Double Vision

Question 1

What causes double vision?

Answer 1

Results from two eyes not moving synchronously together

Question 2

What is Ophthalmoplegia or Ophthalmoparesis?

Answer 2

Weakness of eye movements

Question 3

What is all weakness d/t?

Answer 3

• Myopathy
• NMJ disorder
• UMN or LMN lesions

Question 4

Any lesion of visual pathway ANTERIOR to optic chiasm produce ____ ____ ____.

Answer 4

Monocular visual distrubances

Question 5

Any lesion POSTERIOR to optic chiasm produces ___ ___ ___ ___.

Answer 5

Hemianoptic visual field disturbances

Question 6

What is Marcus Gunn pupil?

Answer 6

Afferent pupillary defect

Dilation in eye w/ light shining into it (swinging light test)

Question 7

What does an optic chiasm lesion produce?

Answer 7

Bitemporal hemianopsia

Question 8

What is the hx of a myopathy?

Answer 8

• Subacute or chronic
• Other weak muscles
• Thyroid dz
• Mitochondrial myopathies

Question 9

What are the PE findings of myopathy?

Answer 9

• Dysconjugate eye movements causing diplopia
• Pupil is NEVER affected
• Findings of thyroid dz

Question 10

What are the PE findings of thyroid dz?

Answer 10

• Myxedema
• Exophthalamous
• Slow relaxation phase of DTRs
• Hair loss
• Brittle nails

Question 11

What are the presenting features in >90% if Myasthenia Gravis cases?

Answer 11

Diplopia &/or Ptosis

Question 12

Who gets Myasthenia Gravis?

Answer 12

Young females & older males

Question 13

What is the course of Myasthenia Gravis?

Answer 13

Subacute or chronic w/ waxing & wanning of sx

Question 14

What are the PE findings of Myasthenia Gravis?

Answer 14

• Ptosis
• Diplopia
• Pupil is NEVER affected
• Dysarthria/dysphagia
• Facial, axial or limb weakness
• Normal DTRs & sensation

Question 15

What dramatically improves Myasthenia Gravis sx?

Answer 15

IV injection of Endrophonium (Tensilon) a short acting acetylcholinesterase drug

Question 16

What is Myasthenia gravis?

Answer 16

AI dz in which auto-Ab’s directed at post-synaptic Ach receptors at NMJ

Question 17

What is the tx for Myasthenia gravis?

Answer 17

• Acetylcholinesterase drugs
• Corticosteroids
• Immuosuppressive drugs
• Thymectomy if tumor or hyperplasia

Question 18

How can the Oculomotor nerve be damaged?

Answer 18

Mass lesion compressing b/w the edge of the tentorium & brainstem (herniation of the uncus of the temporal lobe) or by hematoma, neoplasm, etc

Question 19

What is the first thing that occurs in oculomotor nerve damage?

Answer 19

Dilation of pupil d/t peripheral PSN autonomic fibers followed by Opthalmoplegia of all the CN III innervated eye muscles

Question 20

What are the sx of Oculomotor nerve lesion?

Answer 20

• Acute onset
• Diplopia & ptosis of same eye
• No waxing/waning
• Multiple vascular RF

Question 21

What are the Vascular RF?

Answer 21

• Advanced age
• DM
• HTN
• Hyperlipidemia
• Smokers
• Vasculitis

Question 22

What is Ipsilateral Ophthalmoplegia?

Answer 22

• Adduction is impaired
• Abduction is intact
• Pupil is unaffected

Question 23

What are the technological features of Oculmotor nerve lesion?

Answer 23

Brain MRI scans are normal or reveal incidental ABN

Question 24

What is the tx for Oculomotor nerve lesion?

Answer 24

• Eye patch to reslove diplopia
• Watchful waiting
• RF reduction

Question 25

What are the PE findings of Abducens nerve lesion?

Answer 25

* Ophthalmoparesis is paralysis/weakness of abduction w/ all extraocular fxn intact * Weakness, sensory loss, AMS, HA or papilledema if inc ICP or compressing CN VI

Question 26

What are the technological features of Abducens nerve lesion?

Answer 26

Brain imaging evidence of cause of inc ICP or indications of vascular RF

Question 27

What is the onset of Ophthalmoplegia?

Answer 27

* Acute--Vascular in elderly * Subacute--Demyelinating in young * Gradual--Neoplastic

Question 28

What are the PE findings of Opthalmoplegia?

Answer 28

* Unilateral or bilateral * Horizontal eye movements the adducting eye cannot cross the midleine & abducting eye develops nystagmus

Question 29

What are the technological features of Internuclear Ophthalmoplegia?

Answer 29

Brain MRI w/ & w/o contrast ID lesion in the pons b/w the nucleus of CN III & CN VI

Question 30

What is the hx of Wernicke's Encephalopathy?

Answer 30

Alcoholism & nutritional def or other cond assoc w/ thiamine def such as gastric surgery & failure to take thiamine supplements

Question 31

What are the sx of Wernicke's Encephalopathy?

Answer 31

* Memory loss * Diplopia * Numbness & tingling * Confabulation * Ataxia * Peipheral neuropathy

Question 32

What are the tech features of Wernicke's Encephalopathy?

Answer 32

MRI evidence of scattered deep white matter brain changes in upper brainstem & diencephalon or normal MRI

Question 33

What is the 1st finding to clear after giving IV thiamine to a Werneicke's Encephalopathy pt?

Answer 33

Ophthalmoplegia