Transcript nystagmus 2013

NYSTAGMUS
Assist.Prof. Dr.Vildan Öztürk
Ophthalmology
Yeditepe University Hospital
Definition
Nystagmus is a repetetive, involuntary oscillations of
the eye. (defoveating-foveating )
Oscillations may be ;
-vertical
-horizontal
-torsional
-non-specific
Described in fast component’s direction.
fine - coarse
moderate - high
Classification
1-Jerk nystagmus: slow drift followed by a fast
corrective phase.
-gaze evoked (ie. vestibuler )
-gaze paretic (brainstem)
2-Pendular nystagmus
-velocity equal in both directions
-horizontal, vertical, oblique, rotatory
3-Mixed nystagmus
-pendular in primary position, jerk on lateral
gaze
Physiological Nystagmus
1- Endpoint nystagmus: fine jerk nystagmus when eyes
are in extreme positions of gaze
Physiological Nystagmus
2-Optokinetic nystagmus: jerk nystagmus induced by
repetitive stimuli across the visual field.
• Optokinetic drum,
• slow phase is pursuit, fast is saccadic movement.
• pursuit by parieto-occipital
• saccadic by frontal
• detect malingerers and test children
• determines the cause of homonymous hemianopia
Physiological Nystagmus
3- Vestibular nystagmus:
Jerk nystagmus caused by altered input from the
vestibular nuclei to the horizontal gaze centers.
- pursuit by vestibular nuclei
- saccadic by brain stem
- caloric stimulation test
(COWS = cold-opposite, warm-same)
Congenital forms of nystagmus
 Infantile nystagmus
 Latent nystagmus
 Nystagmus blockage syndrome
Infantile nystagmus
 Inheritance XLR or AD
 Onset at age of 2-3 months, wide swinging eye
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horizontal movements
At age of 4 months, small pendular movements are
added
At age 6-12 months, jerk nystagmus and null point
develops
Compensatory head nodding develops
It may be dampened by convergence and is not
present during sleep
Infantile nystagmus
Etiology
 Idiopathic
 Albinism
 Aniridia
 Leber’s congenital amaurosis
Infantile nystagmus
 Differential diagnosis
 Opsoclonus
 repetitive , irregular eye movements by cerebellar or
brainstem disease
 Spasmus nutans
 uni/bilateral, small amp. /high freq,
 head nodding, head turn with nystagmus,
 onset 3months- 18 months, resolves between 3 years of
age.
 Glioma of the optic chiasm needs to be ruled out
 Latent nystagmus: worsens when one eye is closed
 Nystagmus blockage syndrome:strabismus with eyes and
head in a position to minimize associated nystagmus
Infantile nystagmus
 Workup
1- History
2- Ocular examination
3- CT and MRI to rule out organic pathology
Congenital forms of nystagmus
 Infantile nystagmus
 Latent nystagmus
 Nystagmus blockage syndrome
Latent nystagmus
 Dissappears when both eyes are open
 Horizontal nystagmus, when the other eye is covered
 Associated with infantile esotropia and dissociated
vertical deviation
 Fast phase in direction of fixating eye
 For testing visual acuity, fogging rather than occluding
the opposite eye
Congenital forms of nystagmus
 Infantile nystagmus
 Latent nystagmus
 Nystagmus blockage syndrome
Nystagmus blockage syndrome
Any nystagmus that;
• decreases when the fixating eye is in adduction
• demonstrates an esotropia to dampen the nystagmus.
Congenital forms of nystagmus
 Treatment
1-Maximize vision by refraction
2-Treat amblyopia
3-If small face turn; prescription of prism in
glasses
4-If large face turn; muscle surgery
Acquired forms of nystagmus
 Etiology
 Visual loss( cataract, cone dystrophy)
 Toxic- metabolic ( alcohol intoxication,
barbiturates, lithium, salicylates, other
antikonvulsants and seadtives)
 CNS disorders ( thalamic hemorrage, tumor,
stroke, trauma, MS)
Nystagmus with localizing neuroanatomic
significance
See-saw
-pendular oscillation that consists of
elevation and intorsion of one eye and
depression and extorsion of the fellow eye
that alternates every half cycle
-chiasmal and rostral midbrain lesions
Convergence-retraction nystagmus
 Contraction of the extraocular muscles,
particularly medial recti
 Convergence-like movements accompanied by
retraction of the globe into the orbit when the
patient attemps to look up.
 Pineal tumor
 Dorsal midbrain abnormality (vascular accidents)
Upbeat nystagmus
 Vertical, fast phase beating upwards
 Posterior fossa lesions, drugs, Wernicke
encephalopathy
Downbeat nystagmus
 Vertical, fast phase beating downwards
 Cervicomedullary junction lesions (Arnold-chiari
malformation)
 Drugs
 Wernicke encephalopathy
Periodic alternating nystagmus
 Jerk nystagmus with rythmic changes in
amplitude and in direction, usually every 2
minutes
 The cycle repeats continuously
 Cervicomedullary junction lesions
 Cerebellar disease
 Demyelination
 Trauma
 Drugs
Rebound nystagmus
 Triggered by changing direction of the gazes
 The lesion involves the cerebellum
Gaze evoked nystagmus
 Appears as the eyes look to the side
 Alcohol intoxication, sedatives, cerebellar
or brain stem disease
Vestibular nystagmus
 Horizontal or horizontal rotatory nystagmus
 May be accompanied by vertigo, tinnitus,
deafness
 due to dysfunction of vestibular endorgan,
eighth cranial nerve
Differential Diagnosis
 Superior oblique myokymia; small, unilateral,
vertical and torsional eye movements seen with a
slit lamp, benign, resolves spontaneously,
 Trt. with carbamazepine
 Opsoclonus: rapid, chaotic conjugate saccades,
drug intoxication, tm or following infarction.
 Myoclonus: pendular oscillation associated with
contraction of non-ocular muscles (tongue, fascial
muscles). Involves olive nucleus in medulla
Workup
 History: strabismus or amblyopia in childhood,
drug or alcohol use, vertigo, episodes of weakness,
numbness or decreased vision in the past?
 Family history: albinism, nystagmus, eye disorder?
 Ocular examination
 Eye movement recording
 Visual field examination (bitemporal hemianopia/
see-saw)
 Drug /toxin/dietary screen of the urine and serum
 CT or MRI scanning
Treatment
 Underlying etiology must be treated
 Periodic alternating nystagmus may respond to
baclofen.
 Severe disabling nystagmus can be treated with
retrobulber injections of botulinum toxin.
 Correction with prismatic glasses, contact lenses
 Orthoptic treatment
 Surgery