• Like
Ahd   neuro-opthalmology - v. patel - nystagmus (1)
Upcoming SlideShare
Loading in...5

Thanks for flagging this SlideShare!

Oops! An error has occurred.

Ahd neuro-opthalmology - v. patel - nystagmus (1)



Published in Health & Medicine , Business
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
No Downloads


Total Views
On SlideShare
From Embeds
Number of Embeds



Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

    No notes for slide


  • 1. Overview of NYSTAGMUSVivek Patel MD
  • 2. OBJECTIVES Definition, description Neuroanatomical basis Instrinsic localizing value Representative cases
  • 3. DEFINITION Disorder of ocular motor instability resulting inspontaneous, involuntary, rhythmic oscillationsof the eyes Congenital vs. acquired “jerk” nystagmus vs. pendular “true” nystagmus vs. nystagmoid movements
  • 4.  Conjugate vs. disconjugate vs. dissociated Trajectory may be horizontal, vertical, torsional,or mixed Description of amplitude, frequency, velocity,and intensity may vary with changes in gaze position May be influenced by the integrity of theafferent visual system May exhibit a “null” point
  • 5.  3 main mechanism of maintaining steadygaze: 1) fixation: a) prevent retinal image driftb) suppress unwanted saccades 2) VOR 3) eccentric gaze holding
  • 6.  Pulse (phasic) and step (tonic) outputs must bebalanced for appropriate gaze-holding. Significant cerebellar (vermis) calibration Horizontal: phasic = PPRFtonic = NPH, MVN = neural integratorsVertical: phasic = riMLFtonic = iNC = neural integrator
  • 7. NEUROANATOMICAL BASISLeigh & Zee, Neurology of Eye Movements, 3rded., 1998Leigh & Zee, Neurology of Eye Movements, 3rded., 1998
  • 8. Not always a sign of disease… Physiological: Usually conjugate Preserves clear vision during self-rotation unsustained end-point nystagmus Vestibular nystagmus (brief sustained rot.) OKN (visually driven….uses pursuit mech.)
  • 9. CHILDHOOD NYSTAGMUS Congenital nystagmus: usually recognized in first few months of life – life long May have good vision or poor vision Most often occurs in isolation (motor), but may be associatedwith albinism, LCA, achromatopsia, or optic atrophy Uniplanar, horizontal trajectory irrespective of gaze position No oscillopsia Reversal of OKN direction Exponential increase in slow phase velocity Conjugate Null point (may have resultant head turn) Amplified by attempted fixation (distant) Dampened by convergence and darkness Absent in sleep Association with esotropia
  • 10.  Latent nystagmus: Usually appears within first few months of life Horizontal jerk nystagmus appearing onlyunder monocular viewing conditions Fast phase beats away from occluded eye Strong association with esotropia Usually poor stereopsis May explain subnormal visual acuity testedmonocularly Manifest latent nystagmus: Present even when both eyes are open Loss of peripheral fusion
  • 11.  Monocular nystagmus of childhood: Usually monocular, vertical, low amplitude oscillation Eye with nystagmus may have afferent visual dysfunction Requires neuroimaging (chiasmal glioma) Spasmus Nutans: Asymmetric or monocular low-amplitude oscillations May be horizontal, vertical or torsional Head nodding Torticollis or abnormal head posture Begins in infancy, usually resolved by age 3 to 5 Requires neuroimaging
  • 13. PERIPHERAL VS. CENTRALVESTIBULAR NYSTAGMUSPERIPHERAL Severe vertigo Days to weeks duration Hearing loss, tinnitusassociated Usually horizontal withtorsion Very rarely purely vertical ortorsional Dampened with visualfixation Commonly peripheralvestibular organ dysfunction:labyrynthitis, meniere’sCENTRAL• None or mild vertigo• Often chronic• May be purely vertical ortorsional• visual fixation usually has noeffect• Etiologies commonlyvascular, demyelination,pharmacologic, toxic• Downbeat, upbeat, torsional
  • 14.  Gaze evoked nystagmus: One of the most common forms of centralnystagmus Inability to maintain eccentric gaze “leaky integrator” -- miscalibration between pulseand step inputs Symmetric cerebellar flocculus implicated Age, anti-convulsant therapy, alcoholicdegeneration, stroke, demyelination Baclofen effective
  • 15.  Downbeat nystagmus: Defect in vertical gaze holding Asymmetric inputs from vertical semi-circularcanals produce upward slow drift of eyes Defect in fastigial nuclei calibration Secondary downward corrective fast phase Obeys Alexander’s law Localizes to cervico-medullary junction Arnold-Chiari malformation Treatment with baclofen, clonazepam, base-outprisms
  • 16.  Upbeat nystagmus: Present in primary position or upgaze Classically localizes to a lesion of anterior cerebellarvermis More generally implicates posterior fossa disease Etiologies include stroke, cerebellar degeneration,demyelination, toxic exposures Periodic alternating nystagmus: Horizontal oscillation characterized by a periodic reversalin the direction of nystagmus due a shift in the null point Duration of cycles from 30 seconds to 6 minutes Classically a lesion of the cerebellar nodulus MS, drugs, ethanol, paraneoplastic syndromes Baclofen effective
  • 17. •Bruns nystagmus:• associated with CPA tumors• high frequency, low amplitudenystagmus (fast-phase away from lesion)• low frequency, large amplitudenystagmus on ipsilateral gaze (fast phasetoward lesion)• shift from eye movement response tovestibular imbalance to that of defectivegaze holding
  • 18.  See-saw nystagmus: Disconjugate vertical nystagmus (pendular vs. jerk) Upward moving eye intorts while downard eye extorts Localizes to lesions of diencephalon Visual fields may be useful (disruption of afferents to cerebellum) Ocular flutter/opsoclonus: Burst-like, incoordinated saccadic excursions with high frequency,low amplitude No intersaccadic latency Purely horizontal: ocular flutter Multiplanar: opsoclonus Reflect pause cell dysfunction (pons) Must consider paraneoplastic etiology: SCC of lung, ovarian,breast CA Neuroblastoma in children
  • 19. Acquired pendular nystagmus: Can be vertical, horizontal, torsional, or anycombination (usually one predominates) Usually disconjugate or dissociated Oscillopsia ++ MS, whipple’s, oculopalatal myoclonus Combination of afferent dysfunction andcerebellar calibration
  • 20.  Oculopalatal myoclonus: Vertical pendular eye movements associated with rhythmicupward movement of palate Caudal brainstem pathology: red nucleus, inferior olive, anddentate nuc. Convergence-retraction nystagmus: Commonly associated with dorsal midbrain syndrome May be associated with other Parinaud’s findings Not a true nystagmus: co-contraction of horizontal recti onattempted upgaze Localizes to pretectal area, posterior commissure, INC Pineal cyst or tumor, demyelination, stroke
  • 21. SUMMARY Recognize physiologic vs. pathological Appropriate characterization important Presence of nystagmus may correlate with significantafferent visual dysfunction Recognition of nystagmus may facilitate subsequentneurological or medical investigations (know where tolook) Treatment options do exist