Epidural Blood Patch on Cerebrospinal Fluid Leakage Caused by Iatrogenic Dural Injury After Transforaminal Lumbar Interbody Fusion / 대한신경손상학회지

A 65-year-old woman who underwent transforaminal lumbar interbody fusion at L4-5 for very severe spinal stenosis combined with a hard disc and instability presented with a headache on postoperative day (POD) 3 and cerebrospinal fluid (CSF) leakage on POD 5. Follow-up lumbar spine computed tomography (CT) was performed on POD 7, and fluid collection at the operation site was observed on CT images. Under the diagnosis of iatrogenic dural injury, absolute bed rest and lumbar drain catheter insertion at the L2-3 level were performed for three days, but the patient continued to complain of severe headache until POD 10. We reoperated on POD 10 and observed a dural defect with CSF leakage. The surgery was completed after ensuring that the CSF leakage was resolved by dural repair. However, 10 days after the reoperation, the amount of hemovac drainage still did not decrease and was measured to be more than 250 mL. There was no improvement in the patient’s symptoms. Twenty days after the first surgery, an epidural blood patch was applied to the epidural space at the site of dural injury, and the patient’s symptoms improved.

A Comparative Study on the Treatment of Osteoporotic Vertebral Compression Fractures With Early Ambulation and at Least 1 Week of Absolute Bed Rest / 대한신경손상학회지

Objective@#This study aimed to determine whether absolute bed rest (ABR) is essential for the conservative treatment of osteoporotic vertebral compression fractures (OVCFs). @*Methods@#This study included 115 patients diagnosed with OVCFs. The patients in group A were allowed to ambulate as soon as possible, while those in group B underwent ABR for at least 1 week. X-ray images at baseline and 1 week, 2 weeks, 1 month, 3 months, and 6 months after trauma were obtained from both groups for assessment. In each group, ABR-related complications including constipation, indigestion, Foley catheter insertion, urinary tract infection, cough/sputum, dizziness, and neurasthenia were investigated. @*Results@#In both groups, the compression rates, Cobb angles, and visual analog scale scores did not differ significantly at baseline and the first, second, third, fourth, and fifth follow-ups. In terms of constipation, indigestion, dizziness, and neurasthenia, group A reported a significantly higher complication rate than group B (p<0.05). @*Conclusion@#The prognosis did not differ significantly between patients who underwent ABR for at least 1 week and those who started walking as soon as possible. The incidence of complications due to ABRs was lower in the early ambulatory group. Therefore, it may be helpful to start walking as early as possible during the conservative treatment of OVCFs.

Initial Dead Space and Multiplicity of Bone Flap as Strong Risk Factors for Bone Flap Resorption after Cranioplasty for Traumatic Brain Injury / 대한신경손상학회지

OBJECTIVE: Bone flap resorption (BFR) is a complication of cranioplasty (CP) that increases the risk of brain damage and can cause cosmetic defects. In this study, the risk factors for BFR were examined to improve the prognosis of patients after CP for traumatic brain injury (TBI). METHODS: This study was conducted in 80 patients with TBI who underwent decompressive craniectomy and CP with an autologous bone graft between August 2006 and August 2017. BFR was defined as a >0.1 ratio of the difference between the initial bone flap area and the last bone flap area to the craniectomy size and a < 0.5 ratio of the last bone flap thickness to the bone thickness of the contralateral region on computed tomography scans and plain skull radiographs. The patients were divided into the BFR and non-BFR groups, and medical data were compared between the two groups. RESULTS: Among the 80 patients, 22 (27.5%) were diagnosed as having BFR after CP. The earliest cases of BFR occurred at 57 days after CP, and the latest BFR cases occurred at 3,677 days after CP. Using multivariate logistic regression analyses, the initial dead space size (odds ratio [OR], 1.002; 95% confidence interval [CI], 1.001–1.004; p=0.006) and multiplicity of the bone flap (OR, 3.058; 95% CI, 1.021–9.164; p=0.046) were found to be risk factors for BFR. CONCLUSION: The risk factors for BFR in this study were the initial dead space size and multiplicity of the bone flap.

Aortic Injury during Transforaminal Lumbar Interbody Fusion

Aortic injury during transforaminal lumbar interbody fusion (TLIF) is a rare but severe complication. We experienced aortic injury during TLIF at L3–4 with a 59-year-old woman diagnosed with an adjacent segment disease at L3–4. Severe bleeding occurred during disc space expansion, and the blood pressure dropped to 60/40 mmHg. The patient’s vital sign stabilized after compression with gauze and Gelfoam in addition to blood transfusion. The patient was treated with endovascular repair using a percutaneous technique after intertransverse fusion at L3–4 was completed. She recovered and is being followed-up in the outpatient department.

Osteoblast and Bacterial Culture from Cryopreserved Skull Flap after Craniectomy: Laboratory Study

OBJECTIVE: Cranioplasty using a cryopreserved skull flap is a wide spread practice. The most well-known complications of cranioplasty are postoperative surgical infections and bone flap resorption. In order to find biological evidence of cryopreserved cranioplasty, we investigated microorganism contamination of cryopreserved skulls and cultured osteoblasts from cryopreserved skulls. METHODS: Cryopreserved skull flaps of expired patients stored in a bone bank were used. Cryopreserved skulls were packaged in a plastic bag and wrapped with cotton cloth twice. After being crushed by a hammer, cancellous bone between the inner and outer table was obtained. The cancellous bone chips were thawed in a water bath of 30°C rapidly. After this, osteoblast culture and general microorganism culture were executed. Osteoblast cultures were done for 3 weeks. Microorganism cultures were done for 72 hours. RESULTS: A total of 47 cryopreserved skull flaps obtained from craniectomy was enrolled. Of the sample, 11 people were women, and the average age of patients was 55.8 years. Twenty four people had traumatic brain injuries, and 23 people had vascular diseases. Among the patients with traumatic brain injuries, two had fracture compound comminuted depressed. The duration of cryopreservation was, on average, 83.2 months (9 to 161 months). No cultured osteoblast was observed. No microorganisms were cultured. CONCLUSION: In this study, neither microorganisms nor osteoblasts were cultured. The biological validity of cryopreserved skulls cranioplasty was considered low. However, the usage of cryopreserved skulls for cranioplasty is worthy of further investigation in the aspect of cost-effectiveness and risk-benefit of post-cranioplasty infection.

Chronic Paraspinal Muscle Injury Model in Rat

OBJECTIVE: The objective of this study is to establish an animal model of chronic paraspinal muscle injury in rat. METHODS: Fifty four Sprague-Dawley male rats were divided into experimental group (n=30), sham (n=15), and normal group (n=9). Incision was done from T7 to L2 and paraspinal muscles were detached from spine and tied at each level. The paraspinal muscles were exposed and untied at 2 weeks after surgery. Sham operation was done by paraspinal muscles dissection at the same levels and wound closure was done without tying. Kyphotic index and thoracolumbar Cobb's angle were measured at preoperative, 2, 4, 8, and 12 weeks after the first surgery for all groups. The rats were sacrificed at 4, 8, and 12 weeks after the first surgery, and performed histological examinations. RESULTS: At 4 weeks after surgery, the kyphotic index decreased, but, Cobb's angle increased significantly in the experimental group (p<0.05), and then that were maintained until the end of the experiment. However, there were no significant differences of the kyphotic index and Cobb's angle between sham and normal groups. In histological examinations, necrosis and fibrosis were observed definitely and persisted until 12 weeks after surgery. There were also presences of regenerated muscle cells which nucleus is at the center of cytoplasm, centronucleated myofibers. CONCLUSION: Our chronic injury model of paraspinal muscles in rats shows necrosis and fibrosis in the muscles for 12 weeks after surgery, which might be useful to study the pathophysiology of the degenerative thoracolumbar kyphosis or degeneration of paraspinal muscles.

Management and Outcome of Spontaneous Cerebellar Hemorrhage

OBJECTIVE: Spontaneous cerebellar hemorrhage (SCH) is less common than supratentorial intracerebral hemorrhage. This study investigated the treatment of SCH and the relation between its clinical and radiological manifestation and outcome. MATERIALS AND METHODS: We presented a SCH management protocol in our institute and analyzed the clinical and radiological findings in 41 SCH patients. The outcomes of each method (surgery and conservative treatment) were compared among patients with initial Glasgow Coma Scale (GCS) score of 9-13 and hematoma volume greater than 10 mL. RESULTS: Two (4.9%), 16 (39%), and 23 (56.1%) patients had an initial GCS score of 3-8, with 3-8, 9-13, and 14-15, respectively. Initial GCS score showed significant correlation with Glasgow Outcome Scale (GOS) score (p = 0.005). The mean largest hematoma diameter was 3.2 +/- 1.5 cm, and the mean volume was 11.0 +/- 11.5 mL. Both of them showed significant inverse correlation with GOS score (p < 0.001). Among patients with an initial GCS score of 9-13 and hematoma volumes greater than 10 mL, 3 (50%) had good outcome and 3 (50%) had poor outcome in the surgical, and all of those in the conservative treatment group had poor outcomes. The outcome distribution differed significantly in the surgical and conservative groups (p = 0.030). CONCLUSION: Initial GCS score and largest hematoma diameter and volume on brain computed tomography are important determinants of outcome in SCH patients. The surgery group showed better outcome than the conservative treatment group among those with an intermediate neurological status and large hematomas.

Management and Outcome of Spontaneous Cerebellar Hemorrhage

OBJECTIVE: Spontaneous cerebellar hemorrhage (SCH) is less common than supratentorial intracerebral hemorrhage. This study investigated the treatment of SCH and the relation between its clinical and radiological manifestation and outcome. MATERIALS AND METHODS: We presented a SCH management protocol in our institute and analyzed the clinical and radiological findings in 41 SCH patients. The outcomes of each method (surgery and conservative treatment) were compared among patients with initial Glasgow Coma Scale (GCS) score of 9-13 and hematoma volume greater than 10 mL. RESULTS: Two (4.9%), 16 (39%), and 23 (56.1%) patients had an initial GCS score of 3-8, with 3-8, 9-13, and 14-15, respectively. Initial GCS score showed significant correlation with Glasgow Outcome Scale (GOS) score (p = 0.005). The mean largest hematoma diameter was 3.2 +/- 1.5 cm, and the mean volume was 11.0 +/- 11.5 mL. Both of them showed significant inverse correlation with GOS score (p < 0.001). Among patients with an initial GCS score of 9-13 and hematoma volumes greater than 10 mL, 3 (50%) had good outcome and 3 (50%) had poor outcome in the surgical, and all of those in the conservative treatment group had poor outcomes. The outcome distribution differed significantly in the surgical and conservative groups (p = 0.030). CONCLUSION: Initial GCS score and largest hematoma diameter and volume on brain computed tomography are important determinants of outcome in SCH patients. The surgery group showed better outcome than the conservative treatment group among those with an intermediate neurological status and large hematomas.

Erector Spinal Muscular Schwannoma of the Dorsal Ramus Nerve: A Case Report

We present a rare case of intramuscular schwannoma originating from the dorsal ramus nerve in a 62-year-old woman. The mass grew slowly, with pain developing upon touch five years prior. No neurological deficit was detected. The mass was observed in the erector spinae muscles in magnetic resonance imaging (MRI), and surgical excision was performed. The mass was well encapsulated with clear margin. The lesion appeared to originate from the cranial side. We completely removed the mass including the origin. Histopathology confirmed a schwannoma diagnosis. This is the first report, to our knowledge, of a dorsal ramus-nerve schwannoma within the erector spinae muscles.

Stereotactic Hematoma Removal of Spontaneous Intracerebral Hemorrhage through Parietal Approach

OBJECTIVE: To determine the advantages of parietal approach compared to Kocher's point approach for spontaneous, oval-shaped intracerebral hemorrhage (ICH) with expansion to the parietal region. METHODS: We divided patients into two groups : group A had burr holes in the parietal bone and group B had burr holes at Kocher's point. The hematoma volume, Glasgow coma scale (GCS) score, and modified Barthel Index (mBI) score were calculated. At discharge, we evaluated the patients' Glasgow outcome scale (GOS) score, modified Rankin Scale (mRS) score, motor grade, and hospitalization duration. We evaluated the patients' mBI scores and motor grades at 6 months after surgery. RESULTS: The hematoma volume in group A was significantly less than that in group B on postoperative days 1, 3, 5, 7, 14, and 21. Group A had significantly higher GCS scores than did group B on postoperative days 1 and 3. Group A had higher mBI scores postoperatively than did group B, but the scores were not significantly different. No differences were observed for the GOS score, mRS score, motor grade at discharge, or duration of hospitalization. The mBI score of group A at 6 months after surgery was significantly higher, and more patients in group A showed muscle strength improvement. CONCLUSION: In oval-shaped ICH with expansion to the parietal region, the parietal approach is considered to improve the clinical symptoms at the acute phase by removing the hematoma more effectively in the early stages. The parietal approach might help promote the long-term recovery of motor power.

Clinical Features According to the Histological Types of the Outer Membrane of Chronic Subdural Hematoma / 대한신경손상학회지

OBJECTIVE: The aim of our study was to classify the outer membrane of chronic subdural hematoma (CSDH) histologically and to determine the clinical and radiological meaning of the classified membranes. METHODS: The outer membrane specimen of 31 patients who underwent surgery for CSDH were acquired in this study. The specimen was classified into four types and each were analyzed of the symptoms on the admission day and during the period from trauma to surgery. The radiological features such as subdural fluid density, Hounsfield number, thickness of the hematoma, and midline shift were analyzed. RESULTS: There were 6% of type I, 29% of type II, 39% of type III, and 26% of type IV neomembranes. The cases of CSDH accompanied by neurologic deficit were highest from type IV of 63%, followed by type II with 56%. On the radiological findings such as Hounsfield unit, hematoma thickness and midline shift, only hematoma thickness between type II and III were statistically significant (p=0.021). The hematoma thickness and midline shift were greatest in type II. On computed tomography scans, the isodense, hyperdense and laminar type that shows the high recurrence rate formed 75% of type II and 67% of type IV while type III had the low possibility of recurrence rate (33%). CONCLUSION: We have identified that the outer membrane have the tendency to develop from type I to IV in time while type II and type IV may have more risk of neurologic deficit and the high possibility of recurrence.

Relationship Between Systemic Thrombogenic or Thrombolytic Indices and Acute Increase of Spontaneous Intracerebral Hemorrhage

OBJECTIVE: The objective of this study was to determine the correlations between changes in thrombogenesis or thrombolysis related factors, and the acute increase of a spontaneous intracerebral hemorrhage (sICH). MATERIALS AND METHODS: From January 2009 to October 2011, 225 patients with sICH were admitted to our hospital within 24 hours of onset. Among them, 111 patients with hypertensive sICH were enrolled in this study. Thrombogenic or thrombolytic factors were checked at admission. The authors checked computed tomography (CT) scans at admission and followed up the next day (between 12-24 hours) or at any time when neurologic signs were aggravated. Cases in which the hematoma was enlarged more than 33% were defined as Group A and the others were defined as Group B. RESULTS: Group A included 30 patients (27%) and group B included 81 patients (73%). Factors including activated partial thromboplastin time, prothrombin time, fibrinogen, and D-dimer showed a greater increase in group A than in group B. Factors including antithrombin III, factor V, and factor X showed a greater increase in group A than in group B. CONCLUSION: Based on the results of this study, it seems that the risk of increase in hematoma size can be predicted by serum thrombogenic or thrombolytic factors at admission.

Long Term Effect on Adjacent Segment Motion after Posterior Cervical Foraminotomy

OBJECTIVE: Posterior cervical foraminotomy (PCF) is a motion-preserving surgical technique. The objective was to determine whether PCF alter cervical motion as a long-term influence. METHODS: Thirty one patients who followed up more than 36 months after PCF for cervical radiculopathy from January 2004 to September 2008 were enrolled in this study. The range of motion (ROM) of whole cervical spine, the operated segment, the cranial and the caudal adjacent segment were obtained. The clinical result and the change of ROMs were compared with those in the patients performed anterior cervical discectomy and fusion (ACDF) during the same period. RESULTS: In PCF group, the ROM of whole cervical spine had no significant difference in statistically at preoperative and last follow up. The operated segment ROM was significantly decreased from 11.02+/-5.72 to 8.82+/-6.65 (p<0.05). The ROM of cranial adjacent segment was slightly increased from 10.42+/-5.13 to 11.02+/-5.41 and the ROM of caudal adjacent segment was decreased from 9.44+/-6.26 to 8.73+/-5.92, however these data were not meaningful statistically. In ACDF group, the operated ROM was decreased and unlike in PCF group, especially the ROM of caudal adjacent segment was increased from 9.39+/-4.21 to 11.33+/-5.07 (p<0.01). CONCLUSION: As part of the long-term effects of PCF on cervical motion, the operated segment motions decreased but were preserved after PCF. However, unlikely after ACDF, the ROMs of the adjacent segment did not increase after PCF. PCF, by maintaining the motion of the operated segment, imposes less stress on the adjacent segments. This may be one of its advantages.

The Clinical Course of Subdural Hygroma with Head Injury / 대한신경손상학회지

OBJECTIVE: Traumatic subdural hygroma (T-SDG) has been generally treated using conservative management rather than surgical methods. This study was performed to evaluate the clinical course of T-SDG with radiologic studies. METHODS: A retrospective study was conducted among patients diagnosed with T-SDG from January 2011 to December 2011. The patients were categorized into two groups. Group A has the widest width of T-SDG below 8 mm, Group B more than 8 mm. Computed tomography (CT) and magnetic resonance imaging (MRI) were carried out in both groups. RESULTS: Seventy-four patients were confirmed with T-SDG and were grouped as follows: 44 patients in Group A and 30 patients in Group B. There was no significant difference in age and sex ratio between group A and B. It took more time to resolve T-SDG in Group B (95.2+/-86.4 days) than Group A (14.4+/-6.7)(p<0.001). However, no significant difference was observed in the Glasgow Coma Scale (GCS) between the groups. In 10 patients of Group B, T-SDG developed into chronic subdural hematoma and one of these patients underwent surgery. CONCLUSION: Most T-SDGs were resolved after some period in this study. Surgery does not seem to be necessary in resolving T-SDG.

The Clinical Course of Subdural Hygroma with Head Injury / 대한신경손상학회지

OBJECTIVE: Traumatic subdural hygroma (T-SDG) has been generally treated using conservative management rather than surgical methods. This study was performed to evaluate the clinical course of T-SDG with radiologic studies. METHODS: A retrospective study was conducted among patients diagnosed with T-SDG from January 2011 to December 2011. The patients were categorized into two groups. Group A has the widest width of T-SDG below 8 mm, Group B more than 8 mm. Computed tomography (CT) and magnetic resonance imaging (MRI) were carried out in both groups. RESULTS: Seventy-four patients were confirmed with T-SDG and were grouped as follows: 44 patients in Group A and 30 patients in Group B. There was no significant difference in age and sex ratio between group A and B. It took more time to resolve T-SDG in Group B (95.2+/-86.4 days) than Group A (14.4+/-6.7)(p<0.001). However, no significant difference was observed in the Glasgow Coma Scale (GCS) between the groups. In 10 patients of Group B, T-SDG developed into chronic subdural hematoma and one of these patients underwent surgery. CONCLUSION: Most T-SDGs were resolved after some period in this study. Surgery does not seem to be necessary in resolving T-SDG.

Comparative Study on the Period of Absolute Bed Rest of Vertebral Compression Fracture

OBJECTIVE: As a conservative treatment of compression fractures, absolute bed rest (ABR) for a certain period has been recommended, but no guideline on the period has yet been established. Considering that a long ABR period may adversely affect patients, the difference in prognosis according to the ABR period was investigated in this study. METHODS: A prospective study was conducted who were diagnosed with compression fracture. Groups A and B were put on ABR (one week for group A and two weeks for group B). X-ray images at baseline, 1, 2, 4, and 8 weeks were obtained from both groups, for assessment purposes. RESULTS: The compression rates of both groups were no significant difference at baseline, 1, 2, 4, and 8 weeks. The conditions of 25.9% and 21.2% of the subjects deteriorated in groups A and B, showing no significant difference. Between the groups of age and bone mineral densities (BMD), no significant difference was observed in the incidence of deterioration. In terms of complications development including constipation and other Gastrointestinal problems, voiding difficulty, etc., group A reported 57.4%, and group B, 84.8%, showing a significant difference (p-value=0.001). CONCLUSION: No significant difference in the conservative period was observed between the groups. Group B, however, reported a higher complications development rate than group A. Therefore, a short ABR period may be helpful in the early stage of conservative treatment.

Spinal Epidural Hematoma Related to Intracranial Hypotension

A 45-year-old female patient visited the hospital complaining of severe sudden headache and posterior neck pain. The patient did not have any traumatic history or abnormal neurologic finding. The patient had sudden quadriplegia and sensory loss. Cervical spine MRI scan was taken, and the compatible findings to acute epidural hematoma were shown. The emergency operation was performed. After the operation, the patient recovered all motor and senses. As there was CSF leakage in the postoperative wound, this was confirmed by cervical spinal computed tomography (CT). Then lumbar drainage was thus performed. The opening pressure upon lumbar puncture was not measured as it was very low. As a result of continous CSF leakage, dural repair was performed. After the operation, the patient had been discharged without neurologic deficits. In this case, it is sensible to suspect intracranial hypotension as a possible cause of spinal EDH.

Single Incision Percutaneous Pedicle Screw Fixation for Transforaminal Lumbar Interbody Fusion

OBJECTIVE: Percutaneous pedicle screw fixation (PPSF) offers some of the advantages of minimally invasive surgery. However, an additional skin incision is necessary in order to gain these advantages. The author recently performed a modified PPSF through a single skin incision and it yielded good results. Here, we report the single incision percutaneous pedicle screw fixation (SIPPSF). METHODS: The medical records of 51 patients who underwent single segment transforaminal lumbar interbody fusion (TLIF) with pedicle screw fixation (PSF) between December 2009 and December 2011 were reviewed. The patients were divided into 3 groups according to the PSF technique used; conventional group (Group C), SIPPSF (Group S) and PPSF through multiple skin incisions (Group M). Operation time, estimated blood loss (EBL) and pain intensity before and after the operation using a numeric rating scale (NRS) were evaluated. RESULTS: The number of patients in Group S, Group C and Group M was 25, 17 and 9, respectively. The NRS demonstrated a reduction in pain intensity in all the patients, and there were no differences in NRS scoring between the three groups. Group S showed a reduction in the EBL compared to Group C (p=0.001) and a reduction in the operation time compared to Group M(p=0.003). CONCLUSION: The author supposes that the type of skin incision does not correlate significantly with the clinical results of TLIF with PPSF. However, it can be considered that SIPPSF offers the advantage of avoiding an additional paramedian skin incision.

Single Incision Percutaneous Pedicle Screw Fixation for Transforaminal Lumbar Interbody Fusion

OBJECTIVE: Percutaneous pedicle screw fixation (PPSF) offers some of the advantages of minimally invasive surgery. However, an additional skin incision is necessary in order to gain these advantages. The author recently performed a modified PPSF through a single skin incision and it yielded good results. Here, we report the single incision percutaneous pedicle screw fixation (SIPPSF). METHODS: The medical records of 51 patients who underwent single segment transforaminal lumbar interbody fusion (TLIF) with pedicle screw fixation (PSF) between December 2009 and December 2011 were reviewed. The patients were divided into 3 groups according to the PSF technique used; conventional group (Group C), SIPPSF (Group S) and PPSF through multiple skin incisions (Group M). Operation time, estimated blood loss (EBL) and pain intensity before and after the operation using a numeric rating scale (NRS) were evaluated. RESULTS: The number of patients in Group S, Group C and Group M was 25, 17 and 9, respectively. The NRS demonstrated a reduction in pain intensity in all the patients, and there were no differences in NRS scoring between the three groups. Group S showed a reduction in the EBL compared to Group C (p=0.001) and a reduction in the operation time compared to Group M(p=0.003). CONCLUSION: The author supposes that the type of skin incision does not correlate significantly with the clinical results of TLIF with PPSF. However, it can be considered that SIPPSF offers the advantage of avoiding an additional paramedian skin incision.

Traumatic Epidural Hematoma of the Posterior Cranial Fossa / 대한신경손상학회지

OBJECTIVE: Epidural hematoma of posterior fossa is less common than epidural hematoma of supratentorial area, and there are not many articles about epidural hematoma of posterior fossa. This study investigated patients who underwent surgery of epidural hematoma of posterior fossa, and the relation between the clinical manifestation and postoperative outcome. METHODS: A retrospective analysis performed of 27 patients who underwent operation for acute traumatic epidural hematoma of posterior fossa from January 2004 to December 2011. Analyzed factors were gender, age, Glasgow Coma Scale (GCS) measured upon presentation to the hospital, preoperative GCS score, cause of trauma, time elapsed from the accident to the presentation to the hospital, time elapsed from the presentation to the hospital to the surgery, radiographic findings (brain CT findings), and Glasgow Outcome Scale (GOS). RESULTS: Two patients (7.4%) had GCS score on admission of 3-8, 11 (29.6%) had 9-12, and 17 (66.7%) had 13-15. In 1 (3.7%) patient, GCS score changed from 13 to 10, and preoperative GCS score was significantly correlated with GOS score (p<0.05). Mean thickness of hematoma was 19.3+/-7.5 mm, and was significantly correlated with GOS score (p<0.05). GOS score was 4-5 in 24 patients (88.9%), 3 (severe disability) in 1 patient (3.7%), and 1 (death) in 2 patients (7.4%). CONCLUSION: In the patients underwent surgery for epidural hematoma of posterior fossa, 88.9% had favorable outcome (in GOS score of 4 or more). Preoperative GCS score and thickness of hematoma on brain computed tomography are important determinants of prognosis.