Sook Young Sim

Reconstructive treatment of ruptured blood blister-like aneurysms with stent and coil.

BACKGROUND Controversy remains about the optimal treatment for blood blister--like aneurysms (BBAs). OBJECTIVE To evaluate clinical and angiographic outcomes after reconstructive treatment for BBA with stent and coil. METHODS Thirty-four patients (6 men, 28 women; mean age, 47.3 years) with ruptured BBAs underwent reconstructive treatment with stent and coil. Posttreatment courses and outcomes were retrospectively evaluated. RESULTS Initial treatments were ≥ 2 overlapping stents with or without coiling (n = 28) and single stent with coiling (n = 6). Three BBAs rebled on days 9, 11, and 15 after treatment, resulting in 1 death. Except for 3 patients who died early, 31 patients were followed up for 7 to 80 months (median, 32 months). One patient recovered completely but died of complications of systemic lupus erythematosus at 25 months. Of the remaining 30 patients, 25 had favorable outcomes (modified Rankin scale, 0-2) and 5 had unfavorable outcomes. Angiographic follow-up was available in the 32 BBAs. Eight (25.0%) recurred, all within 5 weeks. In the multiple stents group (n = 26), 22 BBAs showed improvement or complete healing, but 4 (15.4%, 2 rebleedings) had recurrence. In the single stent with coiling group (n = 6), 2 BBAs were stable but 4 (66.7%, 1 rebleeding) had recurrence. Single stent with coiling and Hunt and Hess grade ≥ 4 were 2 independent risk factors for recurrence (P < .05). CONCLUSION Reconstructive treatment with stent and coil appears a viable option for BBAs. Single stent with coiling and Hunt and Hess grade ≥ 4 were 2 independent risk factors for recurrence. Follow-up angiography should be considered mandatory soon after treatment. ABBREVIATIONS BBA, blood blister--like aneurysmICA, internal carotid arterymRS, modified Rankin ScaleSAH, subarachnoid hemorrhage.

Silent Microembolism on Diffusion-Weighted MRI after Coil Embolization of Cerebral Aneurysms

Purpose The purpose of this study was to investigate the frequency and risk factors of procedure-related thromboembolism on diffusion-weighted imaging (DWI) associated with aneurysmal coil embolization. Materials and Methods We prospectively evaluated 39 consecutive patients with a cerebral aneurysm with DWI after coil embolization. All hyperintense lesions on DWI with a drop of apparent diffusion coefficient values were classified into acute thromboembolic infarction (larger than 5 mm in maximal diameters, and located in the vascular territory of the parent artery) and silent microembolism (single or multiple tiny dot-like lesion, less than 5 mm, usually 1-2 mm in size). Possible risk factors for thromboembolic events included vascular risk factors, aneurysmal factors, and procedure-related factors. Results Hyperintense lesions on DWI were seen in 17 (43.6%) patients and symptomatic DWI positive lesions were four (10.3%). Acute thromboembolic infarction was observed in seven (17.9%) patients and silent microembolism in 14 (35.9%) patients. Numbers of silent microembolism ranged from 1 to 15 (mean: 2.86, standard deviation: 3.74). Silent microembolisms were located at ipsilateral (n=3, 21.4%), contralateral (n=5, 35.7%), bilateral (n=4, 28.6%), and not related (n=2, 14.3%) to the procedure site. There were no statistical significant risk factors in acute thromboembolic infarction. However, incidence of silent microembolisms was significantly correlated with left side approach (odds ratio, 4.44, 95% confidence interval, 1.08-18.36; P=0.03). Conclusion Left side approach may have increased the likelihood of asymptomatic multiple scattered microemboli after aneurysmal coiling procedures. Particular care must be taken in the handling of guiding catheters, especially when proving left side great vessels.

Atypical metronidazole-induced encephalopathy in anaerobic brain abscess.

Metronidazole-induced encephalopathy is a very rare complication of the long standing use of metronidazole. The encephalopathy is bilateral and symmetric in nature. We report on the magnetic resonance imaging (MRI) and clinical course of metronidazole-induced encephalopathy in a 60-year-old female with a persistent anaerobic brain abscess after draining of the abscess. After 3 months of metronidazole administration, the patient complained of dysarthria, tingling sense of all extremities, and left hemiparesis. MRI revealed symmetric hyperintensity lesions in medulla, pons, dentate nuclei of cerebellum, and splenium of corpus callosum, all of which represent typical findings of metronidazole-induced encephalopathy. In addition, asymmetric lesions in midbrain, thalamus, putamen and cerebral subcortical white matter were noted. The patient recovered after discontinuation of metronidazole and the remaining abscess was successfully treated with meropenem and levofloxacine.

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.

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.

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.

Pathophysiology of Subarachnoid Hemorrhage

Spontaneous subarachnoid hemorrhage (SAH) is an important cause of stroke. It is associated with high mortality and morbidity. SAH has differing hemorrhagic patterns, clinical course, prognosis, and therapeutic method, depending on the cause of the bleeding. The most common etiology of SAH is a rupture of an aneurysm arising at the intracranial artery. This chapter describes the underlying pathogenesis of aneurysmal formation, growth, and rupture. Not only the initial hemorrhage but also the ways in which pathophysiological processes following aneurysmal SAH may influence the complicated clinical course of survivors. Furthermore, the chapter discusses updated pathophysiology of post-hemorrhagic phenomena, including aneurysmal rebleeding, hydrocephalus, early brain injury, delayed cerebral ischemia, and medical complications. Finally, non-aneurysmal SAH is rare but is associated with diverse etiologies; the chapter summarizes proposed mechanisms of bleeding and clinical characteristics of non-aneurysmal SAH.

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

BackgroundPredicting 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.MethodsBetween 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.ResultsThe 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.ConclusionsPatients 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.

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.