Factors associated with rebleeding after coil embolization in patients with aneurysmal subarachnoid hemorrhage

Objective@#Aneurysmal subarachnoid hemorrhage (aSAH) has a high mortality rate, and hemorrhage amounts and perioperative rebleeding importantly determines prognosis. However, despite adequate treatment, prognosis is poor in many ruptured aneurysm cases. In this study, we identified and evaluated factors related to perioperative rebleeding in patients with aSAH. @*Methods@#The medical and surgical records of 166 patients that underwent endovascular embolization for a ruptured cerebral aneurysm at a single institution from 2014 to 2016 were retrospectively analyzed to identify risk factors of rebleeding. All patients were examined for risk factors and evaluated for increased hemorrhage by brain computed tomography at 3 days after surgery. @*Results@#This series included 54 men (32.5%) and 112 women (67.5%) of mean age 58.3±14.3 years. After procedures, 26 patients (15.7%) experienced rebleeding, and 1 of these (0.6%) experienced an intraoperative aneurysmal rupture. External ventricular drainage (EVD) (odds ratio [OR] 5.389, [95% confidence interval (CI) 1.171- 24.801]) and modified Fisher grade (OR 2.037, [95% CI 1.077-3.853]) were found to be independent risk factors of rebleeding, and perioperative rebleeding was strongly associated with patient outcomes (p＜0.001). @*Conclusions@#We concluded the rebleeding risk after aSAH is greater in patients with large hemorrhage amounts and a high pre-operative modified Fisher grade, and thus, we caution neurosurgeons should take care in such cases.

Spinal Cord Infarction After Transarterial Chemoembolization for Hepatocellular Carcinoma / 대한신경손상학회지

Transarterial chemoembolization (TACE) is an effective treatment for unresectable hepatocellular carcinoma (HCC). It is considered relatively safe. However, fatal complications such as pulmonary edema and liver abscesses can occur. Spinal infarction due to local embolism of the central nervous system after TACE is a very rare, but fatal complication. Here, we report a case of spinal cord infarction after TACE for ruptured HCC. Paraplegia occurred at the T10 sensory level 6 hours after the procedure. The patient received steroid megadose therapy but died 5 days later due to exacerbation of metabolic acidosis and blood loss. This case demonstrates the need for a comprehensive and extensive study of arterial blood flow prior to angiography.

Factors Associated With Subdural Hygroma Following Mild Traumatic Brain Injury / 대한신경손상학회지

Objective@#Subdural hygroma (SDG) is a complication of traumatic brain injury (TBI). In particular, the outcome and outpatient treatment period may vary depending on the occurrence of SDG. However, the pathogenesis of SDG has not been fully elucidated. Therefore, this study aimed to identify the risk factors associated with the occurrence of SDG after mild TBI. @*Methods@#We retrospectively analyzed 250 patients with mild TBI admitted to a single institution between January 2021 and December 2021. The SDG occurrence and control groups were analyzed according to the risk factors of SDG, such as age, history, initial computed tomography (CT) findings, and initial laboratory findings. @*Results@#The overall occurrence rate of SDG was 31.6% (n=79). A statistically significant association was found between preoperative diagnoses and the occurrence of SDG, such as subarachnoid hemorrhage (odds ratio [OR], 2.36; 95% confidence interval [CI], 1.26–4.39) and basal skull fracture (OR, 0.32; 95% CI, 0.12–0.83). Additionally, age ≥70 years (OR, 3.20; 95% CI, 1.74–5.87) and the use of tranexamic acid (OR, 2.12; 95% CI, 1.05–4.54) were statistically significant factors. The prognostic evaluation of patients using the Glasgow Outcome Scale (GOS) did not show any statistical differences between patients with and without SDG. @*Conclusion@#SDG was not associated with the prognosis of patients assessed using the GOS. However, depending on the occurrence of SDG, differences in patient symptoms may occur after mild TBI. Therefore, the early evaluation of patients with mild TBI and determination of the probability of developing SDG are important.

Emergent Vertebral Artery Embolization during C12 Screw Fixation for Rheumatoid Arthritis / 대한신경손상학회지

The subaxial screw fixation technique is commonly used for fixation in a wide range of cervical diseases, including traumatic, degenerative, and neoplastic diseases, rheumatoid arthritis (RA), and spondyloarthropathy. Although it is regarded as a relatively safe procedure, several complications may be encountered during surgery, such as vertebral artery (VA) and nerve root injuries, facet violation, and mass fracture. We report a case of endovascular embolization after VA injury during a high cervical spinal surgery. A 48-year-old woman was scheduled for C-1-2-3 posterior fixation. Plain radiography of the cervical spine revealed a severely unstable state. During dissection around the C1 lateral mass on the right side, sudden brisk arterial bleeding was observed. On vertebral angiography, flow voiding was noted above the right V3 portion. After checking patent collateral flow from the contralateral VA, routine coil embolization was performed to pack the V3 segment. Iatrogenic vascular injuries due to spinal surgery are rare but serious complications. For patients with RA, we recommend careful preoperative evaluation before a high cervical surgical procedure to avoid iatrogenic VA injury and endovascular interventions that are safe and effective in the diagnosis and treatment of such vascular injuries.

Influence of Antithrombotic Medication on the Risk of Chronic Subdural Hematoma Recurrence after Burr-Hole Surgery

Objective@#: Chronic subdural hematoma (CSDH) is one of the most common intracranial hemorrhages. It can be managed with a simple surgical treatment such as burr-hole trephination and drainage. However, it has a relatively high recurrence rate. The mechanisms and risk factors for the recurrence have not yet been clearly identified and studies have reported varying results. @*Methods@#: We analyzed 230 patients with CSDH who were treated with burr-hole trephination and drainage at our institution from March 2011 to March 2016. The patients were divided into recurrence and non-recurrence groups and the medical records of each group were used to analyze the risk factors associated with CSDH recurrence. @*Results@#: After burr-hole trephination and drainage, CSDH recurrence was observed in 49 (21.3%) of the 230 patients. In univariate analysis, none of the factors showed statistical significance with respect to CSDH recurrence. In multivariate analysis, preoperative antithrombotic medication was the only independent risk factor for CSDH recurrence (odds ratio, 2.407; 95% confidence interval, 1.047–5.531). @*Conclusion@#: The present study found that preoperative antithrombotic medication was independently associated with CSDH recurrence.

Missed Skeletal Trauma Detected by Whole Body Bone Scan in Patients with Traumatic Brain Injury

Objective@#: Unclear mental state is one of the major factors contributing to diagnostic failure of occult skeletal trauma in patients with traumatic brain injury (TBI). The aim of this study was to evaluate the overlooked co-occurring skeletal trauma through whole body bone scan (WBBS) in TBI. @*Methods@#: A retrospective study of 547 TBI patients admitted between 2015 and 2017 was performed to investigate their cooccurring skeletal injuries detected by WBBS. The patients were divided into three groups based on the timing of suspecting skeletal trauma confirmed : 1) before WBBS (pre-WBBS); 2) after the routine WBBS (post-WBBS) with good mental state and no initial musculoskeletal complaints; and 3) after the routine WBBS with poor mental state (poor MS). The skeletal trauma detected by WBBS was classified into six skeletal categories : spine, upper and lower extremities, pelvis, chest wall, and clavicles. The skeletal injuries identified by WBBS were confirmed to be simple contusion or fractures by other imaging modalities such as X-ray or computed tomography (CT) scans. Of the six categorizations of skeletal trauma detected as hot uptake lesions in WBBS, the lesions of spine, upper and lower extremities were further statistically analyzed to calculate the incidence rates of actual fractures (AF) and actual surgery (AS) cases over the total number of hot uptake lesions in WBBS. @*Results@#: Of 547 patients with TBI, 112 patients (20.4 %) were presented with TBI alone. Four hundred and thirty-five patients with TBI had co-occurring skeletal injuries confirmed by WBBS. The incidences were as follows : chest wall (27.4%), spine (22.9%), lower extremities (20.2%), upper extremities (13.5%), pelvis (9.4%), and clavicles (6.3%). It is notable that relatively larger number of positive hot uptakes were observed in the groups of post-WBBS and poor MS. The percentage of post-WBBS group over the total hot uptake lesions in upper and lower extremities, and spines were 51.0%, 43.8%, and 41.7%, respectively, while their percentages of AS were 2.73%, 1.1%, and 0%, respectively. The percentages of poor MS group in the upper and lower extremities, and spines were 10.4%, 17.4%, and 7.8%, respectively, while their percentages of AS were 26.7%, 14.2%, and 11.1%, respectively. There was a statistical difference in the percentage of AS between the groups of post-WBBS and poor MS (p=0.000). @*Conclusion@#: WBBS is a potential diagnostic tool in understanding the skeletal conditions of patients with head injuries which may be undetected during the initial assessment.

Sphenoid Sinus Fat Packing in Transsphenoidal Surgery: Long-Term Fate Assessment Using Magnetic Resonance Imaging

Background and Objectives@#Following the transsphenoidal approach (TSA), appropriate sphenoid sinus fat packing has been preferred to prevent postoperative cerebrospinal fluid leakage; however, studies on the behavior of fat tissue transplanted in the sphenoid sinus are lacking. This study aimed to determine the long-term fate of these fat grafts using magnetic resonance imaging (MRI).Subjects and Method: A total of 139 postoperative MRI scans of 41 patients who underwent sphenoid sinus fat packing using the standard TSA were evaluated. Additionally, MRI time series indicating the vital fat volumes were assessed postoperatively. @*Results@#In 82.9% of cases, the fat volumes measured in the final MRI scans declined to 60% of the initial volume. The fat tissue volume decreased significantly with time, with a median half-life of 18 months. Typically, the sphenoid sinus was eventually almost filled with air rather than transplanted fat. In the subgroup analysis, the fat clearance rate was significantly lower in patients with residual tumors than in those without such remnants (p=0.013). @*Conclusion@#Long-term MRI surveillance of fat grafts in the sphenoid sinus revealed that the transplanted fat graft had degraded and was gradually eliminated.

Neurologic complications in patients with carotid artery stenting

OBJECTIVE: Carotid artery stenting is helpful in patients with carotid artery stenosis and is a common method of treatment. However, data on the neurological consequences that might arise from, especially Asian patients after CAS is not enough. The purpose of this study was to investigate the outcome and prognostic factors affecting CAS patients.METHODS: From January 2013 to June 2018 it was enrolled 97 patients who underwent CAS with severe carotid artery stenosis in a single institution. We retrospectively reviewed neurologic complications such as restenosis, ipsilateral or contralateral stroke, and hyperperfusion during the 6-month follow-up period.RESULTS: There were no complication occured during the procedure in all 97 patients. Neurologic complications occurred in 30 patients (30.9%) after the procedure, and ipsilateral stroke 6 (6.2%), contralateral stroke 9 (9.4%), restenosis 2 (2.1%) and hyperperfusion 13 respectively. One of them had died (1.0%), of which the rest were discharged after symptoms improve. On univariate analysis, DM and pre-op NIHSS score was associated with the risk of CAS complication, exclusively. On the binary logistic regression for risk factors, DM (OR 0.144, 95% CI [0.029–0.718]), history of radiotheraphy (OR 36.103, 95% CI [1.009–1291.789]) and preoperative NIHSS (OR 1.266, 95% CI [1.059–1.513]) showed independent risk factors associated with post procedural neurological complications, statistically.CONCLUSION: Carotid artery stenting is a relatively safe and reliable long-term outcome for patients with carotid artery stenosis. However, careful observation should be taken after procedure immediately for any possible complications.

The Risk Factors of Subdural Hygroma after Decompressive Craniectomy / 대한신경손상학회지

OBJECTIVE: Subdural effusion, also known as subdural hygroma (SDG), is a secondary complication that can occur after decompressive craniectomy (DC). However, the pathogenesis of SDG is not fully understood. It is unclear whether SDG occurrence is related to preoperative patient status or surgical technique. The purpose of this study is to identify risk factors for SDG after DC. METHODS: Fifty-nine patients who underwent DC from January 2016 to December 2016 at the same institution were analyzed. We retrospectively reviewed the clinical and radiological features of the patients. We divided the patients into two groups based on the occurrence of SDG after DC. The risk factors for SDG were analyzed. RESULTS: The overall SDG rate after DC was 39% (23 patients). A statistically significant association was observed between preoperative diagnosis, e.g., subdural hemorrhage (SDH; odds ratio [OR], 4.99; 95% confidence interval [CI], 1.36–18.34) or subarachnoid hemorrhage (SAH; OR, 4.18; 95% CI, 1.07–16.32), and the occurrence of SDG after DC. Traumatic brain injury (OR, 4.91; 95% CI, 1.35–17.91) and preoperative cortical opening (OR, 4.77; 95% CI, 1.39–16.32) were important risk factors for SDG. Several surgical techniques did not show a statistically significant association with SDG. The occurrence of SDG after DC was related to the length of hospital stay (p=0.012), but not to prognosis. CONCLUSION: After DC, SDG is not related to patients' prognosis but to the length of hospital stay. Therefore, it is necessary to study the occurrence of postoperative SDG by confirming the presence of preoperative SDH, SAH, and cortical opening.

Cranial Nerve Palsy after Onyx Embolization as a Treatment for Cerebral Vascular Malformation

The Onyx liquid embolic system is a relatively safe and commonly used treatment for vascular malformations, such as arteriovenous fistulas and arteriovenous malformations. However, studies on possible complications after Onyx embolization in patients with vascular malformations are limited, and the occurrence of cranial nerve palsy is occasionally reported. Here we report the progress of two different types of cranial nerve palsy that can occur after embolization. In both cases, Onyx embolization was performed to treat vascular malformations and ipsilateral oculomotor and facial nerve palsies were observed. Both patients were treated with steroids and exhibited symptom improvement after several months. The most common types of neuropathy that can occur after Onyx embolization are facial nerve palsy and trigeminal neuralgia. Although the mechanisms underlying these neuropathies are not clear, they may involve traction injuries sustained while extracting the microcatheter, mass effects resulting from thrombi and edema, or Onyx reflux into the vasa nervorum. In most cases, the neuropathy spontaneously resolves several months following the procedure.

Factors Affecting Optimal Time of Cranioplasty: Brain Sunken Ratio / 대한신경손상학회지

OBJECTIVE: After a rigorous management of increased intracranial pressure by decompressive craniectomy (DC), cranioplasty (CP) is usually carried out for functional and cosmetic purposes. However, the optimal timing of CP remains controversial. Our study aims to analyze the relationship between the optimal timing of CP and the post-operative complications. METHODS: From January 2013 to December 2015, ninety patients who underwent CP in a single institution were analyzed. We set the independent variables as follows: 1) patient characteristics; 2) the time interval between the DC and CP; 3) operation time; 4) anesthesia time; and 5) pre-operative computed tomography (CT) findings such as a degree of sunken brain by ratio of A (the median length from scalp to midline) to B (the length from midline to inner table of skull at this level). The dependent variables of this study are the event of post-operative complications. RESULTS: The overall complication rate was 33.3%. There was no statistical significance in the time interval between the DC and CP in the groups with and without complications of CP (p=0.632). However, there was a significant statistical difference in the degree of sunken brain by ratio (A/B) between the two groups (p<0.001). CONCLUSION: From this study, we conclude that it is better to determine the optimal timing of CP by the pre-operative CT finding than by the time interval between the DC and CP. Hereby, we suggest a potentially useful determinant of optimal timing of CP.

Traumatic Cerebrospinal Fluid Leak: Diagnosis and Management / 대한신경손상학회지

Cerebrospinal fluid (CSF) leaks are one of the common complications after traumatic brain injuries (TBI). The risks of CSF leaks can be detrimental to the outcomes of the patients. Early diagnosis and proper management is imperative for it is strongly associated with a better long-term prognosis of the patients. Diagnostic tools for CSF leaks are still under debate. Nevertheless, many reports of successful treatments for CSF leaks have been published with introduction of various repair techniques for leakage sites even though it is surgically challenging. Hereby, we review about the pathophysiology, manifestations as well as the update of the clinical diagnosis and current management of CSF leaks.

Biomarkers of Physiological Disturbances for Predicting Mortality in Decompressive Craniectomy / 대한신경손상학회지

OBJECTIVE: Of many critical care regimens, the management of physiological disturbances in serum is particularly drawing an attention in conjunction with patient outcome. The aim of this study was to assess the association of serum biochemical markers with mortality in head trauma patients with decompressive craniotomy. METHODS: Ninety six patients with acute subdural hematoma underwent decompressive craniectomy between January 2014 and December 2015. The clinical data and laboratory variables of these patients were recorded and analyzed retrospectively. The pre-operative and post-operative day (POD) 0, day 1 and day 2 serum variables were measured. These were compared between the survivors and non-survivors. RESULTS: The factors of a large amount of intra-operative blood loss, shorter length of intensive care unit stays, and the needs for mechanical ventilation were related with mortality in the patients with decompressive craniectomy. These clinical factors were associated with the physiological derangements of sera. The average difference in serum chloride concentration between the pre-operative and POD 2 measurements (p=0.0192) showed a statistical significance in distinguishing between survivors and non-survivors. The average differences in albumin (p=0.0011) and platelet count (p=0.0004) between the pre-operative and POD 0 measurements suggested to be strong predictors of mortality in decompressive craniectomy. CONCLUSION: Isolated values of physiological biomarkers are not sufficient enough to predict in-hospital mortality. This study emphasizes the importance of a combined prognostic model of the differences in the pre-operative and post-operative hyperchloremia, thrombocytopenia, and hypoalbuminemia to identify the risk of mortality in decompressive craniecomy.

Endovascular Treatment of Giant Serpentine Aneurysm of the Middle Cerebral Artery

Giant serpentine aneurysms are uncommon types of aneurysmal disease and have angiographically authentic features. We report a case of a 44-year-old male with headache and seizure. He presented a giant serpentine aneurysm arising from the middle cerebral artery (MCA). It was a large intracranial aneurysm thrombosed as a mass-like lesion while it maintained its outflow drainage into the distal MCA branches. The balloon occlusion test (BOT) was performed to test the tolerance of temporary collateral circulation. Following routine cerebral angiography, we performed an endovascular embolization on the proximal artery of MCA. He was discharged from the hospital with alert mental status and mild Gerstmann syndrome. The short-term follow-up imaging studies showed the decreased mass effect, and the patient presented an improved Gerstmann syndrome. After a careful evaluation of BOT, an endovascular embolization can be one of the powerful therapeutic instruments for giant serpentine aneurysm.

Clinical Analysis of Delayed Surgical Epidural Hematoma / 대한신경손상학회지

OBJECTIVE: A small epidural hematoma (EDH) that has been diagnosed to be nonsurgical by initial brain computed tomography (CT) can increase in size and need surgical removal, resulting in a poor prognosis. However, there have been few studies, which focused delayed operated EDH. Therefore, we analyzed the clinical factors to determine the predicting factors of delayed operated EDH. METHODS: Between January 2011 and January 2014, 90 patients, who were admitted due to EDH, were enrolled in this study. None of the patients were indicated for operation initially. Based on the presence of surgery, we classified the patients into a delayed-surgery group (DG) and a non-surgical group (NG). Additionally, we analyzed them according to the following: time interval between the trauma and the initial CT, gender, age, medical history, drinking, change of mean arterial pressure (MAP), volume of EDH and other traumatic brain lesion. RESULTS: Among the 90 patients, the DG was 19 patients. Compared with NG, the DG revealed increased MAP, less presence of drinking, and a short time interval (DG vs. NG: +9.684 mm Hg vs. -0.428 mm Hg, 5.26% vs. 29.58%, 1.802 hours vs. 5.707 hours, respectively, p<0.05). Analyzing the time interval with receiver operating characteristic, there was 88.2% sensitivity and 68.3% specificity at the 2.05-hour cut-off value (area under the curve=0.854). CONCLUSION: According to our results, the time interval between the trauma and the initial CT along with blood pressure change are potential predicting factors in the cases of delayed operation of EDH.

Middle Meningeal Artery Embolization in Recurrent Chronic Subdural Hematoma Combined with Arachnoid Cyst / 대한신경손상학회지

Chronic subdural hematoma (CSDH) is a collection of old blood and its breakdown products between the surface of the brain parenchyma and the outermost layer called the dura. The most common treatment option for primary CSDH is burr-hole trephination; however, the treatment method for recurrent CSDH is still widely debated. An arachnoid cyst (AC) is a sac filled with cerebrospinal fluid located between the brain or spinal cord and the arachnoid membrane, which is one of the three meninges covering the brain or spinal cord. Although it is rare, the cyst is associated with CSDH in juveniles, and the recurrence rate of CSDH increases in such cases. Much of the literature has supported the preventive role of middle meningeal artery (MMA) embolization in recurrent CSDH. We report a 13-year-old male patient with recurrent CSDH and AC where the early intervention of MMA embolization was proven effective in preventing the further recurrence of CSDH.

Delayed Traumatic Subarachnoid Hemorrhage in a Polytraumatized Patient with Disseminated Intravascular Coagulation / 대한중환자의학회지

The precise mechanism involved in DIC and delayed traumatic subarachnoid hemorrhage (DT-SAH) remains unclear in multiple-trauma patients. Hereby, we describe a polytraumatized patient with DIC who died due to DT-SAH. A 75-year-old female patient was admitted to our Emergency Department complaining of abdominal pain and drowsiness after a pedestrian accident. Her initial brain computerized tomography (CT) finding was negative for intracranial injury. However, her abdominal CT scan revealed a collection of retroperitoneal hematomas from internal iliac artery bleeding after a compressive pelvic fracture. This event eventually resulted in shock and DIC. An immediate angiographic embolization of the bleeding artery was performed along with transfusion and anti-thrombin III. Her vital signs were stabilized without neurological change. Fourteen hours after admission, she suddenly became comatose, and her follow-up brain CT scan revealed a dense DT-SAH along the basal cisterns with acute hydrocephalus. This event rapidly prompted brain CT angiography and digital subtraction angiography, which both confirmed the absence of any cerebrovascular abnormality. Despite emergency extraventricular drainage to reverse the hydrocephalus, the patient died three days after the trauma. This paper presents an unusual case of DT-SAH in a polytraumatized patient with DIC.

Delayed Traumatic Subarachnoid Hemorrhage in a Polytraumatized Patient with Disseminated Intravascular Coagulation / 대한구급학회지

The precise mechanism involved in DIC and delayed traumatic subarachnoid hemorrhage (DT-SAH) remains unclear in multiple-trauma patients. Hereby, we describe a polytraumatized patient with DIC who died due to DT-SAH. A 75-year-old female patient was admitted to our Emergency Department complaining of abdominal pain and drowsiness after a pedestrian accident. Her initial brain computerized tomography (CT) finding was negative for intracranial injury. However, her abdominal CT scan revealed a collection of retroperitoneal hematomas from internal iliac artery bleeding after a compressive pelvic fracture. This event eventually resulted in shock and DIC. An immediate angiographic embolization of the bleeding artery was performed along with transfusion and anti-thrombin III. Her vital signs were stabilized without neurological change. Fourteen hours after admission, she suddenly became comatose, and her follow-up brain CT scan revealed a dense DT-SAH along the basal cisterns with acute hydrocephalus. This event rapidly prompted brain CT angiography and digital subtraction angiography, which both confirmed the absence of any cerebrovascular abnormality. Despite emergency extraventricular drainage to reverse the hydrocephalus, the patient died three days after the trauma. This paper presents an unusual case of DT-SAH in a polytraumatized patient with DIC.

Retrieval of Unintended Migrated Detached Coil: Case Report

Owing to the rapid development of intervention techniques and devices, endovascular coil embolization of cerebral arteries has become standardized. It is particularly preferred when a patient presents with an unruptured intracranial aneurysm of the posterior communicating artery (PcomA). However, the risk of thrombogenic complications of the coil migration may also result in a large cerebral infarction. When coil migration occurs during embolization, a procedure for removal of the embolic coil should be performed immediately. We experienced a clinically rare case of migration of a framing coil to the distal middle cerebral artery aneurysm during endovascular embolization of an unruptured PcomA aneurysm. The migrated coil was barely retrieved using snare techniques.

Which Emphasizing Factors Are Most Predictive of Hematoma Expansion in Spot Sign Positive Intracerebral Hemorrhage?

OBJECTIVE: The spot sign is related with the risk of hematoma expansion in spontaneous intracerebral hemorrhage (ICH). However, not all spot sign positive patients undergo hematoma expansion. Thus, the present study investigates the specific factors enhancing the spot sign positivity in predicting hematoma expansion. METHODS: We retrospectively studied 316 consecutive patients who presented between March 2009 to March 2011 with primary ICH and whose initial computed tomography brain angiography (CTA) was performed at our Emergency Department. Of these patients, 47 primary ICH patients presented spot signs in their CTA. We classified these 47 patients into two groups based on the presence of hematoma expansion then analyzed them with the following factors : gender, age, initial systolic blood pressure, history of anti-platelet therapy, volume and location of hematoma, time interval from symptom onset to initial CTA, spot sign number, axial dimension, and Hounsfield Unit (HU) of spot signs. RESULTS: Of the 47 spot sign positive patients, hematoma expansion occurred in 26 patients (55.3%) while the remaining 21 (44.7%) showed no expansion. The time intervals from symptom onset to initial CTA were 2.42+/-1.24 hours and 3.69+/-2.57 hours for expansion and no expansion, respectively (p=0.031). The HU of spot signs were 192.12+/-45.97 and 151.10+/-25.14 for expansion and no expansion, respectively (p=0.001). CONCLUSIONS: The conditions of shorter time from symptom onset to initial CTA and higher HU of spot signs are the emphasizing factors for predicting hematoma expansion in spot sign positive patients.