Gaze palsy

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Transcript of Gaze palsy

Gaze Palsy

Gaze Palsy Presenter- Dr Shubhangini J Moderator-Dr Monica Samant

Ocular Motor system-

Supranuclear structure 7pathway that descend into brainstem placed proximal to ocular motor nuclei FEF, infranuclear- structure & pathway that ascend in the brainstem to the ocular motor nuclei eg vestibular nuclei, internuclear- connection betn ocular motor nuclei eg MLF ,nuclear ocular motor nuclei themselves.2

Supranuclear control of ocular motility-

Eye Movements-

Versional movements are divided in fast eye movement-saccades,slow eye movements-pursuit4

Saccadic System-

Velocity of saccadic eye movement varies between 30-800 deg with duration of 2-140msec. Saccadic command originates from portion of premotor cortex ant to motor strip called FEF. Fibres travel down in anterior limb of int capsule reaching med cerebral peduncle. At the level of trochlear Nucleus decussate &synapse in horizontal gaze centre of pons PPRF. Gaze centre is ill defined struc. Extending from trochlear nucleus-abducen nucleus lying ventrally to reticular formation neurons within PPRF send message to paraabducens nucleus. Interneuron fibre decussate to opp. MLF Excitation of lt FEF causing RT horizontal saccade5

Malfunction in any of these subsystem can result in gaze abnormalitiesparallel control pathway 4 saccades originates in SC .lesion in FEF &SC leads transient C/L gaze dysfunction6

Smooth Pursuit System

7It is a slow movement ,maintain fixation on an object that is moving slowly in space,max velocity of 90/sec. Neural pathway arises in peristriate cortex of the occipital motor area (7&8) fibres descend &terminate in ipsilateral PPRF for horizontal pursuit ipsilateral mesencephalic reticular formation for vertical pursuit ---directly to ocular motor nuclei .rt occipital lobe controls pursuit to the right &left occipital lobe to the left

Brainstem nucleus primarily control vertical gaze is riMLF( sup to occulomotor nucleus in midbrain )projects dorsally to innervate 3 4 nerve,travelling through post commisure.upgaze paralysis is feature of dorsal midbrain syn(parinaud). Downgaze pathway originate in riMLF travels ventrally .B/L lesions are needed to effect downgaze located dorsomedial to red nucleus8

Vestibulocerebellar system-Important input of gaze systemModulate eye movementsStabilize eye against the gravitatinal & accelerational forceMaintaining clear vision

Info 4m utricule & saccules inititate eye movements, vestibular nuclei send afferent to I/P cerebellar hemisphere--- 3,4,6 nerves via MLF connections are C/L 3,4 nuclei. (The horizontal canal excites the ipsilateral medial rectus muscle and the contralateral lateral rectus muscle. The anterior canal excites the ipsilateral superior rectus muscle and the contralateral inferior oblique muscle. The posterior canal excites the ipsilateral superior oblique muscle and the contralateral inferior rectus muscle.

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Cerebellum-

Eye movementsFixation accuracySuppress the vestibulo-ocular reflexControls smoothness of pursuit movements Accuracy of saccades

Lesion of Supranuclear oculomotor pathways -Based on anatomical location-Lesions of internuclear systemImmediate premotor structure in the brainPPRFPosterior commisureRostral mesencephalonCerebral hemisphereDescending pathway from cerebral hemisphereSuperior colliculusThalamus

Clinical ExaminationAsymptomatic for gaze palsyBlurring of visionDiplopia

Diplopia is present in deficiencies of vergence movements ,disconjugate abnormalities such as skew deviation & INO12

Pre-requisite-Observe position of eye in primary gazeDuctions Versions & vergence Pursuit Saccades

Pt is asked to pursue a slow moving object with each eye separately (duction) together (versions&vergence) pic needed,performing saccades by looking quickly 4m primary position to eccentric gaze (examiner nose to examiners finger &back to nose up &down left & right)13

Oculocephalic maneuvers-Dolls eye reflexTilt the head 30 degree forward & fixate a distant targetRotate the head in direction opposite to gaze palsy Direct projection from vestibular system to ocular motor nuclei Prenuclear,nuclear infranuclear reflex does not overcomeLesion in cerebral cortex overcome by VOR

Diff btn supranuclear,nuclear,infranuclear lesions14

Vestibular ocular reflex -Tilt the head by 60 degree & irrigate external auditary meatus with cool/warm water In normal subject/supranuclear gaze palsy eye deviate towards the irrigated side- nystagmus with fast phase to opposite sideFast phase towards the stimulated eye when warm water is used

Supranuclear eye movement disorder-

Vertical gaze palsy-Midbrain lesionB/L cerebral hemisphere dysfunctionParkinsons diseaseProgressive supranuclear palsylipidosis

Lesion in dorsal midbrain upgaze paresis,lesion in ventral midbrain downgaze paresis.17

Parinaud syndrome-Dorsal midbrain syndromeLesion of posterior commisure & MRFCause- compression by mass in pineal regionDilatation of third ventricleMidbrain infarctionmultiple sclerosisAV malfomationPoor to absent upgazeConvergence retraction nystagmus in upgazeColliers signSetting sun sign

Convergence retraction nystagmus is not a true nystagmus, is unique part seen best when pt attempts to saccade up,on attempted fast up gaze eye pulls in &globe retracts (optokinetic drum with stripes moving downward pt makes attempt to correct upward saccades it converge &retracts the globe due co- contraction of EOM)Colliers sign- lid retractionSetting sun sign-conjugate downgaze in primary position18

Parinaud syndrome-EMG shows co-contraction of occulomotor innervated muscles- retraction of globeNeuroimaging scanSurgical treatment causes resolution of ocular findings

Upgaze palsy normal downgaze, horizontal movement, pupil mid dilated to light bt react to near reflex20

Hydrocephalous with parinauds syndrome21

Progressive supranuclear palsy- Lesion of mesencephalic structure-Steele-Richardson-Olszewski syndromeOnset after 40 yearsDisorder of basal gangliaMarked rigidity trunk & neckLittle tremorDifficulty with vertical eye movements down > upProgresses to horizontal gaze disorderEnd stage global ophthalmoplegia

Neurodegenerative disorder,Resembles parkinsons diseaseOculocephalic maneuvers/caloric test confirms supranuclear gaze palsy22

Progressive supranuclear palsy- Vertical direction more severely affected initially Voluntary saccades affected first, convergence, and smooth pursuit later Slowing of saccade velocitySupranuclear movements primarily affected (vestibulo-ocular reflex spared)Square wave jerksGait abnormalitiesNuchal rigidity

Progressive supranuclear palsy-Eyelid abnormalities: upper eyelid retraction reduced blink rate apraxia of eyelid opening blepharospasmPostural instability with falls (often backwards)Cervical and axial dystonia

Cardinal directions of gaze, showing limited range of voluntary ductions in all directions, with up and down-gaze most severely affected.25

Progressive supranuclear palsy-Wilsons diseaseHuntington diseasKernicterous

WD-saccades may be slowed and a supranuclear upgaze palsy may occur HD-Vertical saccades are affected more than horizontal saccades. Fixation instability is prominentKernicterus, or neonatal jaundice, can cause upgaze paresis, which usually is supranuclear Horizontal saccades may be slow.

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Parkinsons disease-Lesion of descending pathway from cerebral hemisphereUpgaze palsy affecting saccades followed by pursuitCogwheel pursuit

Saccades in other gaze slow smoothness of pursuit is disrupted27

Lipidosis-Lipid storage disease variant of niemann picks diseaseVertical saccadesIntact vertical oculocephalic maneuversProgressive dementia in late childhoodChoreoathetosishepatosplenomegaly

Whipples disease-Involvement of CNS supranuclear gaze palsyInitially verticalProgressive dementiaHypersomniaAtaxiaUveitis

Monoocular elevation paresis-No ocular deviation in primary gaze Inability to elevate one eyePrenuclear congenital unilateral midbrain lesion Oculocephalic maneuver is normal Lesion in pretectum Connection of riMLF to the occulomotor nucleiForced duction & tensilon test are negative

Condition may be congenital or aquired mimicked by muscle disease thyroid ophthalmopathy ,myasthenia gravis chr progressive external ophthalmoplegia30

Monoocular elevation paresis-

Double Elevator Palsy, is an inability to elevate one eye, usually resulting in one eye that is pointed downward relative to the other eye (hypotropia)Affected eye is usually elevated by bells reflex31

Skew deviation-Skew deviation is a vertical divergenceprenuclear lesion of the vertical vestibulo-ocular pathways in the brainstem or cerebellum.Comitant, associated with cyclotorsion of one or both eyes. Noncomitant it can mimic a partial third or fourth cranial nerve palsy

Skew deviation in primary gaze32

Skew deviation-Occur most commonly with vascular lesions of the pons or lateral medulla (Wallenberg's syndrome)lesions of the midbrain or upper ponsAlternating skew deviation, the hypertropia changes with the direction of gaze. The adducting eye usually is hypotropic,mimick superior oblique overaction.

Skew deviation-

Figure showing physiologic and pathologic skew deviation. In the physiologic ocular tilt reaction (left), the compensatory head tilt predominates, with only a small skew deviation or static ocular counterroll(Ocular counter-rolling is a normal vestibular reflex that allows people to maintain horizontal orientation of the environment ) In the pathologic ocular tilt reaction (ri