M. SOLTAN SANJARI, M.D. RASSOUL AKRAM HOSPITAL I. U. M. S. NYSTAGMUS M. SOLTAN SANJARI, M.D. RASSOUL AKRAM HOSPITAL I. U. M. S.

NYSTAGMUS Nystagmus is a rhythmic oscilation of one or both eyes about one or more axes.

NYSTAGMUS Ethiology 1. Secondary to visual deficit 2. Secondary to intracranial lesions and drug toxicit 3. Congenital benign idiopathic

NYSTAGMUS Mechanisms: 1. The nystagmus intensity is too high, or vision is too poor for complete suppression 2. Concomitant disorder of the smooth pursuit system 3. The fixation and smooth pursuit systems are themselves at fault

NYSTAGMUS Classification: 1. Clinical appearance 2. The waveform as revealed by ENG 3. Etiological grounds

NYSTAGMUS Terminology: Congenital Jerk and Pendular Nystagmus 1.Sensory Defect Nystagmus (SDN) 2. Congenital Idiopathic Nystagmus (CIN) Jerk and Pendular Nystagmus Axes of Oscillations Direction Null Zone Amplitude, Frequency, Intensity

NYSTAGMUS Terminology: Manifest, Latent, Latent Component Gaze-evoked, Gaze-paretic, Gaze-dependent Asymmetry and Dissociated

NYSTAGMUS Examination: Family History Time of onset Ocular Examination ERG, PVEP ENG

NYSTAGMUS ENG 1. Jerk N. with an accelerating slow phase 2. Jerk N. with an decelerating slow phase 3. Constant velocity or linear slow phase 4. Pendular N.

NYSTAGMUS Physiologic Nystagmus 1. OKN 2. Induced Vestibular N. 3. End Point N. 4. Voluntary N.

Voluntary

Vestibular

OKN

NYSTAGMUS Latent Nystagmus (LN): Most common Before 6 mo. Horizontal, Jerk, Conjugate Wave form Primary position, Add., Abd. Head turn Genetic factor

MLN plus Alternating fixation strabismus fast phases always in the direction of the fixating eye misdiagnosed as having CN, because the nystagmus is present with both eye opens

NYSTAGMUS SDN, and CIN: Sensory Defect ? Incidence 9/1 Horizontal, Circumrotatory in early infancy Null Zone ( 1/3 is eccentric ) Intensity Inheritance Optokinetic Response Wave form Visual Performance Oscillopsia

Congenital nystagmus Characteristics: Binocular Similar amplitude in both eyes Usually uniplanar (horizontal) in all gazes Diminished by convergence Increased by fixation attempt Superimposition of latent component Abolished in sleep Head oscillations

Head posture

Wandering eye

Sensory Defect Nystagmus Consequent to bilateral visual loss cannot be distinguished from CIN in a patient with coexisting primary visual abnormalities. Monocular visual loss may produce monocular nystagmus, usually vertical, at any age from birth through adult life (it may mimic spasmus nutans, particularly if there is associated head nodding)

NEUROLOGICAL AND NEUROMUSCULAR NYSTAGMUS Gaze Paretic Nystagmus The most common form of N. after infancy Mismatch between gaze-holding circuit and EOM dynamics Head thrusts Cerebellar Disease, Drugs, Myasthenia, Vestibular Disease, …………….

NEUROLOGICAL AND NEUROMUSCULAR NYSTAGMUS Rebound Nystagmus Usually with GPN Unilateral or bilateral Not dependent to vision No change with illumination Flocculus tumors Chronic vestibulocerebellar disease

NEUROLOGICAL AND NEUROMUSCULAR NYSTAGMUS Acquired Pendular Nystagmus High frequency, Low frequency, Horizontal, Vertical, Circular, Elliptical, Unilateral, Bilateral Demyelinating, Oculopalatal myocolonus, Drugs, Glue stiffing, Late low vision, Neurodegeneratives, Chiasmal Glioma, Craniopharyngioma Head thrust

Acquired Pendular Nystagmus

Acquired Pendular Nystagmus

Acquired Pendular Nystagmus

Acquired Pendular Nystagmus

See-saw Nystagmus

NEUROLOGICAL AND NEUROMUSCULAR NYSTAGMUS See-saw Nystagmus Elevates and Intorts Depresses and Extorts Bitemporal hemianopia (Maddox 1914) Parasellar and Chiasmal Lesions Damage to the pathway of zonaincerta to the interstitial nucleus of Cajal (Thalamic lesion) Congenital and Idiopathic

See-saw Nystagmus

NEUROLOGICAL AND NEUROMUSCULAR NYSTAGMUS Vestibular Nystagmus Peripheral and Central Dizziness, Vertigo, Oscillopsia Central adaptation Recovery Nystagmus Vestibular Neuritis Positional Nystagmus Benign paroxysmal Positional Vertigo

NEUROLOGICAL AND NEUROMUSCULAR NYSTAGMUS Downbeat Nystagmus  Lateral gaze Craniocervical Abnormality, Cerebellar Degeneration,  ICP, Drugs, Nutritional Deficiencies Upbeat Nystagmus Pontomedulary Junction, Midbrain, Vermis Lesions Organophosphate Poisoning

Down beaten and horizontal Nystagmus MS

Upbeat Nystagmus

Upbeat Nystagmus

Downbeat Nystagmus

Downbeat Nystagmus

Downbeat Nystagmus

NEUROLOGICAL AND NEUROMUSCULAR NYSTAGMUS Torsional Nystagmus Sometimes only detect by ophthalmoscopy Midpontine , Central vestibular connections Lesions Part of SSN, Peripheral vestibular Nystagmus, SDN/CIN, LN.

NEUROLOGICAL AND NEUROMUSCULAR NYSTAGMUS Abduction Nystagmus INO, Myasthenia, After strabismus surgery Periodic Alternating Nystagmus Acquired. Part of SDN/CIN 90 Second each cycle Ping-Pong Gaze Lower brain stem, Cerebellar, Anomalies Drugs, Chronic alcoholism. Baclofen Sometimes useful

NEUROLOGICAL AND NEUROMUSCULAR NYSTAGMUS Epileptic Nystagmus Rare but may be the only sign of seizure Usually Horizontal Lid Nystagmus Usually associated with vertical nystagmus Icthal phenomenon, Posterior fossa lesions,

NEUROLOGICAL AND NEUROMUSCULAR NYSTAGMUS Convergence-Retraction Nystagmus Posterior commissure Lesions: Hemorrhage, Infarct, Demyelinating, Hydrocephalus. Downward OKN  CRN

NEUROLOGICAL AND NEUROMUSCULAR NYSTAGMUS Head Oscilations (Head shaking - Head nodding) 1. SDN/CIN 2. Bobble-Head Doll Syndrome 3. Spasmus Nutans

NEUROLOGICAL AND NEUROMUSCULAR NYSTAGMUS Spasmus Nutans (Nodding Spasm) Triad: 1. Asymetric APN 2.Head Nodding 3. Head Tilt or Turn 4mo. - 2 years improved before 5 years Poor Family ERG Neuroimaging

Management

Management Aims Vision improvement Oscillopsia Improvement Head posture elimination Treatment of Strabismus

Non-Surgical Management Treatment of amblyopia Refractive errors correction Minus therapy Partial field occlusion Contact lenses Prisms Head posture Vision

Non-Surgical Management Systemic medications Baclofen ( CN, See-saw, PAN ) Clonazepam ( Downbeaen ) Carbamazepine ( SO myokymia ) Botulinum toxin ( Diplopia, ptosis, filamentary keratopathy,... )

Surgical Treatment To eliminate a compensatory head posture To decrease nystagmus amplitude, or for both reasons strabismus surgery may convert manifest-latent nystagmus to latent nystagmus, causing improvement of binocular visual acuity

Head Turn “the eyes should always be shifted in the direction of the anomalous head posture” Head turn or tilt of more than 15 to 20 is of cosmetic or functional significance Ascertain beyond doubt by repeated examinations that the direction of the null zone and thus of the head turn is consistent

Head Turn Kestenbaum-Anderson Procedure Posterior Fixation Suture Modified Anderson Procedure Modification for coexisting heterotropia

Chin-Up or Down Large recession of vertical muscles Think about lids position Vertical R & R

Head Tilt Horizontal or vertical muscles displacement For head tilt to right: Transposing right SR nasally and right IR temporally and opposite in left eye or Supraplacement of right LR and infraplacement of right MR

To decrease nystagmus amplitude Large recession of 4 horizontal muscles Disinsertion and reinsertion of 4 horizontal muscles (Hertel)

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