Introduction to Neuro-ophthalmology

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This is the lecture I gave today for sixth year medical students in power point format. I had to remove some of the movies to limit file size.

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Introduction to Neuro-ophthalmology

  1. 1. Introduction to Neuro-Ophthalmology <ul><li>Raed Behbehani , MD FRCSC </li></ul>
  2. 2. Neuro-ophthalmology <ul><li>Diseases of the eye and the neurological apparatus that serves it (optic nerve and chiasm, cranial nerves, visual pathways and cortex). </li></ul><ul><li>60% of our brain is linked to vision </li></ul><ul><li>Afferent: Optic nerve, retina, chiasm, visual pathyways, cortx. </li></ul><ul><li>Efferent: Cranial nerve III,IV,VI, ocular muscles, brain stem control centers. </li></ul>
  3. 3. Afferent System
  4. 4. Efferent System Cranial Nerves III, IV, VI Horizontal and Vertical Gaze Center Smooth Pursuit and Saccade control
  5. 5. Symptoms <ul><li>Loss of vision (transient, constant, mono- or binocular). </li></ul><ul><li>Diplopia. </li></ul><ul><li>Ptosis. </li></ul><ul><li>Visual disturbances. </li></ul><ul><li>Pupil irregularities. </li></ul><ul><li>Eyelid or Facial spasms. </li></ul>
  6. 6. Clinical Approach <ul><li>History is the most important part or the assessment. </li></ul><ul><li>“ Where” is the lesion ? </li></ul><ul><li>“ What” can be the lesion ? </li></ul><ul><li>Is this an emergency ? </li></ul>
  7. 7. Diseases of the Afferent System <ul><li>Optic neuritis </li></ul><ul><li>Ischemic optic neuropathy (Arteritic vs Non-Arteritic) </li></ul><ul><li>Other optic neuropathies (compressive, papilledme, inflammatory, heriditary). </li></ul><ul><li>Chiasmopathies. </li></ul><ul><li>Strokes causing visual field defects. </li></ul>
  8. 8. Diseases of the Efferent System <ul><li>Cranial Neuropathies (III, IV, VI). </li></ul><ul><li>Nystagmus. </li></ul><ul><li>Ocular Myasthenia. </li></ul><ul><li>Blepharospasm, Hemifacial Spasm. </li></ul><ul><li>Pupillary Abnormalities. </li></ul>
  9. 9. What I can do for a patient with vision loss? <ul><li>Before you refer, you can do a lot ! </li></ul><ul><li>History : Sudden or chronic (urgency) </li></ul><ul><li>Check visual acuity (use near vision cards). </li></ul><ul><li>Check for relative afferent pupillary defect. </li></ul><ul><li>Do a visual field by confrontation. </li></ul><ul><li>Ophthalmoscopy. </li></ul>
  10. 10. How to check for RAPD
  11. 11. Visual Field by Confrontation
  12. 12. Direct Ophthalmoscopy
  13. 13. Optic Neuritis <ul><li>Sudden loss of vision. </li></ul><ul><li>Pain with eye movements. </li></ul><ul><li>Females > Males. </li></ul><ul><li>RAPD present. </li></ul><ul><li>Optic disc normal. </li></ul><ul><li>MRI is important for MS risk determination. </li></ul>
  14. 14. MRI in optic Neuritis White matter lesion predicts high risk for development of MS ( 70% over 15 years)
  15. 15. Ischemic Optic Neuropathy <ul><li>Age > 50. </li></ul><ul><li>Acute , painless , loss of vision. </li></ul><ul><li>Diabetes, hypertesnion, and hyperlipedemia. </li></ul><ul><li>RAPD present. </li></ul><ul><li>Ophthalmoscopy : disc edema +- hemorrhage. </li></ul>
  16. 16. Ischemic optic neuropathy
  17. 17. Arteritic Ischemic Optic Neuropathy <ul><li>Patient > 60. </li></ul><ul><li>Headache, malaise, myalgia, weight loss fever, jaw claudications, and transient loss of vision. </li></ul><ul><li>ESR, CRP are high. </li></ul><ul><li>Need to start systemic steroids immediately and do then do a TA biopsy. </li></ul>
  18. 18. Temporal Arteritis
  19. 19. Retinal Artery Occlusion <ul><li>Painless loss of vision. </li></ul><ul><li>May be preceded by Amaurosis Fugax. </li></ul><ul><li>Source of emboli usually carotid or cardiac. </li></ul><ul><li>Less common causes: Vasuclitis (GCA, Anti-phospholipid syndrome). </li></ul><ul><li>Order Carotid Doppler Study and, Echocardiography. </li></ul>
  20. 20. Central Retinal Artery Occlusion
  21. 21. Branch Retinal Artery Occlusion
  22. 22. Compressive lesions <ul><li>Slowly progressive loss of vision. </li></ul><ul><li>Can by uni-lateral or bilateral. </li></ul><ul><li>Pituitary tumors, craniopahryngiomas, and meningiomas of the skull base. </li></ul><ul><li>Require neuro-imaging (MRI) for diagnosis. </li></ul>
  23. 23. Visual field defects
  24. 24. Pituitary tumors
  25. 25. Pituitary Tumors
  26. 26. Homonymous Hemianopsia
  27. 27. Papilledema <ul><li>Disc edema due to raised intracranial pressure (mass, pseudotumor cerebri). </li></ul><ul><li>Headache, transient visual obscurations, Diplopia, and tinnitus. </li></ul><ul><li>Normal visual acuity and visual fields early. </li></ul><ul><li>Ophthalmoscopy. </li></ul><ul><li>Urgent CT scan of the head with contrast. </li></ul>
  28. 28. Papilledema
  29. 29. Idiopathic Intracranial Hypertension (pseudotumor cerebri) <ul><li>Women > Men (9:1) in childbearing age. </li></ul><ul><li>90% of affected women are obese. </li></ul><ul><li>Normal CT/MRI/MRV and CSF analysis. </li></ul><ul><li>Recent weight gain (last 6 months). </li></ul><ul><li>Medications-linked : Tetracycline for acne , oral contraceptives, insulin-like growth factors in children. </li></ul><ul><li>Aim of treatment is stop progressive loss of vision (Diuretics and Surgery). </li></ul>
  30. 30. Diplopia <ul><li>Key question “Is it only in one eye ?” , “ Does it go away when you close either eye ?” </li></ul><ul><li>Monocular diplopia is always refractive in origin (cataract, astigmatism). </li></ul><ul><li>Examine lids and pupils in addition to eye movement. </li></ul><ul><li>Examine all cranial nerves. </li></ul>
  31. 31. Oculomotor Nerve Palsy
  32. 32. Pupil-involving Third Nerve Palsy UrgentMRI/MRA or MRI/CTA
  33. 33. Abducens Nerve Palsy
  34. 34. Trochlear Neve Palsy <ul><li>Patients complain of vertical diplopia. </li></ul><ul><li>Can present with abnormal head tilt. </li></ul><ul><li>Can be congenital or acquired. </li></ul>
  35. 35. Trochlear Nerve Palsy - Head Tilt Test
  36. 36. Cranial Neuropathies (III,IV,VI) <ul><li>Ischemic (diabetes, hypertension and hyperlipidemia). </li></ul><ul><li>Demyelinating. </li></ul><ul><li>Compressive (tumor, aneurysm). </li></ul><ul><li>Trauma. </li></ul><ul><li>Raised ICP. </li></ul>
  37. 37. Multiple Cranial Neuropathies (III,IV,VI) <ul><li>Ischemic cranial neuropathies are almost always isolated. </li></ul><ul><li>If multiple simultaneous CN, suspect lesion in the posterior orbit/cavernous sinus region. </li></ul><ul><li>Usually due to mass lesion. </li></ul>
  38. 38. Cavernous Sinus
  39. 39. Ocular Myasthenia <ul><li>Myasthenic signs restricted to the ocular muscles. </li></ul><ul><li>Fatiguable diplopia and ptosis. </li></ul><ul><li>Ice test or rest test in the clinic demonstrate improvement. </li></ul><ul><li>Acetylcholine receptor antibodies (positive in 50 % only). </li></ul><ul><li>Single fiber EMG. </li></ul>
  40. 40. Ocular Myasthenia before ice test after ice test 2 minutes
  41. 41. Pupillary Abnormalities <ul><li>Anisocoria : Unequality of pupils size. </li></ul><ul><li>It can be accidental discovery. </li></ul><ul><li>Physiologic in 40% of patients </li></ul><ul><li>It can be isolated or associated with lid or ocular motility abnormalities. </li></ul><ul><li>Can be iatrogenic or self-induced (pharamacologic). </li></ul><ul><li>N </li></ul>
  42. 42. Pupil Examination <ul><li>Shine light directly at pupil (light response). </li></ul><ul><li>Test near response (miosis with accomodation). </li></ul><ul><li>Check pupil sizes and measure it in both light and dark. </li></ul><ul><li>Parasympathetic (constrict) and Sympathetic (dilate) control. </li></ul>
  43. 43. Pupil Light Reflex
  44. 44. Diagnosis ?
  45. 45. Horner Syndrome <ul><li>A defect in oculosympathetic flow to the eye (pupil does not dilate in dark). </li></ul><ul><li>Ptosis, miosis and pseudo-enophtalmos. </li></ul><ul><li>Internal carotid artery dissection, neck trauma or surgery, brain stem strokes (Wallerburg Syndrome), Apical lung tumors. </li></ul><ul><li>Urgent MRI/MRA of the head and neck for acute Horner’s Syndrome. </li></ul>
  46. 46. Oculosympathetic Pathway
  47. 47. Adies Pupil <ul><li>Pupil is larger with light/near dissociation (pupil does not constrict well to light but does for near). </li></ul><ul><li>Can be associated with diminished deep tendon reflexes (Holmes-Adies Syndrome). </li></ul>
  48. 48. Benign Essential Blepharospasm
  49. 49. Hemifacial Spasm
  50. 50. Summary <ul><li>Neuro-ophthalmic problems of the afferent and efferent visual system are common. </li></ul><ul><li>Afferent diseases include optic nerve, chisamopathies and visual pathway diseases. </li></ul><ul><li>Efferent diseases include cranial neuropathies, pupillary abnormalities and facial spasms. </li></ul><ul><li>There is no substitute for good medical history and examination. </li></ul>

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