Download Clinical Quickies

Clinical Quickies
1. On opening day at Yankee stadium, Alex Rodriguez gets hit in the eye with a line
drive from Derek Jeter. He is admitted to the CPMC ER. What part of his orbit is likely
fractured and why? And, with which sinus and cavity does the orbit now communicate?
Because the orbital contents are incompressible, ‘orbital compression injury’ from
getting hit in the eye with a ball transmits forces from the eye to the orbital walls.
The orbital floor is weak and most prone to fracture. Such an injury provides
communication between the nasal cavity and the orbit via the maxillary sinus.
2. You walk into CP small group with ‘tired eyes’ because your class parties like
animals every Thursday night –you can’t seem to keep your eyes wide open no matter
how hard you try. Why?
The superior tarsal muscle is a smooth muscle with sympathetic innervation. Its
contraction accentuates the opening of the palpebral fissure. Lack of muscle tone
due to decreased sympathetic activity or low circulating levels of epinephrine results
in difficulty keeping the eyes wide open.
3. Little Johnny gets smacked on the back of the head while staring cross-eyed at the
love of his life. Now he can’t uncross his eyes. Seriously, if this happened what CN
would be lesioned?
There would be a bilateral lesion of CN VI that would result in loss of innervation
and therefore tone of the lateral recti. The intrinsic tone of the medial recti
(innervated by CNIII) would then pull the eyes medially resulting in ‘crossed eyes’.
4. You’re back in the CPMC ER and a patient was stabbed in neck and has gotten an
infection that has tracked all the way down into his thoracic mediastinum. How did this
infection spread?
The infection spread through the retropharyngeal or ‘danger’ space. It lies between
the oropharynx that is covered by the superificial layer of deep fascia and the
somatic neck that is covered by the prevertebral fascia.
5. Your teenage cousin pops a huge zit that was just lateral to his nose. Hours later he
has a headache and pain behind his eye. What happened?
Bacteria from the zit entered the angular vein, which is connected to the cavernous
sinus via the inferior ophthalmic vein. Thus, depending on the direction of blood
flow (these veins have no valves) an infection on the face can be conveyed to the
cavernous sinus where it is difficult to treat.
6. Alex Rodriguez is angered by Jeter and decides to hit him on the side of the head
with a bat. What hematoma will Jeter likely get from such an injury? Second,
physical examination reveals that Jeter has difficulty moving his eyes medially
and superiorly. What CN is being affected and why?
A blow to the side of the head can fracture the temporal bone and result in the
rupture of the middle meningeal artery. Arterial blood will accumulate in the
epidural space resulting in an epidural hematoma. The blood forms a focalized
swelling that can displace the brain. If displacement is severe, the brain can
herniate onto the brainstem and compress CN III resulting in disorders in eye
movement.