Case Reports

Vertebral Artery Dissection in Active-Duty Soldier Due to Mixed Martial Arts Choke Hold

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Discussion

Spontaneous vertebral artery and carotid artery dissections are collectively referred to as sCADs. Spontaneous cervical artery dissections are a rare condition with a higher incidence of internal carotid dissections than are VADs (1.72 vs 0.97 per 100,000 people).1 In contrast to the general stroke population, patients with sCADs are typically younger (mean age 45.3 years); and more than half of the patients are male.1,2

Spontaneous cervical artery dissections are typically characterized by subintimal tears of the vertebral artery leading to the accumulation of an intramural hematoma and creation of a “false lumen” in the arterial wall.3 A sVAD is more often found in the pars transversaria (V2; 35%) or atlas loop (V3; 34%) segments of the vertebral artery than in the prevertebral (V1; 20%) or intracranial (V4; 11%) segments.3-5 The etiology of these injuries is thought to be minor trauma to the neck in the context of a likely underlying connective tissue disease, though no direct association with a particular disease has been shown.

Biopsy evaluation of the superficial temporal arteries of patients with sCADs have revealed pathologic changes of the media and adventitial layers, including vacuolar degeneration and capillary neoangiogenesis, which are not found in the arteries of control patients.5 Although definitive association with a known connective tissue disease is rare, angiographic evidence of fibromuscular dysplasia, a nonspecific marker of connective tissue disease, is noted in as many as 15% to 20% of patients.6 Consequently, routine connective tissue disease screening is not recommended in these patients. One study found that about 40% of sCAD patients can recall minor cervical trauma in the preceding month in comparison to only 10% of other patients with stroke, leading to the moniker of “bottoms-up” or “beauty-parlor strokes” for these injuries. The most common mechanisms of minor neck trauma causing sCADs include tennis and golf swings, yoga, and roller-coaster rides.7,8

Usually symptomatic at presentation, the most frequently encountered sCAD symptoms are head or neck pain (80%), brain ischemia (56%), and Horner syndrome (25%).1 A study of 161 consecutive patients with internal carotid (n = 135) or vertebral artery (n = 26) dissections revealed that headache was reported by 69% of those with sVADs, and when present, was the initial manifestation in 33%. Headaches typically were ipsilateral to the dissection, located posteriorly in 83% of patients, and lasted an average duration of 72 hours. Neck pain, which was noted in 46% of sVAD patients, was predominantly posterior and ipsilateral in location as well.9 Ischemic symptoms of sVAD may include posterior circulation symptoms, such as vertigo, ataxia, diplopia, and leg weakness as well as lateral medullary (Wallenberg) syndrome characterized by dizziness, postural instability, limb hypotonia/ataxia, blurred vision, and nystagmus.

In a study of 169 patients with sCAD, brain ischemia occurred in 77% (131 patients) including 67% (n = 114) with ischemic stroke and 10% (n = 17) with transient ischemic attack. Head and/or neck pain was noted in 88% of those with brain ischemia.4 Etiologies for infarction included thromboembolic (85%), hemodynamic (12%), and mixed (3%).10 Isolated local symptoms are rare with one study of 245 patients with sCAD revealing only 20 (8%) presenting with pain only. Of those with pain only, 6 presented with headache, 2 with neck pain, and 12 with both.11

Diagnosis of sVAD requires a high index of suspicion and is confirmed by diagnostic testing. Previously, invasive angiography was the diagnostic gold standard, but with the improvement in quality of CT and MR angiography, these noninvasive modalities have become the tests of choice. There have been no studies to date revealing a definitive benefit of one modality over the other. A meta-analysis of 25 articles that compared the use of CT and MR angiography for the diagnosis of carotid and VAD revealed similar sensitivity and specificity.12 In contrast, a study involving 10 patients with confirmed sVAD who had both CT and MR angiographies during evaluation showed more total findings consistent with dissection on CT than with MR angiography when graded by 2 neuroradiologists. Additionally, the neuroradiologists subjectively rated CT angiography as preferential to MR in showing the imaging findings of dissection in 8 of 10 cases of vertebral dissection.13

Treatment for sCAD remains heavily debated. The use of IV thrombolysis within the standard time window for acute ischemic stroke is advocated for these patients. A meta-analysis of patients with sCAD vs matched patients with stroke from other causes treated with IV thrombolysis showed no difference in mortality at 3 months (9.0% vs 8.8%) or symptomatic intracranial hemorrhage (3.3% vs 3.0%). Additionally, similar percentages of patients had excellent (30.9% vs 37.4%) and favorable (58.2% vs 52.2%) 3-month functional statuses as expressed by the Modified Rankin Score (mRS).14,15

Debate remains regarding subacute therapy for sCAD with either antiplatelet or anticoagulant therapy. A randomized study of 250 patients with cervical artery dissection (118 carotid, 132 vertebral) in which 126 patients were assigned to antiplatelet therapy and 124 patients were assigned to anticoagulant therapy showed an overall low rate of recurrent stroke (2%). There was no significant difference in efficacy between the therapy groups with stroke or death occurring in 3 antiplatelet patients and 1 anticoagulated patient. Adverse effects were very low in both groups with no deaths and only 1 major bleed in the anticoagulation group. Of note, stroke rates were lower in this study than prior observational studies.16

A nonrandomized study of 88 patients with extracranial sCAD showed overall low rates of recurrent ischemic stroke at 3 months with 1/59 (1.7%) in the antiplatelet group and 1/28 (3.6%) in the anticoagulation group (P 17 Given this low overall rate of recurrent stroke in prior studies, a guideline recommendation for antiplatelet or anticoagulant therapy cannot be made at this time.

The overall prognosis for this condition is fair. Functional status and recurrence risk are favorable, with one study finding a mRS score of 1 Additionally, a historic cohort study of 432 patients with first event of sCAD revealed that after a mean follow-up of 31 months, only 4 (0.9%) patients had a recurrent ischemic stroke either due to incomplete recanalization of the artery (n = 2) or recurrent sCAD (n = 2), and only 4 (0.9%) total recurrences of sCAD were report (2 without associated ischemic strokes).18 Further, a prospective study of 61 patients with confirmed sVAD revealed complete recanalization of 45.9% at 3 months, 62.3% at 6 months, and 63.9% at 12 months, suggesting that recanalization occurs mostly during the initial 6 months. There was no identified association between outcome and complete recanalization with favorable outcomes observed in 55 (90.2%) of patients and no further ischemic symptoms during follow-up.19

Neck maneuvers have been cited as a more common cause of sCAD in several previous studies. One retrospective study found chiropractic neck manipulation to be the etiology in 12 of 141 patients with CT- or MR- confirmed sCAD.20 As noted previously, to the authors’ knowledge this is the first reported case of a sVAD occurring after a mixed martial arts choke hold. While sports-related strokes are rare, one evaluation of 70 published cases found that 80% were due to sCAD. Commonly associated sports in this study included football, yoga, wrestling, tennis, golf, and swimming.21 Grappling-related neck manipulation has been noted as an etiology in a few case reports.

Hyperextension of the neck was deemed to be the etiology in boys aged 11 years and 17 years who developed a sCAD while participating in Judo and backyard wrestling, respectively.22,23 In the martial arts realm, there is a case report of a 26-year-old male who developed a sVAD after rapid head turning during a solo Kung Fu maneuver as well as a report of a 41-year-old male experiencing a right VAD complicated by a posterior infarction several days after straining his neck during a mixed martial arts competition.24,25 The patient denied any choke hold or direct blow to the neck.

The present case is different in that it is the first reported case of a sVAD occurring after a submission maneuver. Prior grappling-related sVADs were associated with hyperextension or rapid acceleration/deceleration forces on the neck. Isometric force to the neck is a rarely described mechanism for development of this injury. Although there are isolated and infrequent forensic case reports of carotid dissection with strangulation injuries, the authors believe this is the first documented case of a sVAD attributed to a combatives submission.

In the context of the military health system, it is important to be aware of this potential complication of combatives as instruction in close-quarters combat continues to be an important part of military training.

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