Otherwise, things have been unremarkable. Your child has a fair amount of
manual dexterity and can easily grasp objects with her fingers. However, her shoulder and
arm do not seem to work properly. Examination reveals the following: Atrophy of shoulder
and arm musculature, inability to abduct the shoulder, and loss of sensation along the
posterior lateral surface of the arm. The forearm is in a prone position, the arm adducted
and the elbow is in a partially flexed position. The doctor explains that your daughter has
Erb's palsy, possibly resulting from the delivery at birth. Use your knowledge of the
anatomy of the upper limb and your Segmental Innervation Chart to answer the following:

1. Explain the anatomy of Erb's palsy including the branches of the brachial plexus that are
involved. ____________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________

2. Indicate those muscles that would be affected by this condition. For each muscle
affected, give the function(s) of that muscle and state whether the muscle is weak or
paralyzed. __________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________

3. What movements of the shoulder and elbow joint would the patient be able to perform?
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________

4. How are movements of the scapula affected? ____________________________________
___________________________________________________________________________
___________________________________________________________________________

5. Would you expect this individual to be prone to shoulder dislocations? Explain your
answer. ____________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________