Understanding eye movement • Cranial n. – III(oculomotor n.), IV(trochlear n.) VI(abducens n.) • Steady on retina – Fixation: hold image of stationary object on fovea – Vestibulo-ocular reflex : hold image of stationary object on retina during brief movement – Optokinetic: hold the image steady on retina during sustained head movement
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Unilat. Or bilat. ProptosisLid retraction with lid lagPtosisOrbital congestionRestriction of EOMVisual loss d/t exposure, glaucoma, Compressive Optic neuropathy
Dx. CT or MRI - Enlarged EOMTFT – usually, normalAutoantibodies
Tx. Treat thyroid abnormalityLubricate corneaIOP controlPosition – Head elevation at nightOcular occlusion for diplopiaSteroids, surgery, radiation, stop smoking
Myositis
Clini-cal Px.
Pain over periorbital lesionPeriorbital sweling, proptosis, chemosisDiplopia, Restriction of EOMPtosis, Lid retractionEnlargement & enhancement of structure
Class Infectious – Trichinosis(parasitic infection), orbital cellulitis, abscessNon-infectious – pseudotumor(idiopathic inflammation of or-bital contents)
Clinical Px. Unilat. Or bilat. Fluctuating ptosisFluctuating binocular diplopiaWorsen after exercise, tired, improved with rest(sleep test)Ptosis improves with ice appliance(ice test)Pupil : always normalall EOM or limited to one EOMSystemic Sx. : swallowing difficulty, resp. sx.
Tx. Refer to neurologistPyridostigmin(Mestinon)CorticosteroidImmuneosuppressantsThymectomySx. Tx. Of diplopia, ptosis: surgery->rarely necessary, stable pt.
Ocular Myasthenia fluctuating
The lesion of Cranial n.
6th n. anatomy
– Nucleus(med. Dorsal pontomedullary jc.)(->contralat. MLF->subnucleus of 3rd n.) -> subarachnoid space->cav-ernous sinus(lat. of int. caroid a.)->sup. Orbital fissure, annulus of Zinn ->lat. Rectus m.
• Nucleus(periaqueductal gray matter)->Cross over (mid-brain)->subarachnoid space->Between cerebellar a. and post. cerebral a.->cavernous sinus(above V1)->sup. orbital fissure, annulus of Zinn->Sup. Oblique m.
4th n. palsy common cause
Head tilting
Evaluatioin
• Trauma? No further Work up• Pt (>50 yrs)– CBC, BC, CRP, ESR, glucose, lipid
• Brain MRI
3rd n. anatomy
• Complex of subnuclei(dorsal of midbrain) –>subarachnoid space->sup. Cerebral a. and post. Cerebral a.-> cavernous sinus->sup. orbital fissure, annulus of zinn->sup. division(levator, SR), inf. Division(parasym,MR,IR,IO)
Classification
Pupil muscle
Partial Not all muscle involved
Com-plete
Involvement
All muscle involved
Anisocoria
Sparing isocoria
3rd n. common cause
Evaluation
The lesion of multiple cranial n.
Orbital apex syndrome
• Combination of– Ophthalmoplegia (multiple cranial n. palsy)– Honer syn– Pain and V1 sensory loss– Visual loss
• Classic cause – Neoplasm, infection• Biopsy, CT, MRI
Cavernous sinus syndrome
• Combination of– Ophthalmoplegia (multiple cranial n. palsy)– Honer syn– Pain and V1 sensory loss
Lt. cavernous sinus menin-gioma
Cavernous sinus aneurysm
Miller Fisher syndrome
Triad
Ataxia
Ophthalmoplegia
Areflexia
The lesion of Internuclear or supranuclear
Horizontal gaze paresis
• Lesion of 6th n. nucleus– Loss of ipsilat. Voluntary and reflexive conju-
gate movement– Ipsilat. Facial weakness
Internuclear ophthalmople-gia
• Lesion of MLF– Ipsilesional deficit of adduction– Nystagmus– Convergence may overcome adduction deficit