When to Consider Prophylactic Antimigraine Therapy in Children with Migraine

PURPOSE OF REVIEW

Headache is not an uncommon complaint in children, and recognition of migraine is increasing in children and adolescents. Treatment options consist of abortive and preventive medications; however, when to start the preventive treatment is not clear in the pediatric population. This article reviews current guidelines and practices to provide a better clinical approach in the management of migraines in children and adolescents.

RECENT FINDINGS

Currently, the only FDA-approved medical treatment option for preventive therapy in chronic migraine in adolescents is topiramate. However, the Childhood and Adolescent Migraine Prevention Study (CHAMP) did not endorse superiority of topiramate or amitriptyline over placebo. At this time, there is no clear consensus on when to start preventive therapy in children and adolescents with migraines. The decision is multifactorial and should be initiated after a thorough discussion with the patient and caregiver(s) about related risks and benefits of treatment. Education regarding various modalities of treatment and ensuring compliance is essential to treatment success.

One-Year Risk of Recurrent Stroke and Death Associated with Vertebrobasilar Artery Stenosis and Occlusion in a Cohort of 10,515 Patients

BACKGROUND

The natural history of vertebrobasilar artery (VBA) stenosis or occlusion remains understudied.

METHODS

Patients with diagnosis of ischemic stroke or transient ischemic attack (TIA) who were noted to have VBA stenosis based on computed tomography or magnetic resonance imaging or catheter-based angiogram were selected from Taiwan Stroke Registry. Cox proportional hazards model was used to determine the hazards ratio (HR) of recurrent stroke and death within 1 year of index event in various groups based on severity of VBA stenosis (none to mild: 0-49%; moderate to severe: 50-99%: occlusion: 100%) after adjusting for differences in demographic and clinical characteristics between groups at baseline evaluation.

RESULTS

None to mild or moderate to severe VBA stenosis was diagnosed in 6972 (66%) and 3,137 (29.8%) among 10,515 patients, respectively, and occlusion was identified in 406 (3.8%) patients. Comparing with patients who showed none to mild stenosis of VBA, there was a significantly higher risk of recurrent stroke (HR 1.21, 95% CI 1.01-1.45) among patients with moderate to severe VBA stenosis. There was a nonsignificantly higher risk of recurrent stroke (HR 1.49, 95% CI 0.99-2.22) and significantly higher risk of death (HR 2.21, 95% CI 1.72-2.83), among patients with VBA occlusion after adjustment of potential confounders.

CONCLUSIONS

VBA stenosis or occlusion was relatively prevalent among patients with TIA or ischemic stroke and associated with higher risk of recurrent stroke and death in patients with ischemic stroke or TIA who had large artery atherosclerosis.

Acute hypertensive response in patients with intracerebral hemorrhage pathophysiology and treatment

Acute hypertensive response is a common systemic response to occurrence of intracerebral hemorrhage which has gained unique prominence due to high prevalence and association with hematoma expansion and increased mortality. Presumably, the higher systemic blood pressure predisposes to continued intraparenchymal hemorrhage by transmission of higher pressure to the damaged small arteries and may interact with hemostatic and inflammatory pathways. Therefore, intensive reduction of systolic blood pressure has been evaluated in several clinical trials as a strategy to reduce hematoma expansion and subsequent death and disability. These trials have demonstrated either a small magnitude benefit (second intensive blood pressure reduction in acute cerebral hemorrhage trial and efficacy of nitric oxide in stroke trial) or no benefit (antihypertensive treatment of acute cerebral hemorrhage 2 trial) with intensive systolic blood pressure reduction compared with modest or standard blood pressure reduction. The differences may be explained by the variation in intensity of systolic blood pressure reduction between trials. A treatment threshold of systolic blood pressure of ≥180 mm with the target goal of systolic blood pressure reduction to values between 130 and 150 mm Hg within 6 h of symptom onset may be best supported by current evidence.

Effect of epidural blood injection on upright posture intolerance in patients with headaches due to intracranial hypotension: A prospective study

BACKGROUND

We performed a prospective study to quantify changes in various aspects of upright posture intolerance in patients with intracranial hypotension.

METHODS

Six patients were provided a standard questionnaire before, immediately after epidural blood patch injection and at follow-up visit within 1 month after epidural blood injection inquiring: (a) How long can they stand straight without any support? (b) Do they feel any sense of sickness when they sit or lie down after standing? (c) How long do they have to wait before they are comfortable standing again after they have stood straight? (d) How effectively and fast can they get up from sitting or lying position to stand straight? and (e) Rate their activities in upright posture without support on a standard vertical visual analogue scale between 100 (can do everything) and 0 (cannot do anything).

RESULTS

All patients responded that they could not stand straight for ≥30 min (four responding <5 min) on pretreatment evaluation. All patients reported improvement in this measure immediately postprocedure with two reporting ≥30 min. At follow-up, three patients reported further improvement and one patient reported worsening in this measure. The magnitude of improvement ranged from 10 to 80 points increase immediately postprocedure in their ability to perform activities, while they are standing without any support on visual analogue scale. At follow-up, four patient reported additional improvement in their ability to perform activities, while they are standing without any support (ranged from 10 to 20 points increase compared with immediately postprocedure rating).

CONCLUSIONS

We present semiquantitative data on various aspects of upright posture intolerance in patients with intracranial hypotension before and after epidural blood injection.

Blood Pressure-Attained Analysis of ATACH 2 Trial

BACKGROUND AND PURPOSE

We compared the rates of death or disability, defined by modified Rankin Scale score of 4 to 6, at 3 months in patients with intracerebral hemorrhage according to post-treatment systolic blood pressure (SBP)-attained status.

METHODS

We divided 1000 subjects with SBP ≥180 mm Hg who were randomized within 4.5 hours of symptom onset as follows: SBP <140 mm Hg achieved or not achieved within 2 hours; subjects in whom SBP <140 mm Hg was achieved within 2 hours were further divided: SBP <140 mm Hg for 21 to 22 hours (reduced and maintained) or SBP was ≥140 mm Hg for at least 2 hours during the period between 2 and 24 hours (reduced but not maintained).

RESULTS

Compared with subjects without reduction of SBP <140 mm Hg within 2 hours, subjects with reduction and maintenance of SBP <140 mm Hg within 2 hours had a similar rate of death or disability (relative risk of 0.98; 95% confidence interval, 0.74-1.29). The rates of neurological deterioration within 24 hours were significantly higher in reduced and maintained group (10.4%; relative risk, 1.98; 95% confidence interval, 1.08-3.62) and in reduced but not maintained group (11.5%; relative risk, 2.08; 95% confidence interval, 1.15-3.75) compared with reference group. The rates of cardiac-related adverse events within 7 days were higher among subjects with reduction and maintenance of SBP <140 mmHg compared to subjects without reduction (11.2% versus 6.4%).

CONCLUSIONS

No decline in death or disability but higher rates of neurological deterioration and cardiac-related adverse events were observed among intracerebral hemorrhage subjects with reduction with and without maintenance of intensive SBP goals.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01176565.

Abstract 52: Global Cerebral Edema in Patients With Primary Intracerebral Hemorrhage: Results From Brain Edema at Cerebral Hemorrhage (BEACH) Study

Background: Recent data supports presence of neuronal injury and blood brain barrier breakdown in brain regions distant to hematoma in patients with intracerebral hemorrhage (ICH). We determined the prevalence of global cerebral edema and its impact on clinical outcome in patients with ICH recruited in a multicenter clinical trial.

Methods: BEACH was a pre-planned prospective observational study (N=278) nested in the Antihypertensive Treatment of Acute Cerebral Hemorrhage (ATACH)-2 clinical trial which randomized ICH patients with SBP ≥ 180 mmHg who presented within 4.5 hours of symptom onset. The aim of the ATACH-2 was to ascertain whether SBP reduction to < 140 mmHg would yield reduction in death and disability (defined as modified Rankin Scale 4-6) at 90 days compared to the current guideline. Total brain volume, parenchymal hematoma volume, and peri-hematoma edema volume were measured on CT scans acquired on admission and at 24 (±8) hours (and later intervals when available) post-randomization using computerized image analysis software(Analyze. Inc). Global cerebral edema was defined as 5% or greater increase in the brain volume (excluding parenchymal hematoma and peri-hematoma edema volumes) on follow up CT scan compared with baseline scan.

Results: A total of 48 (17%) of 278 patients had global cerebral edema by 24 hours CT scan. The median increase in total brain volume was 9 cm3 (range 5 - 20 cm3). Additional occurrence of global cerebral edema was seen in 3% and 1% of patients by 48 hours and 72 hours, respectively. Baseline characteristics were similar, but median NIHSS was higher and median GCS score was lower in patients with global cerebral edema. The prevalence of global cerebral edema was significantly lower in intensive SBP reduction group compared to standard SBP reduction group (12% vs 23%, p-value: 0.02). While not statistically significant, higher rates of death or disability at 90 days were observed among subjects with global cerebral edema within 24 hours (48% vs 36%, p-value: 0.12)

Conclusion: Global cerebral edema at 24 hours occurred in 17% of the BEACH subgroup of ATACH 2 subjects. Global cerebral edema was associated with higher level of clinical severity of disease and its prevalence was significantly lower among intensive SBP reduction group.

Concurrent Angioplasty Balloon Placement for Stent Delivery through Jugular Venous Bulb for Treating Cerebral Venous Sinus Stenosis. Technical Report

OBJECTIVE

To report upon technique of concurrent placement of angioplasty balloon at the internal jugular vein and sigmoid venous sinus junction to facilitate stent delivery in two patients in whom stent delivery past the jugular bulb was not possible.

CLINICAL PRESENTATION

A 21-year-old woman and a 41-year-old woman with worsening headaches, visual obscuration or diplopia were treated for pseudotumor cerebri associated with transverse venous stenosis. Both patients had undergone primary angioplasty, which resulted in improvement in clinical symptoms followed by the recurrence of symptoms with restenosis at the site of angioplasty.

INTERVENTION

After multiple attempts at stent delivery through jugular venous bulb were unsuccessful, a second guide catheter was placed in the ipsilateral internal jugular vein through contralateral femoral venous approach. A 6 mm × 20 mm (left) or 5 × 15 mm (right) angioplasty balloon was placed across the internal jugular vein and sigmoid sinus junction and partially inflated until the inflation and relative straightening of the junction was observed. In both patients, the internal jugular vein and sigmoid sinus junction was successfully traversed by the stent delivery system in a parallel alignment to inflated balloon. Balloon mounted stent was deployed at the site of restenosis with near complete resolution of lumen narrowing delivery and improvement in clinical symptoms.

CONCLUSION

We report a technique for realignment and diameter change with concurrent placement and partial inflation of angioplasty balloon at the jugular venous bulb to facilitate stent delivery into the sigmoid and transverse venous sinuses in circumstances where multiple attempts at stent delivery are unsuccessful.

Effect of Carotid Revascularization Endarterectomy Versus Stenting Trial Results on the Performance of Carotid Artery Stent Placement and Carotid Endarterectomy in the United States

BACKGROUND

CREST (Carotid Revascularization Endarterectomy Versus Stenting Trial) results, published in 2010, showed no difference in the rates of composite outcome (stroke, myocardial infarction, or death) between carotid artery stent placement (CAS) and carotid endarterectomy (CEA).

OBJECTIVE

To identify any changes in use and outcomes of CAS and CEA subsequent to the CREST results.

METHODS

We estimated the frequency of CAS and CEA procedures in the years 2009 (pre-CREST period) and 2011 (post-CREST period), using data from the National Inpatient Sample (NIS). Demographic and clinical characteristics and in-hospital outcomes of pre- and post-CREST CAS-treated and post-CREST CEA-treated patients were compared with pre-CREST CEA-treated patients.

RESULTS

A total of 225,191 patients underwent CEA or CAS in the pre- and post-CREST periods. The frequency of CAS among carotid revascularization procedures did not change after publication of the CREST results (12.3% vs. 12.7%, P = .9). In the pre-CREST period, the CAS group (compared with the CEA group) had higher rates of congestive heart failure (P < .001), coronary artery disease (P < .001), and renal failure (P < .001). The post-CREST CAS group had a higher frequency of atrial fibrillation (P = .003), congestive heart failure (P < .0001), coronary artery disease (P < .0001), and renal failure (P = .0001). Discharge with moderate to severe disability (P < .0001) and postprocedure neurological complications (P = .005) were more frequently reported in the post-CREST CAS group. After adjusting for age, sex, and risk factors, the odds ratio (OR) for moderate to severe disability was 1.0 (95% confidence interval [CI]: 0.8-1.2) in the pre-CREST CAS group and 1.4 (95% CI: 1.1-1.7) in the post-CREST CAS group compared with the reference group. The adjusted OR for neurological complications in the pre-CREST CAS group was 1.6 (95% CI: 1.2-2.1, P = .002), and 1.5 (95% CI: 1.1-2.0, P = .01) in the post-CREST CAS group.

CONCLUSION

The frequency of CAS and CEA for carotid artery stenosis has not changed after publication of the CREST. The demographics, pretreatment comorbidity profile, and in-hospital complication rates remained unchanged during the 2 time periods.

Syncope in Patient with Bilateral Severe Internal Carotid Arteries Stenosis/Near Occlusion: A Case Report and Literature Review

BACKGROUND

Syncope is commonly worked up for carotid stenosis, but only rarely attributed to it. Considering paucity of such cases in literature, we report a case and discuss the pathophysiology.

DESIGN/METHODS

We report a patient with high-grade bilateral severe internal carotid artery (ICA) stenosis who presented with syncopal episodes in the absence of stroke, orthostatic hypotension, significant cardiovascular disease, or vasovagal etiology. We reviewed all literature pertaining to syncope secondary to carotid stenosis and other cerebrovascular disease.

RESULTS

A 67-year-old man presented with two brief syncopal episodes. History and physical examination was not suggestive of seizure or vasovagal syncope. Other workup was negative for any stroke or syncope secondary to cardiac or vasovagal etiology. Magnetic resonance angiography (MRA) revealed bilateral ICA severe stenosis. This was confirmed by transfemoral carotid vessels angiography. Internal carotid angioplasty and stenting was performed on one side. After this, the patient remained asymptomatic. After one month, carotid endarterectomy (CEA) of contralateral side was performed. Patient remained symptom free after that. On review of literature, we identified only 12 cases of syncope attributable to carotid stenosis and reviewed 24 cases attributable to other cerebrovascular disease.

CONCLUSION

Syncope secondary to carotid stenosis, especially in the absence of any focal ischemic events is rare. It can only be expected in those patients who have bilateral hemodynamically significant carotid disease, which is unlikely in the absence of any focal ischemic events.

A population-based study of the incidence and case fatality of non-aneurysmal subarachnoid hemorrhage

BACKGROUND

There is a paucity of reliable and recent data regarding epidemiology of non-aneurysmal subarachnoid hemorrhage (SAH) in population-based studies.

OBJECTIVES

To determine the incidence and case fatality of non-aneurysmal SAH using a population-based design.

METHODS

Medical records and angiographic data of all patients from Stearns and Benton Counties, Minnesota, admitted with SAH were reviewed to identify incident case of non-aneurysmal SAH. Patients with a first-time diagnosis of non-aneurysmal SAH (based on two negative cerebral angiograms performed ≥7 days apart) between June 1st, 2012 and June 30th, 2014 were considered incident cases. We calculated the incidences of non-aneurysmal and aneurysmal SAH adjusted for age and sex based on the 2010 US census.

RESULTS

Of the 18 identified SAH among 189,093 resident populations, five were true incident cases of non-aneurysmal SAH in this population-based study. The age- and sex-adjusted incidence of non-aneurysmal SAH were 2.8 [95 % confidence interval (CI) 2.7-2·9] per 100,000 person-years which was lower than aneurysmal SAH incidence of 7.2 [95 % CI 7.1-7.4] per 100,000 person-years. The age-adjusted incidence of non-aneurysmal SAH was similar (compared with aneurysmal SAH) among men; 3.2 [95 % CI 3.1-3.3] per 100,000 person-years versus 2.2 [95 % CI 2.1-2.3] per 100,000 person-years, respectively. The age-adjusted case fatality rate at 3 months was 4.46 and 0.0 per 100,000 persons for aneurysmal and non-aneurysmal SAH, respectively.

CONCLUSIONS

The incidence of non-aneurysmal SAH was higher than previously reported particularly among men.

Detachable-Tip Microcatheters for Liquid Embolization of Brain Arteriovenous Malformations and Fistulas: A United States Single-Center Experience

BACKGROUND

The US Food and Drug Administration recently approved a detachable-tip microcatheter, the Apollo microcatheter (eV3, Inc, Irvine, California), to prevent catheter entrapment during embolization of brain arteriovenous malformations (AVMs) using liquid embolic systems.

OBJECTIVE

To report technical aspects and clinical results of cerebral embolizations with the Apollo microcatheter in 7 embolizations in 3 adult patients.

METHODS

A 62-year-old man presented with an AVM in the parieto-occipital region measuring 3.6 × 1.6 cm with major cortical feeders from the right middle cerebral artery (MCA) and minor contribution from the distal right anterior cerebral artery. Two pedicles originating from the MCA were embolized. A 48-year-old woman presented with a left frontal AVM measuring 3.3 × 1.8 cm with arterial feeders from the left MCA, left middle meningeal artery, and contralateral anterior cerebral artery. Three pedicles originating from the left MCA were embolized. A 76-year-old man presented with an arteriovenous fistula with multiple fistulous connections and feeders from both vertebral and occipital arteries and the left posterior cerebral artery draining into the left transverse, torcula, and left sigmoid sinus. Two major occipital artery feeders were embolized.

RESULTS

Seven Apollo microcatheters were used with the Onyx 18 liquid embolic system. The length of the detachable tip was 15 mm in 2 and 30 mm in 5 embolizations. The mean microcatheter in-position time within the pedicle was 20 minutes. Detachment of tip occurred in 3 instances. No limitations in accessing target arterial feeders and safe tip disengagement were noted despite prolonged injection times.

CONCLUSION

Our initial experience supports the feasibility, safety, and effectiveness of detachable-tip microcatheters in treating brain AVMs and arteriovenous fistulas.

Abstract TP28: Impact of Variations in Thrombolysis in Cerebral Infarction Grading Scheme Between Clinical Trials on Rates of Post Thrombectomy Partial Recanalization

Background: There have been different methods in clinical trials to quantify partial angiographic recanalization after mechanical thrombectomy for large vessel acute ischemic stroke.

Objective: To determine the variation in quantification between different methods for grading angiographic recanalization.

Methods: We reviewed clinical and angiographic data for consecutive patients who underwent mechanical thrombectomy at a single center. The post procedural angiographic recanalization was graded using three different methods which were used by the Interventional Management of Stroke III (IMSIII) trial investigators (filling>50% of territory affected), Endovascular treatment for Small Core and Anterior circulation Proximal occlusion with Emphasis on minimizing CT to recanalization times (ESCAPE) trial investigators (filling all branches but with delay) and definition used by Multicenter Randomized Clinical trial of Endovascular treatment for Acute ischemic stroke in the Netherlands (MRCLEAN) investigators (filling of more than 66% of territory affected).

Results: Post procedural angiograms were reviewed for 61 consecutive patients (mean age ± SD, 73.52 ± 14.4, 26 were men) who underwent mechanical thrombectomy. The initial median NIHSS score was 14.The occlusion site was in middle cerebral artery (n= 39), internal carotid artery (n= 15), anterior cerebral artery (n = 3), posterior cerebral artery (n = 1), orbital artery (n = 2), basilar artery (n = 1) TICI 2b was categorized in 19 patients by IMS III definition and in 12 patients by MRCLEAN criteria that was categorized 2a by ESCAPE method. TICI 2b was categorized in 19 patients by IMS III method was categorized as 2a by the MRCLEAN definition. The rate of favorable outcome (mRS 0-2) in patients classified as TICI 2b in IMS III was 10 of 19 (52.6%) but not in other trials was 24 of 42(57%).

Conclusions: The differences in definitions used between trials and impact upon rates of partial recanalization (TICI 2b) reported should be recognized

Lumbar Catheter Placement Using Paramedian Approach Under Fluoroscopic Guidance

BACKGROUND

Lumbar catheter placement under fluoroscopic guidance may reduce the rate of technical failures and associated complications seen with insertion guided by manually palpable landmarks.

METHODS

We reviewed our experience with 43 attempted lumbar catheter placements using paramedian approach under fluoroscopic guidance and ascertained rates of technical success, and clinical events.

RESULTS

Among the 43 patients, 18, 1, and 1 patients were on aspirin (with dipyrimadole in 2), clopidogrel, and combination of both, respectively. Lumbar catheter placement was successful in 42 of 43 attempted placements. Floroscopic guidance was critical in three patients; one patient had severe cerebrospinal fluid (CSF) depletion (empty thecal sac phenomenon) following pituitary surgery leading to no cerebrospinal fluid return despite correct placement confirmation under fluoroscopy. Two patients had spinal needle placement at the junction between epidural and cerebrospinal fluid spaces (junctional position) leading to cerebrospinal fluid return but inability to introduce the lumbar catheter. After confirmation of position by the injection of contrast or radiographic landmarks the needle was advanced by indenting the subcutaneous tissue or reinserting at a spinal level above the first insertion. The lumbar catheter remained in position over a mean period (±standard deviation) of 4.1(±2.3) days. Improvement in hydrocephalus was seen in two patients with intracranial mass lesions. One patient developed cerebrospinal fluid leakage through the insertion track following removal of catheter and required skin suturing at the site of insertion.

CONCLUSIONS

We observed a high technical success rate with low rate of complications even in patients with intracranial mass lesions, those on ongoing antiplatelet medications or in whom insertion would not be possible guided by manually palpable landmarks.

A Population-Based Study of the Incidence and Case Fatality of Intracerebral Hemorrhage of Undetermined Etiology

BACKGROUND

There is a paucity of reliable recent data regarding epidemiology of intracerebral hemorrhage (ICH) of undetermined etiology in population-based studies.

OBJECTIVES

To determine the incidence and case fatality of ICH of undetermined etiology using a population-based design.

METHODS

Medical records and neuroimaging data of all patients with ICH from Stearns and Benton Counties, Minnesota, between June 1st, 2012 and June 30th, 2014 were reviewed. Patients with a first-time diagnosis of ICH were categorized as of undetermined etiology if ICH was without features typical of hypertensive etiology with normal or no magnetic resonance imaging (MRI)/angiograms. We calculated the incidences of [1] probable and possible hypertensive ICH; [2] related to arteriovenous malformation, cavernous malformation, or aneurysmal rupture (angiographic or MRI diagnoses); [3] secondary to anticoagulation; and [4] of undetermined etiology adjusted for age and sex based on the 2010 US census.

RESULTS

Of the 50 identified ICHs among 136,654 resident populations, seven were true incident cases of ICH of undetermined etiology in this population-based study. The age- and sex-adjusted incidence of ICH of undetermined etiology was 2.6 [95% confidence interval (CI) 0.7-4.9] per 100, 000 person-years, which was lower than probable and possible hypertensive ICH incidence of 12.8 [95% CI 8.4-17.2] per 100,000 person-years. The age-adjusted case fatality rate at 1 month was 8.14 and 0.4 per 100,000 persons for probable and possible hypertensive ICHs and ICHs of undetermined etiology, respectively.

CONCLUSIONS

Our results should prompt further studies into identification of causes in ICH patients presently classified as ICH of undetermined etiology to reduce the incidence and case fatality of such ICHs.

Detection of Intraparenchymal Hemorrhage After Endovascular Therapy in Patients with Acute Ischemic Stroke Using Immediate Postprocedural Flat-Panel Computed Tomography Scan

PURPOSE

To assess the diagnostic value of parenchymal hyperdense lesions visualized on the flat-panel CT scan in detecting/excluding intraparenchymal hemorrhage (IPH) after the endovascular treatment of acute stroke patients.

METHODS

Two separate cohorts of acute ischemic stroke patients who underwent endovascular treatment were evaluated. In the first group, patients were evaluated for hyperdense parenchymal lesions immediately after the treatment with flat-panel CT scan; whereas, in the second group, patients underwent multidetector CT scan post procedure. IPH was defined as hyperdensity that persisted for >24 hours on follow up CT scan.

RESULTS

A total of 30 patients were evaluated with flat panel, and 135 with multidetector CT scan immediately after the endovascular treatment. Hyperdense lesions were visualized on 7/30 (23%) of those evaluated with flat-panel CT versus 74/135 (55%) of those evaluated with multidetector CT scan. Based on 24-hour follow up imaging, hyperdense parenchymal lesions on immediate postprocedural flat-panel or multidetector CT studies had 100% sensitivity and negative predictive value for IPH; whereas, the specificity, and positive predictive value of such lesions were 88% and, 57% on the flat panel; and 53% and, 27% on the multidetector CT study, respectively.

CONCLUSION

The absence of hyperdense lesions on immediate postprocedural flat-panel CT scan of ischemic stroke patients can exclude IPH with a high sensitivity and negative predictive value. The hyperdense parenchymal lesions visualized on flat-panel versus multidetector CT studies may have comparable sensitivity and negative predictive value for the detection of IPH.

Catheter-Based Trans-Epidural Approach to Aspirate Cervical and Thoracic Epidural Abscesses: A Cadaveric Feasibility Study

BACKGROUND

Approaching and aspirating cervical and high thoracic epidural abscesses through a trans-epidural route from the lumbar region access represents an alternative method for selected patients.

OBJECTIVE

We determined the feasibility of catheter-based manipulation and aspiration using the trans-epidural route.

MATERIAL AND METHODS

A custom designed infusion-suction catheter system that includes an outer suction catheter and inner infusion catheter in concentric relation with radio-opaque marker bands was tested in a cadaveric preparation to determine (1) the ability to place an aspiration catheter over a guidewire using a percutaneous approach within the posterior lumbar epidural space; (2) the highest vertebral level a catheter can be advanced within the epidural space; and (3) the ability to aspirate artificial purulent-like material placed in the cervical and thoracic level epidural space.

RESULTS

We were able to advance two infusion-suction catheter systems from a 14G Touhy spinal needle inserted via an oblique parasagittal approach at the L2-L3 intervertebral space. The infusion-suction catheter was advanced up to the level of the cervical vertebral level of C2 within the epidural space under fluoroscopic guidance. We were able to aspirate artificial purulent-like material directly injected with a 22G Quincke spinal needle at vertebral levels C4-C5 and at vertebral levels T10-T11 by aspiration and manipulation of the outer catheter within the epidural space at levels C3-C7 and T9-L1, respectively.

CONCLUSIONS

Our observations support the further exploration of a percutaneous catheter-based trans-epidural approach to treat epidural abscesses. The trans-epidural approach may be used alone or as a staged or concurrent approach with open surgical treatment.

Occurrence and Management Strategies for Catheter Entrapment with Onyx Liquid Embolization

In June 2012, Food and Drug Administration (FDA) issued a warning about the risk of catheter entrapment associated with Onyx embolization. We used our experience, literature review, and FDA Manufacturer and User Facility Device Experience (MAUDE) data review to identify five strategies to address catheter entrapment: 1/. Surgical resection of vessel at point of entrapment of catheter and retraction from exterior portion at the femoral region; 2/. Advancing and closing the loop of snare over the entrapped catheter followed by retraction; 3/. Advancing the distal access catheter over the entrapped catheter and retraction with forward movement of the distal access catheters; 4/. Inflation of balloon catheter coaxial to the entrapped catheter with subsequent retraction; and 5/. Intravascular retention and internalization of microcatheter. In the MAUDE data, there were 77 reports of catheter entrapment with Onyx embolization; microcatheter was retracted by surgical excision in 15, endovascular snare or other retriever devices in 5, deliberately entrapped inside the vessel using stent in 1, and left without intervention within intravascular compartment in 27 patients.

Prevalence of and Factors Associated with Dural Thickness in Patients with Mild Cognitive Impairment and Alzheimer's Disease

BACKGROUND AND PURPOSE

We performed this study to evaluate the prevalence of and factors associated with dural thickening in patients with mild cognitive impairment and Alzheimer's disease.

METHODS

Alzheimer's disease neuroimaging initiative participants with axial FLAIR sequence magnetic resonance imaging (MRI) images were analyzed. Dural thickness was defined by a linear strip of hyperintense tissue signal along the dura mater observed in at least two different images without evidence of leptomeningeal involvement.

RESULTS

Dural thickening was seen in 83 (34%) of 242 persons analyzed (mean age [±SD] 74±7 years: 150 were men) with either mild cognitive impairment or Alzheimer's disease. The mini mental score was not different in persons with (26±0.3) and without (26±0.2) dural thickening (p = 0.6). The proportion of patients with moderate or severe cognitive impairment (defined by mini mental status score) was similar at baseline and at 12-month evaluations. The rates of annual progression according to Alzheimer's disease assessment scale (p = 0.06) and clinical dementia scale (p = 0.001) were higher in persons without dural thickening. The annual rate of volume loss in entorhinal cortex was higher among persons with dural thickening.

CONCLUSIONS

We found relatively high prevalence of dural thickening in patients with mild cognitive impairment and Alzheimer's disease.

Rates and predictors of 5-year survival in a national cohort of asymptomatic elderly patients undergoing carotid revascularization

BACKGROUND

Current American Heart Association guidelines recommend carotid revascularization for asymptomatic patients on the basis of life expectancy.

OBJECTIVE

To determine the rates and predictors of 5-year survival in elderly patients with asymptomatic carotid artery stenosis who underwent either carotid artery stent placement (CAS) or carotid endarterectomy (CEA).

METHODS

The rates of 5-year survival were determined by use of Kaplan-Meier survival methods in a representative sample of fee-for-service Medicare beneficiaries ≥65 years of age who underwent CAS or CEA for asymptomatic carotid artery stenosis with postprocedural follow-up of 3.4 ± 1.7 years. Cox proportional hazards analysis was used to assess the relative risk of all-cause mortality for patients in the presence of selected comorbidities, including ischemic heart disease, chronic renal failure, and atrial fibrillation, after adjustment for potential confounders such as age, sex, race/ethnicity, and procedure type.

RESULTS

A total of 22,177 patients with asymptomatic carotid artery stenosis were treated with either CAS (n = 2144) or CEA (n = 20,033). The overall estimated 5-year survival rate (±SE) was 95.3 ± 0.00149; it was 95.5% and 93.8% in patients treated with CEA and CAS, respectively. After adjustment for potential confounders, relative risk of all-cause 5-year mortality was significantly higher among patients with atrial fibrillation (relative risk, 1.8; 95% confidence interval, 1.5-2.1) and those with chronic renal failure (relative risk, 2.1; 95% confidence interval, 1.7-2.6).

CONCLUSION

Risks and benefits must be carefully weighed before carotid revascularization in elderly patients with asymptomatic carotid artery stenosis who have concurrent atrial fibrillation or chronic renal failure.

Catheter-Based Transepidural Approach to Cervical and Thoracic Posterior and Perineural Epidural Spaces: A Cadaveric Feasibility Study

BACKGROUND AND OBJECTIVES

Approaching the cervical and high thoracic level epidural space through transepidural route from lumbar region represents a method to lower the occurrence of complications associated with direct approach. The authors performed a cadaveric pilot project to determine the feasibility of various catheter-based manipulation and cephalad advancement using the transepidural route.

STUDY DESIGN AND METHODS

Two cadavers were used to determine the following: 1. Ability to place a guide sheath over a guidewire using a percutaneous approach within the posterior lumbar epidural space; 2. The highest vertebral level catheter can be advanced within the posterior epidural space; 3. Ability to cross midline within the posterior epidural space; and 4. Ability to catheterize the perineural epidural sheaths of the nerve roots exiting at cervical and thoracic vertebral levels.

RESULTS

We were able to advance the catheters up to the level of cervical vertebral level of C2 within the posterior epidural space under fluoroscopic guidance from a sheath inserted via oblique parasagittal approach at the lumbar L4-L5 intervertebral space. We were able to cross midline within the posterior epidural space and catheterize multiple perineural epidural sheaths of the nerve roots exiting at cervical vertebral level of C2, C3, and C4 on ipsilateral or contralateral sides. We also catheterized multiple epidural sheaths that surround the nerve roots exiting at the thoracic vertebral level on ipsilateral or contralateral sides.

CONCLUSIONS

We were able to advance a catheter or microcatheter up to the cervical vertebral level within the posterior epidural space and catheterize the perineural epidural sheath of the nerve root exiting at cervical and thoracic vertebral levels. Such observations support further exploration of percutaneous catheter based transepidural approach to cervical and thoracic dorsal epidural spaces for therapeutic interventions.

Complex Partial Epilepsy Associated with Temporal Lobe Developmental Venous Anomaly

BACKGROUND

Developmental venous anomalies (DVA) are found incidentally but sometimes patients with these anomalies present with varying degrees of neurologic manifestations.

OBJECTIVE

We report a patient with early onset complex partial epilepsy and associated DVA and discuss the natural history, neuroimaging and clinical characteristics, and management.

CASE DESCRIPTION

A 21-year-old man presented with a history of complex partial epilepsy with secondary generalization which started at the age of 4 years. An electroencephalogram (EEG) was performed which demonstrated spike and wave discharges predominantly in the left frontotemporal region. A magnetic resonance imaging (MRI) was performed which demonstrated a linear flow void suggestive of a DVA. The angiogram demonstrated DVA that connected with the left transverse venous sinus and an anastomotic vein between the straight sinus and the transverse venous sinus traversing the brain parenchyma. He was started on carbamezipine for the treatment of complex partial seizures.

CONCLUSIONS

Temporal lobe DVA may be associated with complex partial seizures and can be diagnosed by MRI and angiographic findings.

Middle Cerebral Artery Residual Contrast Stagnation on Noncontrast CT Scan Following Endovascular Treatment in Acute Ischemic Stroke Patients

BACKGROUND AND PURPOSE

We evaluated the relationship between middle cerebral artery (MCA) residual contrast stagnation on immediate postprocedural noncontrast CT scan and intraparenchymal hemorrhage (IPH) after endovascular treatment in acute ischemic stroke patients.

METHODS

The clinical and imaging data from patients with acute unilateral MCA M1 occlusion who underwent endovascular treatment over a 3.5-year period were reviewed. Bilateral M1 segments were selected on the first postangiography CT scan, and average attenuation was determined in Hounsfield units (HU); the difference between average HU values was calculated. Postprocedural CT scans were also evaluated for presence of IPH, defined as hyperdensity persisting on follow-up CT scans obtained >24-hours postprocedure.

RESULTS

Of 80 patients included in our series; 10/80 developed IPH on immediate postprocedural CT scan. Patients with IPH had a higher (ipsilateral-contralateral) M1 residual attenuation difference (P < .001). An average ipsilateral M1 attenuation which was ≥5 HU greater than contralateral artery had a 3.8 times increase in relative risk of IPH (95% confidence interval: 2-7.1).

CONCLUSION

On immediate postprocedural noncontrast CT scan of stroke patients with acute MCA M1 occlusion after endovascular treatment, higher residual contrast stagnation in the affected MCA, compared to contralateral artery, is associated with an increased risk of IPH.

Abstract 77: Histopathological Characteristics Of Iv Recombinant Tissue Plasminogen Resistant Thrombi In Patients With Acute Ischemic Stroke

Background: It remains unclear whether certain thrombus characteristics in patients with acute ischemic stroke result in lack of lysis with IV rt-PA. We performed this study to evaluate the histopathological characteristics of in vivo thrombi retrieved from acute ischemic stroke patients resistant to IV rt-PA prior to endovascular treatment.

Methods: The thrombus was removed from the device or retrieval catheter by gentle disassociation and processed for paraffin section preparation and hematoxylin and eosin (H&E) staining. Each slide was reviewed by an independent pathologist and classified as RBC dominant, fibrin dominant, and mixed based on the content. The characteristics were compared with thrombi retrieved from IV rt-PA naïve patients.

Results: Thrombi were retrieved from a total of 19 patients (mean age±SD; 73.4 ±14.8 years) who underwent mechanical thrombectomy. IV rt-PA resistant thrombi were retrieved in 9 of 19 patients with a time interval (min±SD) between IV rt-PA initiation and thrombus retrieval of 174±48 mins. The IV rt-PA resistant thrombi were characterized as: RBC dominant (n=4), fibrin dominant (n=2), and mixed (n=3). The proportion of mixed thrombi were lower in those who did and who did not receive IV rt-PA prior to endovascular treatment (3 of 9 versus 5 of 10, p=0.2). The rates of partial or complete recanalization were similar between RBC dominant (8 of 9), fibrin dominant (2 of 2), and mixed thrombi (8 of 8, p=0.5). The time interval between symptom onset and thrombus retrieval was 349±98 min±SD for RBC dominant, 242±15 (min±SD) for fibrin dominant, and 456±313 (min±SD) for mixed thrombi (p=0.3).

Conclusions: In our preliminary observations, we did not find any differences in histomorphology of IV rt-PA resistant and naïve thrombi in acute ischemic stroke patients.

Abstract T P71: Risk Of Ischemic Stroke During Periods Of Warfarin Discontinuation For Surgical Procedures: A Longitudinal Study Of 4060 Patients With Atrial Fibrillation

BACKGROUND: The risk of ischemic stroke during periods of warfarin discontinuation for surgical procedures is recognized nut not well characterized. We performed this study to quantitate the risk of ischemic stroke associated with strial fibrillation during periods of warfarin discontinuation.

METHODS: We evaluated the association of warfarin discontinuation for procedure with the incidence of ischemic stroke using pooled repeated measures and Cox proportional hazards analyses during follow-up after adjusting for age, gender, obesity, diabetes mellitus, hypercholesterolemia, cigarette smoking, and study period in a cohort of A total of 4060 patients were randomized into the AFFIRM study. Patients enrolled in the study had AF plus at least one other risk factor for stroke or death: age >65 yrs, systemic hypertension, diabetes mellitus, congestive heart failure, transient ischemic attack, prior stroke, left atrium 50+ mm, left ventricular fractional shortening <25%, or left ventricular ejection fraction <40%.

RESULTS: Warfarin discontinuation for procedure occurred in 17 (0.5%) of the 11,116 person observations with a mean follow-up period of 9.9+/-1.0 years. The rate of ischemic stroke was higher among participant with warfarin discontinuation (17 of 3313 person observations versus 209 of 36505 person observations, p=0.047). Warfarin discontinuation was associated with an increased risk for ischemic stroke (relative risk [RR], 2.2; 95% CI, 0.5 to 9.3). among the 11,802 person observations after adjusting for potential confounders.

CONCLUSIONS: The risk associated with discontinuation of warfarin for procedures must be recognized and considered in the risk benefit analysis of any procedure.

Abstract 41: Mixed Vasopressin Antagonism as a Directed Therapy for Cerebral Edema in Acute Stroke Patients

Introduction: Conivaptan, a mixed vasopressin receptor (V1a and V2) antagonist approved by FDA for use in hypervolemic/euvolemic hyponatremia, reduces early cerebral edema in experimental stroke models through regulation of plasma osmolality and AQ-4/GFAP modulation

Hypothesis: To evaluate the safety and effectiveness of conivaptan in reducing midline shift, brain volume, and neurological deficits in acute stroke patients.

Methods: We analyzed clinical and radiological data collected from a prospective protocol. Patients (n=8) with acute stroke who demonstrated neurological deficits secondary to cerebral edema and demonstrated lack of improvement with hypertonic saline and serum sodium of 145 mmol or greater were included. Intravenous conivaptan 40 mg per day was administered and daily CT scans obtained for 3 days. Daily GCS score, fluid input/output, net brain volume, pineal shift and septum pellucidum shift were ascertained to assess the effectiveness of conivaptan. Since brain edema is maximum at 3-4 days of stroke onset, subgroup analysis of stroke patients (n=4) in whom time interval between symptom onset and conivaptan administration was in that range was undertaken.

Results: Analysis revealed mean age 56 ± 15 years and gender ratio of 1 with average pineal shift increase from 2.42mm to 2.87mm, decrease in average septum pellucidum shift from 4.17mm to 3.29mm and improvement in mean GCS score from 7.25 to 9.12. Subgroup analysis of 4 patients who received conivaptan within 4 days demonstrated a decrease in the average pineal shift from 2.32mm to 2.02mm; average septum pellucidum shift decrease from 2.68mm to 2.48mm. Average GCS score of patients improved from 5.75 to 9.25. No significant changes were noted in the overall net brain volume.

Conclusions: We observed clinical and radiological improvement after early administration (<4 days) of conivaptan in acute stroke patients as evidenced by reduction in the mean pineal gland and septum pellucidum shift and significant improvement in GCS. Further clinical safety trials are underway to study the efficacy of conivaptan in treatment of brain edema in acute ischemic and hemorrhagic stroke.

Abstract T P137: Cerebral Ischemic Events In Patients With Therapeutic Warfarin Treatment

Background: Patients on long term warfarin treatment can have cerebral ischemic events despite therapeutic levels. We sought to determine unique patient attributes that result in ischemic events on therapeutic warfarin treatment.

Methods: We reviewed the medical records and imaging data of consecutive patients with cerebral ischemic events who were on long term warfarin treatment over a 4 year period. We stratified the patients based on international normalized ratio (2.0-3.0 versus <2.0) and compared the demographic and clinical characteristics between the two groups of patients.

Results: A total of 163 patients (mean age±SD; 77.3 ± 11.2) on long term warfarin treatment were admitted with cerebral ischemic events (97 ischemic strokes and 40 transient ischemic attacks). The mean age was not different between patients who were sub therapeutic and therapeutic on warfarin (78.2 ±11.6 versus 77.5±10.5, p=0.7). The proportion of patients with hypertension (87.2% versus 84.0%, p=0.6), diabetes mellitus (44.2% versus 50.0 %, p=0.5), and cigarette smoking (7.0% versus 6.0%, p=0.8), was similar between the two groups. Patients who were therapeutic on warfarin were more likely to have large vessel atherosclerosis (8.0% versus 2.3 %, p=0.1) and small vessel disease (2.0% versus 1.2 %, p=0.6) and less likely to have atrial fibrillation (66.0% versus 77.5%, p=0.2) as the underlying etiologies for ischemic events. IV alteplase was used in 5 and none of patients who were sub therapeutic and therapeutic on warfarin, respectively.

Conclusions: Patients who have concurrent predisposing factors appear to be at risk for cerebral ischemic events despite therapeutic warfarin treatment and concomitant preventive strategies should be evaluated.

Abstract T MP10: Arterial Reocclusion And Distal Embolization During Endovascular Treatment Using New Generation Stent Retrievers In Acute Ischemic Stroke Patients

BACKGROUND AND PURPOSE: Arterial reocclusion and distal embolization have been identified in previous studies of endovascular treatment in patients with acute ischemic stroke. We determined the rates of reocclusion and distal embolization during endovascular treatment using new generation stent retrievers.

MATERIALS AND METHODS: Acute ischemic stroke patients underwent mechanical thrombectomy using new generation stent retrievers without intra-procedural heparin or proximal flow arrest for angiographically demonstrated arterial occlusion. "Distal embolization" was defined qualitatively as appearance of an occlusion on a downstream vessel. "Arterial reocclusion" was defined as subsequent reocclusion of the target vessel after initial recanalization had been achieved. The rates were compared with data from 4 previous prospective acute stroke protocols prior to availability of stent retrievers.

RESULTS: The median initial National Institutes of Health Scale Score (NIHSS) for these patients was 14 (range 34-0); mean time from symptom onset to treatment was 5.2 +/- 2.6 hr. Arterial reocclusion occurred in 2.3% of these patients, whereas distal embolization occurred in 24% of the 86 patients. The rates of arterial reocclusion (3.0% versus 1.9%) and distal fragmentation (21.2% versus 30.8%) were similar in patients who did or did not receive IV alteplase prior to thrombectomy. Arterial reocclusion, but not distal embolization, was associated with a lower likelihood of favorable outcome at 1-3 months (P = .05; odds ratio, 3.9; 95% confidence interval, 0.01-0.98) after adjusting for age, initial NIHSS, sex, time to treatment, initial angiographic grade, symptomatic intracranial hemorrhage, and final recanalization. The rates of arterial reocclusion (2.1% versus 2.6% of 86 patients, p=0.8) and distal embolization (35.4% versus 18.4% of 86 patients, p=0.8) were not similar in patients treated with and without stent retrievers.

CONCLUSIONS: Arterial reocclusion and distal embolization occur in 16%-18% of acute ischemic stroke patients undergoing mechanical thrombectomy with new stent retrievers without IV heparin or proximal flow arrest. The rates are no higher than those observed in cohorts treated without stent retrievers.

Abstract W P370: Acute Ischemic Stroke In Acute Myocardial Infarction Patients Receiving Iv Rt-pa: An Analysis Of Thrombolysis In Myocardial Infarction (timi) Ii Trial

Background: Increased platelet activation is observed during acute myocardial infarction (MI) and further increased by administration of recombinant tissue plasminogen activator (rt-PA).

Methods: We analyzed data from 3,339 patients between the ages of 18 and 75 years who received intravenous rt-PA within 4 hours of the onset of MI and were randomly assigned to an invasive strategy or a conservative strategy in TIMI II trial. We ascertained the occurrence of ischemic stroke within 72 hours of randomization and associated outcomes.

Results: A total of 8 (0.23%) of 3331 patients suffered an ischemic stroke within 72 hours. The mean age (±SD) was 64.4 years (±6.3) and 7 were men. The proportion of patients who developed cardiogenic shock (37.5% versus 5.3%, p<0.0001) and renal failure (12.5% versus 1.7%, p=0.02) was higher among those who developed ischemic stroke. There was no difference in the rate of subsequent invasive strategy in those who developed ischemic stroke (50.0% versus 50.3%, p=0.9). The occurrence of intracranial hemorrhage (37.5% versus 0.7%, p<0.0001) and in hospital mortality (37.5% versus 4.8%, p<0.0001) was significantly higher among patients who developed ischemic stroke compared those who were stroke free.

Conclusions: Ischemic stroke in the immediate period following IV rt-PA for MI is rare but associated with very high rates of intracranial hemorrhage and in hospital mortality.

Abstract T P66: Safety and Effectiveness of Intravenous Recombinant Tissue Plasminogen Activator in Acute Ischemic Stroke Patients on Aspirin and Clopidogrel

Background: The number of acute ischemic stroke patients who are on both aspirin and clopidogrel treatment at time of acute ischemic event is increasing. There is limited data regarding the safety and efficacy of intravenous recombinant tissue plasminogen activator (rt-PA) treatment in such patients.

Methods: We reviewed the medical records and imaging data of consecutive patients with acute ischemic stroke who received IV rt-PA within 4.5 hours of symptom onset. We stratified the patients based on active regular use of antiplatelet medications: monotherapy (aspirin or clopidogrel), combination therapy (aspirin and clopidogrel), and no therapy and compared the rates of symptomatic intracerebral hemorrhage (ICH), neurological improvement (≥4 points in National Institutes of Health Stroke Scale [NIHSS], and favorable outcome (modified Rankin scale [mRS] 0-1) at discharge between the three groups.

Results: A total of 88 acute ischemic stroke patients (mean age±SD; 69.88 ±15) were treated with IV rt-PA within the study duration. Of the 88 patients 45 (50.6%), 37 (41.6%), and 52 (58.4) were on monotherapy, combination therapy, or no therapy at time of presentation. The proportion of patients who developed symptomatic ICHs were similar (p=0.8) in monotherapy, combination therapy, and no therapy groups (3.3%, 0.0%, and 4.1%, respectively). The rates of neurological improvement were greater in patients on monotherapy (20%) (p=0.03) followed by combination therapy (11.1%), and no therapy groups (2.0%). There was no significant reduction in the rate of favorable outcome at discharge among patients on combination treatment compared with no treatment (odds ratio 0.8 , 95% confidence interval 0.4-1.8 ) after adjusting for age and initial NIHSS score strata (<10, 10-19, and ≥20).

Conclusions: Compared with patients on no antiplatelet treatment, acute ischemic stroke patients who are actively using aspirin and clopidogrel appear to have similar risks and benefits with IV rt-PA treatment.

Flow-independent dynamics in aneurysms: intra-aneurysm pressure measurements following complete flow cessation in internal carotid artery aneurysms

PURPOSE

To determine if complete flow obliteration by covered stents reduces intra-aneurysm pressures in internal carotid artery (ICA) aneurysms.

METHODS

A single lumen microcatheter was placed into the aneurysm sac prior to covered stent deployment in 3 patients and connected to a pressure monitoring system. The intra-aneurysm pressure was continuously monitored, and readings were recorded prior to and immediately after stent deployment and at 5-minute intervals up to 20 minutes after stent placement. Complete occlusion of flow into the aneurysms was confirmed by carotid angiography.

RESULTS

There was no change in mean pressure within the aneurysm before and immediately after stent placement (80 mmHg) in any patient, nor was there a change in waveform of the intra-aneurysm pressure recording. The average of intra-aneurysm pressures among the 3 patients was higher (99 mmHg) at 10 and 15 minutes after stent placement. In 2 patients, the microcatheter was retracted into the parent arterial lumen; no difference in pressure was noted.

CONCLUSION

Our observations suggest no change in the pressures within the aneurysm after complete flow cessation (flow-independent). These findings may assist clinicians in better understanding aneurysm hemodynamics and rupture after covered stent deployment.

Effect of intra-arterial injection of lidocaine and methyl-prednisolone into middle meningeal artery on intractable headaches

The present report describes the effect of intra-arterial injection of a dose of 40 mg lidocaine and 20 mg methylprednisolone into the middle meningeal artery of two patients suffering from severe headaches. The effect of injection of lidocaine and methylprednisolone was short lasting with effect manifesting within 5 min and lasting 5-8 h after injection. Both patients reported improvement in headache intensity after 24 h post-procedure. Intra-arterial injection of lidocaine and methylprednisolone may represent another treatment strategy for headaches not responsive to standard treatment.

Percutaneous inferior cervical sympathetic ganglion blockade for the treatment of ventricular tachycardia storm: case report and review of the literature

Running Title: Sympathetic Block for Ventricular Tachycardia Storm.

INTRODUCTION

We present the case of a patient with ventricular tachycardia storm refractory to medical therapy and multiple catheter ablations, successfully managed by percutaneous left inferior cervical sympathetic ganglion block.

SUMMARY

A 70-year-old man with a history of ischemic cardiomyopathy and previous placement of implantable defibrillator developed intractable ventricular tachycardia recalcitrant to intravenous amiodarone, lidocaine, and multiple catheter ablations with radiofrequency energy and direct current. The patient received numerous defibrillator shocks that did not result in sustained restoration of sinus rhythm. A percutaneous inferior cervical sympathetic ganglion block was performed under fluoroscopic guidance, with the administration of bupivacaine by infiltration of the tissue between the left internal carotid artery and the cervical vertebral bodies.

RESULTS

Two and a half hours after the procedure, ventricular tachycardia converted to sinus rhythm. One month after discharge from the hospital, the patient remained free from sustained ventricular tachycardia and did not report discharges from his implantable defibrillator.

CONCLUSION

Percutaneous cervical sympathetic ganglion blockade appears to be an effective intervention in the treatment of ventricular tachycardia storm. Additional data are required before incorporating this technique into the management algorithm of incessant ventricular tachycardia.

Worse in-hospital outcomes in patients with transient ischemic attack in association with acute kidney injury: analysis of nationwide in-patient sample

OBJECTIVES

The effect of acute kidney injury (AKI) on outcomes of transient ischemic attack (TIA) is largely unknown. We wanted to determine the impact of AKI on the outcomes of patients admitted with TIA.

METHODS

Data from all adult patients admitted to the U.S. hospitals between 2005 and 2011 with a primary discharge diagnosis of TIA and secondary diagnosis of AKI were included, using the nationwide in-patient dataset. The association of AKI with TIA-related mortality and discharge outcomes was analyzed after adjusting for potential confounders using logistic regression analysis.

RESULTS

Of the 1,173,340 patients admitted with TIA, 45,974 (3.8%) had AKI. Dialysis was required in 29 (0.06%) patients. TIA patients with AKI had higher rates of moderate-to-severe disability (21.2 vs. 13.7%, p ≤ 0.0001), and in-hospital mortality (0.6 vs. 0.1%, p ≤ 0.0001) compared with those without AKI. After adjusting for age, sex, and potential confounders; TIA patients with AKI had higher odds of moderate-to-severe disability [OR 1.3, 95% CI 1.2-1.4, p < 0.0001] and death (OR 4.2, 95% CI 3.0-6.1, p < 0.0001).

CONCLUSIONS

AKI in patients with TIA is associated with significantly higher rates of moderate-to-severe disability at discharge and in-hospital mortality compared with those without AKI.

Dural venous sinuses distortion and compression with supratentorial mass lesions: a mechanism for refractory intracranial hypertension?

OBJECTIVE

To determine the effect of supratentorial intraparenchymal mass lesions of various volumes on dural venous sinuses structure and transluminal pressures.

METHODS

Three set of preparations were made using adult isolated head derived from fresh human cadaver. A supratentorial intraparenchymal balloon was introduced and inflated at various volumes and effect on dural venous sinuses was assessed by serial intravascular ultrasound, computed tomographic (CT), and magnetic resonance (MR) venograms. Contrast was injected through a catheter placed in sigmoid sinus for both CT and MR venograms. Serial trasluminal pressures were measured from middle part of superior sagittal sinus in another set of experiments.

RESULTS

At intraparenchymal balloon inflation of 90 cm(3), there was attenuation of contrast enhancement of superior sagittal sinus with compression visualized in posterior part of the sinus without any evidence of compression in the remaining sinus. At intraparenchymal balloon inflation of 180 and 210 cm(3), there was compression and obliteration of superior sagittal sinus throughout the length of the sinus. In the coronal sections, at intraparenchymal balloon inflations of 90 and 120 cm(3), compression and obliteration of the posterior part of superior sagittal sinus were visualized. In the axial images, basal veins were not visualized with intraparenchymal balloon inflation of 90 cm(3) or greater although straight sinus was visualized at all levels of inflation. Trasluminal pressure in the middle part of superior sagittal sinus demonstrated a mild increase from 0 cm H(2)O to 0.4 cm H(2)O and 0.5 cm H(2)O with inflation of balloon to volume of 150 and 180 cm(3), respectively. There was a rapid increase in transluminal pressure from 6.8 cm H(2)O to 25.6 cm H(2)O as the supratentorial mass lesion increased from 180 to 200 cm(3).

CONCLUSIONS

Our experiments identified distortion and segmental and global obliteration of dural venous sinuses secondary to supratentorial mass lesion and increase in transluminal pressure with large volume lesions. The secondary involvement of dural venous sinuses may represent a mechanism for refractory intracranial hypertension.

Abstract W P140: Neuroanatomical Correlates of Atrial Fibrillation: A Longitudinal MRI study

Background: We hypothesized that atrial fibrillation maybe associated with structural changes in particular regions of the brain.

Objectives: To determine baseline volume and rate of volume change of whole brain, hippocampus, and entorhinal cortex.

Methods: We analyzed clinical and neuroimaging data collected as part of Alzheimer’s Disease Neuroimaging Initiative from 200 normal controls and 400 individuals with mild cognitive impairment (MCI) recruited at approximately 50 sites in the United States and Canada. Patients with atrial fibrillation were identified based on baseline clinical/cognitive assessments and age and gender matched controls without atrial fibrillations were selected (1:1 ratio). All participants underwent 1.5 T structural MRI at specified intervals (6 or 12 month) for 2-3 years.

Results: A total of 40 persons with atrial fibrillation were included [Age mean (±SD) 78±6, 23 (57.5) were men]. There were no patients with stroke and 10 controls who had a previous history of stroke. There was no difference in whole brain and ventricular volumes at baseline MRI between cases and controls. There was significantly lower entorhinal cortex volume on right (p=0.001) and left (p=0.002) sides in patients with atrial fibrillation. There was significantly lower volume for middle temporal lobes on right (p=0.001) and left (p=0.001) sides. The rate of progression of atrophy in entorhinal cortex and middle temporal lobes was not different between patients with atrial fibrillation and controls.

Conclusions: The association of atrial fibrillation with volume loss in entorhinal cortex and middle temporal lobes may provide new insights into pathophysiology of atrial fibrillation.

Abstract W P26: Meta-analysis Of Studies Using Solitaire And Trevo Pro Stent Retriever Devices For Mechanical Thromboembolectomy In Acute Cerebral Ischemia

Objective: To report rates of recanalization and symptomatic intracerebral hemorrhage (SICH) after mechanical thromboembolectomy using Solitaire and Trevo Pro devices in acute cerebral ischemia using meta-analysis of published studies.

Methods: We identified all studies that used Solitaire or Trevo devices for mechanical thromboembolectomy in treatment of acute cerebral ischemia using a search on PubMed and Cochrane libraries, stroke trials database, proceedings of neurology and neurosurgery related conferences, and supplemented by a review of bibliographies of selected publications. Recanalization was assessed using TICI >2a and rates of SICH were recorded. For the meta-analysis, forest plots and statistical analysis including event rates [ER] with 95% confidence intervals [CI] based on both fixed and random models were performed using Comprehensive Meta-Analysis Software. The presence of publication bias was interrogated by funnel plot of Standard Error by log odds ratio.

Results: Eighteen studies with Solitaire device and five with Trevo device were identified and included in the meta-analysis. There were a total of 433/505 (85%, ER 0.85 [CI] 0.80-0.88, P<0.001) successful recanalizations with Solitaire device whereas 196/243 (80%, ER 0.80 [CI] 0.74-0.85, P<0.001) successful recanalizations were noted with Trevo device. The incidence of SICH was 45/505 (9%, ER 0.09 [CI] 0.06-0.14, P<0.001) with Solitaire device and 17/243 (6%, ER 0.06 [CI] 0.049-0129, P<0.001) with Trevo device after mechanical thrombectomy. There was no publication bias.

Conclusions: Meta-analysis of studies reveals similar rates for recanalization and SICH after mechanical thromboembolectomy using Solitaire or Trevo Pro devices.

Abstract T P34: Residual Contrast Enhancement of Middle Cerebral Artery on Non-contrast Ct (ncct) After Endovascular Treatment in Ischemic Stroke Patients

Background: Residual contrast enhancement of cerebral arteries is frequently visualized on follow up non-contrast CT (NCCT) after endovascular treatment in acute ischemic stroke and may represent distal microvascular no-reflow phenomenon.

Objective: To evaluated the prevalence of and correlation between post- endovascular treatment residual contrast enhancement of middle cerebral artery (MCA) on follow up NCCT with clinical and imaging outcomes in patients with acute ischemic stroke.

Methods: We analyzed clinical and radiographic data from all patients with acute MCA occlusion who underwent endovascular treatment at two centers over a 6-year period. The M1 segment of affected MCA was selected with free-hand region of interest on the first post-angiography NCCT; and the average attenuation was determined in Hounsfield units (HU). Bivariate correlation between the MCA contrast enhancement and clinical/imaging outcome was determined.

Results: A total of 89 patients (mean age ± SD, 66.4 ± 15.5 years) with MCA occlusion were included. The median time interval between the first follow up NCCT and the time of catheterization, and the time of recanalization (if successful) were 1.7 h (interquartile range: 1.2 - 2.4), and 0.8 h (interquartile range: 0.5 - 1.6), respectively. MCA contrast enhancement with an average attenuation of >40 HU was seen in 74 of 89 patients. There was no significant correlation between the average attenuation of the affected MCA on post- endovascular treatment NCCT and post- endovascular treatment “Thrombolysis in Cerebral Infarction” (TICI) score (p=0.43), Qureshi score (p=0.61), discharge National Institutes of Health Stroke Scale (NIHSS) score (p=0.34), or 3-month modified Rankin score (p=0.51). However, the MCA contrast enhancement was inversely correlated with time interval between NCCT and catheterization (p<0.001) and angiographic recanalization (p<0.001).

Conclusion: In patients with acute ischemic stroke, the residual contrast enhancement of the affected MCA on NCCT post- endovascular treatment does not correlate with status of recanalization or clinical outcome.

Abstract 114: Interim Recanalization in Acute Ischemic Stroke Patients Selected for Endovascular Treatment by CT Angiography

Background: In the Interventional Management of Stroke III trial, there was a 35% incidence of improvement or resolution of occlusion in IV alteplase treated patients selected by computed tomographic (CT) angiogram for endovascular treatment.

Objective: To determine the frequency of resolution or change in occlusion site in patients with CT angiogram demonstrated occlusion in IV alteplase treated or untreated patients.

Methods: All acute ischemic stroke patients who underwent a computed tomographic (CT) angiogram and subsequently underwent endovascular treatment were included. The CT angiogram images were reviewed by an independent reviewer to determine presence and location of arterial occlusion and severity of occlusion was classified by a previously described grading scheme. The cerebral angiographic images were reviewed for similar endpoints. Clinical outcome at discharge was determined using modified Rankin scale (mRS).

Results: CT angiogram was performed in 151 patients (mean age ± SD of 64±16 years) prior to endovascular treatment. The mean interval (±SD) between CT angiogram and cerebral angiogram was 190±10 (min) and 66 of 151 patients (43.7%) received IV alteplase prior to cerebral angiography. The rate of any recanalization prior to cerebral angiography was 28 of 151 (18.5%) and no change in occlusion was found in 92 (60.9%) patients whereas 31 (20.5%) patients showed worsening in occlusion based on the grading scheme. The rate of interim recanalization was similar in IV alteplase treated patients versus untreated patients (19.6% vs % 17.6, p= 0.7) The frequency of Angiographic recanalization following endovascular treatment was similar in both groups (67.8% versus 71.2%, p=0.7), After adjusting for age and initial NIHSS score strata, interim recanalization was not associated with higher rate of mRS 0-2 at discharge (OR 1.9, 95% CI 0.7-5.2).

Conclusions: A relatively high proportion of patients have interim recanalization between CT angiogram and cerebral angiogram in acute ischemic stroke patients selected for endovascular treatment.

Abstract W P45: Differentiation of Contrast Extravasation From Intracranial Hemorrhage on Non-Contrast CT After Endovascular Treatment in Patients With Acute Ischemic Stroke

Background: Distinction of intracranial hemorrhage (ICH) from contrast extravasation after endovascular treatment is crucial for guiding subsequent management in patients with ischemic stroke. We evaluated the imaging characteristics that can help differentiate these two entities on post-endovascular treatment non-contrast CT (NCCT).

Methods: Clinical and neuroimaging data for all patients with acute ischemic stroke who underwent endovascular treatment at two medical centers over a 6-year period were reviewed. The first post- endovascular treatment NCCT was evaluated for presence of parenchymal hyperdense lesion(s). In patients with parenchymal hyperdensity, the lesion was selected with free hand region-of-interest on the axial slice with the highest visual contrast against parenchymal background (i.e. the lesion appears brighter). ICH was defined as a hyperdensity persisting >48 hours on serial follow up CTs or confirmed by MRI study.

Results: A total of 135 patients (mean age ± SD, 66.4 ± 15.6 years) were included. The median delay between angiography and the first follow up NCCT was 1.9 hours (interquartile range, 1.3 - 2.9). Of the 135 patients, 74 (55%) patients had hyperdense lesion(s) on NCCT; of whom, 20 met the definition of ICH, and 54 were contrast extravasation, which resolved on follow up CTs. A receiver operating characteristic analysis showed that the average attenuation can differentiate ICH from contrast extravasation with an area under the curve of 0.78 (p=0.01). An average attenuation of <50 Hounsfield Units (HU) was 100% specific for contrast extravasation versus ICH - which was seen in 24/54 (44%) patients with contrast extravasation. Notably, 8/61 (13%) patients with no hyperdense lesion on first follow up CT developed late-onset ICH.

Conclusion: In our series, an average attenuation of <50 HU on the axial slice with highest contrast was 100% specific for differentiating contrast extravasation from ICH among patients with hyperdensity on first post-angiography NCCT.

Increased weight loss with reduced viral replication in interleukin-10 knock-out mice infected with murine cytomegalovirus

The anti-inflammatory cytokine interleukin (IL)-10 plays an important role in the regulation of host-immune responses. Here we studied the role IL-10 plays in host responses to cytomegalovirus (CMV) infection. We demonstrate that manifestations of murine CMV (MCMV) disease are more severe in IL-10 knock-out mice, despite significantly reduced levels of viral replication. Cytokine analysis of serum revealed increased levels of interferon (IFN)-gamma, monocyte chemotactic protein 1 (MCP-1) and IL-6, all of which are potent stimulators of inflammatory responses. Depletion of IFN-gamma by monoclonal antibodies in IL-10 knock-out mice failed to improve the physical condition of the mice, while increasing viral replication. In contrast, serum levels of IL-6 in the knock-out animals were unaffected by IFN-gamma depletion and remained significantly elevated early in the course of infection. These data suggest that increased weight loss observed in IL-10 knock-out mice may be attributed to the uncontrolled production of proinflammatory cytokines, including IL-6.

Development and characterization of a series of soluble tetrameric and monomeric streptavidin muteins with differential biotin binding affinities

The strong biotin-streptavidin interaction limits the application of streptavidin as a reversible affinity matrix for purification of biotinylated biomolecules. To address this concern, a series of single, double, and triple streptavidin muteins with different affinities to biotin were designed. The strategy involves mutating one to three strategically positioned residues (Ser-45, Thr-90, and Asp-128) that interact with biotin and other framework structure-maintaining residues of streptavidin. The muteins were produced in soluble forms via secretion from Bacillus subtilis. The impact of individual residues on the overall structure of streptavidin is reflected by the formation of monomeric streptavidin to different extents. Of the three targeted residues, Asp-128 has the most dramatic effect (Asp-128 > Thr-90 > Ser-45). Conversion of all three targeted residues to alanine results in a soluble biotin binding mutein that exists 100% in the monomeric state. Both wild-type and mutated (monomeric and tetrameric) streptavidin proteins were purified, and their kinetic parameters (on- and off-rates) were determined using a BIAcore biosensor with biotin-conjugated bovine serum albumin immobilized to the sensor chip. This series of muteins shows a wide spectrum of affinity toward biotin (K(d) from 10(-6) to 10(-11) m). Some of them have the potential to serve as reversible biotin binding agents.

Circulating soluble CD4 directly prevents host resistance and delayed-type hypersensitivity response to Cryptococcus neoformans in mice

In the present study, we examined the effect of soluble CD4 (sCD4) on host resistance and delayed-type hypersensitivity (DTH) response to Cryptococcus neoformans using a novel mutant mouse that exhibits a defect in the expression of membrane-bound CD4 but secretes high levels of sCD4 in the serum. In these mice, host resistance to this pathogen was impaired as indicated by an increased number of live pathogens in the lung. To elucidate the mechanism of immunodeficiency, three different sets of experiments were conducted. First, administration of anti-CD4 mAb restored the attenuated host defense. Second, in CD4 gene-disrupted (CD4KO) mice, host resistance was not attenuated compared to control mice. Third, implantation of sCD4 gene-transfected myeloma cells rendered the CD4KO mice susceptible to this infection, while similar treatment with mock-transfected cells did not show such an effect. These results indicated that immunodeficiency in the mutant mice was attributed to the circulating sCD4 rather than to the lack of CD4+ T cells. In addition, DTH response to C. neoformans evaluated by footpad swelling was reduced in the mutant mice compared to that in the control, and the reduced response was restored by the administration of anti-CD4 mAb. Finally, serum levels of IFN-gamma, IL-12 and IL-18 in the mutant mice were significantly reduced, while there was no difference in Th2 cytokines, such as IL-4 and IL-10. Considered collectively, our results demonstrated that sCD4 could directly prevent host resistance and DTH response to C. neoformans through interference with the production of Th1-type cytokines.

NK cells eliminate Cryptococcus neoformans by potentiating the fungicidal activity of macrophages rather than by directly killing them upon stimulation with IL-12 and IL-18

In the present study, we examined whether natural killer (NK) cells have direct fungicidal activity against Cryptococcus neoformans. Splenic NK cells were obtained from SCID mice and stimulated with a combination of interleukin (IL)-12 and IL-18 in flat culture plates or round tubes. They were then or at the same time cultured with the yeast cells and the number of viable yeast cells was examined. We could not detect direct fungicidal activity by NK cells under any culture condition, although they produced a large amount of IFN-gamma and exerted marked cytotoxic activity against YAC-1 cells. On the other hand, NK cells significantly potentiated the nitric oxide-mediated cryptococcocidal activity of thioglycolate-elicited peritoneal macrophages obtained from SCID mice upon stimulation with IL-12 and IL-18. The culture supernatants of NK cells stimulated with IL-12 and IL-18 provided similar results when used in place of NK cells. The induction of macrophage anticryptococcal activity by NK cells and NK cell culture supernatants were both mediated by IFN-gamma because the specific mAb almost completely abrogated such effect. Considered collectively, our results suggested that NK cells may play a regulatory role in potentiating macrophage-mediated fungicidal mechanisms in host resistance to infection with C. neoformans rather than exerting a direct killing activity against the fungal pathogen.

Neonatal T cells in an adult lung environment are competent to resolve Pneumocystis carinii pneumonia

Initiation of the pulmonary inflammatory response to Pneumocystis carinii is delayed by 3 wk in mice infected as neonates compared with adults. There was no difference in the proliferative response of draining lymph node T cells from mice infected as neonates compared with adults when stimulated in vitro with either Con A or anti-CD3 mAB: However, TNF-alpha and IFN-gamma mRNA expression in the lungs of P. carinii-infected neonates was significantly lower than in adults indicating a lack of appropriate activation signaling in the local environment. This may have been due to active suppression because TGF-beta mRNA expression was significantly elevated in neonatal lungs compared with adults. To determine whether T cells from 10-day-old mice would effect resolution of P. carinii if harbored in an adult lung environment, cells were adoptively transferred to SCID mice with established P. carinii infections. There was no difference in the kinetics of T cell migration into the lungs or of clearance of P. carinii organisms when SCID mice were reconstituted with splenocytes from young mice as compared with adult mice. Furthermore, splenocytes from young mice stimulated both TNF-alpha and IFN-gamma mRNA expression to levels that were similar to that in the lungs of SCID mice reconstituted with adult cells. These data indicate that neonatal lymphocytes are competent to resolve P. carinii infection when harbored in an adult lung environment, suggesting that the neonatal lung environment, and not the T cells, is ineffective at responding to P. carinii infection.

Piezoresponse of the cyo-operon coding for quinol oxidase subunits in a deep-sea piezophilic bacterium, Shewanella violacea

We have isolated the genes for quinol oxidase from a deep-sea piezophilic bacterium, Shewanella violacea. Analysis of the deduced amino acid sequences of the cyo subunits showed that this oxidase has high similarity to Escherichia coli bo-type quinol oxidase. Northern blot analysis showed that these genes are expressed at a high level when the bacterium is grown at elevated pressure. Upstream in the cyo-operon, a sigma54-binding motif and an octamer sequence unit were found, suggesting that these elements may play a role in regulation of expression of the cyo-operon in response to changes in pressure.

Delayed inflammatory response to Pneumocystis carinii infection in neonatal mice is due to an inadequate lung environment

Challenge of neonatal mice with an intranasal inoculation of Pneumocystis carinii results in a subclinical infection that takes 6 wk to resolve, whereas adult mice resolve a comparable challenge within 3 wk. This delayed clearance is due to a delayed inflammatory response in neonatal mice; however, the reason for this delay has been unknown. To determine whether the neonatal lung environment is sufficient to attract immunocompetent lymphocytes into the lungs, an adoptive transfer strategy was employed in which splenocytes from adult BALB/c mice were transferred into P. carinii-infected neonatal or adult SCID mice. All adults, but no pups, resolved their infections by day 37 postreconstitution. Despite reconstitution with adult splenocytes, pups had a negligible lung inflammatory response until day 24, whereas adult mice had activated CD4(+) and CD8(+) cells in the lung by day 13. The delay in neonates corresponded to delayed kinetics of expression of lung cytokines TNF-alpha and IFN-gamma mRNA and chemokines lymphotactin, RANTES, and macrophage inflammatory protein-1ss mRNA. Phagocytic cells from neonatal mice were significantly less efficient than adult cells at migrating to the draining lymph nodes after phagocytosing fluorescent beads. There were fewer dendritic cells and Ia(+) myeloid cells in the lungs of P. carinii-infected neonatal mice compared with adults. These data indicate that the lung environment of neonatal mice is insufficient for migration of T cells, due at least in part to inefficient phagocytosis and migration of APCs to the lymph nodes as well as delayed chemokine and TNF-alpha mRNA expression.