Management Approach to Isolated Ocular Motor Nerve Palsies

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1 Management Approach to Isolated Ocular Motor Nerve Palsies Alfredo A. Sadun, MD, PhD Thornton Professor of Vision Doheny Eye Institute Departments of Ophthalmology and Neurosurgery Keck/USC School of Medicine

2 Efferent visual system--- III rd nerve IV th nerve VI th nerve

3 A little anatomy will be necessary

4 III The third nerve: Has the largest nucleus Most subnuclei Largest number of muscles to innervate

5 Complex anatomy but basically: Ptosis is bilateral SR contralateral

7 THIRD NERVE PALSIES The third nerve exits come into close approximation to the posterior communicating artery Pupillary fibers are peripheral

8 THIRD NERVE PALSIES Intracavernous segment of the third nerve Anatomy.. Close proximity to cranial nerves IV, V, and VI, the venous sinuses and the carotid artery. Clinical implications.. Within the cavernous sinus, an isolated 3 rd nerve palsy is less likely.

9 THIRD NERVE PALSIES Syndromes of the third nerve Pupil-sparing 3 rd nerve palsies Associated with microvascular disease 10% of microvascular 3 rd s s have pupil involved <5% of compressive 3 rd s s initially spare pupil Is the 3 rd complete or evolving?

microvascular 3 rd s s have pupil involved <5% of compressive 3

10 THIRD NERVE PALSIES Aberrant regeneration of the third nerve When 3 rd nerve fibers are disrupted, axonal sprouting into incorrect axon cylinders leading = (aberrant) reinnervation Classical sign is pseudo-von Graefe s lid retraction with down gaze Common causes are aneurysm, trauma, meningioma NEVER ISCHEMIC!

= (aberrant) reinnervation Classical sign is pseudo-von Graefe s lid

11 THIRD NERVE PALSIES Incidence in adults and children CAUSE Congenital Aneurysm Neoplasm Diabetes Trauma Inflammatory other ADULTS 0% 18% 18% 17% 12% 1% 35% CHILDREN 43% 7% 7% 0% 20% 13% 7%

12 IV The fourth nerve: Exits from the dorsal midbrain/pons Crosses under medullary vellum Wraps about brain stem Thinnest of the cranial nerves

14 What does the fourth cranial nerve do? It innervates the contralateral superior oblique muscle Primarily, it is an incyclotorter It is an infraductor when the eye is in adduction It may be an abductor

15 When to suspect a 4 th nerve palsy? Patients with sudden onset of vertical diplopia following closed head trauma Patients in the vasculopathic age group who have sudden onset of vertical diplopia Patients in adulthood with intermittent, gradually worsening vertical diplopia and spontaneous head tilt Congenital 4 th nerve palsies decompensate later in life

the vasculopathic age group who have sudden onset of vertical diplopia Patients in

16 When to suspect a 4 th nerve palsy?-2 When the neurologist can t t figure it out! When the ductions and versions seem full The diplopia must be unassociated with other neurological symptoms or signs; otherwise suspect skew deviation

17 Diagnosing a 4 th cranial nerve Use the 3-step 3 test Which eye is hypertropic? palsy Which gaze makes the hypertropia worse? Which head tilt makes the hypertropia worse? Or do the pen lowering test Which way does the arrow point?

18 Rough actions of non horizontal muscles SR IO IO SR IR SO SO IR

19 Right hyper SR IO IO SR IR SO SO IR

20 Right hyper; worse L gaze SR IO IO SR IR SO SO IR

21 Right hyper; worse L gaze; worse R head tilt SR IO IO SR IR SO SO IR

22 Pen test R SO Palsy

23 And bilateral 4 th nerve palsies? Right hypertropia on left gaze Left hypertropia on right gaze Torsional diplopia on down gaze Double Maddox rod test > 10 degrees

24 Work-up of isolated 4 th nerve palsy Clinical examination Regular follow-up Imaging rarely indicated

25 Treatment of 4 th nerve palsies 50% of traumatic 4 th nerve palsies resolve by 6 months >90% of microvascular 4 th nerve palsies resolve by 6 months Decompensating congenital 4 th nerve palsies (check vertical vergence amplitudes) -- are usually amenable to prism treatment Surgery consists of Ipsilateral inferior oblique recession

26 VI The sixth nerve: Begins at the floor of the IV th Ventricle The fascicle descends through the pyramidal tract Is fixed at two points

27 VI

28 Nucleus of the Sixth Cranial Nerve (Abducens) The VI th cranial nerve lies: Adjacent to the nuclei of V th, VII th and VIII th cranial nerves, the sympathetic pathway and the pyramidal tracts th,

30 Clivus portion of the VI th cranial nerve At the anterior clivus,, the nerve bends to course under the petroclinoid ligament and into Dorello s canal, where the nerve sheath adheres. Therefore VIths are NOT LOCALIZING!

31 Lesions of the petrous portion of the VI th cranial nerve Approximation of VI to the mastoid air cells, the nerve is susceptible to infection Gradinigo s Syndrome: Ipsilateral 6 th cranial nerve palsy Ipsilateral facial pain originally from mastoiditis; ; now Ca.

32 Causes of VI th cranial nerve palsy in children and adults Cause Unknown Trauma Neoplasm Ischemia Inflammation & Increased ICP Misc. Adults 22% 10% 30% 9% 5% -- 24% Children 9% 20% 40% 0% 22% 8% 1%

33 Clinical Approach to Isolated VI th cranial nerve palsies Etiologies Sudden onset VI th in the middle- aged or elderly patient having DM, HTN, or both are almost always microvascular. Spontaneous resolution within weeks Chronicity implies compression, necessitating imaging

35 Typical Diabetic Ophthalmoplegia Sudden onset Variable binocular diplopia 10 20% pain 6 caveats!

36 1.Pupil Involvement = Compressive

37 2. Multiple simultaneous cranial nerves is not microvascular

38 3. Must not be over 45 years of age

39 4. Signs and Symptoms of Temporal Arteritis -ESR - TA biopsy

40 5. Watch incomplete thirds carefully. They may evolve.

41 6. Recovery by 2-3 months. Otherwise, continue high viscosity workup.

42 What s s in the High Viscosity W/U? It It s s you that s s moving slowly First you do the obvious and urgent: If it looks compressive (e.g. pupil): MRI If it could be GCA: ESR, CRP, etc. Then you do the less obvious and less urgent in stages assuming no recovery 1) Blood testing, basic 2) Tensilon testing a month later 3) More exotic blood testing 4) MRI a month later

43 Blood Testing 1 (High Yield) Hgb A1c Electrolytes CBC, ESR, CRP Ab to AcetylCholine Receptors AB to MuSK (muscle specific kinase)

44 Blood Testing 2 (Low Yield) ANA RF Cholesterol Triglycerides Clotting factors Anti Cardiolipin Ab Anti Phospholipid Ab Anti Smooth muscle Ab

45 Then you can relax-- --Claude Monet

Doctor, I See Double : Managing Cranial Nerve Palsies

1 Doctor, I See Double : Managing Cranial Nerve Palsies Joseph W. Sowka, OD, FAAO, Diplomate Professor of Optometry Nova Southeastern University, College of Optometry 3200 South University Drive Fort Lauderdale,