The fact that this is available for free in youtube is just amazing. Thanks to whoever is posting them. And of course thank you Dr. Lee for letting them do it. Best regards from Costa Rica.
If I suggest that we do CT , CTA , MRI and MRA in the ER in my hospital I will be immediately expelled from the program for costing the hospital a lot of money lol. Anyway , that was a great video! Thank you so much !
It's a nice description of 3rd nerve, I however, would suggest a correction at 1:40, PComA runs medial to the basilar part of 3rd nerve, it was drawn laterally.
I have this since birth and got diagnosed when I was 11. . . I got a squint eye surgery to get my left eye to be fixated in the middle. . . Im really insecure to look at people and its really difficult for me to make eye contact. People tend to think of me as snobbish because of it and it really affected my confidence growing up with all of the bullying. Up until now, Im really insecure even to look in the mirror.
Terrified, double vision in both eyes, started suddenly 2 wks ago, urgent hospital test MRI does not show anything, I have occasional headaches but pain in right eye I had thyroid nodules 2mm a yrs 3 unfounded biopsies 12 mos ago, thyroid appears normal size. Urgent labs tests says level are normal, diabetes type 2 has always been under control for 25 yrs, fasting 90 -115, avoid blood sugar spikes, but have every other 2-3 month to 170 but work fast to reduce within 1 hr. blood pressure normal, bad sleeping habits not enough rest, seen by 2 Drs but they are unsure of reasons, should not the MRI tell them? Not sure what to think, can you tell me whats wrong?
Have you ever encountered this as a sequela of trauma? Or specifically a sports head injury? In the absence of aneurysm or bleed, what else would be highest on the differential?
Not enough information to do a proper analysis, but I can provide you with some pointers to figure it out. Hopefully this problem of yours has already resolved... So 1st, is it a complete 3rd nerve palsy (surgical 3rd nerve) or is it a partial 3rd nerve palsy (medical 3rd nerve). Now tracing from where the 3rd nerve nucleus is all the way to the end organ which is the muscles levator palpebrae superioris, superior rectus, inferior rectus, medial rectus and inferior oblique. We can make educated guesses of the possible pathology if we have accompanying symptoms. So the 3rd nerve nucleui lies in the midbrain, it is the oculomotor nucleus and the edinger westphal nucleus. The oculomotor nucleus is in charge of the somatic/voluntary function where as the edinger westphal nucleus is incharge of the parasympathetic portion of the 3rd nerve. So if you have a gaze palsy at rest with the absence of mydriasis then it could be only the oculomotor nucleus is involved, if you have both the nucleus involved then you would have a complete ptosis of the eyelid and eye and the mydriasis of the pupil. In this instance the lesion could be in the brain stem but away from the CN3 nuclei or the lesion could be outside of the brain stem. So lets say it is the lesion is still in the brainstem the key giveaway is you have accompanying contralateral hemiparesis, hemiataxia and chorea-athetosis (read up on benedikt vs weber vs claude syndrome). So moving on with the course of the 3rd nerve, it exits the ventral midbrain surface and now enters the interpeduncular cisterns. If you have a posterior circulation aneurysm, it could impinge the 3rd nerve here and cause it's palsy. Moving ahead at the level of suprasellar cistern, if you have a pcom aneurysm it could cause the palsy. Moving ahead the nerve enters thru the cavernous sinus and lesion here could cause the 3rd nerve palsy and finally the nerve enters and innervates the eye muscles via the superior orbital fissure. So if you have some soft tissue edema or orbital wall fracture, it could be the cause for your palsy. There is also a published article about a case of isolated 3rd nerve palsy that you can reference. www.ncbi.nlm.nih.gov/pmc/articles/PMC3873360/
I’m curious if you’ve seen this often in Chiari patients (due to pressure on the brainstem.) I have a ptosis and anisocoria that seems to come and go, as well as convergence insufficiency. 7-8mm Chiari Malformation.
I have all the obvious symptoms of the 3rd nerve palsy: pupil dilation, Diplopia (comes and goes), a little drooping eyelid in the eye corner where the pain comes. But doctors can’t find out its reason and I am still without a diagnosis for the third year. It started with just pain and now the last year I am in despair, because of Diplopia. The MRI s and CTs don’t show anything to them😢
I was diagnosed 3rd CNP, my symptons are right eye 12 dioptor exotropia which wobbles and left eye strained.. Constant diplopia. Two muscle surgeries and prisms were all a failure and I resort to patching strained eye to eliminate blurry vision. Both neuro opthamalogist told me in my case nothing can be done.
Thank you very much for your teaching Dr. Lee. Very easy to understand. I'm trying to learn this topic but it seems like my textbook cannot give me enough information so I look it up online. Can you recommend me some kind of resources or books for a 3th-year medical student? My textbook just lists out the causes of 3rd nerve palsy without telling me which one is clinically important or the prevalence of the diseases so I want to know more. Thank you.
I am 27 years old male، I have bilateral unreactive dilated pupil since 1 year. No ptosis ، no other systemic involment، CT and MRI are normal. Dx is not known till.
The fact that this is available for free in youtube is just amazing. Thanks to whoever is posting them. And of course thank you Dr. Lee for letting them do it. Best regards from Costa Rica.
What a pleasure to learn from Dr. Lee! Respect, and thank you!
Thanks for putting out this video, Dr Lee. It has been awhile for me but now I watched it so I can send it to my son who is in med school now.
Sir, god bless you. May you live forever !
thank you DR.ANDREW it helps a lot
please upload video on CNIII sub nucleus and their specific enervation to the extraocular muscles
regards
If I suggest that we do CT , CTA , MRI and MRA in the ER in my hospital I will be immediately expelled from the program for costing the hospital a lot of money lol. Anyway , that was a great video! Thank you so much !
lol
Fantastic! You're an excellent teacher Dr Lee :) Made my revision a lot easier
Thank you sir, from Papua New Guinea🇵🇬
OMG, you are amazing. You help me to understand the concepts
This is a fantastic lecture. Greetings fro Sri Lanka
Thank you sir this is incredibly helpful and easy to memorize
It's a nice description of 3rd nerve, I however, would suggest a correction at 1:40, PComA runs medial to the basilar part of 3rd nerve, it was drawn laterally.
I have this since birth and got diagnosed when I was 11. . . I got a squint eye surgery to get my left eye to be fixated in the middle. . . Im really insecure to look at people and its really difficult for me to make eye contact. People tend to think of me as snobbish because of it and it really affected my confidence growing up with all of the bullying. Up until now, Im really insecure even to look in the mirror.
wow! this is sooo good
Terrified, double vision in both eyes, started suddenly 2 wks ago, urgent hospital test MRI does not show anything, I have occasional headaches but pain in right eye I had thyroid nodules 2mm a yrs 3 unfounded biopsies 12 mos ago, thyroid appears normal size. Urgent labs tests says level are normal, diabetes type 2 has always been under control for 25 yrs, fasting 90 -115, avoid blood sugar spikes, but have every other 2-3 month to 170 but work fast to reduce within 1 hr. blood pressure normal, bad sleeping habits not enough rest, seen by 2 Drs but they are unsure of reasons, should not the MRI tell them? Not sure what to think, can you tell me whats wrong?
Have you ever encountered this as a sequela of trauma? Or specifically a sports head injury? In the absence of aneurysm or bleed, what else would be highest on the differential?
Not enough information to do a proper analysis, but I can provide you with some pointers to figure it out.
Hopefully this problem of yours has already resolved...
So 1st, is it a complete 3rd nerve palsy (surgical 3rd nerve) or is it a partial 3rd nerve palsy (medical 3rd nerve).
Now tracing from where the 3rd nerve nucleus is all the way to the end organ which is the muscles levator palpebrae superioris, superior rectus, inferior rectus, medial rectus and inferior oblique. We can make educated guesses of the possible pathology if we have accompanying symptoms.
So the 3rd nerve nucleui lies in the midbrain, it is the oculomotor nucleus and the edinger westphal nucleus. The oculomotor nucleus is in charge of the somatic/voluntary function where as the edinger westphal nucleus is incharge of the parasympathetic portion of the 3rd nerve. So if you have a gaze palsy at rest with the absence of mydriasis then it could be only the oculomotor nucleus is involved, if you have both the nucleus involved then you would have a complete ptosis of the eyelid and eye and the mydriasis of the pupil. In this instance the lesion could be in the brain stem but away from the CN3 nuclei or the lesion could be outside of the brain stem. So lets say it is the lesion is still in the brainstem the key giveaway is you have accompanying contralateral hemiparesis, hemiataxia and chorea-athetosis (read up on benedikt vs weber vs claude syndrome).
So moving on with the course of the 3rd nerve, it exits the ventral midbrain surface and now enters the interpeduncular cisterns. If you have a posterior circulation aneurysm, it could impinge the 3rd nerve here and cause it's palsy. Moving ahead at the level of suprasellar cistern, if you have a pcom aneurysm it could cause the palsy. Moving ahead the nerve enters thru the cavernous sinus and lesion here could cause the 3rd nerve palsy and finally the nerve enters and innervates the eye muscles via the superior orbital fissure. So if you have some soft tissue edema or orbital wall fracture, it could be the cause for your palsy.
There is also a published article about a case of isolated 3rd nerve palsy that you can reference.
www.ncbi.nlm.nih.gov/pmc/articles/PMC3873360/
Thank you Doctor!
Hello Dr.
diplopia on lateral gaze and hemiparesis where do you localize the lesion
thank you
I’m curious if you’ve seen this often in Chiari patients (due to pressure on the brainstem.)
I have a ptosis and anisocoria that seems to come and go, as well as convergence insufficiency. 7-8mm Chiari Malformation.
I have all the obvious symptoms of the 3rd nerve palsy: pupil dilation, Diplopia (comes and goes), a little drooping eyelid in the eye corner where the pain comes. But doctors can’t find out its reason and I am still without a diagnosis for the third year. It started with just pain and now the last year I am in despair, because of Diplopia. The MRI s and CTs don’t show anything to them😢
So good.
I was diagnosed 3rd CNP, my symptons are right eye 12 dioptor exotropia which wobbles and left eye strained.. Constant diplopia. Two muscle surgeries and prisms were all a failure and I resort to patching strained eye to eliminate blurry vision. Both neuro opthamalogist told me in my case nothing can be done.
Thank you very much for your teaching Dr. Lee. Very easy to understand. I'm trying to learn this topic but it seems like my textbook cannot give me enough information so I look it up online. Can you recommend me some kind of resources or books for a 3th-year medical student? My textbook just lists out the causes of 3rd nerve palsy without telling me which one is clinically important or the prevalence of the diseases so I want to know more. Thank you.
among videos, try Dr Najeeb, it takes time to go through but worth it. Among books, Kenneth Lindsay, Blumenfeld or Claudia Krebs.
Does a stroke cause an ilpsilateral or contralateral CN III palsy pls?
Grateful for any help 🙏
Why not just MRI and MRA?
Is there a cure for this.
Time, mine lasted about six weeks.
@@ninaappelt9001 mine is caused by tumor
Thank you for explaining so clearly
Thank you very much Dr. Lee
Please where are you from?
hes in hpuston tx
I am 27 years old male، I have bilateral unreactive dilated pupil since 1 year.
No ptosis ، no other systemic involment،
CT and MRI are normal.
Dx is not known till.
Thanks Jackie Chan
Fun fact a whole bunch on doctors tried to find what caused my 3rd nerve palsy and came back with idiopathic.