Congenital Bilateral C2 Transverse Foramina Stenosis Causing Adult-Onset Vertebrobasilar Insufficiency and Posterior Circulation Stroke

Bow Hunter Phenomenon From Advanced Cerebrovascular Disease Treated With Subclavian Artery Stenting and Carotid Endarterectomy

Bow Hunter syndrome (BHS) is a rare disorder characterized by mechanical occlusion of the vertebral artery (VA) during neck rotation, resulting in symptomatic, transient, and positional vertebrobasilar insufficiency. We describe a case of a 76-year-old female who presented with dizziness and right ear tinnitus triggered by right head rotation. Her symptoms would immediately resolve upon returning her head to the neutral position. CT angiogram showed 80% stenosis of the left subclavian artery origin, 50%-70% stenosis of the proximal right internal carotid artery (ICA), and near occlusive stenoses of the origins of the bilateral VAs. After failing conservative management, the patient was treated with left subclavian artery stenting, followed by a right carotid endarterectomy (CEA) 6 weeks later. Follow-up at 1 month showed resolution of paroxysmal symptoms and no neurological sequelae. To our knowledge, there have not yet been reported cases of patients with concurrent BHS, subclavian artery stenosis, and carotid artery stenosis. We suggest that global revascularization via subclavian artery stenting and CEA may be considered as treatment for patients with BHS complicated by other cerebrovascular disease secondary to stenoses of the ICA and subclavian artery. This approach obviates the need for more complex surgery or endovascular intervention of the VA.

Ischemic Stroke Secondary to Dynamic Vertebral Artery Stenosis: Case Report and Review of the Literature

Ischemic stroke secondary to dynamic vertebral artery stenosis or occlusion, also known as “bow hunter's syndrome,” is a rare stroke mechanism. We report a case of a 24-year-old man with multiple hereditary exostosis (MHE) diagnosed at childhood. His first presentation to a neurologist was due to neck pain and clinical syndrome suggestive of ischemia in the vertebrobasilar territory. A therapeutic occlusion was done successfully without complication. The patient was discharged two days later on aspirin alone. In follow up one year later he continued to be symptom free. Moreover, this stroke mechanism has been reported extensively in the literature in isolation or secondary to many underlying diseases. In total, there are 168 cases reported in the published English literature, in either case reports or small series. In this review, we found that by far, vertebral artery occlusion at the atlanto-axial (C1-2) level dominated most reported cases. The most frequent presentation that led to further investigation was syncope or pre-syncope provoked by head rotation to one side. To our knowledge, there is no previous report of any stroke syndrome related to MHE before our case. In this paper, we report the first case secondary to MHE and review the literature up to date since the first reported case in 1952.

Reconstruction of anatomy and care provisioning in a severe case of spondyloepiphyseal dysplasia

OBJECTIVE

This analysis aims to clinically and socially contextualize a set of human remains (TBK Br8) with severe systemic skeletal dysmorphology from Tashbulak, Uzbekistan (8th-11th c. Common Era [CE]).

MATERIALS

One well-preserved and nearly-complete human skeleton.

METHODS

Remains were assessed and documented macroscopically.

RESULTS

Endochondrally derived skeletal elements in TBK Br8 were observed to be underdeveloped. Extensive proliferation of bone had invaded all but one observable joint, variably occluding most intervertebral foramina, the lumbar vertebral canal, and transverse foramina of the cervical spine.

CONCLUSIONS

The remains were diagnosed with spondyloepiphyseal dysplasia (SED), possibly the subtype progressive pseudorheumatoid dysplasia (spondyloepiphyseal dysplasia tarda with progressive arthropathy. Rendered functionally paraplegic by the time of death, TBK Br8 likely suffered from widespread areas of numbness, tingling, weakness and/or pain in the lower limbs and thorax, and perhaps transient psychological symptoms.

SIGNIFICANCE

The severity of TBK Br8's disease would have had significant implications to their daily interactions in a society with deep roots in nomadic lifeways, and is a testament to the care required to enable survival.

LIMITATIONS

Radiology, genetic, and histologic analyses are unavailable.

SUGGESTIONS FOR FUTURE RESEARCH

Focused genetic testing for mutations previously shown to be associated with spondyloepiphyseal dysplasias.

Bow Hunter's Syndrome: A rare cause of vertebrobasilar insufficiency

Bow Hunter's syndrome, also referred to as rotational occlusion of the vertebral artery, is caused by dynamic compression of a patient's dominant vertebral artery. We reported a case of successful clinical and imaging work up of Bow Hunter's Syndrome that occurred in a 79-year-old female patient. We discussed the clinical presentation, imaging findings, and subsequent management options of this rare syndrome. The gold standard for diagnosis is dynamic cerebral angiography, which allows the reproduction of symptoms with head turn greater than 30-45 degrees. Subsequent management is based on the underlying etiology causing rotational compression.

Unilateral segmental agenesis of the vertebral artery at the C2 level

PURPOSE

To report a case of unilateral segmental agenesis of the vertebral artery (VA).

METHODS

We describe the angiographic and MRI features of a segmental VA agenesis (C2 segment).

RESULTS

VA agenesis is caused by the absence of the anastomotic connection normally linking two adjacent intersegmental arteries; in the reported observation, a paravertebral extraforaminal anastomosis replaced the C2 segment normally joining the 1st and 2nd cervical intersegmental arteries through the C2 transverse foramen.

CONCLUSION

We present an observation of segmental VA agenesis. This variant is consistent with the developmental history of the VA. It appears exceptional but is more likely underappreciated.