Assist.Prof. Dr.Vildan ÖztürkOphthalmology

Yeditepe University Hospital

NYSTAGMUS

DefinitionNystagmus 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 - coarsemoderate - high

Classification1-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 Nystagmus1- Endpoint nystagmus: fine jerk nystagmus when eyes

are in extreme positions of gaze

Physiological Nystagmus2-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 Nystagmus3- 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 nystagmusLatent nystagmus

Nystagmus blockage syndrome

Infantile nystagmusInheritance XLR or ADOnset at age of 2-3 months, wide swinging eye

horizontal movementsAt age of 4 months, small pendular movements are

addedAt age 6-12 months, jerk nystagmus and null point

developsCompensatory head nodding developsIt may be dampened by convergence and is not

present during sleep

Infantile nystagmusEtiologyIdiopathicAlbinismAniridiaLeber’s congenital amaurosis

Infantile nystagmusDifferential diagnosisOpsoclonus

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 closedNystagmus blockage syndrome:strabismus with eyes and

head in a position to minimize associated nystagmus

Infantile nystagmusWorkup

1- History2- Ocular examination

3- CT and MRI to rule out organic pathology

Congenital forms of nystagmus

Infantile nystagmusLatent nystagmus

Nystagmus blockage syndrome

Latent nystagmusDissappears when both eyes are openHorizontal nystagmus, when the other eye is covered Associated with infantile esotropia and dissociated

vertical deviationFast phase in direction of fixating eyeFor testing visual acuity, fogging rather than occluding

the opposite eye

Congenital forms of nystagmus

Infantile nystagmusLatent 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 nystagmusTreatment 1-Maximize vision by refraction

2-Treat amblyopia 3-If small face turn; prescription of prism in glasses4-If large face turn; muscle surgery

Acquired forms of nystagmus

EtiologyVisual 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 nystagmusVertical, fast phase beating downwards

Cervicomedullary junction lesions (Arnold-chiari malformation)

DrugsWernicke 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 diseaseDemyelinationTraumaDrugs

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 nystagmusMay be accompanied by vertigo, tinnitus,

deafness

due to dysfunction of vestibular endorgan, eighth cranial nerve

Differential DiagnosisSuperior 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

WorkupHistory: 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 examinationEye movement recordingVisual field examination (bitemporal hemianopia/

see-saw)Drug /toxin/dietary screen of the urine and serumCT or MRI scanning

TreatmentUnderlying etiology must be treatedPeriodic alternating nystagmus may respond to

baclofen.Severe disabling nystagmus can be treated with

retrobulber injections of botulinum toxin. Correction with prismatic glasses, contact lensesOrthoptic treatmentSurgery