Shifts in Diagnostic Testing for Headache in the Emergency Department, 2015 to 2021.

Importance: Subarachnoid hemorrhage is typically diagnosed by noncontrast head computed tomography (CT); lumbar puncture is recommended if computed tomography is nondiagnostic, although CT cerebral angiography has been promoted as an alternative to lumbar puncture in this diagnostic pathway. The outcomes of this debate in practice have not been studied. Objective: To determine whether CT cerebral angiography use has increased in lieu of lumbar puncture among emergency department (ED) patients with headache, with an increase in unruptured intracranial aneurysm detection. Design, Setting, and Participants: This retrospective cohort study took place in 21 community EDs of an integrated health care system in Northern California between 2015 and 2021. Participants were adult (aged >17 years) health plan members with a chief concern of headache. Exclusions were prior diagnoses of subarachnoid hemorrhage, unruptured intracranial aneurysm, cerebral arteriovenous malformation, or cerebrospinal fluid shunt. Data were analyzed from October to November 2023. Exposures: CT cerebral angiography and/or lumbar puncture during the ED encounter. Main Outcomes and Measures: Primary and secondary outcomes were 14-day and 90-day unruptured intracranial aneurysm detection, respectively. Safety outcomes were missed diagnoses of subarachnoid hemorrhage or bacterial meningitis. The annual incidence of unruptured intracranial aneurysm detection was normalized to the incidence of subarachnoid hemorrhage (UIA:SAH ratio). Average annualized percentage changes were quantified using joinpoint regression analysis. Results: Among 198 109 included ED encounters, the mean (SD) age was 47.5 (18.4) years; 140 001 patients (70.7%) were female; 29 035 (14.7%) were Black or African American, 59 896 (30.2%) were Hispanic or Latino, and 75 602 (38.2%) were White. Per year, CT cerebral angiography use increased (18.8%; 95% CI, 17.7% to 20.3%) and lumbar punctures decreased (-11.1%; 95% CI, -12.0% to -10.4%), with a corresponding increase in the 14-day UIA:SAH ratio (3.5%; 95% CI, 0.9% to 7.4%). Overall, computed tomography cerebral angiography use increased 6-fold relative to lumbar puncture, with a 33% increase in the detection of UIA. Results were similar at 90 days and robust to sensitivity analyses. Subarachnoid hemorrhage (1004 cases) and bacterial meningitis (118 cases) were misdiagnosed in 5% and 18% of cases, respectively, with no annual trends (P = .34; z1003 = .95 and P = .74; z117 = -.34, respectively). Conclusions and Relevance: In this cohort study of ED patients with headache, increases in CT cerebral angiography use were associated with fewer lumbar punctures and higher detection of unruptured intracranial aneurysms, with no significant change in missed diagnoses of subarachnoid hemorrhage or bacterial meningitis. While this shift in diagnostic strategy appeared safe in the short-term, the long-term consequences remain unclear.

Misdiagnosis of a Dissecting Aneurysm as a Cerebral Aneurysm: A Preoperative Case Report.

Background: Intracranial Aneurysm (IA) is characterized by abnormal dilation of intracranial arterial walls, a tumor-like protrusion, often occurring in the anterior communicating artery. Intracranial Dissecting Aneurysm (IDA) refers to hemodynamic changes within intracranial arteries, leading to ruptures between blood vessel walls, disrupting normal arterial blood flow within the arterial lumen. IDA is relatively uncommon in the anterior circulation. To date, there have been no reported cases of dissecting aneurysms misdiagnosed as cerebral aneurysms before surgical intervention. This case report presents a patient's detailed clinical diagnosis, treatment, and imaging data. Case Presentation: A 56-year-old female patient experienced post-work headaches. Cranial Computed Tomography (CT), Magnetic Resonance Imaging (MRI), and Digital Subtraction Angiography (DSA) examinations revealed a small hemorrhage following infarction and aneurysms in the initial part of the right A2 segment. Initially, the patient was diagnosed with a ruptured cerebral aneurysm, accompanied by hemorrhage and cerebral vasospasm (cerebral infarction in the right frontal lobe). Subsequently, cerebral aneurysm clipping was performed. During surgery, it was observed that the aneurysm originated from the ipsilateral A2 starting site and displayed dissecting-like changes extending towards the distal end. The final diagnosis confirmed an aneurysm evolving from intracranial artery dissection. Artificial meninges were employed to encase and clip the aneurysm. Post-surgery, the patient was transferred to a superior hospital for A3 bypass. Follow-up assessments indicated a successful recovery. Conclusion: Cerebral aneurysms typically involve larger arteries with rare possibilities of stenosis. Moreover, the cerebral artery is relatively small, making it challenging for Brain Computed Tomography Angiography (CTA) to distinguish true and false lumen within blood vessels. The diagnosis of dissecting aneurysms is difficult and often susceptible to clinical misdiagnosis.

And don't forget your anti in-stent stenosis pill! Commentary on 'Factors associated with in-stent stenosis after cerebral aneurysm embolization using a Pipeline embolization device' by Flores-Milan et al.

In their INR study, Flores-Milan et al. present a retrospective single-centre study that aimed to investigate and determine some of the factors associated with in-stent stenosis (ISS) after intracranial aneurysm (IA) embolization using a commercially available flow diverter stent (FD). The retrospective analyses included ruptured and unruptured intracranial aneurysms treated with standalone flow diverter stent implantation or initial coil obliteration with the FD device placed subsequently two weeks after initial treatment. The article's methodology was carefully tailored to demystify the unknown pathophysiological mechanism behind the entity of interest called in-stent stenosis. Study outcomes also included angiographic evaluation of aneurysm occlusion thrombotic and hemorrhagic events. The authors reported excellent technical and clinical results altogether. The achieved angiographic occlusion rates resonate with the current obliteration results reported in the literature. Mortality and morbidity are congruent with previously published results and were 5.3% and 1.1%, respectively.

Adjuvant hyperbaric oxygen treatment of acute brain herniation after microsurgical clipping of a recurring cerebral aneurysm: a case report.

INTRODUCTION: Acute brain herniation is a life-threatening neurological condition that occasionally develops due to severe complications following cerebral aneurysm clipping. Strategies for managing acute brain herniation have not improved substantially during the past decade. Hyperbaric oxygen treatment (HBOT) may alleviate harmful effects of cerebral hypoxia, which is one of the most important pathophysiological features of acute brain herniation and, therefore, may be useful as an adjuvant therapy for acute brain herniation. A case treated with adjuvant HBOT is reported. CASE REPORT: A 60-year-old asymptomatic man presented with a recurring left middle cerebral artery bifurcation aneurysm with previous stent-assisted embolisation. After craniotomy for surgical clipping of the aneurysm, disturbance of consciousness and right hemiplegia occurred. Computed tomography (CT) images suggested simultaneous cerebral ischaemia and intracranial haemorrhage. Pharmacologic treatment resulted in no improvement. A CT scan acquired five days after surgery showed uncal and falcine herniation. HBOT was administered five days after surgery, and the patient's condition dramatically improved. He became conscious, and his hemiplegia improved following seven sessions of HBOT. Simultaneously, CT images showed regression of the acute brain herniation. CONCLUSIONS: The patient had recovered completely at one year post-treatment. HBOT may be effective in the treatment of acute brain herniation following cerebral aneurysm clipping.

Navigation of a magnetic micro-robot through a cerebral aneurysm phantom with magnetic particle imaging.

Cerebral aneurysms are potentially life threatening and nowadays treated by a catheter-guided coiling or by a neurosurgical clipping intervention. Here, we propose a helically shaped magnetic micro-robot, which can be steered by magnetic fields in an untethered manner and could be applied for a novel coiling procedure. This is shown by navigating the micro-robot through an additively manufactured phantom of a human cerebral aneurysm. The magnetic fields are applied with a magnetic particle imaging (MPI) scanner, which allows for the navigation and tomographic visualization by the same machine. With MPI the actuation process can be visualized with a localization accuracy of 0.68 mm and an angiogram can be acquired both without any radiation exposure. First in-vitro phantom experiments are presented, showing an idea of a robot conducted treatment of cerebral aneurysms.

Iodine-123-Iomazenil SPECT Revealed Recovery of Neuronal Viability in Association with Improvement in Symptoms Following Treatment for Obstructive Hydrocephalus due to a Giant Posterior Cerebral Artery Aneurysm.

BACKGROUND: Early and late images of 123I-iomazenil (123I-IMZ) single-photon emission computed tomography (SPECT) are considered to show cerebral blood flow and neuronal activity, respectively, and this modality may demonstrate temporal dysfunction of the frontal lobes in obstructive hydrocephalus. In this report, we examined 123I-IMZ SPECT in a patient with chronic obstructive hydrocephalus owing to compression of the aqueduct by a partially thrombosed aneurysm of the left posterior cerebral artery for the first time. CASE DESCRIPTION: A woman aged 77 years presented with progression of cognitive decline, gait disturbance, and urinary incontinence. She had a medical history of epilepsy and subarachnoid hemorrhage due to a ruptured left posterior cerebral artery aneurysm, treated conservatively when she was age 56 years. Magnetic resonance imaging revealed a mass lesion in the pineal region, which showed a target sign with gadolinium-based contrast agents, causing obstructive hydrocephalus owing to compression of the cerebral aqueduct. A right vertebral angiogram confirmed the presence of a partially thrombosed giant aneurysm at the left posterior cerebral artery. To rule out the involvement of nonconvulsive status epilepticus in her pathology, we performed 123I-IMZ SPECT, and both early and late images demonstrated low uptake in the bilateral frontal cortex. After surgical trapping of the parent artery and resection of the aneurysm, hydrocephalus was relieved, and the symptoms disappeared along with improvement in early and late 123I-IMZ SPECT images. CONCLUSIONS: The findings in the present case indicate that 123I-IMZ SPECT can detect reversible cerebral blood flow reduction and neuronal viability in the frontal lobes, which may affect the clinical manifestation of obstructive hydrocephalus.

Autologous Transfusion of Blood Aspirated during Suction Decompression in Clipping of Large or Giant Cerebral Aneurysm.

The suction decompression (SD) method, which proactively aspirates the blood flowing into the aneurysm and reduces the internal pressure of the aneurysm, is useful for clipping surgery of large and giant cerebral aneurysm. However, there has been little discussion on re-utilization of blood aspirated during SD. This study aimed to examine the safety, convenience, and usefulness of autologous transfusion of aspirated blood using a transfusion bag. At the time of craniotomy, the cervical carotid artery is fully exposed. An angiocatheter sheath was inserted into the carotid artery and placed in the internal carotid artery. In SD, blood was aspirated from the sheath at a constant speed and quickly stored in a blood transfusion storage bag. Blood aspiration was repeated with a new syringe; once the transfusion bag was full, the blood was re-administered to the patient. Changes in vital sign and hemoglobin/hematocrit values before and after SD were examined in five cases performed in this procedure. The aspirated blood volumes of five cases ranged from 130 to 400 mL, and all aspirated blood was successfully re-transfused. There was no critical change in vital sign, and no significant decrease in the hemoglobin/hematocrit value. No findings suggestive of complications of thrombus formation, infection, and hemolysis were noted. Re-transfusion of aspirated blood during SD using a transfusion bag is a simple and safe method, which can minimize potential risk of re-utilizing aspirated blood, and enables the safe and easy execution of SD regardless of aspirated blood volume.

Complication rate of intraarterial treatment of severe cerebral vasospasm after subarachnoid hemorrhage with nimodipine and percutaneous transluminal balloon angioplasty: Worth the risk?

BACKGROUND AND PURPOSE: Delayed cerebral ischemia (DCI) is a complication of aneurysmal subarachnoid hemorrhage (SAH). Arterial cerebral vasospasm (CVS) is discussed as the main pathomechanism for DCI. Due to positive effects of per os nimodipine, intraarterial nimodipine application is used in patients with DCI. Further, percutaneous transluminal balloon angioplasty (PTA) is applied in focal high-grade spasm of intracranial arteries. However, clinical benefits of those techniques are unconfirmed in randomized trials so far, and complications might occur. We analyzed the occurrence of new infarcts in patients with severe CVS treated intra-arterially to assess benefits and risks of those techniques in a large single-center collective. MATERIALS AND METHODS: All imaging and clinical data of 88 patients with CVS after SAH and 188 procedures of intraarterial nimodipine infusion and additional PTA in selected cases (18 patients, 20 PTA procedures) treated at our institution were reviewed. In the event of new infarcts after endovascular treatment of CVS, infarct patterns were analyzed to determine the most probable etiology. RESULTS: Fifty-three percent of patients developed new cerebral infarction after intraarterial nimodipine and additional PTA in selected cases. Hereunder 47% were caused by persisting CVS. In 6% of patients, 3% of procedures respectively, new infarcts occurred due to complications of the intraarterial treatment including thromboembolism and arterial dissection. Of those, 3% of patients, 2% of procedures respectively, were assigned to thrombembolic complications of digital substraction angiography for intraarterial nimodipine. 17% of all patients treated with PTA (3/18=17%) showed infarction as a complication of PTA (15% of all PTA procedures). In 1% of patients, etiology of new infarction remained unclear. CONCLUSION: Ischemic complications occur in about 6% of patients treated intraarterially for CVS, 3% of procedures respectively. Further, to date a benefit for patients treated with this therapy could not be proven. Therefore, intraarterial treatment of CVS should be performed only in carefully selected cases.

Coadjuvant Treatment of Vasospasm in Ruptured Unsecured Cerebral Aneurysms with Aggressive Angioplasty, Intra-Arterial Nimodipine, and Aneurysm Embolization.

BACKGROUND: Vasospasm is a major cause of morbidity and mortality in patients after aneurysmal subarachnoid hemorrhage. Early treatment of ruptured aneurysms is advocated; delayed intervention complicates the treatment strategy leading to significant vasospasm and poor prognosis. We report an endovascular protocol for occlusion of the unsecured aneurysm and angioplasty for vasospasm in a single session. METHODS: Between January 2011 and May 2017, among 660 patients with aneurysmal subarachnoid hemorrhage, 24 patients with significant vasospasm and unsecured ruptured cerebral aneurysm were reviewed. Continuous nimodipine drip through a pressure line of the guiding catheter was set up. Aggressive angioplasty with a compliant balloon catheter either before or after embolization of the aneurysm in the major branches of vasospastic territory was performed. The goal was complete embolization of the aneurysm. RESULTS: Of 24 patients, 17 had ischemic symptoms at presentation, and the average delay from aneurysm rupture to presentation was 7.58 days. Angioplasty and nimodipine drip were performed on all patients. Severity of vasospasm was significantly reduced, and outcome improved in each patient. Two patients required a second angioplasty. In 20 patients, embolization of aneurysms was achieved without any aneurysmal sac or residual neck. Clinical outcome was good recovery (modified Rankin Scale score 0-2) in 23 patients (95.8%) and moderate disability in 1 patient (modified Rankin Scale score 3). CONCLUSIONS: Aggressive endovascular treatment of patients with unsecured ruptured cerebral aneurysm and associated vasospasm is safe and effective.

Acute thrombus formation on phosphorilcholine surface modified flow diverters.

PURPOSE: Thromboembolic complications remain a limitation of flow diverting stents. We hypothesize that phosphorilcholine surface modified flow diverters (Pipeline Flex with Shield Technology, sPED) would have less acute thrombus formation on the device surface compared with the classic Pipeline Embolization device (cPED). METHODS: Elastase-induced aneurysms were created in 40 rabbits and randomly assigned to receive cPED or sPED devices with and without dual antiplatelet therapy (DAPT) (four groups, n=10/group). Angioplasty was performed to enhance apposition and create intimal injury for a pro-thrombotic environment. Both before and after angioplasty, the flow diverter was imaged with intravascular optical coherence tomography. The outcome measure was the number of predefined segments along the implant relative to the location of the aneurysm with a minimum of 0 (no clot formation) and maximum of 3 (all segments with thrombus). Clot formation over the device at ostia of branch arteries was assessed as either present or absent. RESULTS: Following angioplasty, the number of flow diverter segments with clots was significantly associated with the flow diverter (p<0.0001), but not with DAPT (p=0.3872) or aneurysm neck size (p=0.8555). The incidence rate for clots with cPED was 1.72 times more than with sPED. The clots on the flow diverter at the location corresponding to side branch ostia was significantly lower with sPED than with cPED (OR 0.180; 95% CI 0.044 to 0.734; p=0.0168), but was not associated with DAPT (p=0.3198). CONCLUSION: In the rabbit model, phosphorilcholine surface modified flow diverters are associated with less thrombus formation on the surface of the device.

In vitro and in silico assessment of RF-induced heating around intracranial aneurysm clips at 7 Tesla.

PURPOSE: To examine radiofrequency-induced tissue heating around intracranial aneurysm clips during a 7 Tesla (T) head MR examination. METHODS: Radiofrequency (RF), temperature simulations, and RF measurements were employed to investigate the effects of polarization and clip length on the electric field (E-field) and temperature. Heating in body models was studied using both a conservative approach and realistic exposure scenarios. RESULTS: Worst-case orientation was found for clips aligned parallel to the E-field polarization. Absolute tissue temperature remained below International Electrotechnical Commission regulatory limits for 44 of 50 clinical scenarios. No significant effect on heating was determined for clip lengths below 18.8 mm, and worst-case heating was found for clip length 51.5 mm. The conservative approach led to a maximum permissible E-field of 72 V/m corresponding to B1+ of 1.2 µT, and an accepted power of 4.6 W for the considered RF head coil instead of 38.5 W without clip. CONCLUSION: Safe scanning conditions with respect to RF-induced heating can be applied depending on the information about the clip gained during screening interviews. However, force and torque measurements in the MR system shall be conducted to give a final statement on the MR safety of aneurysm clips at 7T. Magn Reson Med 79:568-581, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Paradoxical undressing associated with subarachnoid hemorrhage in a non-hypothermia case?

Paradoxical undressing is a phenomenon characterizing some fatal hypothermia cases. The victims, despite low environmental temperatures, paradoxically remove their clothes due to a sudden feeling of warmth. In this report, we describe a case of suspected paradoxical undressing in a non-hypothermia case. The victim, a 51-year-old Caucasian man, was found dead wearing only sneakers and socks. All other clothing was found in his car. Postmortem investigations allowed the hypothesis of hypothermia to be ruled out and revealed the presence of a ruptured cerebral aneurysm that caused a subarachnoid hemorrhage, the latter responsible for the death. The absence of any elements suggesting a voluntary undressing or any third party's DNA profile or involvement along with the possibility that the subarachnoid hemorrhage might have determined a hypothalamic injury, somehow rendered conceivable the hypothesis of an inappropriate feeling of warmth due to hemorrhage-induced dysregulation of the hypothalamic temperature-regulating centers.

Effects on vessel measurement accuracy and subsequent occlusion after calcium channel blocker infusion during treatment of cerebral aneurysms with the Pipeline embolization device.

Introduction/Purpose To achieve aneurysm occlusion, flow diverters (FDs) must be accurately sized to maximize coverage over the neck and induce thrombosis. Catheterization for diagnostic angiography can cause vasospasm that may affect vessel measurements. This study evaluates impacts of intra-arterial infusion of a calcium channel blocker (CCB) on angiographic measurements in patients treated with FDs to determine effects on final diameter of the FD and subsequent occlusion. Materials and methods Pre-treatment measurements were recorded for diameter of the distal and proximal landing zones and maximum and minimum diameters between these segments. Post-treatment measurements of the stent following deployment were recorded at these locations. When CCB was infused, post-infusion pre-treatment measurements were recorded. Rates of occlusion were noted for all patients. T-tests were performed to assess for differences in pre- and post-treatment measurements and rates of occlusion between groups with and without CCB infusion. Results Twenty-eight FDs were deployed to treat 25 aneurysms in 24 patients. CCB infusion was performed prior to deployment of 12 (42.9%) devices. No significant difference was noted between groups for pre- and post-treatment measurement changes. Confirmed aneurysm occlusion was more likely to occur in the CCB infusion group (88.9% vs. 36.4%, p = 0.009). Conclusion Optimization of device sizing is important to increase FD density over the aneurysm neck and promote thrombosis. To improve measurement accuracy, CCB infusion can reduce effects of mild vasospasm. Subsequent aneurysm occlusion was more likely to occur following FD treatment when device size selection was based on measurements performed following CCB infusion.

False-negative Interpretations of Cranial Computed Tomography in Aneurysmal Subarachnoid Hemorrhage.

OBJECTIVES: Prior studies examining the sensitivity of cranial computed tomography (CT) for the detection of subarachnoid hemorrhage (SAH) have used the final radiology report as the reference standard. However, optimal sensitivity may have been underestimated due to misinterpretation of reportedly normal cranial CTs. This study aims to estimate the incidence of missed CT evidence of SAH among a cohort of patients with aneurysmal SAH (aSAH). METHODS: We performed a retrospective chart review of emergency department (ED) encounters within an integrated health delivery system between January 2007 and June 2013 to identify patients diagnosed with aSAH. All initial noncontrast CTs from aSAH cases diagnosed by lumbar puncture (LP) and angiography following a reportedly normal noncontrast cranial CT (CT-negative aSAH) were then reviewed in a blinded, independent fashion by two board-certified neuroradiologists to assess for missed evidence of SAH. Reviewers rated the CT studies as having definite evidence of SAH, probable evidence of SAH, or no evidence of SAH. Control patients who underwent a negative evaluation for aSAH based on cranial CT and LP results were also included at random in the imaging review cohort. RESULTS: A total of 452 cases of aSAH were identified; 18 (4%) were cases of CT-negative aSAH. Of these, seven (39%) underwent cranial CT within 6 hours of headache onset, and two (11%) had their initial CTs formally interpreted by board-certified neuroradiologists. Blinded independent CT review revealed concordant agreement for either definite or probable evidence of SAH in nine of 18 (50%) cases overall and in five of the seven (71%) CTs performed within 6 hours of headache onset. Inter-rater agreement was 83% for definite SAH and 72% for either probable or definite SAH. CONCLUSIONS: CT evidence of SAH was frequently present but unrecognized according to the final radiology report in cases of presumed CT-negative aSAH. This finding may help explain some of the discordance between prior studies examining the sensitivity of cranial CT for SAH.

[Improvement of visual functions after successful microsurgical exclusion of a giant aneurysm of the right internal carotid artery using revascularization techniques]. / Uluchshenie zritel'nykh funktsii posle uspeshnogo mikrokhirurgicheskogo vykliucheniia gigantskoi anevrizmy pravoi vnutrennei sonnoi arterii s primeneniem revaskuliariziruiushchikh metodik.

We describe a clinical case of successful treatment of a female patient with a giant paraclinoid aneurysm of the right ICA. The aneurysm had a pseudotumoral course and manifested as pronounced progressive visual impairments. The patient underwent microsurgery including trapping/clipping of the right ICA aneurysm after creation of an EICMA and a high-flow anastomosis between the ECA and the M2 segment of the MCA. The surgery enabled decompression of the optic nerves, avoiding their injury. Postoperatively, the patient underwent transcutaneous electrical stimulation of the optic nerves. The case feature was that the patient developed gradual restoration of the blind eye vision.

Endovascular parent artery occlusion of proximal posterior cerebral artery aneurysms: a report of two cases.

We report two cases of proximal posterior cerebral artery (PCA) aneurysms treated with endovascular parent artery occlusion (PAO) with coils. In both cases, selective injection from the 4 F distal access catheter clearly showed the perforating arteries arising from the PCA. Case No 1, a 49-year-old woman, was successfully treated with preservation of a paramedian artery. Case No 2, a 54-year-old woman, was treated in the same manner. The patient underwent extensive thalamic infarction after the procedure because of paramedian artery occlusion. Endovascular PAO with coils is feasible for proximal PCA aneurysms; however, preservation of perforating arteries arising from the PCA is mandatory.