A 61-year-old woman comes to the physician for a 4-month history of progressively worsening double vision and fatigue. Physical and neurologic examination show a partial ptosis of the right eyelid and a right pupil that is fixed at 1mm.
Which of the following is the most likely explanation for this patient’s findings?
A) Impingement of lower brachial plexus
B) Impingement of upper brachial plexus
C) Impingement of the C8 sympathetic chain
D) Loss of parasympathetic outflow
E) Reduction in oculomotor efferent outflow
