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Myaesthenia gravis ocular variant name

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"ocular myasthenia gravis"

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ocular variant myasthenia gravis name

The ocular variant is called ocular myasthenia gravis (OMG) or ocular MG. It is myasthenia gravis limited to the eye muscles, typically causing fluctuating ptosis and/or diplopia. Bradley and Daroff's Neurology in Clinical Practice

Myasthesnia gravis variants

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"myasthenia gravis" AND classification

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myasthenia gravis clinical variants ocular generalized MuSK LRP4 seronegative congenital neonatal classification

Myasthenia gravis (MG) variants / subtypes

By clinical pattern

  1. Ocular MG (OMG)
    • Limited to extraocular and eyelid muscles
    • Ptosis and diplopia only
  2. Generalized MG (gMG)
    • Ocular symptoms plus weakness of bulbar, facial, neck, limb, and sometimes respiratory muscles
    • Bulbar-predominant MG causes dysarthria, dysphagia, and chewing fatigue.

By antibody status

  1. AChR-antibody positive MG
    • The most common autoimmune subtype.
    • May be ocular or generalized.
  2. MuSK-antibody positive MG
    • Usually generalized, often with prominent facial, bulbar, neck, and respiratory weakness.
    • May have relatively less ocular involvement.
  3. LRP4-antibody positive MG
    • Less common autoimmune subtype; may be ocular or generalized.
  4. Seronegative MG
    • No detectable AChR or MuSK antibodies on routine tests.
    • Some patients have LRP4, agrin, or other antibodies on specialized testing.

By age/associated condition

  1. Early-onset MG
    • Usually begins before age 50, more common in women, often AChR-positive and associated with thymic hyperplasia.
  2. Late-onset MG
    • Begins later in adulthood, more common in men.
  3. Thymoma-associated MG
    • MG associated with a thymic tumor, usually AChR-antibody positive.
  4. Juvenile MG
  • Autoimmune MG beginning in childhood or adolescence.

Related conditions, but not typical autoimmune MG variants

  1. Transient neonatal myasthenia
  • Temporary weakness in some newborns of mothers with autoimmune MG, caused by transfer of maternal antibodies.
  1. Congenital myasthenic syndromes (CMS)
  • Inherited neuromuscular-junction disorders, not autoimmune MG and not caused by AChR/MuSK antibodies.
A practical exam classification is: ocular vs generalized, then AChR-positive, MuSK-positive, LRP4-positive, or seronegative. The textbook also recognizes ocular, bulbar, generalized, congenital, and juvenile forms. MGFA subtype overview

ETM variant of myasthenia gravis

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"myasthenia gravis" AND "ETM"

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"ETM" "myasthenia gravis" variant

ETM is not a standard recognized abbreviation for a myasthenia gravis variant.
You may mean one of these:
  • EOMG: early-onset myasthenia gravis
  • TAMG: thymoma-associated myasthenia gravis
  • OMG: ocular myasthenia gravis
  • LEMS: Lambert-Eaton myasthenic syndrome, which is a different neuromuscular-junction disorder, not a variant of MG.
If “ETM” appeared in your notes or a question, send the exact sentence or an image and I can identify what it means.

Causes of isolated 3rd nerve unilateral palsy

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isolated unilateral third cranial nerve palsy causes pupil sparing aneurysm guideline

Causes of isolated unilateral third cranial nerve (CN III) palsy

1. Microvascular ischemia

Most common in older adults with vascular risk factors:
  • Diabetes mellitus
  • Hypertension
  • Atherosclerotic small-vessel disease
Usually painful, acute, and pupil-sparing. AAO review

2. Compressive lesions

Must be excluded urgently, particularly if there is a dilated or poorly reactive pupil.
  • Posterior communicating artery aneurysm: classic and dangerous cause
  • Internal carotid artery or basilar artery aneurysm
  • Tumors: parasellar/pituitary region, cavernous sinus, sphenoid wing meningioma, metastasis
  • Uncal herniation from an intracranial mass or hemorrhage
A painful, acute third-nerve palsy with ptosis, ophthalmoplegia, and a dilated pupil is a neurovascular emergency until an aneurysm has been excluded. AAO guidance

3. Trauma

  • Head injury
  • Orbital trauma
  • Skull-base fracture
  • Surgical or iatrogenic injury

4. Midbrain lesions

These often have additional neurological signs, but can occasionally appear near-isolated:
  • Ischemic stroke or hemorrhage
  • Demyelination
  • Tumor
  • Cavernoma

5. Inflammatory or infiltrative disease

  • Tolosa-Hunt syndrome
  • Sarcoidosis
  • Tuberculous, fungal, or carcinomatous meningitis
  • Vasculitis, including giant-cell arteritis in an appropriate clinical setting

6. Cavernous sinus or orbital apex pathology

Often later becomes non-isolated due to involvement of CN IV, CN VI, V1/V2, or sympathetic fibers:
  • Cavernous sinus thrombosis
  • Carotid-cavernous fistula
  • Cavernous sinus tumor/inflammation
  • Orbital apex lesion

7. Other causes

  • Myasthenia gravis: can mimic a CN III palsy, but typically causes variable ptosis/diplopia without pupillary involvement and does not follow an exact third-nerve distribution.
  • Ophthalmoplegic migraine, now termed recurrent painful ophthalmoplegic neuropathy
  • Congenital third-nerve palsy
  • Idiopathic palsy

Clinical rule

  • Pupil-involving or partial CN III palsy: urgent CTA/MRA to exclude aneurysm.
  • Even pupil-sparing palsy may require imaging, especially in younger patients, those without diabetes/hypertension, atypical or progressive palsy, severe pain, or no improvement. The textbook notes that a complete pupil-sparing palsy is most often ischemic, especially in diabetes, but pupil findings do not completely rule out compression. Localization in Clinical Neurology
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