Neuro-ophthalmology Illustrated Chapter 8 – Optic Neuropathies 2

Questions:
18. Is the onset of optic neuritis acute or subacute?
19. Is the onset of most cases of optic neuritis painful or painless?
20. Can the pain precede the vision loss in optic neuropathies?
21. Is the pain from acute optic neuropathy usually exacerbated by eye movement?
22. How long does the loss of central vision progress?
23. What 8 factors should be evaluated in a patient with a suspected recent onset of optic neuritis?
24. Under what circumstances should a lumbar puncture be done in optic neuritis?
25. Is bilateral optic neuritis is more common in children than in adults?
26. In optic neuritis, under what circumstances should an MRI of the spine with contrast be obtained?
27. In optic neuritis, under what circumstances should NMO antibodies be obtained?
28. What are the 5 categories in the classification of optic neuritis?
29. Optic neuritis is associated with what 4 demyelinating conditions?  
30. What are examples of bacterial diseases associated with optic neuritis
31. What are examples of viral diseases associated with optic neuritis?
32. What are examples of parasitic diseases associated with optic neuritis? 33. What are examples of fungal diseases associated with optic neuritis?
34. What are the examples of post-vaccination optic neuritis?
35. What are the examples of inflammatory disorders associated with optic neuritis?

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Questions with answers:
18. Is the onset of optic neuritis acute or subacute?
Subacute

19. Is the onset of most cases of optic neuritis painful or painless?
Painful.

20. Can the pain precede the vision loss in optic neuropathies?
Yes.

21. Is the pain from acute optic neuropathy usually exacerbated by eye movement?
Yes.

22. How long does the loss of central vision progress?
It may progress for 7 to 10 days (visual acuity varies from a mild reduction to severe loss).

23. What 8 factors should be evaluated in a patient with a suspected recent onset of optic neuritis?
1. Cat exposure
2. Recent travel
3. Tick bite
4. Immunosuppression
5. Systemic symptoms and signs ( fever, lymphadenopathy, weight loss, skin lesions, cough, and arthralgias)
6. Neurologic symptoms and signs (focal neurologic signs; a history of vertigo, diplopia, numbness, Lhermitte sign, or Uhthoff phenomenon; headaches; and meningismus.)
7. Ocular findings including intraocular inflammation and retinitis.

24. Under what circumstances should a lumbar puncture be done in optic neuritis?
It is not usually required. An LP should be performed when an infectious cause or underlying systemic inflammatory disease is suspected, should always be obtained when the optic neuritis is bilateral and is obtained in most cases of optic neuritis in children.

25. Is bilateral optic neuritis is more common in children than in adults?
Yes.

26. In optic neuritis, under what circumstances should an MRI of the spine with contrast be obtained?
An MRI of the spine with contrast should be obtained if neurologic signs suggest spinal cord disease or if neuromyelitis optica (NMO) is suspected.

27. In optic neuritis, under what circumstances should NMO antibodies be obtained?
NMO antibodies: obtained in the serum of patients with bilateral optic neuritis, recurrent optic neuritis, severe optic neuritis with poor visual recovery, or when there is a spinal cord lesion.

28. What are the 5 categories in the classification of optic neuritis?
1. Optic neuritis associated with demyelinating disease
2. Optic neuritis associated with infectious diseases
3. Optic neuritis associated with a recent vaccination (post-vaccination optic neuritis).
4. Optic neuritis associated with other inflammatory disorders
5. Isolated recurrent optic neuritis (autoimmune optic neuritis)

29. Optic neuritis is associated with what 4 demyelinating conditions?
1. Idiopathic optic neuritis
2. Multiple sclerosis
3. NMO (Devic disease)
4. ADEM (Acute Disseminated Encephalomyelitis)

30. What are examples of bacterial diseases associated with optic neuritis?
Bacterial infections: syphilis, cat scratch disease (Bartonella henselae ), Lyme disease, any bacterial meningitis, mycoplasma pneumoniae, tuberculosis, Whipple disease (Tropheryma whipplei)

31. What are examples of viral diseases associated with optic neuritis?
Herpes zoster, herpes simplex, HIV, Epstein-Barr, coxsackie, adenovirus, cytomegalovirus, hepatitis A and B, measles, mumps, rubeola, rubella

32. What are examples of parasitic diseases associated with optic neuritis?
Toxoplasmosis, cysticercosis, toxocariasis, intraocular nematode infection

33. What are examples of fungal diseases associated with optic neuritis?
Cryptococcosis, aspergillosis, mucormycosis, candidiasis, histoplasmosis

34. What are the examples of post-vaccination optic neuritis?
Hepatitis B virus; rabies virus; tetanus toxoid; variola virus; combined smallpox, tetanus, and diphtheria vaccine; combined measles, mumps, and rubella vaccine; influenza vaccine; bacille Calmette-Guérin (BCG).

35. What are the examples of inflammatory disorders associated with optic neuritis?
Sarcoidosis, Systemic lupus erythematosus, Sjögren syndrome, Polyarteritis nodosa, Wegener granulomatosis, Inflammatory bowel disease, Behcet, Bee and wasp stings, Isolated recurrent optic neuritis (autoimmune optic neuritis)

The information below is from Neuro-ophthalmology Illustrated-2nd Edition. Biousse V and Newman NJ. 2012. Thieme

8.4 Inflammatory Optic Neuropathy (Optic Neuritis)
Inflammation of the optic nerve is called optic neuritis. There are several different types of optic neuritis.

8.4.1 Characteristics
Optic neuritis is characterized by subacute, painful loss of central vision that may progress for 7 to 10 days (visual acuity varies from a mild reduction to severe loss); pain that is usually exacerbated by eye movement and may precede or coincide with visual loss; and abnormal color vision that is usually impaired out of proportion to visual acuity. Optic nerve appearance varies depending on which part of the optic nerve is inflamed. The term retrobulbar optic neuritis is used when the optic nerve appears normal in the acute phase. The terms anterior optic neuritis and papillitis are used when there is optic disc swelling. In both cases, temporal pallor of the disc develops 4to 6 weeks after visual loss. Optic nerve enhancement is often seen on orbital MRI.

8.4.2 Causes
There are multiple causes of optic neuritis, including infectious diseases, such as syphilis and cat scratch disease, and noninfectious inflammation, such as sarcoidosis. However, in most cases, optic neuritis remains idiopathic or is associated with multiple sclerosis. Optic neuritis may also be associated with other primary demyelinating diseases, such as NMO (Devic disease) and acute disseminated encephalomyelitis (ADEM).

8.4.3 Patient Evaluation
Evaluation of the patient includes checking for these characteristics:
● Cat exposure
● Recent travel
● Tick bite
● Immunosuppression
● Associated systemic symptoms and signs, including fever, lymphadenopathy, weight loss, skin lesions, cough, and arthralgias
● Associated neurologic symptoms and signs, including focal neurologic signs; a history of vertigo, diplopia, numbness, Lhermitte sign, or Uhthoff Phenomenon; headaches; and meningismus
● Associated ocular findings, including intraocular inflammation and retinitis.

The cause of optic neuritis is often suspected after the history and clinical examination.
Ancillary tests are obtained to confirm a presumed diagnosis.
Ancillary tests vary based on the foregoing evaluation and include the following:
● MRI of the brain and orbits with contrast (confirms optic nerve enhancement and looks for demyelinating disease in the brain)
● Chest radiograph (looking for sarcoidosis)
● Blood tests (vary based on presumed diagnosis): CBC, platelets, angiotensin-converting enzyme (ACE) level, and syphilis testing
● Lumbar puncture: performed when an infectious cause or underlying systemic inflammatory disease is suspected; should always be obtained when the optic neuritis is bilateral and is obtained in most cases of optic neuritis in children
● MRI of the spine with contrast if neurologic signs suggest spinal cord disease or if NO is suspected
● NMO antibodies: obtained in the serum of patients with bilateral optic neuritis, recurrent optic neuritis, severe optic neuritis with poor visual recovery, or when there is a spinal cord lesion or symptoms suggesting transverse myelitis

8.4.4 Classification
1. Optic neuritis associated with demyelinating disease
● Idiopathic optic neuritis
● Optic neuritis as a manifestation of any of the following:
 ○ Multiple sclerosis
 ○ NMO (Devic disease)
 ○ ADEM
2. Optic neuritis associated with infectious diseases
● Bacterial infections: syphilis, cat scratch disease (Bartonella henselae), Lyme disease, any bacterial meningitis, Mycoplasma pneumoniae, tuberculosis, Whipple disease (syphilis and cat scratch disease are the most common causes)
● Viral infections: herpes zoster, herpes simplex, HIV, Epstein–Barr virus, coxsackie virus, adenovirus, cytomegalovirus, hepatitis A and B virus, measles, mumps, rubella virus (herpes zoster is the most common cause)
● Parasitic infections: toxoplasmosis, cysticercosis, toxocariasis, intraocular nematode infection (toxoplasmosis is the most common cause)
● Fungal infections: cryptococcosis, aspergillosis, mucormycosis, histoplasmosis(cryptococcosis is the most common cause)
3. Post-vaccination optic neuritis
● Hepatitis B virus; rabies virus; tetanus toxoid; variola virus; combined smallpox, tetanus, and diphtheria vaccine; combined measles, mumps, and rubella vaccine; influenza vaccine; bacille Calmette-Guérin (BCG)
4. Optic neuritis associated with other inflammatory disorders
● Sarcoidosis
● Systemic lupus erythematosus
● Sjögren syndrome
● Polyarteritis nodosa
● Wegener granulomatosis
● Inflammatory bowel disease
● Behçet syndrome
● Bee and wasp stings
5. Isolated recurrent optic neuritis (autoimmune optic neuritis)

Reference: 1. Neuro-ophthalmology Illustrated-2nd Edition. Biousse V and Newman NJ. 2012. Thieme

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