1/”Now your mouth will drop when you see the cord compression we caused,” I said to my fellow looking at our targeted #bloodpatch CT, “But take a deep breath—that’s actually what we want.”
A #tweetorial about CSF leaks & blood patches! #medtwitter#CSFleak#neurotwitter#neurorad
2/Epidural blood patches (EBPs) have been around since the 60s. Blood was first injected in the epidural space to try to plug the leak in post-dural puncture HA. It has now been expanded to other CSF leaks. However, controlled studies are lacking & therefore methods vary greatly
3/No one is sure of how EBPs work. Some believe blood directly plugs the leak site. Other believe it’s a pressure effect--injected blood increases epidural pressure, squeezing the thecal sac like a stress ball, elevating subarachnoid CSF pressure to relieve low pressure HA.
4/In reality, it is probably both mechanisms. The pressure effect is likely what provides the immediate relief from the low pressure HA but the direct plug of the leak is likely what provides the long lasting effectiveness.
5/Since direct plugging likely gives long term relief, it’s important to patch the leak site, to increase the likelihood the blood will reach the defect. Finding the leak site could fill a whole other tweetorial. Today we will focus on how to treat the site after it’s found.
6/Leaks occur at 3 main sites: (1) Ventrally, usually from an osteophyte spike tearing the dura (2) At the nerve root sleeve, likely related to a leak from a leaking/torn nerve root sleeve diverticulum (3) Dorsally, usually related to a lumbar puncture or spinal intervention
7/To get a targeted patch for a ventral leak, a transforaminal approach w/a 22g spinal needle is used to access the ventral epidural space. Care should be taken to avoid the nerve root in the foramen. Both fibrin glue & blood are given to maximize the chance of plugging the leak
8/For a leak at the nerve root sleeve, a similar approach for a targeted patch is used, except the needle is stopped short in the foramen and blood/fibrin is given in this region.
9/For a nerve root sleeve leak targeted patch, one should see epidural reflux of contrast, to indicate the whole nerve root sleeve has been coated by the patch. For ventral leaks, it is important to confirm that blood has spread across the ventral epidural space to cover the leak
10/For a dorsal leak, the traditional interlaminar approach to the epidural space is used. This can be achieved using either fluoroscopy or CT depending on the site.
Choice of injection material/volume can and do vary for all these EBPs depending on the proceduralist
11/A significant volume should be given—bc the patch will shrink. I give at least 4cc fibrin & 5-10cc blood—depending on pt tolerance--this guides you. So cord compression is fine, as long as the toes can move. Patch will shrink—like this patch imaged on myelography 3 days later
12/Here is a 3D rendering of targeted EBPs/fibrin at 2 levels punctured during spinal stimulator insertion. You can see that over half the canal is filled by the patch. I always tell my fellows a little rhyme: Remember thecal sac compression will lead to symptom regression!
• • •
Missing some Tweet in this thread? You can try to
force a refresh
If you don’t know the time of stroke onset, are you able to deduce it from imaging?
Here’s a thread to help you date a stroke on MRI!
2/Strokes evolve, or grow old, the same way people evolve or grow old.
The appearance of stroke on imaging mirrors the life stages of a person—you just have to change days for a stroke into years for a person
So 15 day old stroke has features of a 15 year old person, etc.
3/Initially (less than 4-6 hrs), the only finding is restriction (brightness) on diffusion imaging (DWI).
You can remember this bc in the first few months, a baby does nothing but be swaddled or restricted. So early/newly born stroke is like a baby, only restricted
1/”I LOVE spinal cord syndromes!” is a phrase that has NEVER, EVER been said by anyone.
Do you become paralyzed when you see cord signal abnormality?
Never fear—here is a thread on all the incomplete spinal cord syndromes to get you moving again!
2/Spinal cord anatomy can be complex. On imaging, we can see the ant & post nerve roots. We can also see the gray & white matter. Hidden w/in the white matter, however, are numerous efferent & afferent tracts—enough to make your head spin.
3/Lucky for you, for the incomplete cord syndromes, all you need to know is gray matter & 3 main tracts. Anterolaterally, spinothalamic tract (pain & temp). Posteriorly, dorsal columns (vibration, proprioception, & light touch), & next to it, corticospinal tracts—providing motor
1/Do you get a Broca’s aphasia trying remember the location of Broca's area?
Does trying to remember inferior frontal gyrus anatomy leave you speechless?
Don't be at a loss for words when it comes to Broca's area
Here’s a 🧵to help you remember the anatomy of this key region!
2/Anatomy of the inferior frontal gyrus (IFG) is best seen on the sagittal images, where it looks like the McDonald’s arches.
So, to find this area on MR, I open the sagittal images & scroll until I see the arches. When it comes to this method of finding the IFG, i’m lovin it.
3/Inferior frontal gyrus also looks like a sideways 3, if you prefer. This 3 is helpful bc the inferior frontal gyrus has 3 parts—called pars
1/Need help reading spine imaging? I’ve got your back!
It’s as easy as ABC!
A thread about an easy mnemonic you can use on every single spine study you see to increase your speed & make sure you never miss a thing!
2/A is for alignment
Look for: (1) Unstable injuries
(2) Malalignment that causes early degenerative change. Abnormal motion causes spinal elements to abnormally move against each other, like grinding teeth wears down teeth—this wears down the spine
3/B is for bones.
On CT, the most important thing to look for w/bones is fractures. You may see focal bony lesions, but you may not
On MR, it is the opposite—you can see marrow lesions easily but you may or may not see edema associated w/fractures if the fracture is subtle