Neuro-opthalmology always amazes me.
In this patient, there is L 3rd nerve palsy with sparing of the pupil - medical 3rd nerve palsy
Commonest cause are diabetes mellitus and hypertension.
When you get medical 3rd nerve palsy, check for diplopia then other cranial nerves. If only the 3rd nerve involve, test BP and blood glucose.
Other causes include - MS, trauma, collagen vascular disorder, syphilis,etc
It is wise to check for long tract signs and cerebellar signs.
Remember the fancy names ?
Weber syndrome - ipsilateral 3rd nerve palsy with contralateral hemiplegia (lesion in midbrain)
Benedikt's syndrome - ipsilateral 3rd nerve palsy with contralateral involuntary movements such as tremor, chorea and athetosis (lesion in red nucleus of midbrain)
Claude's syndrome - ipsilateral oculomotor paresis with contralateral ataxia and tremor( lesion in 3rd nerve and red ncleus)
Nothnagel's syndrome - unilateral oculomotor paralysis with ipsilateral cerebellar ataxia
To differentiate between central or peripheral - suspect central if unilateral 3rd nerve palsy with superior rectus palsy and bilateral partial ptosis/bilateral 3rd nerve palsy
Medical students : remember this !
SO4 LR6 - superior oblique by 4th CN, lateral rectus by 6th CN, the rest 3rd CN
9 comments:
ya..but, do you know why in medical causes the pupil size is normal, while in surgical causes, the pupil is dilated?
but, y in this pt, there seem no ptosis one?
I think because the pupillary fibres are the outermost that is why easily affected by compression
Yes, thanks anonymous. Yes, the parasympathetic fibres are located outer. I medical 3rd nerve, there is vasculitic changes in the inner fibres which does not supply the parasympathetic. Yes, I agree that this man doesn't have ptosis and not all cases are so classical :)
can we diagnose third nerve palsy depening only on the presence of diplopia on one gaze however the range of movement of the affected muscle is normal because recently I got a case of diplopia on looking upward to the left with disappearance of the outer image on covering the right eye however the range of ocular movement was normal bilaterally. the patient has concomitant URTI
cannot..
as there are other causes of diploplia on looking upward..
first, i think what you said is on looking upward, so it can be either superior recti or inferior oblique has the problem.
but, which eye is the affected?so, try to cover one eye look for disappearance of the troublesome diploplia image.
however, there are few conditions which the image still persists after covering the eye, and they are, as far as i still remember, are astigmatism and dislocated lens.
Moreover, if not mistaken, grave's disease also can cause diploplia, right?
and also, myasthenia gravis can have diplopia too...
is the patient has any other symptoms?
no other symptoms apart from sore throat few days ago and the diplopia is not persistent (NOT MONOCULAR)the outer hazy image disappear on covering the right eye
he doesnt have symptoms or signs of hypethyroidism or myasthenia gravis
I think it's INO~
Hello, how come for me it looks more like INO rather than 3rd nerve palsy? He can still look up, right? I just noticed that he couldn't adduct his eye.
Please clarify.
Thank you very much.
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