A case report of high cervical spinal infarction after stenting with severe stenosis at the beginning of left vertebral artery.

BACKGROUND: Spinal cord infarction is an uncommon nervous system disorder. We present a case of high cervical cord infarction caused by stenting of the origin of the left vertebral artery (VA). The incidence of spinal cord infarction is minimal, and it must be distinguished from a number of other disorders. The diagnosis is primarily based on imaging, clinical symptoms, and history. Currently, there is no focused treatment for spinal cord infarction. Thrombolysis, high-dose glucocorticoid shocks, tube dilatation to promote circulation, and nutritional neurotropic medicines given early in the course of the disease can all help to slow the disease's progression. There is no agreement on the etiology, diagnosis, or therapy options for these people. CASE PRESENTATION: On October 7, 2023, an 81-year-old man was admitted to the hospital primarily for recurrent chest tightness and pain that had persisted for more than 2 years and 1 month. Cerebral angiography upon admission revealed significant blockage of the right VA and stenosis of the left vertebral arterial origin. Six days following admission, a drug-eluting stenting procedure was carried out under local anesthesia to open the left VA origin via the femoral artery. Following the procedure, the patient experienced a progressive loss of muscle strength in all 4 limbs and paraplegia below the cervical 3 spinal cord. One week following the procedure, the patient was released from the hospital. After the procedure, the patient was released 1 week later. After the procedure, the patient's symptoms persisted for a month. CONCLUSION: High awareness for high cervical cord infarction is required when neck discomfort and limb weakness with progressive progression arises after surgery. Complications of high cervical cord infarction following stenting for stenosis of VA origin are uncommon in clinical settings. Patients' prognoses can be improved by prompt diagnosis and care.

Exploring vertebral artery stump syndrome: An overlooked cause of posterior ischemic strokes. A narrative review of current management options.

INTRODUCTION: Stump syndrome is defined as a clinical syndrome resulting from a distal intracranial vessel embolic stroke due to an extracranial vessel occlusion. Similar to the anterior circulation, the recurrence of ischemic strokes in territories supplied by the posterior circulation in the presence of vertebral artery occlusion is termed Vertebral Artery Stump Syndrome (VASS). MATERIAL AND METHODS: We conducted a literature review, identifying 72 patients with transient ischemic attacks (TIAs) or ischemic strokes attributed to VASS, according to Kawano criteria. We categorized all patients in two groups focusing on the therapeutic management those who underwent primary medical treatment and those who received endovascular or surgical treatment either in acute or chronic phase. RESULTS: In the anticoagulant therapy group, only 1 patient had a stroke recurrence. Among the 4 on antiplatelets, all had recurrences, but 3 benefited from switching to anticoagulants or endovascular therapy. In the endovascular therapy group, worse outcomes were linked to acute large vessel occlusion. Endovascular treatment of the vertebral artery, in a chronic phase, was explored in literature for recurrent TIAs or minor strokes suggesting that this could be a viable therapeutic alternative when medical treatment failed in preventing recurrence of ischemic stroke. CONCLUSIONS: Some studies suggest that anticoagulant medical therapy may be beneficial for VASS and endovascular therapy has also been reported for selected patients. However, data on treatment outcomes and prognosis are still underreported, making treatment decisions challenging. Randomized Controlled Trials are needed to establish the optimal treatment approach.

Bilateral Bow Hunter Syndrome Associated with Loss of Cervical Physiological Curvature.

BACKGROUND Bow hunter syndrome is a rare disease that is often overlooked. It presents with complex and variable clinical symptoms and causes, making diagnosis and treatment challenging. This case report focuses on a young patient with bilateral bow hunter syndrome, possibly caused by the loss of cervical physiological curvature. The aim is to enhance understanding and awareness of the disease. It is important to consider the possibility of bow hunter syndrome in young patients with long-term poor neck posture and symptoms such as dizziness, nausea, vomiting, and neck rotation-related symptoms. In such cases, thorough examination of posterior circulation hemodynamics and vascular morphology is recommended. CASE REPORT A 25-year-old woman was admitted to the hospital mainly because of "dizziness for 10 hours." The dizziness was aggravated when the right side of the neck was turned and the body position changed. This was accompanied by visual rotation, nausea, and vomiting. Bow hunter syndrome was diagnosed based on the clinical symptoms and hemodynamic examination of the posterior circulation. The patient was given a cervical collar to limit excessive twisting of the neck and instructed to avoid large-angle deflection of the neck after discharge. During the 3-month follow-up, no characteristic symptoms (such as dizziness) reappeared. CONCLUSIONS Bow hunter syndrome is a rare clinical posterior circulation compression syndrome with complex etiology. This case suggests that the simple disappearance of cervical curvature may be related to the occurrence of bow hunter syndrome. The dynamic monitoring of blood flow by color Doppler ultrasound and transcranial Doppler in different head positions provides clear clues to suspected bow hunter syndrome. With the help of computed tomography angiography, the diagnosis of bow hunter syndrome may be obtained by noninvasive examination.

Bow Hunter Syndrome: An Illustrative Case and Operative Management.

The differential for vertebrobasilar insufficiency is wide and can be caused by posterior circulation infarcts, steal-type phenomena, or other systemic causes. In the absence of imaging findings explaining symptomology, the utility of appropriate history gathering and dynamic angiography cannot be understated in identifying Bow Hunter's syndrome, a rare cause of dynamic vertebrobasilar insufficiency. We present a case of a 69-year-old man who complained of presyncope and severe dizziness when turning his head towards the right. On examination he had no radiculopathy but did have objective evidence of myelopathy. Computed tomography imaging and dynamic angiography demonstrated C3-C4 right uncovertebral joint hypertrophy and near complete stenosis of the right vertebral artery with dynamic head position towards the right. Given vertebrobasilar insufficiency and myelopathy, he was taken to the operating room for C3-C4 anterior cervical discectomy and fusion with vertebral artery decompression (Video 1). The patient provided consent for the procedure. Standard anterior cervical neck dissection was undertaken with additional platysmal undermining to facilitate exposure of the right uncovertebral joint and transverse processes. The vertebral artery was first decompressed above and below the area of most significant stenosis at the respective transverse foramina before the hypertrophied uncovertebral joint was removed. Next, discectomy and posterior osteophyte removal were completed in typical fashion followed by graft, plate, and screw placement. Postoperatively the patient had immediate resolution of symptoms and continued so at eight month follow-up. Imaging demonstrated return to normal caliber of the right vertebral artery and successful decompression.

Vertebrobasilar Insufficiency Syndrome in Extension: Insights into Surgical Treatment.

BACKGROUND: Rotational vertebrobasilar artery syndrome, or bow hunter syndrome, is a rare yet well-documented pathology. This study presents a surgical approach to a latent manifestation of dynamic, extension-only, bilateral codominant vertebral artery compression in the V3 segment, associated with craniocervical instability and central canal stenosis. METHODS: The clinical presentation involves the treatment of positional vertigo resulting from left and high-grade right vertebral artery stenosis during neck extension only. Diagnosis was confirmed through a formal angiogram under provocative maneuvers. Surgical intervention, detailed in this section, employed a multidisciplinary approach, including intraoperative angiograms to ensure patent vertebral arteries precraniocervical fusion. RESULTS: The surgical treatment demonstrated success in addressing extension-only vertebrobasilar syndrome and associated complications of C1-2 pannus and craniocervical instability. Intraoperative angiograms confirmed vertebral artery patency pre- and postsurgical positioning, ensuring the effectiveness of the multidisciplinary approach. CONCLUSIONS: This study concludes by highlighting the successful multidisciplinary surgical treatment of a patient with nonunion of a C1 Jefferson fracture, leading to extension-only vertebrobasilar syndrome complicated by C1-2 pannus and craniocervical instability. The importance of considering vertebral artery dynamic stenosis in cases of positional vertigo or transient neurological symptoms following an injury is emphasized. Surgical stabilization, particularly when conservative measures prove ineffective, is recommended, with careful attention to pre- and postsurgical positioning to verify vertebral artery patency and posterior vasculature integrity.

Effect of endovascular treatment on patients with basilar artery occlusion presenting with different pathologic mechanisms: a systematic review and meta-analysis.

OBJECTIVE: This study aimed to summarize the clinical outcomes of endovascular treatment in patients with basilar artery occlusion (BAO) with different pathologic mechanisms. METHODS: Two independent reviewers searched PubMed/MEDLINE, Embase and Cochrane Library database up to December 2022, patients with different BAO pathological mechanisms (BAO with in situ atherosclerosis vs. embolism alone without vertebral artery steno-occlusion vs. embolism from tandem vertebral artery steno-occlusion) were collected and analyzed. We calculated the odds ratios (ORs) and 95% confidence intervals (CIs) to assess the associations between clinical outcomes and BAO pathological mechanisms. RESULTS: A total of 1163 participants from 12 studies were identified. Compared with embolism alone, patients with in situ atherosclerotic BAO had a lower favorable outcome rate (modified Rankin score [mRS] 0-2: 34.5% vs. 41.2%; OR 0.83, 95% CI 0.70-0.98; P = 0.03) and moderate outcome rate (mRS 0-3: 45.8% vs. 55.4%; OR 0.65, 95% CI 0.47-0.90; P = 0.01) at 3 months and a higher risk of mortality (29.9% vs. 27.2%; OR 1.31, 95% CI 0.96-1.79, P = 0.09; adjusted OR 1.46, 95% CI 1.08-1.96). Tandem BAO had a comparable mortality risk to that of in situ atherosclerotic BAO (OR 1.37, 95% CI 0.84-2.22; P = 0.48) or embolism alone (OR 1.44, 95% CI 0.65-3.21; P = 0.43), and there were no significant differences in favorable or moderate outcomes between tandem BAO and each of the other two BAO mechanisms. CONCLUSION: Among BAO patients with endovascular treatment, embolism mechanism had better clinical outcomes than in situ atherosclerosis, and atherosclerotic mechanism was associated with a higher mortality at 3 months. RCTs are needed to further confirm clinical outcomes of BAO by different mechanisms.

Hidden Bow Hunter's Syndrome Diagnosed Using Dynamic Cerebral Angiography and Successfully Treated with Spinal Surgery: A Case Report and Review of the Literature.

Hidden bow hunter's syndrome (HBHS) is a rare disease in which the vertebral artery (VA) occludes in a neutral position but recanalizes in a particular neck position. We herein report an HBHS case and assess its characteristics through a literature review. A 69-year-old man had repeated posterior-circulation infarcts with right VA occlusion. Cerebral angiography showed that the right VA was recanalized only with neck tilt. Decompression of the VA successfully prevented stroke recurrence. HBHS should be considered in patients with posterior circulation infarction with an occluded VA at its lower vertebral level. Diagnosing this syndrome correctly is important for preventing stroke recurrence.

[Treatment of atherosclerotic lesion of the first segment of subclavian artery]. / Lechenie ateroskleroticheskogo porazheniya pervogo segmenta podklyuchichnoi arterii.

Severe subclavian artery lesion is an important medical and social problem worsening the quality of life and leading to dire consequences. Vertebrobasilar insufficiency is the main syndrome of lesion of the first segment of subclavian artery. About 20% of all ischemic strokes occur in vertebrobasilar basin. At present, surgical treatment of asymptomatic patients with severe lesion of the 1st segment of subclavian artery is still debatable. Open surgery is optimal for occlusion of this vascular segment. Carotid-subclavian transposition is a preferable option with favorable in-hospital and long-term results. However, carotid-subclavian bypass is an equivalent alternative in case of difficult transposition following anatomical and topographic features of vascular architectonics. Endovascular treatment is preferable for isolated subclavian artery stenosis and should certainly include stenting.

Superior cerebellar artery occlusion remaining after thrombectomy for acute basilar artery occlusion.

To investigate the incidence and impact of superior cerebellar artery (SCA) occlusion remaining after thrombectomy for acute basilar artery occlusion (BAO). We retrospectively analyzed data from 116 patients who underwent thrombectomy for BAO. The patency of SCA was assessed on final angiograms. Clinical and radiologic data of the patients were retrieved from a prospectively collected database and analyzed. All patients underwent pretreatment and follow-up DWI to detect new infarctions in SCA territory. Ten patients (8.6%) had SCA occlusions on final angiograms. Of these, two patients had bilateral occlusions. A new infarction with a diameter ranged from 4 to 11 mm in corresponding SCA territory occurred in 5 of 10 patients. No patients with SCA occlusions experienced symptomatic cerebellar hemorrhage or malignant cerebellar infarction. Nine of 12 SCA occlusions showed spontaneous recanalization on follow-up CT angiography. Four of 10 patients showed 90-day favorable outcome (mRS 0-3) and 90-day mortality occurred in one patient. SCA occlusions remaining after thrombectomy for acute BAO had a benign clinical course. Most of these lesions recanalized spontaneously. Our study suggests that attempts to recanalize remnant SCA occlusion may be unnecessary after basilar artery thrombectomy.

Challenges of anaesthetising a child with Bow Hunter's syndrome and dilated cardiomyopathy for occipitocervical fusion.

Paediatric Bow Hunter's syndrome (BHS), or rotational vertebral artery syndrome, is a rare cause of posterior circulation insufficiency in children. It results from mechanical obstruction of the vertebral artery by the transverse process of cervical vertebrae resulting in vertebrobasilar insufficiency during the neck rotation to the sides. Paediatric dilated cardiomyopathy (DCM) is a rare myocardial disease that presents with ventricular dilatation and cardiac dysfunction. This case report describes the successful anaesthetic management of an boy with BHS due to atlantoaxial dislocation and DCM. The child was anaesthetised by keeping the following anaesthetic goals in mind such as maintenance of the heart rate, rhythm, preload, afterload and contractility close to the baseline for both DCM and BHS. Haemodynamic management with optimal fluids, inotrope and a vasopressor and titrating its volume and doses using multimodal haemodynamic monitoring while keeping both cardio and neuroprotective strategies, and the multimodal analgesia techniques helped the child for faster recovery.

The charlotte large artery occlusion endovascular therapy outcome score compares favorably to the critical area perfusion score for prognostication before basilar thrombectomy.

INTRODUCTION: The Critical Area Perfusion Score (CAPS) predicts functional outcomes in vertebrobasilar thrombectomy patients based on computed tomography perfusion (CTP) hypoperfusion. We compared CAPS to the clinical-radiographic Charlotte Large artery occlusion Endovascular therapy Outcome Score (CLEOS). METHODS: Acute basilar thrombosis patients from January 2017-December 2021 were included in this retrospective analysis from a health system's stroke registry. Inter-rater reliability was assessed for 6 CAPS raters. A logistic regression with CAPS and CLEOS as predictors was performed to predict 90-day modified Rankin Scale (mRS) score 4-6. Area under the curve (AUC) analyses were performed to evaluate prognostic ability. RESULTS: 55 patients, mean age 65.8 (± 13.1) years and median NIHSS score 15.55-24, were included. Light's kappa among 6 raters for favorable versus unfavorable CAPS was 0.633 (95% CI 0.497-0.785). Increased CLEOS was associated with elevated odds of a poor outcome (odds ratio (OR) 1.0010, 95% CI 1.0007-1.0014, p<0.01), though CAPS was not (OR 1.0028, 95% CI 0.9420-1.0676, p=0.93). An overall favorable trend was observed for CLEOS (AUC 0.69, 95% CI 0.54-0.84) versus CAPS (AUC 0.49, 95% CI 0.34-0.64; p=0.051). Among 85.5% of patients with endovascular reperfusion, CLEOS had a statistically higher sensitivity than CAPS at identifying poor 90-day outcomes (71% versus 21%, p=0.003). CONCLUSIONS: CLEOS demonstrated better predictive ability than CAPS for poor outcomes overall and in patients achieving reperfusion after basilar thrombectomy.

Exact Basilar Artery Occlusion Location Indicates Stroke Etiology and Recanalization Success in Patients Eligible for Endovascular Stroke Treatment.

INTRODUCTION: Endovascular stroke treatment (EST) is commonly performed for acute basilar artery occlusion (BAO). We aimed to identify the role of the exact location of BAO in patients receiving EST regarding the stroke etiology, recanalization success and prediction of favorable clinical outcome. METHODS: Retrospective analysis of 191 consecutive patients treated for BAO with EST from 01/2013 until 06/2021 in a tertiary stroke center. Groups were defined according to exact location of BAO in I: proximal third, II: middle third, III: distal third and IV: tip of the basilar artery. Univariate and multivariate analyses were performed for BAO location comparing stroke etiology, recanalization result and favorable clinical outcome according to mRS 0-3 90 days after stroke onset. RESULTS: Occlusion sides types I-IV were evenly distributed (37, 36, 60 and 58 patients). Types I and II were more often associated with large artery atherosclerosis (50 vs. 10 patients, p < 0.001). Distal/tip occlusion (types III/IV) occurred mostly in cardiac embolism or embolic stroke of unknown source (89 vs. 12 in types I/II, p < 0.001). Occlusion site correlated with the underlying stroke etiology (AUC [Area under the curve] 0.89, p < 0.0001, OR [odds ratio] for embolism in type IV: 245). Recanalization rates were higher in patients with distal occlusions (type III/IV OR 3.76, CI [95% confidence interval] 1.51-9.53, p = 0.0076). The BAO site is not predicting favorable clinical outcome. CONCLUSION: The exact basilar artery occlusion site in patients eligible for endovascular stroke treatment reflects the stroke etiology and is associated with differing recanalization success but does not predict favorable clinical outcome.

Vertebro-basilar stroke due to Bow-Hunter syndrome: an unusual presentation of rotatory atlanto-axial subluxation in a fourteen year old.

Bow Hunter's syndrome is a rare disorder usually producing transient ischemic symptoms as a result of dynamic compression of the vertebral artery during head turning. We report a case of a 14 year old male presenting with stroke due to occlusion of vertebral artery due to rotatory atlanto-axial subluxation. The patient presented with sudden onset vertigo and ataxia. History revealed led mild torticollis since childhood which was never investigated. MRI and MRA showed infarcts in the bilateral cerebellar hemispheres and the occipital lobes with a hypoplastic left vertebral artery and kinking of the right vertebral artery at the cranio-vertebral junction due to rotatory atlanto-axial subluxation. The patient was successfully treated by C1 lateral mass and C2 sub-facetal screw with rod fixation. Bow-Hunter's syndrome producing transient ischemia is well reported but stroke in the vertebro-basilar territory in a 14 year old due to rotatory atlanto-axial subluxation is uncommon, and to the best of our knowledge, this is the eighth such reported case.

Embolic stroke induced by rotational persistent 1st intersegmental artery compression.

A 45-year-old man suffered multiple cerebral infarctions in the vertebrobasilar artery territory, followed by second stroke against conservative treatment. Radiological examinations revealed intra-arterial defect in left persistent 1st intersegmental artery (PFIA) at C1 level, suggesting mural thrombus, and mechanical compression of left PFIA at the level with head rotation to the right clearly revealed by reconstructed 3-dimensional radiological images, but no findings of atlantoaxial instability. One month after the second stroke, posterior fixation was performed. Postoperative course was uneventful without subsequent stroke for 24 months. This unique case demonstrated that PFIA might associate with cerebral stroke as a clinical condition of bow hunter's stroke even in middle age. Reconstructed 3-dimensional radiological images might be useful for clear demonstration of the pathophysiology in this complex clinical entity.

Clinical response to surgical decompression in atypical pediatric Bow Hunter's syndrome suggesting alternative pathophysiology: Case report.

Bow Hunter's syndrome is a rare cause of posterior circulation ischemia, produced by the mechanical and reversible occlusion of the vertebral artery during cephalic rotation. Diagnosis requires clinical suspicion and careful inspection of images with three-dimensional reconstruction. The study of choice is dynamic digital subtraction angiography (DSA). Treatment alternatives are: medical, surgical or endovascular. We report the case of an 8-year-old boy with recurrent infarctions of the posterior circulation secondary to the dissection of the vertebral artery, in association with an occipital bone spur. Dynamic DSA was negative. Conservative initial management was elected with cervical immobilization and anticoagulation, but due to persistence of symptoms, surgical decompression was decided. The patient did not repeat symptoms postoperatively and returned to his usual life. This is the first case reported to our knowledge of a surgical pediatric patient with asymptomatic atypical compression of VA secondary to BHS, whose dynamic angiography was negative, suggesting an alternative mechanism of the syndrome.

Basilar artery on computed tomography angiography score and clinical outcomes in acute basilar artery occlusion.

OBJECTIVES: This study aimed to evaluate the safety and efficacy of mechanical thrombectomy (MT) in patients with acute basilar artery occlusion (BAO) based on the baseline Basilar Artery on Computed Tomography Angiography (BATMAN) score. METHODS: We selected patients from the BASILAR study and analyzed the effects and safety of standard medical therapy (SMT) and MT for patients with documented BATMAN scores. The patients were subgrouped according to their BATMAN score (0-3, 4-6, and 7-10). The primary outcome was a favorable functional outcome (modified Rankin Scale [mRS] ≤ 3) and mortality after 90 days. RESULTS: This study included 828 patients: 337 with poor BATMAN scores (0-3), 386 with moderate BATMAN scores (4-6), and 105 with good BATMAN scores (7-10). MT was associated with favorable functional outcomes in the poor (adjusted odds ratio [aOR], 11.96; 95% confidence interval [CI], 2.58-55.43; P = 0.002), moderate (aOR, 4.66; 95% CI, 2.11-10.28; P < .001), and good (aOR, 7.71; 95% CI, 2.20-27.02; P = 0.001) BATMAN score subgroups. MT was also associated with low mortality rates in the poor (aOR, 0.10; 95% CI, 0.04-0.27; P < 0.001) and moderate (aOR, 0.31; 95% CI, 0.16-0.57; P = 0.002) BATMAN score subgroups. The BATMAN score was significantly associated with favorable outcomes in both the SMT (aOR, 1.44; 95% CI, 1.08-1.93; P = 0.014) and MT (aOR, 1.31; 95% CI, 1.20-1.44; P < 0.001) groups. CONCLUSION: Higher BATMAN scores were associated with improved prognosis and lower mortality rates after 3 months. MT was associated with improved outcomes in patients with low BATMAN scores despite their worse overall outcomes. UNIQUE IDENTIFIER: ChiCTR1800014759, 2018/02/03.

Vertebral artery stenosis predicts cerebrovascular diseases following radiotherapy for nasopharyngeal carcinoma.

PURPOSE: Radiotherapy for nasopharyngeal carcinoma (NPC) may induce cerebrovascular diseases including ischemic stroke and transient ischemic attack (TIA), which can cause severe disability. However, information on the incidence and predictors of cerebrovascular diseases is scarce. This study aimed to estimate the incidence of cerebrovascular diseases following NPC, and attempts to ascertain the predictors of cerebrovascular diseases to facilitate early prevention. METHODS: We performed a retrospective cohort study on 655 NPC patients who received radiotherapy between 2006 and 2018 in a medical center. This study analyzed the incidence, clinical and imaging presentation of patients with cerebrovascular diseases. Cox proportional hazard model was used to identify risk factors associated with cerebrovascular diseases following radiotherapy. RESULTS: There were 14 patients who developed an ischemic stroke, and 3 patients developed a TIA after a mean follow-up of 5.8 years. Most ischemic events were from large-artery atherosclerosis (76.5%), and the most common symptom of ischemic stroke was unilateral limb weakness (57.1%). The cumulative incidence of ischemic stroke or TIA 15 years after radiotherapy was 9.1% (95% confidence interval [CI] = 4.7-17.2%). Multivariate Cox regression identified vertebral artery stenosis (HR: 18.341; 95% CI = 3.907-86.100; P < 0.001), atrial fibrillation (HR: 13.314; 95% CI = 1.306-135.764; P = 0.029), and hypertension (HR: 7.511; 95% CI = 1.472-38.320; P = 0.015) as independent predictors of ischemic stroke or TIA. CONCLUSION: Our study found that NPC patients with vertebral artery stenosis, atrial fibrillation, or hypertension carry a higher risk for ischemic stroke or TIA. Regular assessment of vertebral artery after radiotherapy was suggested.

Rotational Vertebrobasilar Insufficiency: Is There a Physiological Spectrum? Phase-Contrast Magnetic Resonance Imaging Quantification in Healthy Volunteers.

BACKGROUND: Some cases of cerebral ischemia have been attributed to dynamic flow limitation in neck vessels. It however remains unknown whether this represents the extreme end of a physiological response. METHODS: Eighteen healthy volunteers were recruited to this prospective study. Cervical blood flow (ml/min/m2) was assessed using phase-contrast MRI, and cerebral perfusion ratios were assessed using arterial spin labeling perfusion at neutral position, predefined head rotations, as well as flexion and extension. Inter-reader agreements were assessed using intraclass correlation coefficient. RESULTS: The mean age was 38.6 ± 10.8 (range = 22-56) years, for five male participants and 13 females. The means for height and weight were 168 cm and 73.2 kg, respectively. There were no significant differences in individual arterial blood flow with change in head position (P > 0.05). Similarly, the repeated-measures analysis of variance test demonstrated no significant difference in perfusion ratios in relation to head position movement (P > 0.05). Inter-reader agreement was excellent (intraclass correlation coefficient = 0.97). CONCLUSIONS: There is neither significant change in either individual cervical arterial blood flow nor cerebral perfusion within the normal physiological/anatomical range of motion in healthy individuals. It is therefore reasonable to conclude that any such hemodynamic change identified in a patient with ischemic stroke be considered causative.