This document discusses supranuclear disorders of ocular motility. It begins by outlining the hierarchy of ocular motor control, with the cerebral cortex, cerebellum, and basal ganglia at the highest level 1. Level 2 includes brainstem nuclei and cranial nerve nuclei, and level 3 includes the ocular motor nerves and extraocular muscles. The document then discusses various types of eye movements including fast eye movements like saccades, as well as gaze palsies and vertical gaze palsies. It also covers disorders like internuclear ophthalmoplegia, one-and-a-half syndrome, the ocular tilt reaction, and disorders of pursuit movements and optokinetic nystagmus

1. Supranuclear Disorders of Ocular Motility

2. Refrences

3. HIERARCHY
OF OCULAR
MOTOR
CONTROL
Cerebral cortex, cerebellum,
vestibular apparatus, basal
ganglia
Level
1
Brainstem nuclei, ocular
motor cranial nerve nuclei
Level
2
Occular motor nerves & extra
ocular muscles
Level
3

4. SUPRANUCLEAR CONTROL
Level 1
•Cerebral
cortex
•Cerebellum
•Vestibular
apparatus
•Basal
ganglia

5. Classification of eye movements

8. Fast Eye Movements and Gaze Paralysis
• Fast Eye Movements- Saccades
• At the onset of a saccade, the agonist muscle receives an innervational pulse & the
innervational flow to the antagonist muscle is completely inhibited.
• The pulse serves to overcome the viscous resistance in the orbital tissues and the
inertial mass of the globe to initiate a high-speed rotational movement of the eye.
• To stop the eye at its intended target, the pulse is followed by an innervational
plateau that is higher for the agonist and lower for the antagonist than at the
starting position of the saccade.
• This change of the innervational plateau is referred to as a step.

9. Generation of horizontal saccades.
The frontal and other cortical eye fields (left)
decussate
inhibit the omnipause neurons (OPN),
( which lie within the rootlets of the VIth nerve)
[between saccades tonically inhibit the paramedian
pontine reticular formation (PPRF)]
Disinhibited burst neurons in the
PPRF excite cell bodies in the right sixth nerve (VIth) nucleus,
which in turn innervates the ipsilateral lateral rectus (LR) muscle,
which abducts the right eye (RE).
Another set of neurons from the right VIth nerve
nucleus crosses the midline then ascends within the left medial
longitudinal fasciculus (MLF)
These reach the left medial rectus (MR) subnucleus
in the oculomotor complex (IIIrd) in the midbrain that supply the
left medial rectus muscle to adduct the left eye (LE).

10. Examination of Fast Eye Movements
• The patient is asked to change gaze back and forth
between one object and another
• Angular separation of about 20 to 30°
• Larger angles often require more than one saccade
• When examining saccades it is just as important
to notice their velocity as it is their accuracy.

11. Saccadic abnormalities
• Dysmetria refers to saccades of inappropriate amplitude.
• Saccades may be slow.
• An inability to generate saccades is termed saccadic palsy.

12. • Slow saccades are present in spino-cerebellar
degeneration,Huntington’s chorea, and Wilson’s
Disease
• Saccadic palsy may be present transiently in acute
contralateral frontal lobe lesions

13. Saccadic Dysmetria
• Refixation saccades are considered dysmetric when they
consistently over- or undershoot their intended target.
• This leads to small corrective saccades before the target is
properly centered in the visual field.
• Saccades that fall short of the mark are said to by hypometric
• Saccades that move past the target and then double back are
hypermetric

14. • Hypometric saccades are not necessarily pathological; they can be the
product of inattention or poor cooperation.
• Hypermetric saccades on the contrary are always pathological and
strongly suggest the presence of a lesion in the cerebellar vermis.
• Saccades in Parkinson’s disease may be hypometric and associated with an
increased latency.

15. • Dysmetria caused by Wallenberg syndrome
(infarction of the lateral medulla) on the left
side will produce the following findings:
– saccadic movements to the left are
hypermetric,
– right are hypometric
– Upward saccades veer to the left
– Downward saccades veer to the left

16. • Wallenberg’s syndrome is most commonly
caused by occlusion of the ipsilateral vertebral
artery or the posterior inferior cerebellar
artery; demyelinating disease rarely
• Symptoms of Wallenberg’s syndrome
– Horner’s syndrome
– Vertigo
– Skew deviation
– Rotary nystagmus
– Sensations of body and environmental tilt
– Lateropulsion, a compelling sensation of being
pulled toward the side of the lesion

17. Gaze Palsy
• A gaze palsy appears as a limitation of conjugate movement in both eyes,
arises from damage to cerebral structures
• It can be an isolated deficit for binocular movements to the right, left, up,
or down.
• A pure gaze paralysis affects both eyes equally, and there is no strabismus;
unless an unrelated disorder antedated onset of the paresis.
• Due to the proximity of the supranuclear structures to the nuclei and
fascicles of cranial nerves III, IV and VI, gaze palsies are frequently found in
association with paretic strabismus.

18. Psychogenic Inhibition of Gaze Movements
• Prior to initiating a diagnostic workup for a gaze palsy, rule out
whether the problem might be psychological in origin.
• With such a problem the patient cannot, be coaxed into changing
gaze direction past the midline to one side.
• Otherwise, ocular motor functions will be normal.
• Volitional saccades from the “good” side to the midposition will
appear normal.

19. Pontine Gaze Palsy
• The lesion causing a pontine gaze palsy lies ipsilateral to the
paretic gaze direction
• located either in the abducens nucleus or in the paramedian
pontine reticular formation
• Lesions of the abducens nucleus affect both the motor
neurons of the abducens nerve and the internuclear neurons
that project to the motor neurons of the contralateral medial
rectus

20. • The saccadic movements of both eyes toward the side of the
lesion are impaired.
• With total loss of the structures within the PPRF, all fast
movements of both eyes to the ipsilateral side will be lost.
• Pursuit movements, on the other hand, and movements of
the VOR are retained.
• When damage to the PPRF is incomplete, saccadic
movements to the ipsilateral side can be elicited, but their
speed is reduced

21. Eye Movement Disorders Caused by Damage
in the Cerebral Hemispheres
• Focal lesions to individual areas of cerebral cortex do not cause a gaze
palsy
• A patients with a defect in the entire frontal eye field can generate gaze
movements to the contralateral side.
• But, when given the task of looking toward the opposite of an object, the
patient will be unable to suppress the reflex that draws his/her eyes to the
object.
• Hemispheric palsies of gaze generally disappear within 1 or 2 weeks.

22. • Gaze to the opposite side will be paralyzed, and there will be a tonic perseveration
of gaze direction ipsilateral to the lesion.
• The patient is said to be looking at his/her own lesion.
• Strokes with damage to the internal capsule more often will produce gaze
palsies, since this structure contains a close bundling together of descending
fibers from many areas of the cortex.
• This allows most or all of the efferent fibers to be simultaneously damaged.

23. Vertical Gaze Palsy (Dorsal Midbrain Syndrome:
Parinaud’s Syndrome)
• Supranuclear structures responsible for
control of vertical eye movements are
clustered around the Sylvian aqueduct,
rostral to the quadrigeminal plate.
– The rostral interstitial nucleus of the medial
longitudinal fasciculus (riMLF) analogous to
the PPRF for horizontal movements 
generates the pulse for the fast eye
movements in vertical directions
– The nucleus of Cajal; allows for stabilization
of gaze direction at the completion of the
saccade

24. – In the posterior commissure, the decussating
fibers from the riMLF and the nucleus of Cajal
project to the third and fourth cranial nerve
nuclei
• Pineal tumors can affect all three of these
supranuclear structures.
• This commonly elicits dorsal midbrain
syndrome, also known as Parinaud’s
syndrome.
DORSAL MIDBRAIN SYNDROME
 Collier lid retraction
 Light near dissociation
 Nystagmoid convergence retraction
 Upgaze palsy

25. PARINAUD SYNDROME

26. PARINAUD SYNDROME

27. Downward gaze palsy
• May be due to a lesion of the RiN of the MLF within the prerubral fields.
• Occlusion of a single perforating artery, the posterior thalamo-subthalamic
paramedian artery, leads to bilateral lesions.
• In Progressive Supranuclear Palsy and sea-blue histiocytosis, a variant of
Niemann-Pick disease, a downgaze palsy may precede an upgaze palsy.
• Total ophthalmoplegia of supranuclear origin may be present in
PSP, systemic lupus erythematosus and Whipple’s disease.

28. Oculomotor Apraxia
• Oculomotor apraxia describes an eye movement disorder characterized by loss of
or diminished volitional saccades with retention of the fast phases of vestibular
nystagmus.
• Reflexive saccades in the peripheral visual field may be disordered or normal.
• Congenital oculomotor apraxia (Cogan’s syndrome) manifests in newborn infants.
• Congenital oculomotor apraxia affects only horizontal eye movements
• During the first 3 months of life, affected infants are unable to look toward objects
held out to them, and may be mistakenly thought of as blind.

29. • Compensatory mechanism; Thrusting movements of the head (to bring
the eyes into alignment with the object of interest).
• VOR movements negate the movement of the eyes with head turn, the
child must turn the head well beyond the point of interest, allowing to
position the eyes as desired
• In the second phase, with the eyes having taken up fixation, visual pursuit
and VOR inputs serve to keep the eye fixed on the object, while the head
is then able to return to the midposition.
• Congenital oculomotor apraxia gradually disappears during the first two
decades of life

30. • It is not known where the damage
responsible for oculomotor apraxia is
located.
• The PPRF can be excluded as the site
of the lesion, since vestibular stimuli
elicit fast phases of nystagmus in such
patients.

31. • Balint’s syndrome
• An inability to move the eyes to
command despite normal random
and visually directed saccades.
• Unilateral dominant or bilateral
frontoparietal lesions are
responsible.
– Simultagnosia
– Optic ataxia
– Occulomotor apraxia

32. Gaze-Evoked Nystagmus
• Gaze-evoked nystagmus is the result of a gaze-holding deficit.
• The eyes can be moved into an eccentric position by saccades or by the VOR
• However, they cannot be held in the eccentric position. Instead, they drift back
toward the midline and must be redirected repeatedly toward the object of regard
• The structures responsible for fixation maintenance are widely dispersed in the
brainstem (particularly in the nucleus prepositus hypoglossi) and in the
cerebellum.

33. • Thus, gaze-evoked nystagmus tells the examiner very little about the
location of a lesion.
• Confirm whether tranquilizer or antiseizure medications are being used.

34. Internuclear Ophthalmoplegia
and the One-and-a-Half Syndrome
• Internuclear ophthalmoplegia is caused by damage to the internuclear
neurons that exit from the abducens nucleus, decussate to the
contralateral side, rise in the medial longitudinal fasciculus (MLF), and
terminate in the subnucleus of the medial rectus in the nuclear complex of
the third cranial nerve
• An internuclear ophthalmoplegia (INO) is present if an eye cannot be
adducted when changing gaze direction, but will adduct during
accommodative convergence

35. • At first, the involved eye is stimulated to adduct as far as possible via a conjugated
version by letting the patient follow a distant target.
• Subsequently the examiner determines whether the addition of accommodative
convergence allows the eye to adduct any further, by bringing the target near to
the patient, keeping it on the relevant side.
• Even slightly diminished adducting capacity becomes apparent on saccade testing:
The speed of adduction in one eye will be visibly less than the abducting velocity in
the other eye.
• For wide-angle saccadic movements, the examiner can see that the lateral rectus
wins the race to one side, while the adducting fellow eye has to catch up.
• This is true for both unilateral and bilateral INO.

36. INTERNUCLEAR OPHTHALMOPLEGIA

37. BILATERAL INO

38. ONE – AND – A HALF SYNDROME
• Occasionally, in addition to the
damage of one MLF,
the neighboring PPRF and or the
adjacent abducens nucleus
on the ipsilateral side are
simultaneously damaged.
• This produces the so-called one-
and-a-half syndrome.

39. • One-and-a-half syndrome is present when the horizontal movement of
one eye has been completely lost, and it can neither adduct nor abduct
(the “one”), while the fellow eye has lost its capacity to adduct, but retains
normal abduction movements (the “half ”).

40. Ocular Tilt Reaction
• In the petrous pyramid of the temporal bone, are two bony recesses, the utriculus
and the sacculus.
• They contain ciliated sensory receptors.
• Adherent to the ciliae are tiny lime concrements called otoliths.
• Gravitational pull on the otoliths bends the ciliae downward, generating a neural
signal that defines the static rotational orientation of the head.
• The otolithic apparatus thus functions as an accelerometer and tilt receptor that
measures both the force of gravity and the static orientation of the head –feeds
data to the brain through the eighth cranial nerve

41. • A unilateral interruption of the otolithic afferent
pathway causes the ocular tilt reaction (OTR), which
has four components:
– A yoked rotational displacement of both eyes around
the visual axis
– A vertical strabismus (skew deviation)
– A head tilt to one side
– A tilt of the subjective visual perception of the
vertical
• All four components are tilted in the same direction.

42. • The rotational displacement of both eyes and the skew deviation are caused by an
interruption of the otolithic signal to the superior rectus of the ipsilateral eye and
the inferior oblique of the contralateral eye.
• The head tilt arises from a defective projection to the neck muscles and the tilt of
the subjective visual vertical is caused by a faulty projection to the vestibular
cortex.
• The cyclodeviation and the tilt of the subjective visual vertical are in the same
direction in both eyes, but their magnitudes can differ

43. • A lesion of the otolithic pathway in the caudal brainstem (medulla
oblongata or caudal pons)  a tilt to the ipsilateral side
• A lesion damaging the same path in the more rostral portions of the
brainstem (rostral pons or midbrain)  a tilt to the opposite side.
• This reversal of direction at the mid pons is due to a decussation of the
otolithic pathways in the pons.

44. • If a patient indicates the subjective vertical tilted to the right (clockwise), he/she
will perceive vertical structures (e.g., door frames) as if they are all tilted to the left
(counterclockwise).
• In a natural environment, this faulty perception will be seen for the first few
minutes or hours after the lesion’s onset, after which there is rapid adaptation
with a return of normal spatial perception.
• The ocular tilt reaction is the most common sign of intrinsic brainstem damage.
• It is found in about 20% of all unilateral brainstem lesions.

45. Pursuit Movements
• Pursuit movements are the motor response of the eye to a continuously moving
object of regard.
• The smoothness of the pursuit movements is of the greatest diagnostic
importance.

46. Testing of Pursuit movements
• The examiner uses a fixation object fastened to
the end of a rigid wand.
• This is moved at a slow and constant rate, back
and forth, up and down, while the examiner
watches the eye movements of the patient.
• The movement of the test object should cover an
amplitude of 10° to either side of the
midposition.
• Smooth pursuit movements should be seen for
speeds of the target up to about 30°/s.

47. Optokinetic nystagmus
• It is the motor response of the eye to a continuously moving pattern that has
contrasting elements.
• The OKN consists of slow phases that reduce or prevent movement of the image
across the retina, and of fast phases that reset the eyes to succeeding elements of
the pattern.
• An optokinetic stimulus can be generated either by movement of the surrounding
environment, or by movement of the observer in a stationary environment.

48. Testing of OKN
• Experimental testing of OKN used a rotating
drum marked with alternating black and
white stripes.
• For clinical tests of OKN, the examiner uses
a patterned ribbon or band of material, held
approximately 20 in. away from the eyes.
• The band is drawn in the direction to be
tested, holding it at a stable location with
one hand while pulling it past the stabilized
location with the other hand.
OKN function is judged, noting
whether the speed of the slow
phase matches that of the passing
stimulus.

49. Disorders of Pursuit Movements and OKN
• An impairment of pursuit movements in most cases is coupled with a deficit for
the slow phase of OKN.
• A functioning area of the primary visual cortex in one hemisphere is sufficient to
generate normal pursuit movements and OKN responses to both sides.
• In a homonymous hemianopia, caused by an isolated lesion in the primary visual
cortex, the examiner will find no abnormality of OKN.
• If there is damage to the deep white matter in the parieto-occipital lobes on one
side, there will be a loss of pursuit movement and of the slow-phase component of
the OKN to the ipsilesional side.

50. • Lesions in the brainstem and the cerebellum can also damage
both pursuit movements and the slow phases of OKN
• Conversely, pontine disease will cause pursuit movements and
OKN slow phases that are diminished toward the contralateral
side.

51. Vestibulo-Ocular Reflex
• Physiologic Basis for the VOR
– The VOR arising from the labyrinthine canals of the inner ear serves to stabilize the
eye’s position when the head is turned, whether side to side or up and down.
• This allows stabilization of the retinal image and prevents blurring
• The vestibular system compensates for short and quick changes in
rotational acceleration of the head.
• For separate testing of the right and left vestibular apparatus, caloric
lavage of the external auditory canals is done.

52. • For separate testing of the right and left vestibular
apparatus, caloric lavage of the external auditory
canals is done.

53. Functional Loss of One Vestibular Organ
• Acute loss of the right vestibular organ’s function will produce a
nystagmus that has quick phases to the left with a rotary
component.
• This peripheral vestibular nystagmus will be apparent only during
concealment of the image features that allow the pursuit and
fixation maintenance mechanisms to stabilize the eye.
• The basis for peripheral vestibular nystagmus is an imbalance of the
afferent signals from the right and left vestibular organs:

54. • If the right vestibular organ is damaged, the afferent signal (in
case of a stationary head the resting activity) expected to
come from both sides comes from the left side only.
• This disequilibrium is interpreted by the brain to mean that
the head is turning to the left.
• The environment appears to be turning in the direction
opposite to that of the slow phase, and a sensation of nausea
is often present.

55. • the diagnosis of a unilateral loss of vestibular function can still be
established by caloric testing:
– Warm-water lavage of the external auditory canal on the diseased side should in a
normal case cause slow nystagmus phases to the opposite side.
• With loss of function, however, no nystagmus is elicited.

56. Functional Loss of Both Vestibular Organs
• Bilateral loss of vestibular function is not accompanied by any disequilibrium of
the vestibular afferents from both sides, so there will be no nystagmus.
• However, there will be loss of vestibular reflexes.
• Consequently, the patient will experience illusory movement of the environment
(oscillopsia) during any rotational movement of the head.

57. • Typical causes of bilateral loss of vestibular function include Ménière’s
disease and chronic use of aminoglycoside antibiotics.
• In addition, disease within the brainstem, such as multiple sclerosis, can
damage the VOR, resulting in oscillopsia.

58. Central Vestibular Nystagmus
• Central vestibular nystagmus is caused by damage to the vestibular nuclei or to their
connections with the ocular motor nuclei.
• Since the vestibular, optokinetic, and pursuit systems all converge on a common final
pathway through the vestibular nuclei, they are all impaired.
• Due to the loss of the optokinetic and pursuit systems, the sufferer is unable to stop the
nystagmus-driven movement of images across the retina.
• Consequently, central vestibular nystagmus (in contradistinction to peripheral vestibular
nystagmus) cannot be suppressed by the fixation maintenance system.

59. • The result is intractable oscillopsia.
• Treatment is largely unsatisfactory.
• Drugs like baclofen and clonazepam when given in sufficiently high doses
can dampen the nystagmus, but often produce an unacceptable level of
somnolence.

60. Downbeat Nystagmus
• Downbeat nystagmus is a central vestibular nystagmus whose fast phases
are downward.
• Downbeat nystagmus is caused by an interruption of the pathways
connecting the posterior labyrinthine canals through the vestibular nuclei
to the ocular motor nuclei.
• Causes include in particular the Arnold-Chiari malformation, cerebellar
degeneration, and brainstem infarction.
• Downbeat nystagmus can also develop idiopathically in otherwise healthy
people.

61. Disorders of Vergence
• Vergence movements (convergence and divergence) are binocular movements in
opposite directions that serve to align the visual axes of both eyes, so that the
images of objects located at the distance of fixation will fall onto corresponding
retinal locations.
• The supranuclear structures that are responsible for the control of vergence
movements lie in the midbrain.
• When a paralysis of convergence is found, the examiner must decide whether the
eye movement disturbance is isolated or if there are also deficits in
accommodation and/or in accommodative miosis.
• If all three are impaired, the problem is referred to as a paralysis of the near reflex.

62. Test of Convergence
• Convergence can be tested by having the patient fix binocularly on a
fingertip of his/her outstretched hand, held in the midposition, and then
to move the finger tip slowly toward the tip of his/her nose, while
maintaining single binocular vision.
• A normal response has both eyes converging symmetrically toward the
midline plane, accompanied by symmetrical pupillary miosis.

63. Spasm of the Near Reflex
• Spasm of the near reflex is characterized by prolonged and excessive
binocular convergence, accommodation, and miosis.
• Spasm of the near reflex is occasionally mistaken for paretic strabismus.
• A misinterpretation can be avoided, if one notes during examination of an
esotropia with a variable angle between the eyes, whether the pupils
constrict with increasingly convergent positions.
• A characteristic feature of spasm of the near reflex is that diplopia is
intermittent, and that lenses to correct the accommodative myopia
improve acuity.