Chapter 39. Neuro-Ophthalmology: Ocular Motor System

Question 1

Question 39-1:
A 74-year-old man presents with difficulty with voluntary
gaze, but reflex eye movements with head turning are
relatively preserved. What is the most likely cause?
A. Myasthenia gravis
B. Stroke
C. Diabetic mononeuropathy
D. Multiple sclerosis

Answer 1

Answer 39-1: B.
The patient has a supranuclear gaze palsy,
characterized by impaired voluntary gaze but
relative preservation of reflex gaze. This is
most likely to be due to stroke at this age, and
when present would be expected to be acute
and associated with other neurologic signs
such as hemiparesis. Myasthenia gravis
produces isolated muscle weakness which
would not be dependent on mode of
movement initiation. The same can be said for
the other diagnoses listed. (p 712)

Question 2

Question 39-2:
Which of the following are typical of ocular motor apraxia?
A. Inability to perfonn voluntary saccades
B. Preser-fation of spontaneous saccades
C. Can be congenital
D. All are true

Answer 2

Answer 39-2: D.
Ocular motor apraxia can be acquired or
congenital. Acquired ocular motor apraxia can
develop in patients with bilateral parietal
damage and diffuse bilateral cerebral disease.
Patients have difficulty perfonning voluntary
saccades whereas spontaneous saccades and
reflex eye movements are preserved. (P714)

Question 3

Question 39-3:
A 76-year-old man presents with diplopia and is found on
examination to have absent adduction of the left eye with right
gaze, associated with nystagmus of the right eye. He has a
history of diabetes but not hypertension or hyperlipidemia.
Which is the most likely diagnosis?
A. Internuclear ophthalmoplegia due to multiple sclerosis
B. Internuclear ophthalmoplegia due to vascular disease
C. Sixth nerve palsy due to diabetes
D. Myasthenia gravis

Answer 3

Answer 39-3: B.
The examination reports a unilateral INO
which is typically due to damage to the medial
longitudinal fasciculus. In this age, the most
likely cause is vascular disease, with small
vessel disease being the etiology. MS can
cause this same presentation, but would be
uncommon at this age. (P718)

Question 4

Question 39-4:
An 80-year-old woman presents with right
gaze palsy plus the inability to adduct the right eye with left
gaze; there is some associated nystagmus of the left eye.
Which is the most likely localization of the lesion?
A. Cavernous sinus
B. Midbrain
C. Pons
D. Medulla

Answer 4

Answer 39-4: C.
The patient has the one-and-a-half syndrome,
characterized by a gaze pal:;y plus INO. This
is due to a lesion in the dorsal pontine
tegmentum involving the ipsilateral PPRF
plus the ipsilateral MLF. Ocular myasthenia
can produce a similar presentation because of
involvement of multiple ocular muscles
spanning ocular motor nerve innervations.
(p718)

Question 5

Question 39-5:
A patient presents with spasmodic ocular deviations, mainly
upward in direction. The eye movements are conjugate. Which
is the most likely diagnosis?
A. Postencephalitic Parkinson's disease
B. Stroke
C. Neuroleptics
D. MUltiple sclerosis

Answer 5

Answer 39-5: C.
280
The patient exhibits oculogyric crisis.
Neuroleptics are the most common cause in
modem times. Post-encephalitic Parkinson’s
disease was a common cause many years ago,
but is no longer a cause. Other potential
causes are head injury, neurosyphilis, and
intoxication with lithium or carbamazepine.
(p72l-722),

Question 6

Question 39-6:
A patient presents with diplopia and is found to have a vertical
deviation with one eye slightly higher than the other. Eye
movements are otherwise conjugate with the deviation about
the same with gaze. Which is the most likely diagnosis?
A. Ocular myasthenia
B. Midbrain tumor
C. Fourth nerve palsy
D. Skew deviation due to vascular Disease

Answer 6

Answer 39-6: D.
The patient has a skew deviation, which is a
vertical deviation in the eyes, which in most
patients is comitant The location of the lesion
is the pons or medulla and vascular disease is
the most likely etiology. (pnl)

Question 7

Question 39-7:
A newborn male is found to have esotropia during initial
examination, and this is felt to be normal. Two weeks later.
The child is seen for follow-up and is found to have exotropia.
There are no other neurologic deticits. Which is the correct
conclusion?
A. The child had a posterior fossa tumor which is expanding
B. The child has congenital strabismus
C. The child most likely has a mitochondrial defect
D. The child most likely has a thyroid disorder
E. The child is normal

Answer 7

Answer 39-7: [.
Ocular alignment is incomplete at birth. and
there may be shifts from esotropia to
exotropia during the first few weeks. Ocular
aligrunent is established by 3-4 weeks in most
su1;ljects but may be delayed to as long as 5
months. (P711)

Question 8

Question 39-8:
Which is the clinica import of “ wrong-way Eyes”?
A. Normal variant response
B. False localizing sign
C.Indicates fuJnctional ocular motor abnormality
D. None of the above

Answer 8

Answer 39-8: D.
“Wrong-way eyes” is where there is conjugate
eye deviation to the wrong side, i.e., away
from a hemispheric lesion and toward the
hemiplegic side. This is a faise localizing sign
since it suggests a pontine lesion. (P715)

Question 9

Question 39-9:
A patient presents with coma following out-of-hospital cardiac
arrest. Examination shows conjugate horizontal rhythmic
oscillation which cycles about every 5 seconds. Which is the
correct conclusion about this finding?
A. This indicates psychogenicunresponsiveness
B. This is a poor prognostic sign
C. This is an excellent prognostic sign
D. This is usually due to a lesion of the caudal pons and
medulla

Answer 9

Answer 39-9: B.
The patient exhibits ping-pong gaze, with
conjugate horizontal rhythmic oscillations
which cycle every 4-8 seconds. The
localization of !he lesion is bilateral cerebral
or upper brainstem, so that there is a
disconnection that allows for independent
function of the pontine gaze centers. In
general, ping-pong gaze has a poor prognosis
unless the finding is due to a toxic or
metabolic cause. (p 716)