238) A 64 year old woman is evaluated in the emergency room for acute development of double vision and droopy left eyelid. She denies any fever or headache. Her past medical history is significant for diabetes mellitus and hypertension. On physical examination, she is afebrile and her blood pressure 132/88 mm Hg. Head and neck examination reveals ptosis of the left eyelid. Pupillary light reflex is intact . She can not adduct her left eye past the midline. The left eye is deviated downwards and laterally as shown in the picture below. There is no sensory loss on her face and the function of her other facial muscles are intact. Power is normal in all her extremities and deep tendon reflexes are intact.
Which of the following is the most likely cause of her symptoms?
A) Ophthalmoplegic migraine
B) Diabetic Mono-neuropathy
C) Posterior communicating artery aneurysm
D) Weber syndrome
E) Lateral medullary syndrome
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b
bbbbbbb ,occulomotor nerve
ophthalmoplegic migraine
An isolated, pupil-involved third nerve palsy is due to an aneurysm of the posterior communicating artery until proven otherwise.
• An isolated, pupil-spared, complete third nerve palsy in a diabetic patients is likely to be due to small vessel ischemia
http://www.medlink.com/medlinkcontent.asp
here there is pupillary sparing, hence it is due to dm
B
B) Diabetic Mono-neuropathy
The pupillary sparing is due the anatomical arrangement of the nerve fibers in the oculomotor nerve; fibers controlling the pupillary function are superficial and spared from ischemic injuries typical of diabetes. On the converse, a subarachnoid haemorrhage, which leads to compression of the oculomotor nerve, usually affects the superficial fibers and manifests as a palsy with loss of the pupillary reflex. – Wikipedia
B