Periventricular nodular heterotopia associated with a "transmantle band sign" in patients with epilepsy.

OBJECTIVE: Previous studies using advanced magnetic resonance imaging (MRI) techniques have documented abnormal transmantle bands connecting ectopic nodules to overlying cortex in patients with periventricular nodular heterotopia (PNH). We describe a similar finding using conventional MRI techniques. METHODS: Patients were identified by means of a full-text search of radiological reports. All scanning was performed using conventional sequences at 3 Tesla (3T). Scans were reviewed by three neuroradiologists, and we characterized imaging features based on type of PNH and cortical irregularities associated with the transmantle band. RESULTS: A total 57 PNH patients were reviewed, of whom 41 demonstrated a "transmantle band" connecting the nodule to the overlying cortex. One or more periventricular heterotopic nodules was present in all 41 patients-this was bilateral in 29 of 41 (71%) and unilateral in the remaining 29%. In many cases there was more than one such band, and in some cases this band was nodular. In 19 of the cases, the cortex to which the band connected was abnormal, showing thinning in 4 cases, thickening in 5 cases, and polymicrogyria in another 10. SIGNIFICANCE: The transmantle band can be seen frequently in both unilateral and bilateral cases of PNH and can be visualized with conventional 3T MRI sequences. The band highlights the underlying neuronal migration issues at play in the pathogenesis of this disorder, but its underlying role in the complex, patient-specific epileptogenic networks in this cohort has yet to be determined and warrants further investigation.

The presence of pachymeningeal hyperintensity on non-contrast flair imaging in patients with spontaneous intracranial hypotension.

PURPOSE: Traditionally, in the work-up of patients for spontaneous intracranial hypotension, T1 post-contrast imaging is performed in order to assess for pachymeningeal enhancement. The aim of this study is to assess whether pachymeningeal hyperintensity can be identified on a non-contrast FLAIR sequence in these patients as a surrogate sign for pachymeningeal enhancement. METHODS: The patient cohort was identified from a prospectively maintained database of patients with a clinical diagnosis of intracranial hypotension. Patients who had both a post-contrast T1 sequence brain as well as non-contrast FLAR sequence of the brain were reviewed. Imaging was retrospectively reviewed by three independent neuroradiologists. Each study was assessed for the presence or absence of pachymeningeal hyperintensity on the FLAIR sequence. RESULTS: From January 2010 to July 2022, 177 patients were diagnosed with spontaneous intracranial hypotension. In total, 121 were excluded as post-contrast imaging was not performed during their work-up. Twenty-four were excluded as the FLAIR sequence was performed after administration of contrast. Six were excluded as there was no pachymeningeal thickening present on T1 post-contrast imaging, although there were other signs of intracranial hypotension. The study group therefore consisted of 26 patients. Pachymeningeal thickening was correctly identified on the non-contrast FLAIR sequence in all patients (100%). CONCLUSION: Where present, diffuse pachymeningeal hyperintensity can be accurately identified on a non-contrast FLAIR sequence in patients with spontaneous intracranial hypotension. This potentially obviates the need for gadolinium base contrast agents in the work-up of these patients.

Intradural spinal varix: the "doughnut" sign on T 2 weighted MR and confirmation with gadolinium-enhanced arterial and blood pool MR angiography.

Intradural spinal varices are rare lesions, with only three cases being previously reported in the literature. Previously described patients underwent MRI for non-specific low back pain and radiculopathy and were found to have an intradural lesion adjacent to the cauda equina, mimicking a nerve sheath tumour or ependymoma. Consideration of an intradural varix in the differential diagnosis of an intradural extramedullary spinal lesion is necessary to guide appropriate management. We report a case of an intradural spinal varix diagnosed with first-pass arterial and blood pool phase gadolinium-enhanced auto-triggered elliptic centric-ordered MR angiography. Digital subtraction angiography confirmed that there was no shunt but failed to demonstrate the varix. We reviewed the existing literature to look for common clinical and imaging features.

Randomized assessment of rapid endovascular treatment of ischemic stroke.

BACKGROUND: Among patients with a proximal vessel occlusion in the anterior circulation, 60 to 80% of patients die within 90 days after stroke onset or do not regain functional independence despite alteplase treatment. We evaluated rapid endovascular treatment in addition to standard care in patients with acute ischemic stroke with a small infarct core, a proximal intracranial arterial occlusion, and moderate-to-good collateral circulation. METHODS: We randomly assigned participants to receive standard care (control group) or standard care plus endovascular treatment with the use of available thrombectomy devices (intervention group). Patients with a proximal intracranial occlusion in the anterior circulation were included up to 12 hours after symptom onset. Patients with a large infarct core or poor collateral circulation on computed tomography (CT) and CT angiography were excluded. Workflow times were measured against predetermined targets. The primary outcome was the score on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) at 90 days. A proportional odds model was used to calculate the common odds ratio as a measure of the likelihood that the intervention would lead to lower scores on the modified Rankin scale than would control care (shift analysis). RESULTS: The trial was stopped early because of efficacy. At 22 centers worldwide, 316 participants were enrolled, of whom 238 received intravenous alteplase (120 in the intervention group and 118 in the control group). In the intervention group, the median time from study CT of the head to first reperfusion was 84 minutes. The rate of functional independence (90-day modified Rankin score of 0 to 2) was increased with the intervention (53.0%, vs. 29.3% in the control group; P<0.001). The primary outcome favored the intervention (common odds ratio, 2.6; 95% confidence interval, 1.7 to 3.8; P<0.001), and the intervention was associated with reduced mortality (10.4%, vs. 19.0% in the control group; P=0.04). Symptomatic intracerebral hemorrhage occurred in 3.6% of participants in intervention group and 2.7% of participants in control group (P=0.75). CONCLUSIONS: Among patients with acute ischemic stroke with a proximal vessel occlusion, a small infarct core, and moderate-to-good collateral circulation, rapid endovascular treatment improved functional outcomes and reduced mortality. (Funded by Covidien and others; ESCAPE ClinicalTrials.gov number, NCT01778335.).

Natural history and management of basilar trunk artery aneurysms.

BACKGROUND AND PURPOSE: Basilar trunk aneurysms (BTAs), defined as aneurysms distal to the basilar origin and proximal to the origin of the superior cerebellar artery, are rare and challenging to manage. We describe the natural history and management in a consecutive series of BTAs. METHODS: Between 2000 and 2013, 2522 patients with 3238 aneurysms were referred to our institution for aneurysm management. A retrospective review of this database was conducted to identify all patients with BTAs. RESULTS: In total, 52 patients had a BTA. Mean age was 56 (SD±18) years. Median clinical follow-up was 33 (interquartile range, 8-86) months, and imaging follow-up was 26 (interquartile range, 2-80.5) months. BTAs were classified into 4 causal subtypes: acute dissecting aneurysms, segmental fusiform ectasia, mural bleeding ectasia, and saccular aneurysms. Multiple aneurysms were more frequently noticed among the 13 saccular aneurysms when compared with overall population (P=0.021). There was preponderance of segmental ectasia or mural bleeding ectasia (P=0.045) in patients presenting with transit ischemic attack/stroke or mass effect. Six patients with segmental and 4 with mural bleeding ectasia demonstrated increasing size of their aneurysm, with 2 having subarachnoid hemorrhage caused by aneurysm rupture. None of the fusiform aneurysms that remained stable bled. CONCLUSIONS: BTAs natural histories may differ depending on subtype of aneurysm. Saccular aneurysms likely represent an underlying predisposition to aneurysm development because more than half of these cases were associated with multiple intracranial aneurysms. Intervention should be considered in segmental ectasia and chronic dissecting aneurysms, which demonstrate increase in size over time as there is an increased risk of subarachnoid hemorrhage.

Clinical characteristics and preferential location of intracranial mirror aneurysms: a comparison with non-mirror multiple and single aneurysms.

INTRODUCTION: The purpose of our study was to compare the clinical characteristics and preferential localization of aneurysms in three patient groups: single aneurysm, non-mirror multiple aneurysms, and mirror aneurysms. METHODS: We retrospectively reviewed the clinical and radiological data of 2223 consecutive patients harboring 3068 aneurysms registered at the Toronto Western Hospital between May 1994 and November 2010. The patients were divided into single, non-mirror multiple, or mirror aneurysm groups. Expected incidences of mirror aneurysms at each location were calculated on the basis of the single aneurysm incidences at each location. RESULTS: Patients with mirror aneurysms (n = 197) did not differ from patients with non-mirror multiple aneurysms (n = 392) in having female predominance (81.7 vs. 76.3 %) or a family history of intracranial aneurysm (20.5 vs. 17.6 %). When compared with expected incidences at each location, mirror aneurysms were more frequently found at the cavernous internal carotid artery (30 vs. 11.5 %) (p < 0.0001). Mirror aneurysms involving the posterior circulation were less frequent (6.7 %) than aneurysms in the single (19.6 %) or non-mirror multiple aneurysm groups (18.9 %) (p < 0.05). CONCLUSION: Patients with mirror aneurysms had similar clinical characteristics to non-mirror multiple aneurysm patients. Mirror aneurysms showed a predilection for the cavernous carotid artery, whereas they were comparatively rare in the posterior circulation.

Aneurysmal wall enhancement and perianeurysmal edema after endovascular treatment of unruptured cerebral aneurysms.

INTRODUCTION: Perianeurysmal edema and aneurysm wall enhancement are previously described phenomenon after coil embolization attributed to inflammatory reaction. We aimed to demonstrate the prevalence and natural course of these phenomena in unruptured aneurysms after endovascular treatment and to identify factors that contributed to their development. METHODS: We performed a retrospective analysis of consecutively treated unruptured aneurysms between January 2000 and December 2011. The presence and evolution of wall enhancement and perianeurysmal edema on MRI after endovascular treatment were analyzed. Variable factors were compared among aneurysms with and without edema. RESULTS: One hundred thirty-two unruptured aneurysms in 124 patients underwent endovascular treatment. Eighty-five (64.4 %) aneurysms had wall enhancement, and 9 (6.8 %) aneurysms had perianeurysmal brain edema. Wall enhancement tends to persist for years with two patterns identified. Larger aneurysms and brain-embedded aneurysms were significantly associated with wall enhancement. In all edema cases, the aneurysms were embedded within the brain and had wall enhancement. Progressive thickening of wall enhancement was significantly associated with edema. Edema can be symptomatic when in eloquent brain and stabilizes or resolves over the years. CONCLUSIONS: Our study demonstrates the prevalence and some appreciation of the natural history of aneurysmal wall enhancement and perianeurysmal brain edema following endovascular treatment of unruptured aneurysms. Aneurysmal wall enhancement is a common phenomenon while perianeurysmal edema is rare. These phenomena are likely related to the presence of inflammatory reaction near the aneurysmal wall. Both phenomena are usually asymptomatic and self-limited, and prophylactic treatment is not recommended.

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.

Challenges in the management of ruptured and unruptured brainstem arteriovenous malformations: outcome after conservative, single-modality, or multimodality treatments.

BACKGROUND: Brainstem arteriovenous malformations are challenging lesions, and benefits of treatment are uncertain. OBJECTIVE: To study the clinical course of Brainstem arteriovenous malformations and the influence of treatments on outcome. METHODS: We reviewed a prospective series of 31 brainstem arteriovenous malformations. Demographic, morphological, and clinical characteristics were recorded. Factors determining initial and final outcomes (modified Rankin Scale), results of treatments (cure rates, complications), and disease course were analyzed. RESULTS: Brainstem arteriovenous malformations were symptomatic and bled in 93% and 61% of cases, respectively. Examination was abnormal and initial modified Rankin Scale score was < 3 in 71% and 86% of patients, respectively. The average follow-up time was 6.2 years, and 26% of patients rebled (5.9 %/y). Treatment modalities included conservative, radiosurgical, endovascular, surgical, and multimodality treatment in 13%, 58%, 35%, 16%, and 26% of cases, respectively. The obliteration rate was 60% overall and 39% after radiosurgery, 40% after embolization, and 75% after microsurgery, with respective complication-free cure rates of 71%, 50%, and 0%. Overall procedural mortality and morbidity were 2.3% and 18.6%, respectively. Final modified Rankin Scale score was < 3 in 77% of cases. Neurological deterioration (35%) was related to treatment complications in 74% of cases with a negative impact of surgery (P = .04), palliative embolization (odds ratio = 16), and multimodality treatments (odds ratio = 24). Radiosurgery was inversely associated with worsening (odds ratio = 0.06). CONCLUSION: Brainstem arteriovenous malformations require individualized treatment decisions. Single-modality treatments with a reasonable chance of complete cure and low complication rate (such as radiosurgery) should be favored.

Vessel wall MRI to differentiate between reversible cerebral vasoconstriction syndrome and central nervous system vasculitis: preliminary results.

BACKGROUND AND PURPOSE: Prospective differentiation between reversible cerebral vasoconstriction syndrome and central nervous system vasculitis can be challenging. We hypothesized that high-resolution vessel wall MRI would demonstrate arterial wall enhancement in central nervous system vasculitis but not in reversible cerebral vasoconstriction syndrome. METHODS: We identified all patients with multifocal segmental narrowing of large intracranial arteries who had high-resolution vessel wall MRI and follow-up angiography at our institute over a 4-year period and performed a detailed chart review. RESULTS: Three patients lacked arterial wall enhancement, and these all had reversal of arterial narrowing within 3 months. Four patients demonstrated arterial wall enhancement, and these had persistent or progressive arterial narrowing at a median follow-up of 17 months (range, 6-36 months) with final diagnoses of central nervous system vasculitis (3) and cocaine vasculopathy (1). CONCLUSIONS: Preliminary results suggest that high-resolution contrast-enhanced vessel wall MRI may enable differentiation between reversible cerebral vasoconstriction syndrome and central nervous system vasculitis.

Intracranial dural arteriovenous shunts: transarterial glue embolization--experience in 115 consecutive patients.

PURPOSE: To evaluate the effectiveness and safety of transarterial glue embolization of intracranial dural arteriovenous shunts (DAVS). MATERIALS AND METHODS: Institutional review board approval was obtained, with waiver of informed consent, for this retrospective study. From a single-center database of information on 371 intracranial DAVS, data in 115 consecutive patients treated with transarterial glue embolization were identified and assessed. Clinical and angiographic features, including cure rate, complications, and outcome, were evaluated. The treatment results were also compared between the patients in the first half of the consecutive series and those in the second half. The mean glue concentrations used were compared between the first and second halves of the patient series by using the Student t test. RESULTS: One hundred twenty-one lesions were treated with transarterial glue embolization. There were 31 (25.6%) Borden type I lesions, 39 (32.2%) Borden type II lesions, and 51 (42.1%) Borden type III lesions. Angiographic cure with glue embolization was achieved for 36 lesions (29.8%); 17 (14.0%) lesions were cured immediately, and 19 (15.7%) showed progressive thrombosis at follow-up. The angiographic cure rate for Borden type III lesions improved from 10% to 55% in the later group of patients as compared with the earlier group. The mean concentration of glue was significantly lower in the later group of patients. One (0.9%) of the 115 patients suffered permanent morbidity from aggravation of left extremity weakness due to venous thrombosis. Eight patients experienced nonpermanent morbidities, including transient worsening of neurologic status due to venous thrombosis (n = 4), alopecia (n = 2), scalp ulcer (n = 1), and pulmonary embolism (n = 1). Overall, improvement (n = 65) or stabilization (n = 32) of symptoms was seen in 84.3% of the patients. CONCLUSION: Transarterial glue embolization is a safe and effective method of primary treatment for intracranial DAVS, especially Borden type III lesions. Improvement of cure rates in the latter half of this study suggest that technical advances and experience may enhance outcomes.

Postoperative assessment of clipped aneurysms with 64-slice computerized tomography angiography.

BACKGROUND: Multidetector computerized tomography angiography (MDCTA) is now a widely accepted technique for the management of intracranial aneurysms. OBJECTIVE: To evaluate its accuracy for the postoperative assessment of clipped intracranial aneurysms. METHODS: We analyzed a consecutive series of 31 patients that underwent direct surgical clipping procedures of 38 aneurysms. A 64 slice MDCT scanner (Aquilion 64, Toshiba) was used and results were compared with digital subtraction angiographies (DSA). Two independent neuroradiologists analyzed the following data: examination quality, artifacts, aneurysm remnant, and patency of collateral branches. Interobserver agreement, sensitivity, and specificity were calculated. RESULTS: Seventy-nine percent of the aneurysms were located in the anterior circulation. Significant artifacts were found with multiple and cobalt-alloy clips. According to DSA, remnants >2 mm were found in 21% of the cases, and 2 patients had one collateral branch occluded. Sensitivity and specificity of 64-MDCTA for the detection of aneurysm remnants were 50% and 100%, respectively. Sensitivity and specificity of 64-MDCTA for the detection of a significant remnant (>2 mm) and the detection of the occlusion of a collateral branch were, respectively, 67% and 100% and 50% and 100%. No relationship was found with the location, type, shape, size, or number of clips, but missed remnants tended to be larger with cobalt-alloy clips. CONCLUSIONS: 64-MDCTA is a valuable technique to assess the presence of a significant postoperative remnant in single titanium clip application cases and might be useful for long-term follow-up. DSA remains the most accurate postoperative radiological examination.

Middle ear aneurysm treated with an innovative, vessel-preserving, aneurysm-occluding stent.

Middle ear aneurysms are rare and difficult to treat. An innovative, parent vessel-preserving, aneurysm occlusion stent is a treatment alternative. It redirects blood flow away from the aneurysm, resulting in stasis within, and ultimate aneurysm thrombosis. Concurrent coiling is not needed with this stent, eliminating the risk of coils extruding or migrating, or acting as a nidus for infection in the middle ear. We review a successful treatment using this device.

Multidisciplinary care of occipital arteriovenous malformations: effect on nonhemorrhagic headache, vision, and outcome in a series of 135 patients. Clinical article.

OBJECT: In this study, the authors evaluated how an appropriate allocation of patients with occipital arteriovenous malformations (AVMs) who were treated according to different strategies would affect nonhemorrhagic headache, visual function, and hemorrhage risk levels. METHODS: Of the 712 patients with brain AVMs in the Toronto Western Hospital prospective database, 135 had occipital AVMs. The treatment decision was based on patients' characteristics, presentation, and morphology of the AVM. The management modalities were correlated with their outcomes. RESULTS: The mean follow-up period was 6.78 years. Nonhemorrhagic headache was the most frequent symptom (82 [61%] of 135 patients). Ninety-four patients underwent treatment with one or a combination of embolization, surgery, or radiosurgery, and 41 were simply observed. Of the 40 nontreated patients with nonhemorrhagic headache, only 12 (30%) showed improvement. In the observation group 2 patients (22%) had worsening of visual symptoms, and 2 experienced hemorrhage, for an annual hemorrhage rate of 0.7% per year; 1 patient died. In the treatment group, the improvement in nonhemorrhagic headache in 35 patients (83%) was significant (p < 0.0001). Visual deficit at presentation worsened in 2 (8%), and there were 8 new visual field deficits (9%). The visual worsening was not significantly different. There were 2 other neurological deficits (2%) and 2 deaths (2%) related to the AVM treatment. One AVM hemorrhaged. The annual hemorrhage rate was 0.1% per year. The hemorrhage risk in the observation and treatment groups was lower than the observed hemorrhage risk of all patients with AVMs (4.6%) at the authors' institution. CONCLUSIONS: Appropriate selection of patients with occipital AVMs for one or a combination of treatment modalities yields a significant decrease in nonhemorrhagic headache without significant visual worsening. The multidisciplinary care of occipital AVMs can aim for an apparent decrease in hemorrhage risk.

Clinical and angiographic long-term follow-up of completely coiled intracranial aneurysms using endovascular technique.

OBJECT: The anatomical evolution and clinical outcome of completely coiled intracranial aneurysms after endovascular embolization have rarely been studied separately. From their prospective database, the authors reviewed follow-up angiography and clinical outcome of 87 patients whose aneurysms were designated as 100% obliterated on immediate postembolization angiography. METHODS: Ninety-one aneurysms (56 ruptured and 35 unruptured) in 87 patients were included in this study. Clinical outcome was evaluated using the Glasgow Outcome Scale. Follow-up angiographic findings were assessed and categorized as 1 of the following: no recanalization, recanalization with a neck remnant, or recanalization with a body remnant. For statistical analysis, the recanalization rate was correlated with: clinical presentation; the largest aneurysm diameter, aneurysm neck size, and dome-to-neck ratio; aneurysm location; and use of special techniques such as usage of a surface modified coil, balloon remodeling technique, or stent. RESULTS: At the latest clinical evaluation (mean 34.3 months), 81 (93.1%) of the 87 patients (91 aneurysms) had good clinical outcomes (Glasgow Outcome Scale Score 5). The procedure-related morbidity rate (permanent neurological deficit) was 2.3% (2 of 87), and there were no procedure-related deaths. On the latest follow-up angiography (mean 26.4 months), the recanalization rate was 26.4% (24 of 91 aneurysms): 16 (17.6%) with neck remnants and 8 (8.8%) with body remnants. The neck size of the recanalized aneurysms was statistically significantly larger than that of the nonrecanalized aneurysms (p = 0.006), and aneurysms with wide necks (> or = 4 mm) had a higher recanalization rate than those with a narrow neck (< 4 mm) (p = 0.002). There was no bleeding after endovascular treatment during the follow-up period. CONCLUSIONS: Completely coiled aneurysms after endovascular embolization demonstrated good clinical outcome, and there was no bleeding episode after endovascular treatment; however, there was a relatively high recanalization rate.

Aggressive intracranial dural arteriovenous fistula presenting with cerebrospinal fluid rhinorrhea: case report.

OBJECTIVE: This is the first report of an aggressive dural arteriovenous fistula presenting with rhinorrhea. It demonstrates the importance of recognizing increased intracranial pressure, and its underlying cause, as the predisposing factor to a spontaneous cerebrospinal fluid leak because this carries implications for management. CLINICAL PRESENTATION: Ten years after minor trauma and directly after an intercontinental flight, a 43-year-old woman presented with rhinorrhea. Right-sided pulsatile tinnitus had been present for the past 9 years. Imaging demonstrated an intracranial dural arteriovenous fistula of the right transverse sinus with cortical venous reflux. Magnetic resonance imaging findings indicated long-standing increased intracranial pressure. INTERVENTION: The fistula was treated by endovascular means, using both transvenous and transarterial approaches, which led to immediate relief of the tinnitus and resolution of the rhinorrhea within 4 days. CONCLUSION: A dural arteriovenous fistula should be included in the differential diagnosis of underlying causes of increased intracranial pressure when examining a patient with a cerebrospinal fluid leak. Treatment of the fistula should precede attempts to treat the rhinorrhea, especially if the fistula has cortical venous reflux.