What I see in your images doesn’t look like vascular compression. Your right IJV is definitely larger in diameter than the left, but it’s common for one IJV to be dominant & the other to be secondary so I’m guessing your left is your secondary IJV. Alternatively your IJVs could be compressed by the styloids where they enter the skull as it’s right near where the styloids are attached (mastoid process) though I can’t determine that from your images. Thick styloids can sometimes cause compression at that higher level. It does not look like you have compression caused by your C-1 vertebra w/ your head in the position in the scan.
Some people have intermittent compression which happens only when the head is in certain positions i.e. looking up/down, left/right, diagonally left/right, etc. The best way to determine if there is compression is by having a dynamic CT w/ contrast i.e. a CT w/ the head in various positions rather than just in neutral.
Do you have any of the symptoms of IJV compression?
I would guess possible mild compression up high. But my larger suspicion is for nerve compression…vagus nerve and likely some others. Thanks so much for your input!!!
The vagus nerve runs right along the jugular, within the carotid sheath.
@1speechpick First of all I am not a doctor or radiologist so this is purely observational on my end. It is hard to discern any meaningful pathological (disease causing) compression from the 3 slides you put on here without examining the whole CT scan. Having said that, I suspect you might have slight compression on your carotid/carotid sheath by the right Styloid but I can’t say it for sure until I examine the axial images to see if the right Styloid is touching your right carotid. So this can potentially cause compression/irritation of Sympathetic plexus nerve which can manifest as neck pain, headache, eye pain, tinnitus, or dizziness. Also if you have compression on Vagus nerve, it can cause stomach issues. These 2 nerves run along the Carotid sheath so it is possible they are being irritated. I also noticed that your left Hyoid greater horn lies in between the left Carotid artery bifurcation (where it branches into external & internal carotid arteries). This is also associated with a rare syndrome called Carotid Artery Entrapment which can cause all kind of symptoms. It also lies close to Hypoglossal nerve which can cause tongue issues if irritated. So bottom line is, you need to investigate whether your right Styloid is slightly compressing Carotid sheath or if the left Hyoid greater horn is touching one of the branches of your carotid arteries. More images showing the front views would be helpful in the case of Hyoid greater horns to see if they are touching the carotid branches. What are your symptoms? do you have them more when you turn/rotate your neck?
Here is an image from the internet to show you different cranial nerves and the close proximity to the carotid artery
Blue circle shows the area of interest if there was any contact between the right styloid and your carotid artery. It is not clear from this sagittal (side) view. Also, the Cyan arrow (outside the circle) on the second image shows what appears to be calcification of some kind which could potentially touch nerves. Axial view is required as shown on third image
This is an axial view from the internet showing a contact between the styloid and carotid artery. So You will need to examine the axial images in your CT similar to this one. If it is caused by rotation, you won’t be able to find compression on a static CT so you need a dynamic CT done first
Here is the left side showing what appears to be Carotid Artery Entrapment by the Hyoid Bone. I have discussed this before in another thread here called (Input on my 3D pictures?) as shown below. you can have a look but I am not sure you have the same issues as that lady had stroke like episodes.
@KoolDude : I can’t thank you enough for your information reply!!! This will give me a lot of information to discuss with my doctor. All of the symptoms you mentioned in your post, I have them all! The headache is all the time and feels like it comes from nerve pain. I also am very lightheaded and often feel like I’m going to pass out.
I had an appointment with my neurologist today, and he is actually concerned about possible Eagles. He wants to do a skull-base CT without contrast (I guess there is now a nationwide shortage of CT contrast). My thought is…the skull base CT will give information on sizing of styloids but it won’t tell us if the styloids (and other calcifications) are pressing on any ajdacant structures or nerves. Thoughts or opinions on that? What other test would be best?
How do I find the axial images on my head/neck CT angiogram? I did find a frontal view which somewhat shows the hyoid bone. The hyoid bone definitely sits higher on the left and is up against (? compressing) on the internal carotid artery…just like what you said.
Thanks again for your information!!!
@1speechpick I am not sure what the CT without contrast can tell that CT Angio with contrast can’t tell. I think it would be very difficulty to see any vascular issues with CT without contrast as the vessels need contrast to be fully seen. I think your Styloids are not elongated but they do not have to be long to cause vascular/nerve compression. All it takes is the wrong orientation & angle to cause problems. For example, My left styloid is 1.8 cm and is compressing my dominant jugular vein. So I would not seek another CT just obtain measurement as I believe the sizing can be obtained with the current contrast CT. You just need to play with 3D imaging tool to get to the Styloid and measure it. There is good tutorial in this site on free 3D Slicer software ( Making Your Own 3D Images from CT Scan- 3D Slicer Tutorial ). This brief tutorial contains on how to get to the Styloid on different position, you can then measure it with the 3D tool. In order to see the Styloid, you need to remove the frontal mandible bones so you could see whether it is contact with your vessels as well.
As far as Axial images are concerned, The CT Scan Series are labelled with Axial, Sagittal and Coronal. So you can view them with any DICOM viewer such as 3D slicer but you need to know how to get to the styloid and Carotid which might need a little learning on anatomy & how to read CT Scans.
So coming to the frontal view image you provided, the Hyoid bone is indeed between Carotid bifurcation, I can see that clearly that your left Hyoid Greater Cornu is in between the 2 branches of the Carotid artery and is in close proximity to the Interior one (possible touching it which can cause a whole host of symptoms) This needs to be investigated with Dynamic CT angiography at the neck level in order rule out if this is coming into contact with your Carotid Artery when you move your neck or swallow food as swallowing causes the Hyoid bone to move up. This could potentially mess with your Hypoglossal nerve causing tongue issues as well. This is condition (Carotid artery entrapment by the hyoid bone) is linked to stroke as well so the earlier you attend to it the better.
The cyan circle and arrow show where Left Hyoid Cornu might be messing with your Carotid.
The following images are from the study and see how similar your images on the Hyoid bone look to this one. There is also video animation in the study link which you can download and watch how the right horn of the hyoid bone is in between the two branches of the carotid (ICA & ECA)
Here is Study Link : Carotid artery entrapment by the hyoid bone
Here is link to video : Video from the study above to show you how the Hyoid is in between the Carotid branches
@1speechpick It is not normal at all to have the Hyoid Bone in between the branches of the Carotid artery and it is linked with Carotid compression, dissection etc as shown below study. For example, mine does not and many folks I have seen their hyoid bone does not sit in between the branches.
Study link: Carotid Artery Entrapment by the Hyoid Bone-A Rare Cause of Recurrent Strokes in a Young Patient - PubMed
@KoolDude . Thanks for your reply. I forgot to attach the image in my previous post. What do you think the white area on the carotid could be? Artifact, calcification? There’s a white area on the carotid just superior to where the hyoid meets the carotid.
@1speechpick Hard to tell whether it is an artifact of the 3D rendering tool or some early calcification on Carotid artery (which can happen normally or if it is being rubbed by the Hyoid bone). I drew another green arrow to show you another branch of the carotid artery which has white spots. So bottom line it does not show anything that will be meaningful in terms of Carotid disease. The bone being there is the major problem here.
@KoolDude thanks a bunch! I had carotid dopplers done recently and they were fine.
From my photos, it almost looks as though the hyoid has grown into the carotid.
@1speechpick Yeah it is entirely possible that there are no stenosis (narrowing) currently caused by Hyoid bone. It might be it is just touching it but causing no dissection or stenosis. This does not mean, it might not in the future so you need to have it investigated with dynamic imaging (moving your neck/head sideways, up/down and swallowing). Also, rubbing the carotid can cause sympathetic plexus irritation which can cause neck pain, eye pain, headache, dizziness…etc since it runs along the carotid.
You also need to investigate the right Styloid from different angels to see if it is also messing with your carotid at top level.
@KoolDude , yet it would seem that the course the of the hyoid up against the carotid is a disaster waiting to happen
@1speechpick yep but it might be contributing the issues you are already having such as base of the tongue tightness, lightheadedness/ near fainting, headache these are symptoms you can get with it. You might even get syncope with hyoid bone irritating the carotid. So I would not wait until you get carotid stenosis or stroke to address it.
Look at the red arrows pointing to the hyoid horn, hypoglossal nerve and tongue. See how close it is to the Hypoglossal nerve and keep in mind that this internet image is showing a normal hyoid bone which is not wedged against one of the carotid arteries. Now imagine the hyoid bone being inside the branching of the carotid artery
@KoolDude, I have an ENT appointment tomorrow morning, with someone one “the Eagles list”. This doctor also addresses hyoid bone issues. It seems possible I could have a 2 fold issue.
Question. Does the vagus nerve sit in close proximity to the carotid at the level of the hyoid bone? I’m wondering if the hyoid could be putting pressure on the vague nerve as well.
Thanks a million for your helpful posts!
@1speechpick If I was to bet on where Vagus nerve compression would occur it would be the styloid instead of the Hyoid bone as it is close to it than the hyoid. I am not saying it can’t happen with a cases of elongated hyoid horns but it is rare. So I would investigate the RIGHT STYLOID compression on both Vagus nerve and Carotid Artery. If you have many axial images at the carotid level we can investigate it. Also it is important to note that Vagus nerve or nerve compression in general can’t be easily seen in both MRI and CT scan so it assumed when a compression of the Jugular Vein or Carotid is caused by the Styloid process as it runs along these 2 vascular sheath. It is generally diagnosed when the Styloid is being removed through surgery. You will see cases like that in here.
One more thing I would like to add is that, a normal Hyoid Bone should look like your right Hyoid Horn which is not in the Carotid arteries. Perhaps, you could show that to the ENT.
If a styloid process is removed, where does the surgeon anchor the stylohyoid ligament?
Good question, I would have to be a surgeon to answer this so I plead ignorance on this. Simple answer, I really do not know. May be the folks that went through the surgery know from the surgeon. So I would leave it to friends like @Isaiah_40_31 or @Jules to answer this one.
They don’t anchor it anywhere, it’s just left loose at the styloid end (if there’s any calcification on it then that part should be removed) I don’t know why, but it doesn’t seem to make any difference if you don’t have it!
@1speechpick - I am wondering what your symptoms are? I couldn’t find them mentioned. I had compressed jugular veins. I had 5 doctors before I was referred to my 6th one that figured out what I had. My diagnosis was confusing because my symptoms were intermittent at first - depending on my head position. I actually had initial symptoms of carotid artery compression but I think my styloid(s) shifted in position to where they were severely compressing on my jugular veins instead.
I hope you find a doctor that will listen to your symptoms and be able to do the proper diagnostic testing to confirm the diagnosis. Don’t give up! Keep searching. You are worth it. Not many doctors have ever heard of Eagle Syndrome and even less know of the vascular or carotid variants. Even people in the professions that you would think should know, don’t know the symptoms. My son is an Emergency Medicine doctor. When I told him of my diagnosis, he had to look it up. He said that there are over 1000 rare diseases, so it is impossible for doctors to know all of them. It is frustrating. I would imagine everyone on this site has had to battle up hill to get their diagnosis. You are doing a great job researching your condition. Keep going until you find the solution you deserve.
I am attaching a photo of my 3D CT scan with contrast. You can see the shading on the jugular veins. That is the compression. Once the doctor saw this, it confirmed her diagnosis.