Intracranial dural arteriovenous fistulas: association with cerebral venous thrombosis, baseline aggressiveness, and clinical outcomes. A retrospective multicenter study on 263 consecutive patients and literature review.

OBJECTIVE: The pathogenesis of intracranial dural arteriovenous fistulas (icDAVFs) is controversial. Cerebral vein thrombosis (CVT) and venous hypertension are recognized predisposing factors. This study aimed to evaluate the incidence of association between icDAVF and CVT and describe baseline aggressiveness and clinical outcomes for icDAVFs associated with CVT. The authors also performed a literature review of studies reporting icDAVF associated with CVT. METHODS: Two hundred sixty-three consecutive patients in two university hospitals with confirmed icDAVFs were included. A double-blind imaging review was performed to determine the presence or absence of CVT close or distant to the icDAVF. Location, type (using the Cognard classification), aggressiveness of the icDAVF, clinical presentation, treatment modality, and clinical and/or angiographic outcomes at 6 months were also collected. All prior brain imaging was analyzed to determine the natural history of onset of the icDAVF. RESULTS: Among the 263 included patients, 75 (28.5%) presented with a CVT concomitant to their icDAVF. For 18 (78.3%) of 23 patients with previous brain imaging available, CVT preceding the icDAVF was proven (6.8% of the overall population). Former/active smoking (OR 2.0, 95% CI 1.079-3.682, p = 0.022) and prothrombogenic status (active inflammation or cancer/coagulation trouble) were risk factors for CVT associated with icDAVF (OR 3.135, 95% CI 1.391-7.108, p = 0.003). One hundred eighty-seven patients (71.1%) had a baseline aggressive icDAVF, not linked to the presence of a CVT (p = 0.546). Of the overall population, 11 patients (4.2%) presented with spontaneous occlusion of their icDAVF at follow-up. Seven patients (2.7%) died during the follow-up period. Intracranial DAVF + CVT was not associated with a worse prognosis (modified Rankin Scale score at 3-6 months: 0 [interquartile range {IQR} 0-1] for icDAVF + CVT vs 0 [IQR 0-0] for icDAVF alone; p = 0.055). CONCLUSIONS: This was one of the largest studies focused on the incidence of CVT associated with icDAVF. For 6.8% of the patients, a natural history of CVT leading to icDAVF was proven, corresponding to 78.3% of patients with previous imaging available. This work offers further insights into icDAVF pathophysiology, aiding in identifying high-risk CVT patients for long-term follow-up imaging. Annual imaging follow-up using noninvasive vascular imaging (CT or MR angiography) for a minimum of 3 years after the diagnosis of CVT should be considered in high-risk patients, i.e., smokers and those with prothrombogenic status.

Intracranial Dural Arteriovenous Fistulas.

Dural arteriovenous fistulas (DAVFs) are abnormal communications between meningeal arteries and dural venous sinuses and/or cortical veins. Although many fistulas are benign and do not require treatment, some may carry a significant risk of bleeding or cause symptoms and warrant treatment. This review provides a review of various aspects of intracranial DAVFs including epidemiology, pathophysiology, clinical presentation, imaging characteristics, classification, natural history, and management options. By exploring these topics, we aim to enhance understanding of this condition and facilitate patient care.

Risk of Early Versus Later Rebleeding From Dural Arteriovenous Fistulas With Cortical Venous Drainage.

BACKGROUND: Cranial dural arteriovenous fistulas with cortical venous drainage are rare lesions that can present with hemorrhage. A high rate of rebleeding in the early period following hemorrhage has been reported, but published long-term rates are much lower. No study has examined how risk of rebleeding changes over time. Our objective was to quantify the relative incidence of rebleeding in the early and later periods following hemorrhage. METHODS: Patients with dural arteriovenous fistula and cortical venous drainage presenting with hemorrhage were identified from the multinational CONDOR (Consortium for Dural Fistula Outcomes Research) database. Natural history follow-up was defined as time from hemorrhage to first treatment, rebleed, or last follow-up. Rebleeding in the first 2 weeks and first year were compared using incidence rate ratio and difference. RESULTS: Of 1077 patients, 250 met the inclusion criteria and had 95 cumulative person-years natural history follow-up. The overall annualized rebleed rate was 7.3% (95% CI, 3.2-14.5). The incidence rate of rebleeding in the first 2 weeks was 0.0011 per person-day; an early rebleed risk of 1.6% in the first 14 days (95% CI, 0.3-5.1). For the remainder of the first year, the incidence rate was 0.00015 per person-day; a rebleed rate of 5.3% (CI, 1.7-12.4) over 1 year. The incidence rate ratio was 7.3 (95% CI, 1.4-37.7; P, 0.026). CONCLUSIONS: The risk of rebleeding of a dural arteriovenous fistula with cortical venous drainage presenting with hemorrhage is increased in the first 2 weeks justifying early treatment. However, the magnitude of this increase may be considerably lower than previously thought. Treatment within 5 days was associated with a low rate of rebleeding and appears an appropriate timeframe.

Dural arteriovenous fistulas in cerebral venous thrombosis: Data from the International Cerebral Venous Thrombosis Consortium: Data from the International Cerebral Venous Thrombosis Consortium.

BACKGROUND AND PURPOSE: To explore the prevalence, risk factors, time correlation, characteristics and clinical outcome of dural arteriovenous fistulas (dAVFs) in a cerebral venous thrombosis (CVT) population. METHODS: We included patients from the International CVT Consortium registries. Diagnosis of dAVF was confirmed centrally. We assessed the prevalence and risk factors for dAVF among consecutive CVT patients and investigated its impact on clinical outcome using logistic regression analysis. We defined poor outcome as modified Rankin Scale score 3-6 at last follow-up. RESULTS: dAVF was confirmed in 29/1218 (2.4%) consecutive CVT patients. The median (interquartile range [IQR]) follow-up time was 8 (5-23) months. Patients with dAVF were older (median [IQR] 53 [44-61] vs. 41 [29-53] years; p < 0.001), more frequently male (69% vs. 33%; p < 0.001), more often had chronic clinical CVT onset (>30 days: 39% vs. 7%; p < 0.001) and sigmoid sinus thrombosis (86% vs. 51%; p < 0.001), and less frequently had parenchymal lesions (31% vs. 55%; p = 0.013) at baseline imaging. Clinical outcome at last follow-up did not differ between patients with and without dAVF. Additionally, five patients were confirmed with dAVF from non-consecutive CVT cohorts. Among all patients with CVT and dAVF, 17/34 (50%) had multiple fistulas and 23/34 (68%) had cortical venous drainage. Of 34 patients with dAVF with 36 separate CVT events, 3/36 fistulas (8%) were diagnosed prior to, 20/36 (56%) simultaneously and 13/36 after (36%, median 115 [IQR 38-337] days) diagnosis of CVT. CONCLUSIONS: Dural arteriovenous fistulas occur in at least 2% of CVT patients and are associated with chronic CVT onset, older age and male sex. Most CVT-related dAVFs are detected simultaneously or subsequently to diagnosis of CVT.

Dural Arteriovenous Fistulae After Cerebral Venous Thrombosis.

BACKGROUND AND PURPOSE: This analysis examined the frequency of dural arteriovenous fistulae (dAVF) after cerebral venous thrombosis (CVT) in patients included in a randomized controlled trial comparing dabigatran etexilate with dose-adjusted warfarin (RE-SPECT CVT [A Clinical Trial Comparing Efficacy and Safety of Dabigatran Etexilate With Warfarin in Patients With Cerebral Venous and Dural Sinus Thrombosis]), who had systematic follow-up magnetic resonance (MR) imaging. METHODS: RE-SPECT CVT was a Phase 3, prospective, randomized, parallel-group, open-label, multicenter, exploratory trial with blinded end point adjudication. We allocated patients with acute CVT to dabigatran 150 mg twice daily or dose-adjusted warfarin, for 24 weeks and obtained a standardized MR protocol including time-of-flight MR angiography, 3-dimensional phase-contrast venography, and 3-dimensional contrast-enhanced MR venography at the end of the treatment period. A blinded adjudication committee assessed the presence of dAVF in a predefined substudy of the trial. RESULTS: We analyzed development of dAVF in 112 of 120 randomized patients; 57 allocated to dabigatran and 55 to warfarin. For 3 (2.7%) of these 112 patients, quality of follow-up imaging was insufficient to evaluate dAVF. A dAVF (Borden I) was found in 1 patient (0.9%) allocated to warfarin; however, this dAVF was already present at baseline. The patient did not present with hemorrhage at baseline or during the trial and was asymptomatic at follow-up. CONCLUSIONS: Despite systematic imaging, we found no new dAVF 6 months after CVT. Routine follow-up cerebral MR angiography aiming to detect new dAVF 6 months after CVT has a very low yield. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02913326.

Brain capillary telangiectasias: from normal variants to disease.

BACKGROUND: Brain capillary telangiectasias (BCTs) are small, dilated capillary networks in the brain that are most commonly asymptomatic. Though rare, symptomatic cases of BCTs have been reported, and it is therefore important to understand the nature of these lesions in order to facilitate proper recognition. Relative to other intracranial vascular malformations, updated information on the various epidemiologic, radiographic, and pathologic features of BCTs within the published literature may be inadequate. METHODS: We searched the PubMed database for prior reports of symptomatically-manifested BCTs. Moreover, Google Scholar and PubMed were searched in order to review current epidemiologic, radiographic, pathologic, and pathogenetic features of BCTs. RESULTS: Forty-eight published studies were included for a total of 99 individual cases of BCTs with symptomatic manifestations. Thirty-three symptomatic BCTs were hemorrhagic in nature, while 66 were non-hemorrhagic. The mean age at presentation of hemorrhagic lesions was 25.5 years, and the most common location was the supratentorial CNS (54.5%) with motor disturbance representing the most commonly encountered presenting symptom (26.1%). 15.2% of hemorrhagic lesions were treated with surgical removal. In non-hemorrhagic lesions, the mean age at presentation was 39.8 years with the pons being the most common lesion location (78.5%) and headache being the most common presenting symptom (22.2%). 12.1% of patients with non-hemorrhagic lesions were treated with surgical removal. CONCLUSIONS: Despite their rarity, symptomatic BCTs, both hemorrhagic and non-hemorrhagic, can cause devastating neurological sequelae, potentially through multiple mechanisms. The large majority of these lesions do not require intervention, though surgical removal has been achieved with good outcome in select cases. Further documentation of symptomatic manifestations with or without surgical intervention is vital in order to further understand the clinical, surgical, and pathogenic implications of these less-appreciated vascular malformations.

Symptomatic developmental venous anomalies.

Cerebral developmental venous anomalies (DVAs) are variations of venous vascular anatomy related to an underdevelopment of either the superficial or deep venous emissary system, resulting in a dilated transmedullary vein fed by multiple smaller venous radicles responsible for drainage of normal brain parenchyma. While typically benign and found incidentally on imaging studies, DVAs can rarely be symptomatic. The radiographic appearance of DVAs, as well as their symptomatic manifestations, is diverse. Herein, we will discuss the pathophysiology of symptomatic DVAs while providing illustrative case examples depicting each of their pathogenic mechanisms.

Association Between Incomplete Circle of Willis and Carotid Vulnerable Atherosclerotic Plaques.

Objective- Carotid high-risk plaque, characterized by intraplaque hemorrhage, fibrous cap rupture, and large lipid-rich necrotic core, is associated with cerebrovascular events. This study sought to investigate the relationship between high-risk carotid plaque and an incomplete circle of Willis (COW). Approach and Results- Patients were recruited from a multicenter study, Chinese Atherosclerosis Risk Evaluation (CARE-II) and underwent 3-dimensional time-of-flight magnetic resonance angiography for intracranial arteries and 2-dimensional multicontrast magnetic resonance vessel wall imaging for carotid arteries on a 3.0T magnetic resonance scanner. The integrity of the COW in anterior and posterior portions was evaluated. Characteristics of carotid plaques were assessed. Correlation between incomplete COW and carotid plaque features was determined. Of 482 eligible patients, patients with carotid intraplaque hemorrhage showed significantly higher prevalence of an incomplete anterior COW (52.7% versus 38.5%; P=0.022) compared with those without. An incomplete anterior COW was associated with intraplaque hemorrhage before (odds ratio, 1.781; 95% CI, 1.083-2.931; P=0.023) and after adjusted for clinical risk factors (odds ratio, 1.945; 95% CI, 1.139-3.321; P=0.015). The unilateral carotid artery stenosis showed no correlation with incomplete anterior COW and posterior COW (all P>0.025). No significant associations were found between other plaque features and any type of incomplete COW (all P>0.025). Conclusions- An incomplete COW is independently associated with intraplaque hemorrhage of carotid atherosclerotic plaques. Clinical Trial Registration- URL: http://www.clinicaltrials.gov . Unique identifier: NCT02017756.

Prevalence of Developmental Venous Anomalies Increases With Age.

BACKGROUND AND PURPOSE: To test the hypothesis that developmental venous anomalies (DVAs) may develop in the postnatal period, we studied the age-related prevalence of DVAs on contrast-enhanced magnetic resonance imaging. METHODS: Reports from a consecutive series of head magnetic resonance images with intravenous contrast performed over a 2-year period at our institution were reviewed. Studies reporting the presence of a DVA were retrieved and reviewed by a neuroradiologist. Patients were divided into 4 age groups: (1) <1 year old (neonates/infants), (2) 1 to 5 years old (toddlers and preschoolers), (3) 6 to 17 years old (grade schoolers), and (4) ≥18 years old (adults), and DVA prevalence by age group was studied. RESULTS: A total of 18 073 individuals were included. DVA prevalence in the neonate/infant age group was 1.5% (5/335) compared with 7.1% (51/714) in the toddler/preschool age group. In both the grade-school age group and adult age group, DVA prevalence was 9.6% (150/1557 and 1483/15 467, respectively). Neonates/infants were significantly less likely to have DVAs than other age groups (P<0.001). CONCLUSIONS: We found a very low prevalence of DVAs on contrast-enhanced magnetic resonance imaging in patients <1 year old which was significantly lower than other age groups. These findings suggest that postnatal changes in venous architecture and drainage patterns may contribute to the development of DVAs.

Lateral Sinus Dural Arteriovenous Fistulas: Sinovenous Outflow Restriction Outweighs Cortical Venous Reflux as a Parameter Associated with Hemorrhage.

Purpose To investigate whether sinovenous outflow restriction (SOR) is more strongly associated with hemorrhage than cortical venous reflux (CVR) in patients with lateral sinus dural arteriovenous fistulas (DAVFs). Materials and Methods An institutional review board approved this retrospective study and waiver of informed consent was obtained. From 1995 to 2016, 163 cases of lateral sinus DAVFs were included and divided into hemorrhagic and nonhemorrhagic groups based on initial presentation. Their angiograms and magnetic resonance images were evaluated, with two evaluators independently grading CVR and SOR. The SOR was scored as the combined conduit score (CCS), ranging from zero (total occlusion) to 8 (fully patent). The CVR and CCS of the hemorrhagic and nonhemorrhagic groups were compared. Logistic regression models were established for both the CVR and CCS to compare their performances in discriminating DAVF hemorrhage. Results Sinovenous outflow was significantly more restrictive (lower median CCS) in the hemorrhagic group than in the nonhemorrhagic group (1 vs 6.5; P < .001). A CCS of less than or equal to 2 best discriminated between the groups with a sensitivity of 90.0% and a specificity of 88.1%. The CCS model had a higher discriminative performance than did the CVR model (area under the curve, 0.933 vs 0.843; P = .018). Conclusion The CCS grading system semiquantifies SOR. SOR may represent a stronger risk factor associated with hemorrhage in patients with lateral sinus DAVFs than does CVR, and thus may offer guidance in therapeutic decision making. © RSNA, 2017.

Prevalence of cerebral cavernous malformations associated with developmental venous anomalies increases with age.

BACKGROUND AND PURPOSE: To test the hypothesis that the prevalence of cerebral cavernous malformation (CCM) associated with developmental venous anomalies (DVAs) increases with age, we studied the age-related prevalence of DVA-associated CCM among patients with DVAs. MATERIALS AND METHODS: Patients with DVAs on contrast-enhanced MRI exams performed over a 2-year period were included in this study. A single neuroradiologist reviewed all imaging exams for the presence of CCMs. Baseline demographic data collected included age, gender, presence of CNS neoplasm, history of cranial radiation, and history of seizure. Patients were divided into age groups based on decade of life. Cochran-Armitage trend tests were performed to determine if increasing age was associated with CCM prevalence. RESULTS: A total of 1689 patients with DVAs identified on contrast-enhanced MRI were included. Of these patients, 116 (6.9%) had a cavernous malformation associated with the DVA. There was a significant positive association between age and the prevalence of DVA-associated CCM (P = 0.002). The prevalence of DVA-associated CCM was 0.8% for the 0-10 age group, 1.6% for the 11-20 age group, 7.5% for the 21-30 age group, 9.5% for the 31-40 age group, 6.1% for the 41-50 age group, 6.3% for the 51-60 age group, 7.4% for the 61-70 age group, and 11.6% for the >70 age group (P < .0001). CONCLUSIONS: Our study demonstrated an age-related increase in prevalence of DVA-associated cavernous malformations among patients with DVAs. These findings suggest that DVA-associated cavernous malformations are acquired lesions.

Quantitative analysis of unusual entrance of the vertebral artery into the cervical foramen (V2 segment) and its clinical implications.

PURPOSE: Unusual entrance of the vertebral artery into the cervical transverse foramen (UE-V2S) is a relatively common clinical anomaly. Because spinal surgeons should understand the anatomical characteristics and clinical implications of this condition, we aimed to provide a description based on a very large number of UE-V2S anomaly cases. METHODS: We retrospectively analyzed 2207 three-dimensional head-and-neck computed tomographic angiograms (CTAs) that did not have specific vascular abnormalities. After confirming which cases had an unusual vertebral artery (VA) entrance into the transverse foreman (TF), we measured their vertebral artery diameter (VAD), transverse foramen area (TFA) and bilateral pedicle width (PW) from C3 to C7. The shortest horizontal distance from the vertical line in the medial margin of the TF to VA (D-TFVA) was measured in the extra-osseous region to estimate the exact location of the extra-osseous VA, except at the C7 level. RESULTS: An unusual V2 entrance was observed in 11.4 % (252 patients) of all 2207 consecutive patients and 6.5 % (268 courses) of all 4414 courses. The prevalence rankings for the different measures were as follows: unilateral UE-V2S = E5 > E4 > E7 > E3; bilateral UE-V2S = E5 (bilateral) > E4 (Rt) with E5 (Lt) > E4 (bilateral). Generally, the VAD of the anomaly side was statistically smaller than the normal contralateral side, which can induce a smaller TFA value at all sub-axial levels. Cervical pedicle fixation was preferable in the adjacent lower segment of unusual VA entrance level than the normal side in this study due to a broader PW, which was evident on the anomaly side. However, there was no statistical evidence that the side of the C7 entrance of the VA had a narrow PW. The lowest D-TFVA value was -3.8, indicating that we should take care not to exceed 3.8 mm medially into the vertical line of the medial TF wall during dissection when taking an anterior cervical approach. CONCLUSIONS: To avoid an unexpected VA injury and to improve the efficiency of even routine cervical operations, spinal surgeons should determine whether the patient has a UE-V2S and have a full understanding of the clinical characteristics of this anomaly.

Epidemiologic Survey of Dural Arteriovenous Fistulas in Japan: Clinical Frequency and Present Status of Treatment.

BACKGROUND AND PURPOSE: There are few reports describing the prevalence of dural arteriovenous fistulas (dAVFs). We conducted a nation-wide retrograde survey on the clinical frequency and the status of treatment of dAVFs in Japan. METHODS: The first questionnaire was sent to 1,236 certified neurosurgery clinics in Japan to ask about the number of patients treated and the location of dAVF during the 5 years from 1998 to 2002. The second questionnaire was sent to 102 large-volume centers to ask the patients' ages, gender, location of the fistula, clinical presentation, treatment modalities, clinical and radiological results, and recurrence. RESULTS: In the first survey, 1,815 cases were chosen from 338 clinics, including 826 cavernous sinus, 514 transverse-sigmoid sinus, 105 spinal, and 370 lesions in other places. The estimated detection rate was 0.29 per 100,000 persons per year in Japan. In the second survey, there were 1,490 cases (mean age: 62.7 ; 628 men and 850 women) that were culled from 68 high-volume centers. The initial clinical presentation was ocular symptoms (45 % of the cases), tinnitus (20 %), intracranial hemorrhage (16 %), and non-hemorrhagic neurological deficits (20 %). Treatment modality was endovascular therapy (76 % of the patients), open surgery (13 %), irradiation (3.4 %), and conservative therapy (11 %). Angiographic results were total obliteration in 59 % of the patients and subtotal obliteration in 16 %. Clinical symptoms disappeared in 54 % of the patients, improved in 16 %, unchanged in 7 %, worsened in 1.5 %, and death occurred in 1.2 %. Recurrence was reported in 5.9 % of the patients. CONCLUSIONS: This survey delineated the clinical frequency and the epidemiologic features of dAVF in Japan.

Vertebral Artery Hypoplasia Does Not Influence Lesion Size and Clinical Severity in Acute Ischemic Stroke.

BACKGROUND: Vertebral artery hypoplasia (VAH) is common, but its role in acute ischemic stroke (AIS) is uncertain. We aimed to evaluate the frequency, characteristics, and role of VAH in a large typical cohort of patients with AIS. METHODS: Up to 815 AIS patients (52.8% men, mean age 70 ± 14 years) were included in the study. All patients received a stroke work-up including brain imaging and duplex ultrasound. VAH was defined by a vessel diameter of less than or equal to 2.5 mm or a difference to the contralateral side of greater than 1:1.7. Vascular risk factors and stroke features were recorded. The subgroup of patients with posterior circulation AIS and magnetic resonance imaging was analyzed additionally, including the parameter of stroke extent. RESULTS: Up to 111 patients (13.6%) had VAH, with a mean diameter of 2.4 ± .4 mm. Patients with VAH were significantly younger (P = .037) and more often male (P = .033). There was no difference considering the National Institutes of Health Stroke Scale and modified Rankin Scale scores on admission or history of stroke. The distribution of patients without VAH was significantly different among the groups with anterior, posterior, and both circulations ischemia (P = .009). In the group with posterior circulation stroke, 36 patients (20.9%) had VAH. There were no differences in age, sex, history of stroke, risk factors, vascular territory, stroke size, or etiology. VAH patients had less often embolic stroke patterns (P = .009). CONCLUSIONS: VAH is more common in patients with posterior circulation stroke and in younger patients. Apart from that, we found no clear evidence that VAH would be a predisposing factor for stroke or that it increased the risk for larger ischemic lesions in the posterior circulation.

Extracranial internal carotid artery: anatomical variations in asymptomatic patients.

The anatomical variations of internal carotid artery (ICA) are mostly asymptomatic, thus being disregarded and only incidentally diagnosed, with very few symptomatic patients. The awareness of these anomalies is crucial to solve the differential with other neck lesions, preventing accidental injuries during neck surgery. Therefore, the aim of our study is to estimate the prevalence of ICA anomalies, using magnetic resonance angiography (MRA) and computed tomography angiography (CTA). 253 patients underwent head and neck MRA and CTA examinations, with multiplanar and volumetric reformations. For each set of images, the following items were investigated: origin, development, course, persistence of embryonic vessels and anomalous origin of collateral branches. In our series, ICA arose from the bifurcation of the common carotid artery at the level of: C4 in 303 hemi-necks (59.9 %); C3 in 98 hemi-necks (19.3 %); C5 in 57 hemi-necks (11.3 %); C2 in 48 hemi-necks (9.5 %). ICA kinking and/or coiling was found in 105 hemi-necks, and location variation of ICA (reversed-type) in two hemi-necks. In just one case the origin of the ascending pharyngeal artery was from ICA (0.2 %), while an anomalous persistence of the proatlantal artery was noticed in three cases (0.6 %). CTA and MRA showed similar accuracy in detecting ICA anomalies.

Extradural spinal cavernous malformation: a rare but important mimic.

Purely extradural spinal cavernous malformations (ESCMs) are rare, but the number of cases reported seems to be increasing. A 44-year-old woman presented with progressive cervicothoracic back pain, lower limb paraesthesia and hypertonia. MRI showed a well-circumscribed, convex lesion in the T1-4 extradural space causing cord compression and encroaching into the left T2/3 neural foramen. Selective spinal angiography demonstrated a vascular blush at the T2/T3 level corresponding with the mass. A feeding vessel arising from the base of the T1 spinous process was identified and successfully catheterised, but embolisation was precluded by unfavourable anatomy of the posterior spinal artery. At hemilaminectomy, the lesion was found to be an ESCM. The patient went on to make a full recovery. We reviewed 71 cases of ESCM reported in the last decade. Incidence of ESCM is unclear; the largest case series reported on nine patients, but most published accounts were single case studies. Patients presented with back pain (33%), myelopathy (56%) and/or radiculopathy (39%). Onset of symptoms was usually insidious over months to years, but 30% presented with sudden-onset neurological symptoms, often due to spontaneous haemorrhage. Mean age at diagnosis was 44 (range, 2-74; SD, 19.6) years with a 1:1 sex ratio. Lesions were found at all levels except C1-C2, but a strong predilection for the dorsal thoracic spine (68%) was shown. The lesion extended into an intravertebral foramen in at least 24 cases (34%). MRI is the investigation of choice, and angiography of ESCM has rarely been described. Most (87%) were hypo- to isointense on T1 MRI while hyperintensity on T2 (91%) and avid (89%), usually homogenous gadolinium update was almost universal. Perilesional haemosiderin, characteristic of intracranial and intramedullary cavernous malformation was rarely seen. In many cases, meningioma or nerve sheath tumour was misdiagnosed prior to surgery. All patients underwent total (95%) or subtotal (5%) microsurgical resection with excellent results; all improved (23%) or recovered fully (77%) after surgery. Those who presented acutely did worse; 38% had residual deficits.

Dural Arteriovenous Fistulas With or Without Cerebral Venous Thrombosis: A Cross-Sectional Analysis of 511 Patients.

BACKGROUND AND OBJECTIVES: Recent studies suggest a bidirectional relationship of dural arteriovenous fistula (DAVF) with cerebral venous thrombosis (CVT). We aimed to compare the characteristics of patients with DAVF with or without CVT and to analyze the risk factors for the coexistence of CVT in a DAVF population. METHODS: A total of 511 adult patients with DAVF were enrolled consecutively in our hospital from February 2019 through November 2022. Demographic data, clinical manifestations, and imaging characteristics were reviewed in detail. The patients with DAVF were divided into two groups: DAVF with CVT (DAVF-CVT) group and without CVT (DAVF alone) group. Univariate logistic regression and multivariate logistic regression were used to analyze the risk factors for the coexistence of CVT and DAVF. RESULTS: CVT was found in 19.8% of patients with DAVF. In univariate analysis, compared with the DAVF-alone group, the DAVF-CVT group was more likely to have tinnitus ( P = .001), blurred vision ( P < .001), visual field loss ( P = .001), focal neurological deficits ( P = .002), seizures ( P = .008), and cognitive impairment ( P = .046) and less likely to have spinal cord/brain stem dysfunction ( P = .004). In addition, there were significant differences in age ( P = .009), sex ( P = .019), the occurrence of venous cerebral infarction ( P = .001), and DAVF location ( P < .001) between the two groups. Furthermore, multivariate analysis showed that blurred vision, venous cerebral infarction, large sinus DAVF, and multiple DAVF were risk factors for the coexistence of CVT in patients with DAVF, with the odds ratio of 2.416 (95% CI 1.267-4.606, P = .007), 6.018 (95% CI 1.289-28.100, P = .022), 5.801 (95% CI 2.494-13.496, P < .001), and 5.640 (95% CI 2.122-14.989, P = .001), respectively. CONCLUSION: CVT occurred in approximately one fifth of patients with DAVF. Blurred vision, venous cerebral infarction, large sinus DAVF, and multiple DAVF may be the risk factors for predicting the coexistence of CVT in patients with DAVF.

Basilar artery fenestration detected with CT angiography.

OBJECTIVES: To analyse the characteristics of basilar artery (BA) fenestrations and their coexistence with aneurysms and other anomalies in a massive cases by computed tomographic angiography (CTA). METHODS: A total of 5,657 sequential cerebral CTA images performed from January 2006 to February 2012 were reviewed. CTA images were obtained from the raw datasets by using volume rendering and maximal intensity projection reconstruction. RESULTS: One hundred and thirty-two (2.33 %) BA fenestrations were detected with CTA, and most common at the proximal segment (n = 124). BA fenestration-associated aneurysms were found in 34 cases and 7 located at the posterior circulation, and the frequency of posterior circulation aneurysms was significantly different in patients with and without BA fenestrations (P = 0.025). Other associated anomalies included arteriovenous malformation (n = 7) and moyamoya disease (n = 6). BA fenestrations were classified into Type I (74 cases), Type II (15 cases), Type III (41 cases) and Type IV (2 cases). A significant difference was observed between Types II + III associated with convex-lens-like and slit-like fenestrations (P = 0.008). CONCLUSIONS: BA fenestrations were found in 2.33 % with CTA. They were significantly more often associated with posterior circulation aneurysms than those without BA fenestration. The anterior inferior cerebral artery (AICA) tends to originate more often from convex-lens-like fenestration than slit-like. KEY POINTS: • Basilar artery fenestrations were found in 2.33 % of patients undergoing CT angiography. • Fenestrations were seen more often in the lower third with slit-like configurations. • No obvious relationship exists between basilar artery fenestration and aneurysm formation. • Basilar artery fenestrations perhaps predispose a patient to posterior circulation aneurysm formation. • The AICA tends to originate more often from convex-lens-like than slit-like fenestrations.

Cavernous malformations associated with dural arteriovenous shunts in the central nervous system.

INTRODUCTION: Some cerebral cavernous malformations (CCMs) may be associated with vascular malformations that occur on the capillary-venous side of the cerebral circulation. The association between CCMs and dural arteriovenous shunts (DAVSs) is not well known. The purpose of this study is to investigate the relationship between CCMs and DAVSs. METHODS: We retrospectively analyzed 179 patients diagnosed as intracranial DAVSs and performed with digital subtraction angiography (DSA). The DSA images were investigated for the location, cortical venous reflux (CVR), multiplicity, and treatment method/result of DAVS. MR images were investigated for the location, number, and size of CCMs and correlated with the DSA images. RESULTS: Six of the 179 patients with DAVSs presented with coexistent CCMs (3.4 %; M/F = 3:3; mean age, 38 ± 22 years). Five of the six DAVS patients with CCMs were associated with CVR (83 %). The total number of CCMs associated with DAVS was 20. Multiple CCMs (range, 2-7) were seen in four (66 %) of six patients. Eighteen (90 %) of the 20 CCMs were located on the ipsilateral hemisphere of the CVR (n = 10) or adjacent to the deep venous reflux (n = 8). Five de novo CCMs were detected in two patients. All de novo CCMs were located on the ipsilateral hemisphere of the DAVS with CVR or juxtapositioned to abnormally dilated deep vein. CONCLUSION: CCMs may develop in association to DAVSs. The relationship between CCMs and DAVSs suggests the venous pathogenic origin of CCMs and the role of venous hypertension in the de novo development of CCMs.

Factors determining the success of endovascular treatments among patients with spinal dural arteriovenous fistulas.

INTRODUCTION: Despite improvements of embolization agents and techniques, endovascular treatment of spinal dural arteriovenous fistula (SDAVF) is still limited by inconsistent success. The aim of embolization is to occlude initial portion of the draining vein by liquid embolic materials. This study investigates factors that contribute to the success of embolization treatments among SDAVF patients. METHODS: We performed a retrospective analysis on consecutive SDAVF patients who received N-butyl cyanoacrylate (NBCA) glue embolization between January 1992 and June 2012. Univariable and multivariable logistic regression analyses were performed to calculate the probability of successful draining vein occlusion for variable procedure-related factors. RESULTS: We attempted endovascular approach as the first intention treatment in 66 out of 90 consecutive patients. Among them, a total of 43 NBCA glue injections were performed in 40 patients. Successful embolization was achieved in 24 patients (60 %). In multivariable analyses, antegrade flow during microcatheter test injection (OR 13.2, 95 % CI 1.7 to 105.4) and use of glue concentration ≥ 30 % (OR 0.1, 95 % CI 0.01 to 0.8) were detected as significant positive and negative predictors of successful venous penetration, respectively. With persistent antegrade flow, the success rates using a glue mixture of more than 30 % dropped significantly from 85.0 to 42.9 % (p = 0.049). If contrast stagnated during microcatheter injections, success rates were low regardless of glue concentrations. CONCLUSIONS: Presence of antegrade flow toward the draining vein and injection of NBCA glue less than 30 % are associated with higher chance of draining vein penetration and, therefore, successful endovascular SDAVF obliteration.