Case #2 (2-6-2004)

CC: 32 y.o. woman examined in oculoplastics for evaluation and repair of LUL ptosis.

HPI: Patient noted progressive ptosis of the LUL for 5 years, which now blocks her vision. She has no other complaints or problems.

POH/PMH: Healthy, no history of eye problems.

EXAM:

Vision 20/20 OU without correction.
Extraocular motility with -2 elevation defect OU.
VF full OD, VF with ~20% superior VF cut OS.
Pupils: 5 mm in the dark, 3 mm in the light, no RAPD, equally reactive
IOP 18 mmHg OU
Anterior segment normal.
DFE normal.



Pt maintains chin up position. There's RUL retraction and marked ptosis OS. Palpebral fissures are 10 mm OD and 5 mm OS with palpebral function of 15 mm OD and 10 mm OS. You also notice a twitching of the LUL when the patient looks up after looking down.


Feel free to discuss the following:

What tests should you order (I'll post labs when asked for them)?

What's the differential diagnosis?

What's the diagnosis?

What is the treatment of choice, surgically and/or medically?

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Above image on SDN server:

Originally posted by Visionary
Is it artifactual or does the patient have a scar above the LUL? If it is a scar, what's the history?

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Originally posted by nyeyes
I'm thinking levator dehiscence vs horners vs pseudoptosis vs myasthenia.

any Hx of trauma, ptosis/miosis/anhydrosis, lung CA, cervical problems. Is her ptosis cong? Is there extra LUL skin to make it a pseudoptosis? any nerve or muscle issues? any Sx's of fatigue or problems chewing/talking?

I would like to find out: any imaging studies done, cocaine to Dx horners, myasthenia workup - edrophonium, Ab's, conduction studies.

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Her ptosis started 5 years ago. She has no other symptoms. She has no previous ocular surgeries. The scar above the LUL is a piece of scotch tape and an artifact.

nyeyes, nice differential. If you had to order one test, which one would it be?

Originally posted by nyeyes
b/c she didnt display the classic Sx's of horners, the 1st test i would prob do would be anti-Ach Ab's to check 4 myasthenia, whcih could present w/ only a ptosis.
also: is she a smoker? & is she complaining of any breathing/lung Sx's?

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Not a smoker and no breathing/lung symptoms.

1) I apologize, the pupils were 5 mm in the dark and 3 mm in the light. There was no anisocoria. Without anisocoria, a cocaine test for Horner's is not indicated.

2) Old photos confirmed that the ptosis started about 5 years previous.

3) The elevation defect was in both eyes as stated in the case. Forced ductions were negative.

4) MRI scan of the orbits and head were not ordered. There's a test we can do before ordering a MRI scan. Because the symptoms have been present for 5 years, it's not urgent to get a scan. A scan will be needed if the clinical workup is negative.

5) There was no jaw winking or myotonic dystrophy symptoms. There was only twitching of the LUL when looking up after maintaining downgaze.

6) There was no proptosis based on Hertel measurements.

7) We didn't check blood glucose in this case.

8) The VF defect OS was due to the LUL ptosis.

Originally posted by Garp
Hey Andrew-
Last ophtho rotation was in May, so I'm rusty on my eyespeak. Could you explain a few things just for curiosity's sake?
1) "-2 elevation defect"- how high does this scale go?
2) "DFE normal" - what is this abbrev. again?
3) What are expected normal palpebral fissure values, what is "palpebral function", and what is the normal reference value for that?

Thanks. Just trying to get the language down.

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Good questions.

1) The motility defect is usually rated on a scale of 1 to 5 (varies from physician to physician).
1= mild defect
2= mod defect
3= moves eye past midline slightly
4= cannot move eye past midline
5= no movement of eye in direction of gaze.

2) DFE= dilated fundus exam to look at retina and nerve

3) Normal palpebral fissues are about 10 mm. Palpebral function tests the function of the lid, and normal PF is usually 15+ mm. You place thumb firmly on their brow to alleviate accessory muscle involvement and measure the movement of the lid when they look up and down.

1. Does the ptosis worsen with repetition? Or worsen at night?
Any hand grip weakness with repetition?

Ptosis is worse with repetition and worse later in the day. There was no hand grip weakness or signs of skeletal muscle weakness.

2. Does the ptosis improve with rest (eye closure)?

Not significantly.

3. Was the ice-test done?

No... there's a quicker, more definitive test.

4. Is she taking any prescription drugs?

None

5. Is there a family history of autoimmune disorders?

None

6. Any diplopia?

None

Originally posted by cpw
was exopthalmometry done?

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Yes... no proptosis.

Originally posted by TomOD
Ah, come on Andrew,

You keep us in suspense too long. What's the answer?

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I'm letting the cases run about one week before I post the diagnosis.

I'm trying to post the cases once weekly, and I'm also waiting for space on my dept. server for the photos. I just realized that my High Speed Internet account will not be available after I move in 18 months!

This young woman presented with progressive LUL ptosis, Cogan's lid twitch, and bilateral ophthalmoplegia on upgaze. After careful history taking, she states that her RUL retraction is better and her LUL ptosis is less in the morning. Because of equal innervation of the levator (Hering's law), asymmetric ptosis may cause lid retraction on the opposite side as the patient is attempting to maintain lid opening. With lid retraction, you should think of thyroid disease, but usually we do not see ptosis with Grave's ophthalmopathy (however 5% of myasthenia gravis patients could have underlying Grave's).

Myasthenia gravis, although a systemic disease, may present with only ocular symptoms 50% of the time. Patients often present complaining of binocular diplopia, and the ocular motility deficits may mimic other neurologic disorders, e.g. 6th nerve palsy, 4th nerve palsy, internuclear ophthalmoplegia, etc... The hallmarks signs of myasthenia gravis include: fluctuation & fatigability, diplopia, ophthalmoplegia, ptosis, weakness of jaw, weak neck/trunk/limbs, dysphagia, hoarseness, dysarthria, and dyspnea. Clearly, some of these manifestations may be life threatening.

Because some patients with myasthenia may have an underlying thymoma, a CT scan of the chest should be performed. In this case it was negative.

We performed the Tensilon test (edrophonium chloride) IV. This is a short acting acetylcholinesterase inhibitor.

Photo of lids before Tensilon. Note the RUL retraction and LUL ptosis.




Photo of lids after Tensilon. Note the RUL retraction is less and the LUL ptosis improved.



Photo of lids after treatment with Mestinon (pyridostigmine bromide).



Diagnosis of myasthenia gravis can be confirmed by the presence of anti-Ach receptor antibodies, but a NEGATIVE result does not rule-out myasthenia gravis b/c the panel of antibodies screened is not complete. Also, a NEGATIVE Tensilon test does not rule-out the disease either. If myasthenia gravis is still suspected, then a Prostigmin test (longer acting acetylcholinesterase inhibitor) should be given with atropine (prevent life threatening bradycardia and respiratory depression). The ice or sleep test may also be useful.

Differential Diagnoses

* Myasthenia-like syndrome due to medications
* Chronic progressive external ophthalmoplegia (CPEO) & Kearns-Sayre syndrome
* Eaton-Lambert Syndrome
* Third-Nerve Palsy (must rule-out in young person b/c pupil involved third-nerve palsy in a young person WITHOUT vasculopathic risk factors is a PCOM aneurysm until proven otherwise)
* Horner's syndrome (look for anisocoria).
* Levator dehiscence or disinsertion.
* Thyroid disease
* Myotonic dystrophy
* Congenital fibrosis (b/c of the restriction of eye movements)

Originally posted by Redhawk
I have a question. Is a chest CT required for all patients with a diagnosis of Mgravis? During my reading I found that most younger patients (<40) tend to have thymic hyperplasia rather than a thymoma. Also, resection of a thymoma usually doesn't help those with pure ocular myasthenia. Just wondering because I didn't come across that info.

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We order chest CTs in neuro-op here at Iowa. I think most neuro-ophthalmologists will consider doing a chest CT b/c thymomas are surgically resectable.

I've also been taught that resection of a hyperplastic thymus can help reduce the symptoms of myasthenia gravis.

Resection of a thymoma may not help with pure ocular masthenia, but you wouldn't want a thymoma to remain undiagnosed due to its malignant potential and association with death.

http://www.emedicine.com/med/topic2752.htm

The 15-year survival rate of a person with an invasive thymoma is 12.5%, and it is 47% for a person with a noninvasive thymoma. Death usually occurs from cardiac tamponade or other cardiorespiratory complications.