bjjdissection.org

Injury types

Two arteries, two very different injuries.

An artery wall has layers, like a hose made of laminated sheets. A dissection is a tear in the inner lining that lets blood push in between the layers. Where that happens — the carotid at the front of the neck, or the vertebral threaded through the neck bones — changes everything about how it happens and how it feels.

This is uncommon, but it is not obscure. In the general population — where most dissections happen spontaneously, with no injury behind them — dissection causes up to 2.5% of all first strokes, and up to one in five strokes in young adults. The average patient is around 45, and it is slightly more common in men.

Those are not grappling numbers, and they are not a risk estimate for training. Nobody has grappling numbers — what exists is a few dozen published cases with no way to know how many grapplers they were drawn from. Closing that gap is why this site keeps a registry.

Carotid (ICA) ↓
Vertebral (VA) ↓

  • 01 · Carotid — ICA

    Internal carotid artery dissection & pseudoaneurysm

    The internal carotid artery runs up the front-side of your neck, just under where a collar sits — right where a well-placed collar choke sits too.

    What actually tears

    A tear in the inner lining creates a second channel — a false lumen, where blood was never meant to flow. That false channel causes trouble two ways: it can bulge inward and narrow the real channel, reducing blood flow to the brain, and the raw, injured surface can form clots that break off and travel on into the brain — a stroke.

    Where a pseudoaneurysm comes in

    Sometimes the outer wall balloons outward at the injury site, forming a pseudoaneurysm — a bulge contained by the outer layers rather than a full, normal artery wall. Many are followed with repeat imaging rather than treated aggressively. That can change if an aneurysm is expanding, or if symptoms keep returning despite treatment.

    How it’s usually found

    Diagnosis generally involves imaging of the neck vessels — commonly CT angiography or MR angiography. The delay between injury and diagnosis is one of the things this site’s registry tracks, because “it was dismissed as a muscle strain” is a recurring theme in survivor accounts.

    How grappling loads this artery

    The internal carotid is relatively fixed where it enters the skull base and relatively mobile in the neck. In the published case reports from martial arts, injuries to this artery cluster toward that upper, distal end. Why they cluster there is not established — it is tempting to assume the fixed-to-mobile transition explains it, but no study has shown that, and measured neck movement produces far less strain than it takes to tear a healthy artery. The positions below are ones that load the neck, which is not the same as showing they cause harm:

    • Collar chokesCross collar, bow and arrow, loop choke: direct, sustained pressure over the artery’s path.
    • Guillotines and arm-in variationsCompression plus neck flexion and often a twist.
    • Kesa gatame and head-and-arm pressureSustained lateral load on the side of the neck.
    • Stack passes and can openersExtreme flexion, sometimes with rotation, under an opponent’s weight.

    Naming these positions is not saying they are unsafe or should be banned. Chokes are applied millions of times a year worldwide, and the overwhelming majority of them injure nobody: in a survey of 4,307 grapplers, two people reported symptoms that lasted — though someone who stopped training after an injury is less likely to have answered a survey posted on a grappling forum. It is saying that if a dissection occurs, this is the kind of loading that shows up in the story.

  • 02 · Vertebral — VA

    Vertebral artery dissection, segment by segment

    The vertebral arteries run up the back of your neck, threaded through small openings in the neck bones themselves. That bony path is what makes them vulnerable in a completely different way than the carotids — and why the symptoms can look nothing like what people expect from a “stroke.”

    The four segments, and why they matter

    V1

    From where it branches off, up to where it enters the bony canal. Relatively mobile.

    V2

    Inside the bony canal through the neck vertebrae. Fixed in bone, so the artery is dragged along with whatever the neck bones do.

    V3

    The stretch between the top vertebra and the skull, where the artery loops and turns sharply. In the published martial-arts case reports, this is the segment where vertebral injuries cluster.

    V4

    Inside the skull, after piercing the covering of the brain. Dissections here carry different considerations than the neck segments.

    Two different pictures are worth keeping apart here. Among vertebral dissections in the general population — most of which have nothing to do with sport — V2 and V3 are involved at roughly similar rates, with fewer at V1 and fewer still at V4. The clustering at V3 described above is a separate finding, drawn from the much smaller pile of martial-arts case reports. Neither figure corrects the other; they are counts of different groups of people.

    Why the symptoms look different

    The vertebral arteries feed the back of the brain — the brainstem and cerebellum, which handle balance, coordination, eye movement, and swallowing. So a vertebral dissection may announce itself as sudden vertigo, clumsiness on one side, double vision, trouble swallowing, or a severe pain at the back of the head and neck, rather than the classic face-droop-and-arm-weakness picture people associate with stroke.

    This is exactly why these injuries get missed: a dizzy, nauseated grappler with a stiff neck reads as dehydration or a bad shot to the head, not as an arterial emergency.

    How grappling loads these arteries

    V2 is locked inside bone and V3 loops around the top of the spine, and in the published case reports from martial arts, vertebral injuries cluster at V3. Rotation is the theme that keeps recurring in survivor accounts. What no one has established is why — whether that anatomy explains it, or something else does. The positions below load those segments; that is a description of loading, not a claim about cause:

    • Neck cranks and twisting escapes — rotation at end range under force.
    • Stack passing — the neck folded and often twisted under a partner’s full weight.
    • Inversions and ashi garami scrambles — the head bearing load in unusual orientations.
    • Takedowns landing on the head or shoulder — sudden rotation and impact together.

    As with the carotid, this is a description of loading patterns that appear in survivor accounts — not a risk ranking, and not a claim about how likely any position is to cause harm.

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