Neuroopthalmology

Question 1

1. A 27 years old pregnant woman presents with painless progressive vision loss in the right eye. Examination reveals no light perception or direct papillary response in the right eye. A pale right optic nerve, and a superior temporal visual field defect in the left eye. The etiology of her signs and symptoms is most likely :
   A. Pituitary apoplexy
   B. Optic neuritis
   C. PRES ( Posterior Reversible Encephalopathy Syndrome)
   D. Suprasellar meningioma
   E. Functional vision loss

Answer 1

D. Suprasellar meningioma

The constellation of findings is most consistent with a supra sellar lesion. Meningiomas, pituitary adenomas, and glial tumors are known to enlarge during pregnancy. Progesterone receptor positive meningiomas as well as prolactinomas are known to enlarge during pregnancy causing chiasmal compression. Pituitary tumors will typically present with bitemporal blur or vision loss confirmed on formal visusal field testing. Visual acuities and color vision may be mildly affected, and pupil testing is typically normal.

Question 2

2. A 28 years old presents with sub acute onset of dropping of the eyelid and diplopia. He has a long standing history of headaches but no history of trauma. Facial and eye photos are shown. Which is the correct diagnosis?
   A. Third nerve palsy
   B. Sixth nerve palsy
   C. Horner’s syndrome
   D. Gaze palsy

Answer 2

A. Third nerve palsy

This patient has a non – pupil sparing third nerve palsy, characterized by complete ptosis, anisocoria (left pupil larger than right), and paralysis of left medial rectus muscle. Cavernosus Sinus region neoplasms, posterior communicating artery and ischemia (atherosclerosis or diabetic etiology) are the most common causes of third nerve palsy. Up to 20% of the cases may have an undetermained cause. Carotid dissection is suspected in someone who presents with sudden onset of unilateral neck pain, facial pain, and headache, with subsequent cerebral or retinal ischemia. Less commonly , patients may complain of difficulty swallowing and the onset of pulsatile tinnitus. The most common finding on examination is a partial Horner’s syndrome, paresis of hypoglossal nerve, and carotid bruit. A carotid dissection rarely presents with an acute nerve palsy. Ischemic causes of a third nerve palsy spares the pupilomotor fibers that reside on the surface of the third nerve. Compressive causes (trauma, tumor, and aneurysm) affect the pupilomotor fibers in 95% of the time.

Question 3

3. A 55 year old woman developed a severe headache and complains of acute vision loss due to severe bilateral ptosis. Examination also reveals complete ophtalmoplegia of both eyes. This is MOST consistent with which disorder :
   A. Complicated migraine
   B. Kearns – Syre syndrome
   C. Myasthenic crisis
   D. Pituitary apoplexy
   E. PCOM aneurysm

Answer 3

D. Pituitary apoplexy

This is an apopletic event and occurs with infarction and hemorrhage of the pituitary gland. Depending on the size of the hemorrhage, this may involve the optic apparatus and cause vision loss also. However, when the hemorrhage involves primarily the cavernosus sinus then complete ophtalmoplegia and ptosis result. The rate of onset as well as presence of pain is inconsistent with myasthenia. A posterior communicating artery anurysm would only cause ptosis with ophtalmoplegia in one eye. A complicated migraine would not cause any occular motor problems except in a migrainous third nerve palsy, which would bu unilateral again. The Kearns – Sayre syndrome is a mitochondrial disorder that causes slowly progressive ptosis and ophthalmoplegia.

Question 4

4. A patient complains of brief episodes of bilateral vision loss when she bends over or stands up quickly, she also admits to pulsatile synchronous tinnitus. The MOST likely problem associated with this is :
   A. PCOM Aneurysm
   B. Carotid – cavernous fitula
   C. Pseudotumor cerebri
   D. Internal carotid atherosclerosis
   E. Occipital meningioma

Answer 4

C. Pseudotumor cerebri

Papiledema is associated with increased intracranial pressure from variety of etiliogies. Very common complaints from patients include transient visual obscurationts and pulsatile tinitus. Patient with carotid cavernous fistulae may also complain of pulsative tinnitus, but not transient visual obscurations. Carotid atherosclerosis and not bilaterally and simultaneously. Occipital lobe meningiomas and posterior communicating artery aneurysms do not cause these symptoms unless somehow they have resulted in increased intracranial pressure that would cause papiledema to develop.