Rotational Vertebral Artery Occlusion Research Articles

Dynamic vertebral artery occlusion aka bow hunter syndrome causing posterior fossa stroke in a young adult: a case report

BackgroundBow Hunter syndrome (BHS) is a rare, but important cause of posterior circulation stroke. It is also known as Rotational vertebral artery syndrome and is caused by transient dynamic vertebro-basilar insufficiency on movement of the neck in the presence of certain soft tissue or bone anomalies in the cranio-vertebral region.Case presentationWe present a case of Bow hunter syndrome in an 18-year-old adult male who presented with vomiting, occipital headache and loss of balance, with findings of posterior circulation stroke on imaging. Medical causes of young stroke, including vasculitis and clotting disorders were ruled out, following which a diagnostic conventional angiography and CT angiography was performed. The cause of vascular compromise in our case was the presence of vertebral anomalies, in particular, the presence of a partial ponticulus posticus with formation of an incomplete arcuate foramen. He was treated with cervical spine immobilisation and C1–C2 fixation. In addition, our patient had a single posterior inferior cerebellar artery (PICA) on the side of the dynamic insufficiency, which lead to bilateral cerebellar infarcts. Our case is unique because it demonstrates a combination of osseous and vascular developmental anomalies resulting in posterior circulation stroke.ConclusionsThough uncommon, BHS should be considered in the list of differentials in otherwise unexplained cases of posterior circulation stroke. Conventional angiography with dynamic manoeuvres is the modality of choice for documenting the rotational vertebral artery occlusion.

Review of Thyroid Cartilage Compression of the Vertebral Artery

Thyroid cartilage compression of the Vertebral Artery (VA) has been implicated as a rare cause of Rotational Vertebral Artery Occlusion (RVAO). 10 cases have been reported in the literature. This has a higher tendency to affect males and younger patients than other forms of stroke. Patients present with multiple episodes prior to diagnosis. Radiologic studies prove crucial for confirming this condition. An aberrant VA course appears to be a necessary factor. All cases suffer from right side VA compression by the superior thyroid cornu. Conservative therapy with antiplatelet treatment is employed commonly. Most patients have definitive treatment with surgical resection of the right superior thyroid cornu. Theories proposed for these characteristics include VA dominance, structural variability in the thyroid cartilage between genders and also variable thyroid cartilage ossification. Given these findings, we propose the term “thyro-vertebral artery syndrome” for this condition.

A Case of Rotational Vertebral Artery Occlusion Syndrome with a Rare Mechanism

A Case of Rotational Vertebral Artery Occlusion Syndrome with a Rare Mechanism

Atlanto-occipital ligament calcification: a novel imaging finding in pediatric rotational vertebral artery occlusion

We describe a 2-year-old girl with bow hunter syndrome complicated by vertebral artery dissection and multiple ischemic infarcts. Pediatric bow hunter syndrome is a rare and likely under-recognized disorder. Interestingly, our patient had atlanto-occipital ligament calcification on CT scan, an imaging finding that has not been reported in association with bow hunter syndrome and one that might help increase recognition of this dynamic disorder of the posterior circulation.

Rotational vertebral artery occlusion: Case report and review of literature

Rotational vertebral artery occlusion (RVAO) classically involves transient, position-dependent vertebrobasilar insufficiency (VBI) that occurs when an extra-vascular lesion (e.g. osteophyte or fibromuscular band) compresses a dominant vertebral artery with turning of the head to one side. Our patient presented with VBI associated vertigo, dizziness, and lightheadedness that occurred when her head was turned to the right. RVAO was initially suggested by transcranial Doppler ultrasound (TCD) changes that were not supported by initial catheter angiography. After her symptoms worsened over a course of two years, the diagnosis was confirmed with repeat angiography with head rotation. Further imaging with computed tomography and magnetic resonance demonstrated spondylosis at the C5-C6 vertebrae and an osteophyte near the C5 transverse foramen, which caused position-dependent extra-vascular compression. She was treated with surgical decompression and anterior discectomy and fusion at C5-C6. The unique anatomical pathology of this case combined with the diagnostic discrepancy between early TCD and angiography make it an interesting contribution to the otherwise limited body of literature on RVAO.

Abstract WP387: Diagnosis and Surgical Management of Rotational Vertebral Artery Occlusion in Children

Background: Rotational vertebral artery occlusion (RVAO) is associated with significant posterior circulation morbidity, recurrence, and lacks evidenced based treatment recommendations. Upper cervical spine abnormalities, lack of traumatic history, and dynamic vessel imaging aid in diagnosis and treatment options. Here, we evaluate our cohort of children with RVAO for associated musculoskeletal, angiographic, and arterial tortuosity factors in light of management strategies and outcomes. Methods: Five pediatric patients with RVAO were evaluated with dynamic arterial compression with either CT based angiography or digital subtraction angiography. Solitary factors such as ponticulous posticus, hypermobility comorbidities, 3D-print models and arterial tortuosity index were examined in relation to management strategies. Results: Musculoskeletal abnormalities were associated in all cases presenting with evidence of dynamic angiographic compression. Not all cases had evidence angiographic compression. A mild elevation in arterial tortuosity index was observed. All five patients were managed with treatment approaches including antiplatelet/coagulation therapies, vertebral artery decompression, and/or posterior cervical fusion. Conclusion: Treatment strategies relied on identifiable compression factors associated with the level of vertebral artery dissection. In children, upper cervical bony abnormalities and dynamic compression at the VA3 level are common to RVAO diagnosis. Further examination of arterial tortuosity as an index in understanding the susceptibility of children towards RVAO is required.

Combined use of intraoperative indocyanine green and dynamic angiography in rotational vertebral artery occlusion

Rotational vertebral artery occlusion, also known as bow hunter’s syndrome, is a well-documented surgically amenable cause of vertebrobasilar insufficiency. Traditionally, patients have been imaged using dynamic rotational angiography. The authors sought to determine whether intraoperative indocyanine green (ICG) angiography could reliably assess the adequacy of surgical decompression of the vertebral artery (VA). The authors report two patients who presented with multiple transient episodes of syncope provoked by turning their head to the right. Rotational dynamic angiography revealed a dominant VA that became occluded with head rotation to the right side. The patients underwent successful surgical decompression of the VA via an anterior cervical approach. Intraoperative ICG angiography demonstrated patency of the VA with head rotation. This was further confirmed by intraoperative dynamic catheter angiography. To our knowledge, we present the first two cases of the use of ICG combined with intraoperative dynamic rotational angiography to document the adequacy of surgical decompression of the VA in a patient with rotational vertebral artery occlusion. Intraoperative ICG angiography is a useful adjunct and may potentially supplant the need for intraoperative catheter angiography.

Rotational Vertebral Artery Compression Syndrome: Bow Hunter's Stroke

Rotational vertebral artery occlusion is a rare syndrome characterized by vertebrobasilar insufficiency secondary to position-dependent occlusion of the vertebral artery. Most cases reported in the literature have been attributed to osteophytic compression, either from the occipital condyle or within the transverse foramen. However, vertebral artery dissection secondary to motion in the setting of anomalous anatomy has not been reported.To the authors' knowledge, rotational vertebral artery occlusion and dissection secondary to anomalous entrance into the transverse foramen have never been reported. The authors describe the case of a 42-year-old male who presented with multiple posterior circulation transient ischemic attacks. Standard digital subtraction cerebral angiography demonstrated a non−flow-limiting right vertebral artery dissection, while dynamic digital subtraction cerebral angiography was remarkable for right vertebral artery stenosis that worsened with neck rotation. Computed tomography angiography of the neck revealed an anomalous course of the right vertebral artery, which entered the transverse foramen at C4 with preforaminal compression by the anterior tubercle of the C5 transverse process. The patient had no further symptomatic events after decompression of the vertebral artery by resecting the anterior C5 tubercle.In the setting of codominant vertebral circulation and unilateral bony compression, the authors propose that neck rotation led to vertebral artery trauma, causing dissection complicated by thromboembolism. This is a novel and unusual entity that is different from Bowhunter's syndrome.

Upbeat nystagmus during head rotation in rotational vertebral artery occlusion

Upbeat nystagmus during head rotation in rotational vertebral artery occlusion

Rotational vertebral artery occlusion: Mechanisms and long-term outcome

Rotational vertebral artery occlusion: Mechanisms and long-term outcome

Rotational Vertebral Artery Occlusion

To elucidate the mechanisms and prognosis of rotational vertebral artery occlusion (RVAO). We analyzed clinical and radiological characteristics, patterns of induced nystagmus, and outcome in 21 patients (13 men, aged 29-77 years) with RVAO documented by dynamic cerebral angiography during an 8-year period at 3 University Hospitals in Korea. The follow-up periods ranged from 5 to 91 months (median, 37.5 months). Most patients (n=19; 90.5%) received conservative treatments. All the patients developed vertigo accompanied by tinnitus (38%), fainting (24%), or blurred vision (19%). Only 12 (57.1%) patients showed the typical pattern of RVAO during dynamic cerebral angiography, a compression of the dominant vertebral artery at the C1-2 level during contralateral head rotation. The induced nystagmus was mostly downbeat with horizontal and torsional components beating toward the compressed vertebral artery side. None of the patients with conservative treatments developed posterior circulation stroke, and 4 of them (21.1%) showed resolution of symptoms during the follow-ups. RVAO has various patterns of vertebral artery compression, and favorable long-term outcome with conservative treatments. In most patients with RVAO, the symptoms may be ascribed to asymmetrical excitation of the bilateral labyrinth induced by transient ischemia or by disinhibition from inferior cerebellar hypoperfusion. Conservative management might be considered as the first-line treatment of RVAO.

Bilateral mechanical rotational vertebral artery occlusion

Rotational vertebral artery occlusion, or bow hunter's stroke, is reversible, positional symptomatic vertebrobasilar ischemia. The typical mechanism of action is obstruction of a dominant vertebral artery with contralateral head rotation in the setting of baseline ipsilateral vertebral artery stenosis or occlusion. Here we present a rare case of mechanical occlusion of bilateral patent vertebral arteries manifesting as near syncope with rightward head rotation. Diagnostic cerebral angiography showed dynamic right C5 vertebral occlusion and left C2 vertebral occlusion. The patient underwent right C4/5 transverse process decompression. Postoperative angiogram showed patent flow through the right vertebral artery in neutral position and with head turn with resultant resolution of symptoms.

Rotational vertebral artery occlusion associated with occipitoatlantal assimilation, atlantoaxial subluxation, and basilar impression

Rotational vertebral artery (VA) occlusion, also known as bow unter’s stroke, is a rare form of vertebrobasilar ischemia elicited y head rotation, and it results from transient mechanical oblitration of the VA [1]. The VA at the C1–C2 junction is involved ost frequently, and hemodynamic compromise of the domiant VA is usually responsible for ischemic episodes [1]. Various athoanatomies of the craniovertebral junction (CVJ) have been eported to be associatedwith rotational VA occlusion. Adult-onset otational VA occlusion associated with a CVJ anomaly, however, is ery rare. We describe a case of rotational VA occlusion associated ith occipitoatlantal assimilation, atlantoaxial subluxation (AAS), nd basilar impression.

Rotational vertebral artery occlusion in a child with multiple strokes: a case-based update

Rotational vertebral artery occlusion (RVAO), sometimes known as "Bow hunter syndrome," is an important and diagnostically challenging cause of posterior circulation stroke in children. It is caused by impingement of osseous and/or ligamentous structures on the vertebral artery. We review the differential diagnosis and recommended workup for posterior circulation stroke in children. The anatomical cause for pediatric RVAO is most commonly an anomalous bone formation of the rostral vertebral column. Many bony anomalies have been associated with RVAO, including the "ponticulus posticus," a common anomaly of the C1 vertebrae. The definitive diagnosis of RVAO is made with dynamic angiography, and surgical decompression of the vertebral artery prevents recurrent strokes. We report a 15-year-old boy with recurrent posterior circulation ischemic strokes caused by an anomalous ossification of the C1 vertebrae. Three-dimensional (3D) and multiplanar reconstructed CT images showed the anomalous C1 ossification, and cervicocerebral digital subtraction angiography (DSA) revealed an associated vertebral artery (VA) dissection. The patient was initially managed by head immobilization in a hard collar and anticoagulation for 3 months. After healing of the dissection that was confirmed angiographically, dynamic DSA demonstrated reversible occlusion of the VA during contralateral head turn. Surgical decompression of the VA was performed and confirmed by intra-operative DSA with head turning. RVAO is an important diagnosis in children with posterior circulation stroke. Our case demonstrates the need for high clinical suspicion and careful analysis of 3D cervical spine CT images in children with posterior circulation stroke.

Rotational Vertebral Artery Occlusion—Series of 9 Cases

Rotational vertebral artery syndrome (RVAS) is a rare entity about which previously published studies are mostly limited to individual case reports. To report our decade-long experience with this syndrome in 9 patients with compression ranging from the occiput to C6. We utilized a posterior approach for lesions rostral to C4 and an anterior approach for lesions at or caudal to C4. Furthermore, we demonstrated the feasibility and efficacy of a minimally invasive posterior cervical approach. Patient profile, operative indications, surgical approach, operative findings, complications, and long-term follow-up were reviewed and discussed. Average follow-up was 47 months. All procedures provided excellent outcomes by Glasgow Outcome Scale scores. The anterior approach had significantly less blood loss (187.5 mL vs 450 mL, P = .00016) and shorter hospitalization length (2 days vs 4.5 days; P = .0001) compared with the far-lateral approach. There was one complication of cervical instability in the far-lateral approach cohort. As an alternative to the far-lateral surgery, a minimally invasive approach resulted in shorter hospitalization (2 days) and less blood loss (10 mL) while avoiding the complication of cervical instability. We demonstrated the safety, efficacy, and durability of 3 surgical approaches for RVAS. Proper examination, preoperative imaging, and surgical planning were necessary for a satisfactory outcome.

Artery‐to‐Artery Embolism with a Mobile Mural Thrombus Due to Rotational Vertebral Artery Occlusion

Rotational vertebral artery (VA) occlusion can cause ischemic strokes due to hemodynamic insufficiency and possibly artery-to-artery (A-to-A) embolism. The former is known as bow hunter's stroke. The latter has been proposed only from indirect evidence. We have described a 7-year-old boy with cerebral infarction associated with A-to-A embolism due to repetitive rotational VA occlusion. He had a mobile mural thrombus at the VA occlusion site on head rotation. Surgical treatment may effectively prevent recurrences.

Minimally invasive decompression of a suboccipital osseous prominence causing rotational vertebral artery occlusion

Surgical decompression of the vertebral artery (VA) between the suboccipital area and C-1 is typically performed via a large midline incision or a far-lateral approach. Such traditional open approaches are often associated with significant muscle dissection and blood loss. In this case, a 12-year-old boy suffered a stroke related to a VA rotational occlusion (bow hunter syndrome) and dissection due to a prominent suboccipital bone mass. Successful decompression of the VA was performed via a minimally invasive 22-mm tubular retractor. This is the first reported case report of a minimally invasive decompression of the VA between the skull base and C-1.

Simultaneous Bilateral Vertebral Artery Occlusion in the Lower Cervical Spine Manifesting as Bow Hunter's Syndrome -Case Report-

A 59-year-old male had suffered near-syncopal episodes for more than one year that occurred immediately on turning his head to the left. Cerebral magnetic resonance (MR) imaging did not detect any contributing lesions with well-developed posterior communicating arteries. Dynamic radiography of the cervical spine showed mild instability at C5-6 and concomitant intramedullary hyperintensity confirmed by T(2)-weighted MR imaging. Cervical computed tomography demonstrated an osseous protrusion in the right foramen transversarium at C5. Dynamic cerebral angiography revealed simultaneous vertebral artery (VA) occlusion at C6 on the right and C5 on the left associated with leftward head rotation. The VA showed an intact course at the C1 to C2 levels. The patient underwent anterior fusion followed by decompressive foraminotomy at C5-6 and C6-7 and meticulous resection of the markedly thickened fibroligamentous structure which was considered to contribute to the rotational VA occlusion. Postoperatively he no longer suffered near-syncope during head rotation. Bow hunter's syndrome is an infrequent type of vertebrobasilar insufficiency that may need surgical management for potential threat of ischemic stroke. Simultaneous VA occlusion at the lower cervical level can cause bow hunter's syndrome. Dynamic cerebral angiography is a useful modality for evaluating bow hunter's syndrome even if the patient cannot tolerate dynamic examination for the immediate symptom. Accurate anatomical knowledge of the uncovertebral foraminal region combined with intraoperative dynamic study is essential for safe surgery to the VA and favorable outcome.

Rotational vertebral artery occlusion

Rotational vertebral artery occlusion (RVAO), also known as bow hunter’s syndrome, is rare but clinically important: it carries a risk of impending stroke but can be treated by surgical decompression. Most patients who experience RVAO exhibit a stenosis or vessel malformation (e.g., hypoplasia or termination in the posterior inferior cerebellar artery) of the vertebral artery on the same side as the precipitating horizontal head rotation. This movement compresses the dominant vertebral artery (opposite to the head rotation) and thus interrupts the major blood supply to the vertebrobasilar artery territory. A rotational contralateral vertebral artery occlusion was originally considered physiologic after Toole and Tucker1 found compromised blood flow in vertebral arteries due to head rotation in hemodynamic studies of cadavers. However, this was not supported by vertebral angiography of 39 patients in both the neutral head position and …

Proper management of the rotational vertebral artery occlusion secondary to spondylosis

A 66-year-old man with cervical spondylosis noticed severe vertigo when turning his head to the right. He underwent subclavian arteriography elsewhere, which showed a block of the contrast medium in the right vertebral artery (VA) at the C5/6 level when the patient turned his head to the right. After referral to our institute, however, postcontrast CT scan revealed an attenuated shadow of the venous plexus around the right VA at the C3/4 level. Repeated selective angiography with rotation of the head after visualization of the entire VA verified the level of obstruction to be at C3/4. Resection of the C4 transverse process through an anterior approach with drilling of the C3/4 spondylotic spur of the uncinate processi completely resolved the arterial impingement and the symptom. When evaluating rotational VA occlusion, dynamic angiography with selective catheterization is essential in determining which level is affected. The postcontrast CT scan is also useful because it suggests the level even without head rotation.