Gender differences in adult traumatic brain injury according to the Glasgow coma scale: A multicenter descriptive study / 中华创伤杂志(英文版)

PURPOSE@#Patients' gender, which can be one of the most important determinants of traumatic brain injury (TBI) outcomes, is also likely to interact with many other outcome variables of TBI. This multicenter descriptive study investigated gender differences in epidemiological, clinical, treatment, mortality, and variable characteristics in adult TBI patients.@*METHODS@#The selection criteria were defined as patients who had been diagnosed with TBI and were admitted to the hospital between January 1, 2016 and December 31, 2018. A total of 4468 adult TBI patients were enrolled at eight University Hospitals. Based on the list of enrolled patients, the medical records of the patients were reviewed and they were registered online at each hospital. The registered patients were classified into three groups according to the Glasgow coma scale (GCS) score: mild (13-15), moderate (9-12), and severe (3-8), and the differences between men and women in each group were investigated. The risk factors of moderated and severe TBI compared to mild TBI were also investigated.@*RESULTS@#The study included 3075 men and 1393 women and the proportion of total males was 68.8%. Among all the TBI patients, there were significant differences between men and women in age, past history, and GCS score. While the mild and severe TBI groups showed significant differences in age, past history, and clinical symptoms, the moderate TBI group showed significant differences in age, past history, cause of justice, and diagnosis.@*CONCLUSION@#To the best of our knowledge, this multicenter study is the first to focus on gender differences of adult patients with TBI in Korea. This study shows significant differences between men and women in many aspects of adult TBI. Therefore, gender differences should be strongly considered in TBI studies.

S100ß, Matrix Metalloproteinase-9, D-dimer, and Heat Shock Protein 70 Are Serologic Biomarkers of Acute Cerebral Infarction in a Mouse Model of Transient MCA Occlusion

OBJECTIVE: Diagnosing acute cerebral infarction is crucial in determining prognosis of stroke patients. Although many serologic tests for prompt diagnosis are available, the clinical application of serologic tests is currently limited. We investigated whether S100β, matrix metalloproteinase-9 (MMP-9), D-dimer, and heat shock protein 70 (HSP70) can be used as biomarkers for acute cerebral infarction.METHODS: Focal cerebral ischemia was induced using the modified intraluminal filament technique. Mice were randomly assigned to 30-minute occlusion (n=10), 60-minute occlusion (n=10), or sham (n=5) groups. Four hours later, neurological deficits were evaluated and blood samples were obtained. Infarction volumes were calculated and plasma S100β, MMP-9, D-dimer, and HSP70 levels were measured using enzyme-linked immunosorbent assay.RESULTS: The average infarction volume was 12.32±2.31 mm³ and 46.9±7.43 mm³ in the 30- and 60-minute groups, respectively. The mean neurological score in the two ischemic groups was 1.6±0.55 and 3.2±0.70, respectively. S100β, MMP-9, and HSP70 expressions significantly increased after 4 hours of ischemia (p=0.001). Furthermore, S100β and MMP-9 expressions correlated with infarction volumes (p < 0.001) and neurological deficits (p < 0.001). There was no significant difference in D-dimer expression between groups (p=0.843). The area under the receiver operating characteristic curve (AUC) showed high sensitivity and specificity for MMP-9, HSP70 (AUC=1), and S100β (AUC=0.98).CONCLUSION: S100β, MMP-9, and HSP70 can complement current diagnostic tools to assess cerebral infarction, suggesting their use as potential biomarkers for acute cerebral infarction.

The Potential of Diffusion-Weighted Magnetic Resonance Imaging for Predicting the Outcomes of Chronic Subdural Hematomas

OBJECTIVE: Diffusion-weighted magnetic resonance imaging (DW-MRI) has proven useful in the study of the natural history of ischemic stroke. However, the potential of DW-MRI for the evaluation of chronic subdural hematoma (CSDH) has not been established. In this study, we investigated DW-MRI findings of CSDH and evaluated the impact of the image findings on postoperative outcomes of CSDH.METHODS: We studied 131 CSDH patients who had undergone single burr hole drainage surgery. The images of the subdural hematomas on preoperative DW-MRI and computed tomography (CT) were divided into three groups based on their signal intensity and density: 1) homogeneous (iso or low) density on CT and homogeneous low signal intensity on DW-MRI; 2) homogeneous (iso or low) density on CT and mixed signal intensity on DW-MRI; and 3) heterogeneous density on CT and mixed signal intensity on DW-MRI. On the basis of postoperative CT, we also divided the patients into 3 groups of surgical outcomes according to residual hematoma and mass effect.RESULTS: Analysis showed statistically significant differences in surgical (A to B: p < 0.001, A to C: p < 0.001, B to C: p=0.129) and functional (A to B: p=0.039, A to C: p < 0.001, B to C: p=0.108) outcomes and treatment failure rates (A to B: p=0.037, A to C: p=0.03, B to C: p=1) between the study groups. In particular, group B and group C showed worse outcomes and higher treatment failure rates than group A.CONCLUSION: CSDH with homogeneous density on CT was characterized by signal intensity on DW-MRI. In CSDH patients, performing DW-MRI as well as CT helps to predict postoperative treatment failure or complications.

S100ß, Matrix Metalloproteinase-9, D-dimer, and Heat Shock Protein 70 Are Serologic Biomarkers of Acute Cerebral Infarction in a Mouse Model of Transient MCA Occlusion

OBJECTIVE: Diagnosing acute cerebral infarction is crucial in determining prognosis of stroke patients. Although many serologic tests for prompt diagnosis are available, the clinical application of serologic tests is currently limited. We investigated whether S100β, matrix metalloproteinase-9 (MMP-9), D-dimer, and heat shock protein 70 (HSP70) can be used as biomarkers for acute cerebral infarction. METHODS: Focal cerebral ischemia was induced using the modified intraluminal filament technique. Mice were randomly assigned to 30-minute occlusion (n=10), 60-minute occlusion (n=10), or sham (n=5) groups. Four hours later, neurological deficits were evaluated and blood samples were obtained. Infarction volumes were calculated and plasma S100β, MMP-9, D-dimer, and HSP70 levels were measured using enzyme-linked immunosorbent assay. RESULTS: The average infarction volume was 12.32±2.31 mm³ and 46.9±7.43 mm³ in the 30- and 60-minute groups, respectively. The mean neurological score in the two ischemic groups was 1.6±0.55 and 3.2±0.70, respectively. S100β, MMP-9, and HSP70 expressions significantly increased after 4 hours of ischemia (p=0.001). Furthermore, S100β and MMP-9 expressions correlated with infarction volumes (p < 0.001) and neurological deficits (p < 0.001). There was no significant difference in D-dimer expression between groups (p=0.843). The area under the receiver operating characteristic curve (AUC) showed high sensitivity and specificity for MMP-9, HSP70 (AUC=1), and S100β (AUC=0.98). CONCLUSION: S100β, MMP-9, and HSP70 can complement current diagnostic tools to assess cerebral infarction, suggesting their use as potential biomarkers for acute cerebral infarction.

The Potential of Diffusion-Weighted Magnetic Resonance Imaging for Predicting the Outcomes of Chronic Subdural Hematomas

OBJECTIVE: Diffusion-weighted magnetic resonance imaging (DW-MRI) has proven useful in the study of the natural history of ischemic stroke. However, the potential of DW-MRI for the evaluation of chronic subdural hematoma (CSDH) has not been established. In this study, we investigated DW-MRI findings of CSDH and evaluated the impact of the image findings on postoperative outcomes of CSDH. METHODS: We studied 131 CSDH patients who had undergone single burr hole drainage surgery. The images of the subdural hematomas on preoperative DW-MRI and computed tomography (CT) were divided into three groups based on their signal intensity and density: 1) homogeneous (iso or low) density on CT and homogeneous low signal intensity on DW-MRI; 2) homogeneous (iso or low) density on CT and mixed signal intensity on DW-MRI; and 3) heterogeneous density on CT and mixed signal intensity on DW-MRI. On the basis of postoperative CT, we also divided the patients into 3 groups of surgical outcomes according to residual hematoma and mass effect. RESULTS: Analysis showed statistically significant differences in surgical (A to B: p < 0.001, A to C: p < 0.001, B to C: p=0.129) and functional (A to B: p=0.039, A to C: p < 0.001, B to C: p=0.108) outcomes and treatment failure rates (A to B: p=0.037, A to C: p=0.03, B to C: p=1) between the study groups. In particular, group B and group C showed worse outcomes and higher treatment failure rates than group A. CONCLUSION: CSDH with homogeneous density on CT was characterized by signal intensity on DW-MRI. In CSDH patients, performing DW-MRI as well as CT helps to predict postoperative treatment failure or complications.

Subdural Hematoma without Subarachnoid Hemorrhage Caused by the Rupture of Middle Cerebral Artery Aneurysm

Pure subdural hematomas caused by a ruptured intracranial aneurysm are extremely rare. We describe the case of a 42-year-old woman who presented with headache without evidence of head trauma. Magnetic resonance angiography and conventional cerebral angiography revealed a ruptured aneurysm at the right middle cerebral artery bifurcation. The patient underwent surgical treatment and had a good outcome without any neurological deficit. The mechanisms and clinical characteristics of this condition are discussed.

Endovascular Treatment of Symptomatic Vertebral Artery Dissecting Aneurysms

OBJECTIVE: Vertebral artery dissecting aneurysms (VADAs) are rare and many debates are present about treatment options. We review types and efficacy of our endovascular treatments and establish a safe endovascular therapeutic strategy regard to the angio-architecture of VADAs. MATERIALS AND METHODS: Between July 2008 and October 2015, we treated 22 patients with symptomatic VADAs. Fifteen patients presented with subarachnoid hemorrhage from the ruptured VADAs, digital subtraction angiography and magnetic resonance image confirmed the diagnosis and endovascular treatments were followed as their angio-architecture. RESULTS: Clinical results were good in 13 patients (86.7%), and there were no technical problems during endovascular procedures. The other 2 patients with poor prognosis showed severe neurological deficits at the initial evaluation. Among the three different endovascular treatments, there were no radiologic cure in one patient with stent insertion alone, but the patient had no significant clinical symptoms either. CONCLUSION: Endovascular treatments are safe and effective treatment option for managing VADAs and can be the first treatment of choice for most patients. To select proper endovascular treatment according to the angio-architecture of VADAs can reduce the risk of the treatment.

Unusual Presentation of Cerebral Cavernous Malformation

Cerebral cavernous malformations (CMs) are vascular malformations of the central nervous system, which can be detected in the absence of any clinical symptoms. Nodules and cysts with mixed signal intensity and a peripheral hemosiderin rim are considered brain magnetic resonance imaging (MRI) findings typical of CMs. A 48-year-old man was admitted to our hospital because of abnormal MRI findings without significant neurological symptoms. A cyst with an internal fluid-fluid level was found in the left basal ganglia on the initial brain MRI. We decided to observe the natural course of the asymptomatic lesion with serial MRI follow-up. On MRI at the 5-month follow-up, the cystic mass was enlarged and showed findings consistent with those of cystic CM. Surgical resection was performed and the pathological diagnosis was CM. Our experience suggests that the initial presentation of a CM can be a pure cyst and neurosurgeons should consider the likelihood of CMs in cases of cystic cerebral lesions with intracystic hemorrhage.

Is Routine Repeated Head CT Necessary for All Pediatric Traumatic Brain Injury?

OBJECTIVE: Repeated computed tomography (CT) follow up for traumatic brain injury (TBI) patients is often performed. But there is debate the indication for repeated CT scans, especially in pediatric patients. Purpose of our study is to find risk factors of progression on repeated CT and delayed surgical intervention based on the repeated head CT. METHODS: Between March, 2007 and December, 2013, 269 pediatric patients (age 0-18 years) had admitted to our hospital for head trauma. Patients were classified into 8 subgroups according to mechanisms of injury. Types, amount of hemorrhage and amount changes on repeated CT were analyzed as well as initial Glasgow Coma Scale (GCS) scores. RESULTS: Within our cohort of 269 patients, 174 patients received repeat CT. There were progression in the amount of hemorrhage in 48 (27.6%) patients. Among various hemorrhage types, epidural hemorrhage (EDH) more than 10 cc measured in initial CT was found to be at risk of delayed surgical intervention significantly after routine repeated CT with or without neurological deterioration than other types of hemorrhage. Based on initial GCS, severe head trauma group (GCS 3-8) was at risk of delayed surgical intervention after routine repeated CT without change of clinical neurologic status. CONCLUSION: We suggest that the patients with EDH more than 10 cc or GCS below 9 should receive repeated head CT even though absence of significant clinical deterioration.

Modified Open-door Laminoplasty Using Hydroxyapatite Spacers and Miniplates

OBJECTIVE: Cervical laminoplasty has been widely accepted as one of the major treatments for cervical myelopathy and various modifications and supplementary procedures have been devised to achieve both proper decompression and stability of the cervical spine. We present the retrospectively analyzed results of a modified unilateral open-door laminoplasty using hydroxyapatite (HA) spacers and malleable titanium miniplates. METHODS: From June 2008 to May 2012, among patients diagnosed with cervical spondylotic myelopathy and ossification of posterior longitudinal ligament, the patients who received laminoplasty were reviewed. Clinical outcome was assessed using Frankel grade and Japanese Orthopaedic Association score. The radiologic parameters were obtained from plain films, 3-dimensional computed tomography and magnetic resonance images. RESULTS: A total of 125 cervical laminae were operated in 38 patients. 11 patients received 4-level laminoplasty and 27 patients received 3-level laminoplasty. Postoperatively, the mean Frankel grade and JOA score were significantly improved from 3.97 to 4.55 and from 12.76 to 14.63, respectively (p<0.001). Radiologically, cervical curvature was worsened from 19.09 to 15.60 (p=0.025). The percentage of range of motion preservation was 73.32+/-22.39%. The axial dimension of the operated spinal canal was increased from 1.75 to 2.70 cm2 (p<0.001). CONCLUSION: In the presenting study, unilateral open-door laminoplasty using HA spacers and miniplates appears to be a safe, rapid and easy procedure to obtain an immediate and rigid stabilization of the posterior elements of the cervical spine. This modified laminoplasty method showed effective expansion of the spinal canal and favorable clinical outcomes.

Semi-Quantitative Analyses of Hippocampal Heat Shock Protein-70 Expression Based on the Duration of Ischemia and the Volume of Cerebral Infarction in Mice

OBJECTIVE: We investigated the expression of hippocampal heat shock protein 70 (HSP-70) infarction volume after different durations of experimental ischemic stroke in mice. METHODS: Focal cerebral ischemia was induced in mice by occluding the middle cerebral artery with the modified intraluminal filament technique. Twenty-four hours after ischemia induction, both hippocampi were extracted for HSP-70 protein analyses. Slices from each hemisphere were stained with 2,3,5-triphenyltetrazolium chloride (2%), and infarction volumes were calculated. HSP-70 levels were evaluated using western blot and enzyme-linked immunosorbent assay (ELISA). HSP-70 subtype (hsp70.1, hspa1a, hspa1b) mRNA levels in the hippocampus were measured using reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Cerebral infarctions were found ipsilateral to the occlusion in 10 mice exposed to transient ischemia (5 each in the 30-min and 60-min occlusion groups), whereas no focal infarctions were noted in any of the sham mice. The average infarct volumes of the 2 ischemic groups were 22.28+/-7.31 mm3 [30-min group+/-standard deviation (SD)] and 38.06+/-9.53 mm3 (60-min group+/-SD). Western blot analyses and ELISA showed that HSP-70 in hippocampal tissues increased in the infarction groups than in the sham group. However, differences in HSP-70 levels between the 2 infarction groups were statistically insignificant. Moreover, RT-PCR results demonstrated no relationship between the mRNA expression of HSP-70 subtypes and occlusion time or infarction volume. CONCLUSION: Our results indicated no significant difference in HSP-70 expression between the 30- and 60-min occlusion groups despite the statistical difference in infarction volumes. Furthermore, HSP-70 subtype mRNA expression was independent of both occlusion duration and cerebral infarction volume.

Late Infection from Anterior Cervical Discectomy and Fusion after Twenty Years

Anterior cervical discectomy and fusion (ACDF) has been performed for degenerative and traumatic cervical diseases to improve pain and neurologic symptoms including sensory change and motor weakness. Infection, however, is a rare complication of ACDF, and late infection is even much rarer. We present a case of late Infection from ACDF C4-5 using Biocompatible Osteoconductive Polymer (BOP) after twenty years in the absence of an esophageal perforation, Zenker's diverticulum, or recent surgery or bacteremia. Late infection from ACDF after 20 years is extremely rare in the literature. However, possibility of such a late complication should be appreciated during the follow-up period and surgical resection will be required for proper treatment.

Rupture of De Novo Anterior Communicating Artery Aneurysm 8 Days after the Clipping of Ruptured Middle Cerebral Artery Aneurysm

Rapidly developed de novo aneurysm is very rare. We present a rapidly developed and ruptured de novo anterior communicating aneurysm 8 days after the rupture of another aneurysm. This de novo aneurysm was not apparent in the initial 3-dimensional computed tomography and digital subtraction angiography. We reviewed the literature and discussed possible mechanisms for the development of this de novo aneurysm.

Triple Primary Origin Tumor: A Case Report

Generally, among the extradural spinal tumors, metastatic spinal tumor is much more common than primary spinal tumors. Thus, in the case of a spinal tumor patient with cancer history (such as lung cancer, breast cancer, etc.), we used to infer that the spinal lesion is the metastasis from, primary malignancy. We introduce an experience of a case of triple primary origin tumor in a 57-year-old man. When the spinal lesion was found on the abdominal computed tomography scan, he already had a history of colon cancer and liver cancer. Initially, it was thought that the lesion would probably be a metastatic tumor from the liver or colon cancers, and the operation was performed accordingly. In the pathologic final report, however, the mass was proven to plasmacytoma - the third primary lesion. The patient underwent chemotherapy after surgery. Globally, the triple primary origin tumor has been reported very rarely. With this report, we wish to emphasize the necessity of pathologic confirmation and adequate treatment even in a patient with known malignancies.

The Role of Adiponectin in Secondary Inflammatory Reaction in Cerebral Ischemia

OBJECTIVE: In this study, we investigate the role of adiponectin in the interaction between leukocytes and endothelium in the secondary inflammatory reaction of cerebral ischemia. METHODS: Adiponectin knock-out mice group (APN-KO) (n = 8) and wild-type mice group (WT) (n = 8) were prepared. Each group was sub-divided into 2 groups by reperfusion time. One-hour middle cerebral artery occlusion and reperfusion were induced using the intraluminal filament technique. At 6 and 12 hours after the occlusion, the mice were placed on a stereotactic frame to perform craniotomy in the left parietal area. After craniotomy, a straight pial venule was selected as a target vessel. With the fluorescence intravital microscope, the number of rolling leukocytes and leukocytes that adhered to endothelium were counted and documented at 6 and 12 hours after the reperfusion. RESULTS: At 6 and 12 hours after the reperfusion, more rolling leukocyte and leukocyte adhesion were observed in the APN-KO mice than in the WT mice. The difference in leukocyte numbers between the APN-KO and WT mice was found to be statistically significant (p = 0.029) by Mann-Whitney U-test. CONCLUSION: We found that adiponectin inhibits the interaction between the endothelium and leukocytes in cerebral ischemia-reperfusion. Therefore adiponectin might prevent the secondary insult caused by the inflammation reaction.

The Role of Adiponectin in Secondary Inflammatory Reaction in Cerebral Ischemia

OBJECTIVE: In this study, we investigate the role of adiponectin in the interaction between leukocytes and endothelium in the secondary inflammatory reaction of cerebral ischemia. METHODS: Adiponectin knock-out mice group (APN-KO) (n = 8) and wild-type mice group (WT) (n = 8) were prepared. Each group was sub-divided into 2 groups by reperfusion time. One-hour middle cerebral artery occlusion and reperfusion were induced using the intraluminal filament technique. At 6 and 12 hours after the occlusion, the mice were placed on a stereotactic frame to perform craniotomy in the left parietal area. After craniotomy, a straight pial venule was selected as a target vessel. With the fluorescence intravital microscope, the number of rolling leukocytes and leukocytes that adhered to endothelium were counted and documented at 6 and 12 hours after the reperfusion. RESULTS: At 6 and 12 hours after the reperfusion, more rolling leukocyte and leukocyte adhesion were observed in the APN-KO mice than in the WT mice. The difference in leukocyte numbers between the APN-KO and WT mice was found to be statistically significant (p = 0.029) by Mann-Whitney U-test. CONCLUSION: We found that adiponectin inhibits the interaction between the endothelium and leukocytes in cerebral ischemia-reperfusion. Therefore adiponectin might prevent the secondary insult caused by the inflammation reaction.

Fatal Case of Cerebral Aspergillosis : A Case Report and Literature Review

Cerebral aspergillosis is rare and usually misdiagnosed because its presentation is similar to that of a tumor. The correct diagnosis is usually made intra-operatively. Cerebral abscess with fungal infection is extremely rare and few cases have been reported, but it carries a poor prognosis. A 73 year-old man presented with decreased visual acuity and paresis of the right cranial nerve III. Magnetic resonance imaging (MRI) revealed a mass in the right cavernous sinus, extened to the anterior crainial fossa and the superior orbital fissure. During surgery, a well encapsulated pus pocket was found, and histopathological examination of the mass resulted in the diagnosis of aspergillosis. Despite appropriate anti-fungal treatment, the patient eventually died from fatal cerebral ischemic change and severe brain swelling. The correct diagnosis of cerebral aspergillosis can only be achieved by histopathological examination because clinical and radiological findings including MRI are not specific. Surgical intervention and antifungal therapy should be considered the optimal treatment. Early diagnosis and aggressive antifungal treatment provide good results.

Internal Trapping Using Detachable Coils for Ruptured Vertebral Artery-dissecting Aneurysms: Case Report / 대한뇌혈관외과학회지

Ruptured vertebral artery- dissecting aneurysms (VADAs) must be treated as early as possible due to frequent rebleeding in the early stage. We have reported herein two patients with VADAs who were treated using internal trapping using detachable coils. Both patients were young females in their 40's. They had been admitted to the emergency clinic due to severe headaches and mental deterioration. Brain computed tomography (CT) scans revealed a subarachnoid hemorrhages in the posterior fossa, and transfemoral catheter cerebral angiography revealed dissecting aneurysms at the dominant vertebral arteries. Under general anesthesia, embolization of the parent artery, including the aneurysmal portion, using Guglielmi detachable coils was performed without any procedural complications. Before the induction of general anesthesia, a balloon test occlusion was done on both patients. Both patients improved well after surgery. One patient underwent cerebral angiography at six months after surgery and showed no recurrence of the aneurysm or recanalization of the parent artery. Both patients were free of neurologic findings on follow-up at the 6- and 12- month. Based on these results, patients with ruptured VADAs, located in the dominant vertebral arteries, may be successfully treated with urgent internal trapping using an endovascular technique in selected cases.

Clinical Analysis of Patients with Spontaneous Subarachnoid Hemorrhage of Initial Negative Angiography / 대한뇌혈관외과학회지

OBJECTIVE: The purpose of this study was to reveal the incidence of subarachnoid hemorrhage (SAH) of initial negative angiography and to find a useful method of follow up angiography through retrospective review. Additional objective was to determine the relationship between the hidden aneurysm and initial Computed Tomography (CT) pattern (i.e. amount and distribution of SAH). METHODS: Among 593 cases of spontaneous SAH performed initial cerebral angiography, 83 (12%) patients did not show any identifiable vascular lesions in initial angiographic studies. Repeated angiographic studies were performed in 67 patients by using transfemoral catheter angiography (TFCA) in 26 patients, CT angiography (CTA) in 39 and Magnetic Resornance (MR) angiography in 2. RESULTS: Ten (15%) out of 67 patients who underwent repeated angiography revealed aneurysms. At the comparison of initial CT scan and repeated angiography, 31 patients had thick layer of blood and 25% of these patients revealed aneurysms on repeated angiography (P=0.05). According to the initial CT pattern, 38 patients had diffuse blood distribution and 23% of these patients revealed aneurysms on repeated angiography (P=0.05). The timing of follow up angiography was 8.5 +/- 6.0 days (mean +/- SD) after ictus and CTA was applied in the earlier period than TFCA. CONCLUSIONS: If initial CT scans show thick layer of SAH or diffuse type of blood distribution in patients with initial negative angiography, repeated angiographic study should be performed to find hidden vascular lesions. CT angiography might be useful in the detection of hidden aneurysm early in the course.

Clinical Analysis of Patients with Spontaneous Subarachnoid Hemorrhage of Initial Negative Angiography / 대한뇌혈관외과학회지

OBJECTIVE: The purpose of this study was to reveal the incidence of subarachnoid hemorrhage (SAH) of initial negative angiography and to find a useful method of follow up angiography through retrospective review. Additional objective was to determine the relationship between the hidden aneurysm and initial Computed Tomography (CT) pattern (i.e. amount and distribution of SAH). METHODS: Among 593 cases of spontaneous SAH performed initial cerebral angiography, 83 (12%) patients did not show any identifiable vascular lesions in initial angiographic studies. Repeated angiographic studies were performed in 67 patients by using transfemoral catheter angiography (TFCA) in 26 patients, CT angiography (CTA) in 39 and Magnetic Resornance (MR) angiography in 2. RESULTS: Ten (15%) out of 67 patients who underwent repeated angiography revealed aneurysms. At the comparison of initial CT scan and repeated angiography, 31 patients had thick layer of blood and 25% of these patients revealed aneurysms on repeated angiography (P=0.05). According to the initial CT pattern, 38 patients had diffuse blood distribution and 23% of these patients revealed aneurysms on repeated angiography (P=0.05). The timing of follow up angiography was 8.5 +/- 6.0 days (mean +/- SD) after ictus and CTA was applied in the earlier period than TFCA. CONCLUSIONS: If initial CT scans show thick layer of SAH or diffuse type of blood distribution in patients with initial negative angiography, repeated angiographic study should be performed to find hidden vascular lesions. CT angiography might be useful in the detection of hidden aneurysm early in the course.