Initial misdiagnosis of aneurysmal subarachnoid hemorrhage: associating factors and its prognosis.

BACKGROUND: Predicting the fate of patients who are given a misdiagnosis of aneurysmal subarachnoid hemorrhage (aSAH) remains unclear. The purpose was to examine factors associated with initial misdiagnosis of aSAH and to investigate the impact of initial misdiagnosis of aSAH on clinical outcomes. METHODS: Between January 2007 and December 2015, medical records and radiographic data for 3118 consecutive patients with aSAH were reviewed. There were 33 patients who had been documented with an initial misdiagnosis of aSAH, and all met the following criteria: (1) failure to correctly identify aSAH upon initial presentation to health care professionals; and 2) subsequently documented aSAH after the initial misdiagnosis. After applying exclusion criteria, remaining 2898 patients were included in the control group. RESULTS: The most common cause of the misdiagnosis is failure to detect aSAH on the initial radiographic imaging. Misdiagnosis group showed lower initial Glasgow Coma Scale, better Hunt-Hess grade, and lower Fisher's grade. Logistic regression analysis showed that initial HH grade (OR, 0.216; p = 0.014), initial Fisher's grade (OR, 0.732; p = 0.036), and hospital type during initial contact (OR, 2.266; p = 0.042) were independently associated with misdiagnosis of aSAH. CONCLUSIONS: Patients with initially good HH grade, lower Fisher's grade, and visiting non-teaching hospital for initial contact were at risk of being misdiagnosed. Misdiagnosis of aSAH in patients with initial good HH grade did affect clinical outcomes negatively. The rebleeding rate was not significantly different between two groups. However, the mortality rate due to rebleeding was higher in MisDx group than in non-MisDx group.

Post-traumatic headache in patients with minimal traumatic intracranial hemorrhage after traumatic brain injury: a retrospective matched case-control study.

BACKGROUND: No evidence is available on the risks of neurologically asymptomatic minimal traumatic intracranial hemorrhage (mTIH) in patients with traumatic brain injury (TBI) for post-traumatic headache (PTH). The purpose of this study was to investigate whether mTIH in patients with TBI was associated with PTH and to evaluate its risk factors. METHODS: Between September 2009 and December 2014, 1484 patients with TBI were treated at our institution, 57 of whom had mTIH after TBI and were include in this study. We performed propensity score matching to establish a control group among the 823 patients with TBI treated during the same period. Patients with TBI rated their headaches prospectively using a numeric rating scale (NRS). We compared NRS scores between mTIH group (n = 57) and non-mTIH group (n = 57) and evaluated risk factors of moderate-to-severe PTH (NRS ≥ 4) at the 12-month follow-up. RESULTS: Moderate-to-severe PTH was reported by 21.9% of patients (29.8% in mTIH group and 14.0% in non-mTIH group B, p = 0.012) at the 12-month follow-up. The mean NRS was higher in mTIH group than in non-mTIH group throughout the follow-up period (95% confidence interval [CI], 0.11 to 1.14; p < 0.05, ANCOVA). Logistic regression analysis showed that post-traumatic seizure (odds ratio, 1.520; 95% CI, 1.128-6.785; p = 0.047) and mTIH (odds ratio, 2.194; 95% CI, 1.285-8.475; p = 0.039) were independently associated with moderate-to-severe PTH at the 12-month follow-up. CONCLUSIONS: Moderate-to-severe PTH can be expected after TBI in patients with mTIH and post-traumatic seizure. PTH occurs more frequently in patients with mTIH than in those without mTIH.

The course of headache in patients with moderate-to-severe headache due to mild traumatic brain injury: a retrospective cross-sectional study.

BACKGROUND: Little is known about the long-term course of headache in patients with moderate-to-severe headache due to traumatic brain injury (TBI). We evaluated the course of headache in patients with moderate-to-severe headache due to mild TBI. METHODS: Since September 2009, patients with TBI prospectively rated their headache using a numeric rating scale (NRS). From the database containing 935 patients with TBI between September 2009 and December 2013, 259 patients were included according to following criteria: (1) newly onset moderate-to-severe headache (NRS ≥ 4) due to head trauma; (2) age ≥ 15 years; (3) Glasgow Coma Scale ≥ 13; (4) transient loss of consciousness ≤ 30 min; and (5) radiographic evaluation, such as computed tomography or magnetic resonance image. We evaluated initial and follow-up NRS scores to determine the significance of NRS changes and identified risk factors for moderate-to-severe headache at 36-month follow-up. RESULTS: At 36-month follow-up, 225 patients (86.9%) reported improved headache (NRS ≤ 3) while 34 (13.1%) reported no improvement. The NRS scores were significantly decreased within a month (P < 0.001). The follow-up NRS scores at 12-, 24-, and 36-months were lower than those at one month (P < 0.001). Multiple logistic regression analysis showed that post-traumatic seizure (odds ratio, 2.162; 95% CI, 1.095-6.542; P = 0.041) and traumatic intracranial hemorrhage (odds ratio, 2.854; 95% CI, 1.241-10.372; P = 0.024) were independent risk factors for moderate-to-severe headache at 36-month follow-up. CONCLUSIONS: The course of headache in patients with mild TBI continuously improved until 36-month follow-up. However, 13.1% of patients still suffered from moderate-to-severe headache at 36-month follow-up, for whom post-traumatic seizure and traumatic intracranial hemorrhage might be risk factors.

Infraoptic anterior cerebral artery: case series report and literature review.

An infraoptic course of the precommunicating anterior cerebral artery (A1 segment) is a rare anomaly. We report three patients with an infraoptic A1 diagnosed by computed tomography angiography and we review the literature focusing on embryological development. In all three patients, a left infraoptic A1 that originated from the ophthalmic level of the internal carotid artery was diagnosed incidentally. Only one patient had a normal supraoptic A1. The embryogenesis of this anomaly is unclear. We propose that an error in the development of the definitive ophthalmic artery is possible mechanisms giving rise to this anomaly.

Endovascular treatment of ruptured basilar artery trunk aneurysm in the acute period: risk factors for periprocedural complications.

OBJECTIVES: Endovascular treatment (EVT) has become a popular option for the treatment of basilar artery (BA) trunk aneurysms because microsurgery of these lesions is difficult due to narrow surgical fields and perforating arteries or cranial nerves in the brainstem. The purpose of this study is to report our experiences using EVT for ruptured BA trunk aneurysms in the acute period and to evaluate the risk factors for periprocedural complications. METHODS: From October 2004 to December 2020, a total of 27 consecutive patients with ruptured BA trunk aneurysms were treated with EVT. All patients met the following criteria: presence of ruptured BA trunk aneurysms and treatment with EVT for those aneurysms within 72 hours of rupture. The incidence of and risk factors for periprocedural complications were evaluated retrospectively. RESULTS: Among the 27 patients, periprocedural complications occurred in 4 patients (14.8%); mass effect inducing cranial neuropathy due to brainstem compression in 1 (3.7%) and brainstem infarction in 3 (11.1%). Hemorrhagic complications did not occur within 30 days. Subacute or delayed thromboembolic complications were not observed during the follow-up period. Large/giant aneurysm (odds ratio [OR], 6.417; 95% confidence interval [CI], 1.732-18.031; P = 0.045) and stent-assisted coiling (OR, 4.145; 95% CI, 1.018-14.212; P = 0.031) remained independent risk factors for periprocedural complications based on multiple logistic regression analysis. CONCLUSIONS: When performing stent-assisted coiling for ruptured large/giant BA trunk aneurysms, awareness of and caution regarding periprocedural complications, such as brainstem infarction caused by thromboembolism or brainstem compression due to mass effect, are necessary.

Pathophysiology and classification of intracranial and spinal dural AVF.

Dural arteriovenous fistulas (DAVFs) are pathologic shunts between pachymeningeal arteries and dural venous channel. DAVFs are relatively rare, however, DAVFs can lead to significant morbidity and mortality due to intracranial hemorrhage and non-hemorrhagic neurologic deterioration related to leptomeningeal venous drainage. The etiology and pathophysiology of DAVFs is not fully understood. Several hypotheses for development of DAVF and classifications for predicting risk of hemorrhage and neurological deficit have been proposed to help clinical decision making according to its natural history. Herein, incidence, etiology, pathophysiology of development of intracranial and spinal DAVF including their classifications are briefly described with short historical review.

A Single Flow Re-direction Endoluminal Device for the Treatment of Large and Giant Anterior Circulation Intracranial Aneurysms.

PURPOSE: The purpose of this study was to report the author's experiences in treating large (10-25 mm) and giant (>25 mm) intracranial aneurysms (IAs) using a single Flow Re-direction Endoluminal Device (FRED) without assistant coiling, with a focus on procedure-related complications. MATERIALS AND METHODS: A total of 33 patients who were treated with FRED between January 2018 and July 2020 were retrospectively reviewed. The timing of procedure-related complications was chronologically categorized as acute (within 7 days), subacute (8 to 21 days), and delayed (after 21 days) periods. Follow-up angiography was performed at 2 to 27 months (mean 9.7 months), and clinical follow-up was performed at 1 to 31 months (mean 14.1 months) in all patients. RESULTS: Six (18.2%) patients experienced procedure-related complications, including 2 (6.1%) in acute period, 1 (3.0%) in subacute period, and 3 (9.1%) in delayed period. Thromboembolic complications occurred in 5 (15.2%) patients and hemorrhagic complications in 1 (3.0%). Permanent morbidity and mortality rates were 3.0% each. Non-internal carotid artery (ICA) location of IAs (odds ratio 6.532; 95% confidence interval, 1.335-17.816; p=0.034) was the only independent risk factor for procedure-related complications on multivariate logistic regression analysis. CONCLUSION: The procedure-related complication rate was 18.2% in this study. Procedure-related complications might increase when treating large and giant IAs located on a non-ICA, especially on the middle cerebral artery. Therefore, it may be suggested that neurointerventionists and endovascular neurosurgeons should pay attention to the location of IAs when treating large and giant IAs with a single FRED.

Basilar artery trunk aneurysm: clinical and angiographic outcomes of endovascular treatment.

BACKGROUND: Basilar artery (BA) trunk aneurysms are rare, and the clinical characteristics and outcomes of endovascular treatment (EVT) remain unclear. The purpose of this study was to report clinical and angiographic outcomes of BA trunk aneurysm treated with EVT and to analyze risk factors for unfavorable outcomes. METHODS: From October 2004 to December 2020, a total of 40 patients with BA trunk aneurysms underwent EVT. Clinical characteristics and outcomes were evaluated retrospectively from a prospectively collected database. Of the 40 enrolled patients, nine were treated by coiling without stents, 17 were treated by stent-assisted coiling, six by stent only, five by flow diverters, and three by vertebral artery occlusion. RESULTS: In total, 27 (67.5%) patients had subarachnoid hemorrhage as an initial presentation, and 20 (50.0%) had large/giant aneurysms. Procedure-related complications occurred in five patients (12.5%); favorable clinical outcome was achieved in 27 patients (67.5%); and six patients (15.0%) died. Favorable angiographic outcome was achieved in 26 (83.9%) of 31 patients who underwent follow-up angiography. Poor initial Hunt-and-Hess grade (OR 7.67, 95% CI 1.55 to 37.80; p=0.018) was the only independent risk factor for unfavorable clinical outcome. Large/giant aneurysm (OR 8.14, 95% CI 1.88 to 27.46; p=0.047) and long lesion (OR 14.25, 95% CI 1.48 to 69.80; p=0.013) were independent risk factors for unfavorable angiographic outcomes during follow-up. CONCLUSIONS: EVT might be a feasible option for this rare disease entity. Unfavorable angiographic outcome might be expected in a large/giant aneurysm or a long lesion. It can be difficult to treat BA trunk aneurysms by EVT, needing multiple procedures or various techniques due to diverse clinical and angiographic features.

The effect of hematoma evacuation with decompressive craniectomy on clinical outcomes in patients with parenchymal hematoma type 2 of hemorrhagic transformation after middle cerebral artery infarction.

OBJECTIVES: The purpose of this study was to investigate the feasibility of hematoma evacuation (HE) with decompressive craniectomy (DC) and to evaluate whether HE with DC is associated with improvement of clinical outcomes in patients with parenchymal hematoma type 2 (PH2) after middle cerebral artery (MCA) infarction. METHODS: Between March 2007 and August 2020, 73 patients with PH2 after MCA infarction underwent DC. The HE group (n = 28) consisted of subjects who underwent HE with DC and the non-HE group (n = 45) consisted of subjects who underwent only DC without HE. The clinical outcomes were analyzed and compared between groups. RESULTS: Significant differences in clinical outcomes were not observed between the groups at discharge (P = 0.648) and 12-month follow-up (P = 0.346). Mortality rate within 12 months was not significantly different between the groups (log-rank, P = 0.685). There were 12 reoperations in the HE group (42.9%) and three reoperations in the non-HE group (6.7%; P = 0.037). Logistic regression analysis showed the initial National Institutes of Health Stroke Scale score (OR, 2.320; 95% CI, 1.128-5.965; P = 0.046) and the infarction volume (OR, 1.876; 95% CI, 1.935-11.892; P = 0.041) were independently associated with mortality (modified Rankin Scale, 6) within the 12 months. CONCLUSIONS: In patients with PH2 of hemorrhagic transformation after MCA infarction, HE with DC does not change the clinical outcomes or mortality but might increase the reoperation risk.

Endovascular internal trapping of traumatic pericallosal pseudoaneurysm with hydrogel-coated self-expandable coil in a child: a case report.

BACKGROUND: Traumatic intracranial pseudoaneurysms in children must be completely secured from the parent artery because of significant morbidity and mortality from the high risk of rebleeding. However, the trapping of the parent artery involves the risk of ischemia changes distal to the trapped artery and the perforator injury. We describe a first case in the literature of successful trapping in the short segment with hydrogel-coated self-expandable coil in a child with a traumatic pericallosal pseudoaneurysm. CASE DESCRIPTION: A 5-year-old boy was admitted to our institution after enduring a blunt trauma with a stuporous mentality. Initial neuroimaging revealed a small hemorrhage in the corpus callosum with subarachnoid hemorrhage. Two weeks later, computed tomogram showed new callosal hemorrhage and a 4.7 x 5-mm pseudoaneurysm of the right pericallosal artery with mental deterioration and weakness of lower extremity. An endovascular short segmental internal trapping (5 mm) of the right pericallosal artery was conducted to save collateral blood flow, using 2 hydrogel-coated self-expandable coils. The cerebral angiogram of immediately after the trapping and at 3 months' follow-up revealed that the aneurysm had been completely obliterated, with successful maintenance of the distal collateral flow from the contralateral pericallosal artery. The patient recovered with good clinical outcome. CONCLUSION: We suggest that short-segment occlusion by a hydrogel-coated self-expandable coil has become a good alternative for the treatment of traumatic pseudoaneurysms in the distal anterior cerebral artery, although the safety and reliability of this procedure is as yet not definitely proven.

Discrepancy between Angiography and Operative Findings of Small Side Wall Aneurysms in Atherosclerotic Parent Arteries.

Preoperative evaluation of precise aneurysmal geometry is important for the treatment of intracranial aneurysms. We present two cases of unclippable side wall aneurysms due to their extremely low dome height, which appeared as saccular in the preoperative image because of a comparatively narrow atherosclerotic parent arterial lumen. In both cases, a calcified vessel wall was noted preoperatively. Lack of a definitive neck and abrupt discrepancy between the fragile aneurysmal wall and the atherosclerotic parent arterial wall was confirmed intraoperatively in both cases. This study describes an illustrative mechanism for the finding with emphasis on the importance of its preoperative diagnosis. Intracranial atherosclerosis associated with small side walled aneurysms may lead to overestimation of aneurysm height on preoperative imaging of the intravascular compartment.

Reappraisal of Pediatric Diastatic Skull Fractures in the 3-Dimensional CT Era: Clinical Characteristics and Comparison of Diagnostic Accuracy of Simple Skull X-Ray, 2-Dimensional CT, and 3-Dimensional CT.

BACKGROUND: Diastatic skull fractures (DSFs) in children are difficult to detect in skull radiographs before they develop into growing skull fractures; therefore, little information is available on this topic. However, recent advances in 3-dimensional (3D) computed tomography (CT) imaging technology have enabled more accurate diagnoses of almost all forms of skull fracture. The present study was undertaken to document the clinical characteristics of DSFs in children and to determine whether 3D CT enhances diagnostic accuracy. METHODS: Two hundred and ninety-two children younger than 12 years with skull fractures underwent simple skull radiography, 2-dimensional (2D) CT, and 3DCT. Results were compared with respect to fracture type, location, associated lesions, and accuracy of diagnosis. RESULTS: DSFs were diagnosed in 44 (15.7%) of children with skull fractures. Twenty-two patients had DSFs only, and the other 22 had DSFs combined with compound or mixed skull fractures. The most common fracture locations were the occipitomastoid (25%) and lambdoid (15.9%). Accompanying lesions consisted of subgaleal hemorrhages (42/44), epidural hemorrhages (32/44), pneumocephalus (17/44), and subdural hemorrhages (3/44). A total of 17 surgical procedures were performed on 15 of the 44 patients. Fourteen and 19 patients were confirmed to have DSFs by skull radiography and 2D CT, respectively, but 3D CT detected DSFs in 43 of the 44 children (P < 0.001). CONCLUSION: 3D CT was found to be markedly superior to skull radiography or 2D CT for detecting DSFs. This finding indicates that 3D CT should be used routinely rather than 2D CT for the assessment of pediatric head trauma.

Soft-helmet skull remodeling in canine models: intracranial volume unchanged by compensatory skull growth.

OBJECT: Habitual sleeping positions in infants can produce occipital plagiocephaly, which causes strabismus as well as skull and facial asymmetry. This condition can be managed using a hard helmet, but maintaining an infant in such a device is often intolerable. The authors studied whether the shape of a young canine skull could reform while inside a soft helmet and whether intracranial volume would be preserved by the compensatory growth of the skull. METHODS: The authors tracked the head sizes of 14 1-week-old beagles who wore long, soft helmets (study group) and seven beagles who did not (control group). From these measurements, the intracranial volume in each beagle was calculated. All crania were also studied radiologically by using plain skull radiography, computerized tomography (CT), and magnetic resonance (MR) imaging. The crania of all 14 beagles who wore soft helmets quickly adapted, resulting in a narrow, long head only 2 weeks into the experiment. This configuration continued to develop throughout the 7-week experimental period. At 8 weeks of age, animals in the study group showed no significantly different alteration in calculated intracranial volumes (p > 0.05). It is interesting that the helmet-treated animals initially underwent a paradoxical increase in intracranial volume growth. No structural difference in their brains was evident from CT or MR imaging findings, nor was there any functional disability. CONCLUSIONS: Intracranial volume can be preserved by the compensatory growth of the skull during successful remodeling of the developing skull achieved using a soft helmet.

Blood blister-like aneurysms at nonbranching sites of the internal carotid artery.

OBJECT: The clinical features of blood blister-like aneurysms (BBAs) that arise at nonbranching sites of the internal carotid artery (ICA) differ from those of saccular aneurysms. In this study, the authors attempt to describe optimal treatments for BBAs, which have yet to be clearly established. METHODS: Ten of 483 patients with aneurysmal subarachnoid hemorrhage who had been seen at the authors' institution between March 2001 and June 2005 had intraoperatively confirmed BBAs at nonbranching sites of the ICA. All ten patients were women between the ages of 37 and 64 years (mean age 49.3 years); five had a history of hypertension. The BBAs were localized to the right side of the ICA in seven cases. All patients were successfully treated; clipping was undertaken in six, clipping combined with wrapping in three, and trapping in one. These methods were used in conjunction with various other surgical techniques such as brain relaxation by draining cerebrospinal fluid, anterior clinoidectomy, exposing the cervical ICA, gentle subpial dissection (for aneurysms that adhered to the frontal lobe), complete trapping of the ICA before clipping, and protecting the brain. Clip slippage occurred at the end of dural closing in two cases; the aneurysm was completely obliterated using multiple clips combined with ICA stenosis in one of these cases and ICA trapping with good collateral flow in the other. An excellent clinical outcome was achieved in eight patients, whereas two patients were disabled from massive vasospasm. The authors retrospectively reviewed radiological and surgical data in all cases to determine which treatment methods produced a favorable outcome. CONCLUSIONS: Blood blister-like aneurysms located at nonbranching sites of the ICA are difficult to treat. Preoperative awareness and careful consideration of these lesions during surgery can prevent poor clinical outcomes.

Incidence and Characteristics of Remote Intracerebral Hemorrhage After Endovascular Treatment of Unruptured Intracranial Aneurysms.

OBJECTIVE: The purpose of this study was to investigate the incidence and characteristics of remote intracerebral hemorrhage (ICH) after endovascular treatment (EVT) of unruptured intracranial aneurysms (UIAs). METHODS: Between March 2007 and September 2015, 11 patients with remote ICH from a series of 2258 consecutive patients with 2597 UIAs treated via EVT were identified. Baseline demographic characteristics, medical history, radiologic imaging data, characteristics of remote ICH, and clinical outcomes were retrospectively reviewed. The characteristics of patients with remote ICH were compared with those of patients without remote ICH. RESULTS: All hematomas were single lesions located in the subcortical white matter as lobar-type in 9 patients (81.8%) and in the basal ganglia in 2 patients (18.2%). Events occurred mostly within 1 week and up to 3 weeks after EVT. Hematoma was located on the ipsilateral side in 8 patients (72.7%) and in the contralateral side in 3 patients (27.3%). Compared with patients without remote ICH, there were more aneurysms located on the internal carotid artery (ICA) (P = 0.041), more patients treated with stents (P < 0.001), more patients with hypertension (P = 0.026), and poorer clinical outcomes at discharge (P < 0.001) for patients with remote ICH. CONCLUSIONS: The incidence of remote ICH after EVT of UIAs was 0.46%. This event occurred mostly in patients with stents, hypertension, and UIAs on the ICA. It presented mostly as an ipsilateral lobar-type hemorrhage within 1 week after the procedure. This complication should not be neglected because of its poor clinical outcomes.

Spinal Subdural Hematoma Associated with Intracranial Subdural Hematoma.

The simultaneous occurrence of an intracranial and a spinal subdural hematoma (SDH) is rare. We describe a case of cranial SDH with a simultaneous spinal SDH. An 82-year-old woman visited the emergency room because of drowsiness and not being able to walk 6 weeks after falling down. A neurological examination showed a drowsy mentality. Brain computed tomography showed bilateral chronic SDH with an acute component. The patient underwent an emergency burr-hole trephination and hematoma removal. She exhibited good recovery after the operation. On the fourth postoperative day, she complained of low-back pain radiating to both lower limbs, and subjective weakness of the lower limbs. Spine magnetic resonance imaging revealed a thoracolumbosacral SDH. A follow-up spinal magnetic resonance imaging study that was performed 16 days later showed a significant decrease in the size of the spinal SDH. We discuss the pathogenesis of this simultaneous occurrence of spinal and cranial SDH.

Thirteen-year follow-up of parasellar intravascular papillary endothelial hyperplasia successfully treated by surgical excision: case report.

Intracranial intravascular papillary endothelial hyperplasia (IPEH) is very rare, and to our knowledge long-term follow-up results have not been previously published. An 11-year-old boy presented with a 6-month history of progressive visual impairment in the right eye. Magnetic resonance imaging revealed a well-enhanced, large parasellar mass involving the cavernous sinus, right frontal skull base, and ethmoid and sphenoid sinuses. Frontotemporal craniotomy and subtotal resection were performed, and the diagnosis of IPEH was confirmed. The mass increased in size during the following 3 months. A second operation was performed via frontotemporal craniotomy combined with a transsphenoidal approach, and gross-total resection of the tumor was achieved. Adjuvant radiotherapy (5040 cGy) and chemotherapy with interferon were administered. The patient's visual symptoms improved, and there was no recurrence during a 13-year follow-up period. The results of this case indicate that intracranial IPEH can recur with subtotal resection; however, optimal resection with multimodal adjuvant treatment can control the disease for many years, if not permanently.

Quantitative analysis of factors affecting cobalt alloy clip artifacts in computed tomography.

OBJECTIVE: Clip artifacts limit the visualization of intracranial structures in CT scans from patients after aneurysmal clipping with cobalt alloy clips. This study is to analyze the parameters influencing the degree of clip artifacts. METHODS: Postoperative CT scans of 60 patients with straight cobalt alloy-clipped aneurysms were analyzed for the maximal diameter of white artifacts and the angle and number of streak artifacts in axial images, and the maximal diameter of artifacts in three-dimensional (3-D) volume-rendered images. The correlation coefficient (CC) was determined between each clip artifact type and the clip blade length and clip orientation to the CT scan (angle a, lateral clip inclination in axial images; angle b, clip gradient to scan plane in lateral scout images). RESULTS: Angle b correlated negatively with white artifacts (r=-0.589, p<0.001) and positively with the angle (r=0.636, p<0.001) and number (r=0.505, p<0.001) of streak artifacts. Artifacts in 3-D images correlated with clip blade length (r=0.454, p=0.004). Multiple linear regression analysis revealed that angle b was the major parameter influencing white artifacts and the angle and number of streak artifacts in axial images (p<0.001), whereas clip blade length was a major factor in 3-D images (p=0.034). CONCLUSION: Use of a clip orientation perpendicular to the scan gantry angle decreased the amount of white artifacts and allowed better visualization of the clip site.

Traumatic aneurysm of the callosomarginal artery-cortical artery junction from penetrating injury by scissors.

Traumatic intracranial aneurysms (TICAs) are rare and are associated with high rates of morbidity and mortality. TICAs usually result from head injuries caused by traffic accidents, industrial accidents, or gunshots. We report a traumatic aneurysm of the callosomarginal artery-cortical artery junction arising from a penetrating injury by scissors. A 51-year-old woman was admitted to our hospital after suffering a penetrating injury caused by scissors. Computed tomography (CT) and CT-angiography demonstrated a right orbital roof fracture, subarachnoid hemorrhage, frontal lobe hemorrhage, intraventricular hemorrhage, and a traumatic aneurysm of the right callosomarginal artery-cortical artery junction. We trapped the traumatic aneurysm and repositioned a galeal flap. Postoperative CT showed a small infarction in the left frontal lobe. Follow-up angiography two months later showed no residual aneurysm. We suggest that an aggressive surgical intervention be performed whenever TICA is diagnosed.

Are blood blister-like aneurysms a specific type of dissection? A comparative study of blood blister-like aneurysms and ruptured mizutani type 4 vertebral artery dissections.

OBJECTIVE: Blood blister-like aneurysms (BBAs) resemble arterial dissections. The purpose of this study was to investigate the relationship between these two disease entities and highlight commonalities and distinct features. METHODS: Among 871 consecutive patients with aneurysmal subarachnoid hemorrhage, 11 BBAs of internal carotid artery and seven vertebral artery dissections (VADs) with a short segmental eccentric dilatation (Mizutani type 4), which is morphologically similar to a BBA, were selected. The following clinical factors were studied in each group : age, gender, risk factors, Hunt and Hess grade (HHG), Fisher grade (FG), vasospasms, hydrocephalus, perioperative rebleeding rate, and treatment outcome. RESULTS: The mean age was 47.9 years in the BBAs group and 46.4 years in the type 4 VADs group. All the BBA patients were female, whereas there was a slight male predominance in the type 4 VAD group (male : female ratio of 4 : 3). In the BBA and type 4 VAD groups that underwent less aggressive treatment to save the parent artery, 29% (n=2/7) and 66.6% (n=2/3), respectively, eventually required retreatment. Perioperative rebleeding occurred in 72.7% (n=8) and 28.6% (n=2) of patients in the BBA and type 4 VAD groups, respectively. There was no statistical difference in the other clinical factors in both groups, except for the male dominancy in the type 4 VAD group (p=0.011). CONCLUSION: BBAs and ruptured type 4 VADs have a similar morphological appearance but there is a distinct clinical feature in gender and perioperative rebleeding rates. Complete isolation of an aneurysm from the parent artery might be the most important discipline for the treatment of these diseases.