| Affiliation |
(AGL) Chairman, Department of Ophthalmology, The Methodist Hospital, Houston, Texas; Professor of Ophthalmology, Weill Cornell Medicine, New York City, New York; (PD) Class of 2021, Baylor College of Medicine, Houston, Texas |
| Transcript |
You're talking about an acute and bilateral ophthalmoplegia. And usually the eye resident is going to encounter this in the emergency room. So if we have an acute, bilateral ophthalmoplegia, what should we be doing and what should we be thinking in the emergency room? I like the mnemonic "BMW," just like the car company. We have no proprietary interest in this company. And the "B" stands for "brainstem," and so that seems obvious when you have an ophthalmoplegia: it could be from cranial neuropathy, bilateral multiple cranial neuropathy. And that brainstem lesion could be demyelinating or could be ischemic stroke. The thing we are worried about with stroke is if it is "top of the basilar" syndrome where we have the vertebral artery occlusive occlusion and then the thrombosis that propagates, or maybe perhaps we might have a thromboembolic disease, or we might have the artery put pressure on the top of the basilar that is providing blood flow to both sides of the brainstem. So we really need to have a CT in the emergent setting of the head and if it's negative we have to do an MRI because we are looking for brainstem disease - either brainstem hemorrhage, demyelination, ischemia, infarction, something in the brainstem. (1:15) If we have a bilateral ophthalmoplegia and we have pupil involvement, then we still have to think about botulinum toxicity. As you know, Botox is used for wrinkles and for blepharospasms and hemifacial spasms; that is not the kind of botulinum exposure we're talking about. In the ophthalmoplegia patients, these are systemic botulinum toxicities that can be from consumption of food like the prototype, poorly canned food, but also wound botulism. So an acute, bilateral, painless ophthalmoplegia in an awake and alert patient who is paralyzed, with or without pupil involvement, we should still think about botulism being a very very common cause. So brainstem first, image. We also have to think about myasthenia gravis, but only if the pupil is spared. Myasthenia, as you know, does not affect the pupil clinically, and so we have acute bilateral ophthalmoplegia that is painless and pupil-spared, for us to consider myasthenia gravis. And that could be an emergency as well because it could be ocular and generalized myasthenia so we should admit them to the hospital. The other "M" is the Miller Fisher variant of Guillain-Barré syndrome. So normally in Guillain-Barré syndrome, it is an acute, inflammatory, demyelinating polyneuropathy characterized by an ascending polyneuropathy, and they might have areflexia and ataxia and a CSF abnormality called albuminocytologic dissociation, where we have an elevated CSF protein but a normal cell count. So, there's a variant of this Guillain-Barré syndrome, an acute inflammatory demyelinating polyneuropathy, that produces ophthalmoplegia, and that we call the Miller Fisher variant of Guillain-Barré syndrome. There may be a pre-existing trigger, most commonly and classically is an infection of Campylobacter jejuni diarrhea and the test is anti-GQ1b, and you can cover that in a whole another section. (3:10) And the "W", which is also covered in our YouTube video, is the "Wernicke". The Wernicke can definitely present with an acute bilateral ophthalmoplegia, or nystagmus, or both. So, in the ER, an acute bilateral ophthalmoplegia, first thing you want to be thinking about is "BMW": brainstem disease (image that), myasthenia, the Miller Fisher variant, and the Wernicke. In addition to that, we have to think about the "BMW" and the "CAR". The "CAR" is the cavernous sinus, so we have to have imaging, MRI, to make sure we're not dealing with a bilateral cavernous sinus lesion. And the CAR is carcinomatous meningitis, so we need to have a lumbar puncture if the MRI and CT are negative, and what we are looking for is infection or inflammation, but in addition, cancer - carcinomatous meningitis. So we have to make sure it's not regular meningitis, infectious meningitis, inflammatory meningitis, but also the carcinomatous meningitis. So if you just remember "BMW CAR", you'll be able to deal with the acute bilateral ophthalmoplegia in the emergency room. |
