Saturday, August 2, 2008

Internuclear opthalmoplegia


I am currently attending a MS workshop organised by KL GH with Bayer in Cyberview Lodge Resort & Spa. Nice place !

Well, multiple sclerosis is a common exam question and we discussed a little in the optic atrophy topic.

Remember that it is very common to be asked to examine the cranial nerves. Neuroopthalmology can be very interesting.

The above picture shows that the patient is looking to the right. There is failure of adduction of the L eye and nystagmus on the R eye.

The diagnosis is L INO (remember that the pathology is at the site of the failure if the abducted eye)

If you get bilateral INO - it is almost always MS especially when you see a young lady.

So if you get INO, remember to check for RAPD, Lhermitte's by flexing the neck, cerebellar signs and offer to do a fundoscopy to look for optic atrophy. You can also check the lower limbs for upper motor neuron signs in transverse myelitis and if you have that it is surely MS.

Where is the lesion ?

MLF - medial longitudinal fasciculus

Remember the pathway of PPRF and the 6th nerve. I am sure you can figure out the rest.

What is the criteria used for MS ?

Mc Donald's - previously it was Poser criteria

How would you investigate MS ?

MRI brain/spinal cord, neurophysiology study - VEP,SSEP, BAER, LP for oligoclonal band and IgG

McDonald's criteria focusses a lot on MRI.

What would you treat the patient in the acute phase ?

IV methylprednisolone

What is the long term treatment to reduce relapses ?

Beta interferon or glatiramer acetate

2 comments:

merlot said...

i recently examined a lady who supposedly had a right INO. She also has a dense cataract on her left eye and cannot even finger count (left eye). On examination, there is failure of adduction of her right eye; nystagmus on extremes of gaze bilaterally. Would she still qualify as having Right INO?

Anonymous said...

Interesting teaching regarding INO. Only one correction, the lesion is on the ipsilateral failure of adducted eye rather than abducted eye.