Risk Factors and Preoperative Risk Scoring System for Shunt-Dependent Hydrocephalus Following Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE: Shunt-dependent hydrocephalus (SdHCP) is a well-known complication of aneurysmal subarachnoid hemorrhage (SAH). The risk factors for SdHCP have been widely investigated, but few risk scoring systems have been established to predict SdHCP. This study was performed to investigate the risk factors for SdHCP and devise a risk scoring system for use before aneurysm obliteration. METHODS: We reviewed the data of 301 consecutive patients who underwent aneurysm obliteration following SAH from September 2007 to December 2016. The exclusion criteria for this study were previous aneurysm obliteration, previous major cerebral infarction, the presence of a cavum septum pellucidum, a midline shift of >10 mm on initial computed tomography (CT), and in-hospital mortality. We finally recruited 254 patients and analyzed the following data according to the presence or absence of SdHCP : age, sex, history of hypertension and diabetes mellitus, Hunt-Hess grade, Fisher grade, aneurysm size and location, type of treatment, bicaudate index on initial CT, intraventricular hemorrhage, cerebrospinal fluid drainage, vasospasm, and modified Rankin scale score at discharge. RESULTS: In the multivariate analysis, acute HCP (bicaudate index of ≥0.2) (odds ratio [OR], 6.749; 95% confidence interval [CI], 2.843–16.021; p=0.000), Fisher grade of 4 (OR, 4.108; 95% CI, 1.044–16.169; p=0.043), and an age of ≥50 years (OR, 3.938; 95% CI, 1.375–11.275; p=0.011) were significantly associated with the occurrence of SdHCP. The risk scoring system using above parameters of acute HCP, Fisher grade, and age (AFA score) assigned 1 point to each (total score of 0–3 points). SdHCP occurred in 4.3% of patients with a score of 0, 8.5% with a score of 1, 25.5% with a score of 2, and 61.7% with a score of 3 (p=0.000). In the receiver operating characteristic curve analysis, the area under the curve (AUC) for the risk scoring system was 0.820 (p=0.080; 95% CI, 0.750–0.890). In the internal validation of the risk scoring system, the score reliably predicted SdHCP (AUC, 0.895; p=0.000; 95% CI, 0.847–0.943). CONCLUSION: Our results suggest that the herein-described AFA score is a useful tool for predicting SdHCP before aneurysm obliteration. Prospective validation is needed.

Risk Factors and Preoperative Risk Scoring System for Shunt-Dependent Hydrocephalus Following Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE: Shunt-dependent hydrocephalus (SdHCP) is a well-known complication of aneurysmal subarachnoid hemorrhage (SAH). The risk factors for SdHCP have been widely investigated, but few risk scoring systems have been established to predict SdHCP. This study was performed to investigate the risk factors for SdHCP and devise a risk scoring system for use before aneurysm obliteration.METHODS: We reviewed the data of 301 consecutive patients who underwent aneurysm obliteration following SAH from September 2007 to December 2016. The exclusion criteria for this study were previous aneurysm obliteration, previous major cerebral infarction, the presence of a cavum septum pellucidum, a midline shift of >10 mm on initial computed tomography (CT), and in-hospital mortality. We finally recruited 254 patients and analyzed the following data according to the presence or absence of SdHCP : age, sex, history of hypertension and diabetes mellitus, Hunt-Hess grade, Fisher grade, aneurysm size and location, type of treatment, bicaudate index on initial CT, intraventricular hemorrhage, cerebrospinal fluid drainage, vasospasm, and modified Rankin scale score at discharge.RESULTS: In the multivariate analysis, acute HCP (bicaudate index of ≥0.2) (odds ratio [OR], 6.749; 95% confidence interval [CI], 2.843–16.021; p=0.000), Fisher grade of 4 (OR, 4.108; 95% CI, 1.044–16.169; p=0.043), and an age of ≥50 years (OR, 3.938; 95% CI, 1.375–11.275; p=0.011) were significantly associated with the occurrence of SdHCP. The risk scoring system using above parameters of acute HCP, Fisher grade, and age (AFA score) assigned 1 point to each (total score of 0–3 points). SdHCP occurred in 4.3% of patients with a score of 0, 8.5% with a score of 1, 25.5% with a score of 2, and 61.7% with a score of 3 (p=0.000). In the receiver operating characteristic curve analysis, the area under the curve (AUC) for the risk scoring system was 0.820 (p=0.080; 95% CI, 0.750–0.890). In the internal validation of the risk scoring system, the score reliably predicted SdHCP (AUC, 0.895; p=0.000; 95% CI, 0.847–0.943).CONCLUSION: Our results suggest that the herein-described AFA score is a useful tool for predicting SdHCP before aneurysm obliteration. Prospective validation is needed.

Transvenous Embolization of Dural Carotid Cavernous Fistula through the Supraorbital Vein

We describe a case of transvenous embolization through the dilated supraorbital vein to treat a dural carotid cavernous fistula. The approach through the common facial vein or direct access of the superior ophthalmic vein is a commonly used route to the superior ophthalmic vein when the approach via the inferior petrosal sinus is unavailable. In rare cases, the dilated supraorbital vein provides an alternative route and we discuss the technical details.

Bone Flap Resorption Following Cranioplasty with Autologous Bone: Quantitative Measurement of Bone Flap Resorption and Predictive Factors

OBJECTIVE: To quantitatively measure the degree of bone flap resorption (BFR) following autologous bone cranioplasty and to investigate factors associated with BFR. METHODS: We retrospectively reviewed 29 patients who underwent decompressive craniectomy and subsequent autologous bone cranioplasty between April 2005 and October 2014. BFR was defined as: 1) decrement ratio ([the ratio of initial BF size/craniectomy size]–[the ratio of last BF/craniectomy size]) >0.1; and 2) bone flap thinning or geometrical irregularity of bone flap shape on computed tomographic scan or skull plain X-ray. The minimal interval between craniectomy and cranioplasty was one month and the minimal follow-up period was one year. Clinical factors were compared between the BFR and no-BFR groups. RESULTS: The time interval between craniectomy and cranioplasty was 175.7±258.2 days and the mean period of follow up was 1364±886.8 days. Among the 29 patients (mean age 48.1 years, male: female ratio 20: 9), BFR occurred in 8 patients (27.6%). In one patient, removal of the bone flap was carried out due to severe BFR. The overall rate of BFR was 0.10±0.11 over 3.7 years. Following univariate analysis, younger age (30.5±23.2 vs. 54.9±13.4) and longer follow-up period (2204.5±897.3 vs. 1044.1±655.1) were significantly associated with BFR (p=0.008 and 0.003, respectively). CONCLUSION: The degree of BFR following autologous bone cranioplasty was 2.7%/year and was associated with younger age and longer follow-up period.

Impact of Time Interval between Trauma Onset and Burr Hole Surgery on Recurrence of Late Subacute or Chronic Subdural Hematoma

OBJECTIVE: Although subdural hematoma (SDH) is commonly treatable by burr hole surgery in the late subacute or chronic stage, there is no clear consensus regarding appropriate management and exact predictive factors for postoperative recurrence also remain unclear. The aim of this study was to evaluate risk factors associated with recurrence of SDH that requires burr hole surgery in the late subacute or chronic stage. We also identified the appropriate timing of surgery for reducing the recurrence. METHODS: We retrospectively reviewed 274 patients with SDH in the late subacute or chronic stage treated with burr hole surgery in our hospital between January 2007 and December 2014. Excluding patients with acute intracranial complications or unknown time of trauma onset left 216 patients included in the study. RESULTS: Of 216 patients with SDH in the late subacute or chronic stage, recurrence was observed in 36 patients (16.7%). The timing of the operation in patients with late subacute stage (15–28 days) resulted in a significant decrease in recurrence (RR, 0.33; 95% CI, 0.17–0.65; p=0.001) compared to chronic stage (>28 days). Otherwise, no significant risk factors were associated with recurrences including comorbidities and surgical details. CONCLUSION: The results indicated that time from trauma onset to burr hole surgery may be important for decreasing the risk of recurrence. Therefore, unless patients can be treated conservatively without surgery, prompt surgical management is recommended in patients diagnosed as having late subacute or chronic subdural hematoma treatable by burr hole surgery, even when neurological deficits are unclear.

High-Dose Simvastatin Is Effective in Preventing Cerebral Vasospasm after Aneurysmal Subarachnoid Hemorrhage: A Prospective Cohort Study in Korean Patients

OBJECTIVE: The goal of this study was to assess the effect of high-dose simvastatin on cerebral vasospasm and its clinical outcome after aneurysmal subarachnoid hemorrhage (SAH) in Korean patients. METHODS: This study was designed as a prospective observational cohort study. Its subjects were aneurysmal SAH patients who had undergone aneurysm clipping or coiling. They were assigned to 1 of 3 groups : the 20 mg, 40 mg, and 80 mg simvastatin groups. The primary end-point was the occurrence of symptomatic vasospasm. The clinical outcome was assessed with the modified Rankin Scale (mRS) score after 1 month and 3 months. The risk factors of the development of vasospasm were assessed by logistic regression analysis. RESULTS: Ninety nine patients with aneurysmal SAH were treated and screened. They were sequentially assigned to the 20 mg (n=22), 40 mg (n=34), and 80 mg (n=31) simvastatin groups. Symptomatic vasospasm occurred in 36.4% of the 20 mg group, 8.8% of the 40 mg group, and 3.2% of the 80 mg group (p=0.003). The multiple logistic regression analysis showed that poor Hunt-Hess grades (OR=5.4 and 95% CI=1.09-26.62) and high-dose (80 mg) simvastatin (OR=0.09 and 95% CI=0.1-0.85) were independent factors of symptomatic vasospasm. The clinical outcomes did not show a significant difference among the three groups. CONCLUSION: This study demonstrated that 80 mg simvastatin treatment was effective in preventing cerebral vasospasm after aneurysmal SAH, but did not improve the clinical outcome in Korean patients.

Age and Meteorological Factors in the Occurrence of Spontaneous Intracerebral Hemorrhage in a Metropolitan City

OBJECTIVE: The aim of this study was to investigate the correlation between meteorological factors and occurrence of spontaneous intracerebral hemorrhage (ICH) according to age. MATERIALS AND METHODS: We retrospectively analyzed the records of 735 ICH patients in a metropolitan hospital-based population. Observed and expected numbers of ICH patients were obtained at 5degrees C intervals of ambient temperature and a ratio of observed to expected frequency was then calculated. Changes in ambient temperature from the day before ICH onset day were observed. The Wilcoxon-Mann-Whitney test was used to test differences in meteorological variables between the onset and non-onset days. The Kruskal-Wallis test was used for comparison of meteorological variables across gender and age. RESULTS: ICH was observed more frequently (observed/expected ratio > or = 1) at lower mean, minimum, and maximum ambient temperature (p = 0.0002, 0.0003, and 0.0002, respectively). Significantly lower mean, minimum, and maximum ambient temperature, dew point temperature, wind speed, and atmospheric pressure (p = 0.0003, 0.0005, 0.0001, 0.0013, 0.0431, and 0.0453, respectively) was observed for days on which spontaneous ICH occurred. In the subgroup analysis, the ICH onset day showed significantly lower mean, minimum, and maximum ambient temperature, dew point temperature, relative humidity, and higher atmospheric pressure in the older (> or = 65 years) female group (p = 0.0093, 0.0077, 0.0165, 0.0028, 0.0055, and 0.0205, respectively). CONCLUSION: Occurrence of spontaneous ICH is closely associated with meteorological factors and older females are more susceptible to lower ambient temperature.

Postoperative Flat Back: Contribution of Posterior Accessed Lumbar Interbody Fusion and Spinopelvic Parameters

OBJECTIVE: Posterior accessed lumbar interbody fusion (PALIF) has a clear objective to restore disc height and spinal alignment but surgeons may occasionally face the converse situation and lose lumbar lordosis. We analyzed retrospective data for factors contributing to a postoperative flat back. METHODS: A total of 105 patients who underwent PALIF for spondylolisthesis and stenosis were enrolled. The patients were divided according to surgical type [posterior lumbar inter body fusion (PLIF) vs. unilateral transforaminal lumbar interbody fusion (TLIF)], number of levels (single vs. multiple), and diagnosis (spondylolisthesis vs. stenosis). We measured perioperative index level lordosis, lumbar lordosis, pelvic tilt, sacral slope, pelvic incidence, and disc height in standing lateral radiographs. The change and variance in each parameter and comparative group were analyzed with the paired and Student t-test (p<0.05), correlation coefficient, and regression analysis. RESULTS: A significant perioperative reduction was observed in index-level lordosis following TLIF at the single level and in patients with spondylolisthesis (p=0.002, p=0.005). Pelvic tilt and sacral slope were significantly restored following PLIF multilevel surgery (p=0.009, p=0.003). Sacral slope variance was highly sensitive to perioperative variance of index level lordosis in high sacral sloped pelvis. Perioperative variance of index level lordosis was positively correlated with disc height variance (R2=0.286, p=0.0005). CONCLUSION: Unilateral TLIF has the potential to cause postoperative flat back. PLIF is more reliable than unilateral TLIF to restore spinopelvic parameters following multilevel surgery and spondylolisthesis. A high sacral sloped pelvis is more vulnerable to PALIF in terms of a postoperative flat back.

The Usefulness of Compliant Balloon for Recanalization of Acute Ischemic Stroke

OBJECTIVE: We report on our experience using a compliant balloon for treatment of thrombi resistant to simple mechanical thrombolysis. METHODS: We conducted a retrospective investigation of 46 consecutive acute ischemic stroke patients who were treated by intraarterial thrombolysis (IAT) between January 2008 and July 2010. We compared IAT results between the balloon group (BG) and the simple mechanical thrombolysis (with microcatheter and microguidewire) group (SG). The Thrombolysis in Myocardial Infarction (TIMI) grading system was used for grading of the degrees of vessel recanalization. In addition, a modified Thrombolysis in Cerebral Infarction (TICI) score was used for post-IAT TIMI grade 2 patients. Modified Rankin Scale scores were used at three months for assessment of clinical outcomes. RESULTS: Twenty of the 46 subjects were treated with a compliant balloon. The mean initial National Institutes of Health Stroke Scale score was 15.1 in the BG and 14 in the SG. The mean time from symptom onset to initiation of IAT was 225 minutes in the BG and 177 in the SG (p = 0.004). The overall rate of successful recanalization (TIMI grade 2 or 3) was 85% in the BG and 73% in the SG (p = 0.476). In the TIMI grade 2 group, modified TICI 2b was 90% in the BG and 16% in the SG (p = 0.001). Postprocedure intraparenchymal hemorrhage occurred in two subjects in the BG and 10 subjects in the SG (p = 0.029). No significant difference in clinical outcomes was observed between the BG and SG (p = 0.347). CONCLUSIONS: The compliant balloon showed high potential for recanalization following acute ischemic stroke, especially when simple mechanical thrombolysis had failed.

Risk Factors Affecting Clinical Outcome of Ruptured Vertebrobasilar Saccular Aneurysms

OBJECTIVE: Ruptured vertebrobasilar (VB) saccular aneurysm is a difficult lesion to treat, and is associated with high rates of morbidity and mortality. The aim of this study is to investigate the risk factors associated with the clinical outcome of ruptured VB aneurysms. METHODS: A retrospective review of 29 patients with ruptured VB saccular aneurysms between 2002 and 2010 was conducted between Jan 2002 and Dec 2010. Univariate and multivariate analyses were performed for determination of the statistical significance of the Glasgow Outcome Scale (GOS) at three months, according to age, initial Hunt-Hess grade, the presence of acute hydrocephalus, and treatment modality. RESULTS: The study included 24 (82.7%) females and five (17.3%) males, with a mean age of 59 years (range, 22-78 years). Seventeen patients were treated with surgical clipping and 12 patients were treated with endovascular coil embolization. No statistical significance was observed between clinical outcome and treatment modalities (clipping or coiling; p = 0.803). Seventeen (58.6%) patients achieved favorable outcome, defined as GOS score of 4-5, at 3 months. Procedure-related complications occurred in seven patients (24.1%). Results of multivariate analysis indicated that initial Hunt-Hess grade and the presence of acute hydrocephalus were independent predictors of unfavorable outcome, defined as GOS score of 1-3 (Odds ratio (OR) = 8.63, Confidence interval (CI) [95%] 1.11-66.84, p = 0.039 and OR = 36.64, CI [95%] 2.23-599.54, p = 0.012, respectively). CONCLUSION: The present study suggests that the clinical outcomes are related to the initial Hunt-Hess grade and the presence of acute hydrocephalus in ruptured saccular VB aneurysms.

Assessment of Recanalization after Intra-Arterial Thrombolysis in Patients with Acute Ischemic Stroke : Proposed Modification of the Qureshi Grading System

OBJECTIVE: We aimed to investigate the correlation between the success of recanalization and a modified version of the Qureshi grading system in acute ischemic stroke patients. METHODS: We retrospectively analyzed the intra-arterial thrombolysis (IAT) records of 37 patients who were evaluated by Thrombolysis in Myocardial Infarction (TIMI) and a modified version of the Qureshi grading systems as follows : 1) post-IAT Qureshi grade, 2) modified Delta Qureshi grade : pre-IAT group grade - post-IAT group grade (grade 1 : Qureshi grades 0-2 and grade 2 : Qureshi grade 3-5) and 3) Delta Qureshi grade (post-IAT Qureshi grade - pre-IAT Qureshi grade). Successful recanalization was defined as follows : 1) post-IAT TIMI grades 2 and 3, 2) post-IAT Qureshi grade 0-2, 3) modified Delta Qureshi grade=1, and 4) Delta Qureshi grade of > or =2 and/or post-IAT Qureshi grade=0. We investigated the correlation between the post-IAT TIMI grade and the modified Qureshi grade and also compared the various grading systems with modified Rankin Scale scores for evaluating the clinical outcome at 3 months. RESULTS: The post-IAT Qureshi grade and Delta Qureshi grade and/or post-IAT Qureshi grade were significantly correlated with the TIMI grade (gamma=0.976 and, 0.942, respectively). Further, post-IAT Qureshi grade and Delta Qureshi grade and/or post-IAT Qureshi grade showed a significantly stronger association with clinical outcome than did the post-IAT TIMI grade (p=0.001 and, 0.000 vs. 0.083, respectively). CONCLUSION: Our preliminary results suggest that the modified Qureshi grading system is a useful tool for assessing the success of recanalization after IAT.

Epidural Fluid Collection after Cranioplasty : Fate and Predictive Factors

OBJECTIVE: Infection and bone resorption are major complications of cranioplasty and have been well recognized. However, there are few clinical series describing the epidural fluid collection (EFC) as complication of cranioplasty. This study was planned to identify the predictive factors and fate of EFC after cranioplasty. METHODS: We reviewed retrospectively the demographic, clinical, and radiographic data in 59 patients who underwent a first cranioplsty following decompressive craniectomy during a period of 6 years, from January 2004 to December 2009. We compared demographic, clinical, and radiographic factors between EFC group and no EFC group. The predictive factors associated with the development of EFC were assessed by logistic regression analysis. RESULTS: Overall, 22 of 59 patients (37.3%) suffered from EFC following cranioplasty. EFC had disappeared (n=6, 31.8%) or regressed (n=6, 31.8%) over time on follow up brain computed tomographic (CT) scans. However, 5 patients (22.7%) required reoperation due to symptomatic and persistent EFC. Predictive factors for EFC were male [odds ratio (OR), 5.48; 95% CI, 1.26-23.79], air bubbles in the epidural space (OR, 12.52; 95% CI, 2.26-69.28), and dural calcification on postoperative brain CT scan (OR, 4.21; 95% CI, 1.12-15.84). CONCLUSION: The most of EFCs could be treated by conservative therapy. Air bubble in the epidural space and dural calcification are proposed to be the predictive factors in the formation of EFC after cranioplasty.

Aneurysmal Rebleeding : Factors Associated with Clinical Outcome in the Rebleeding Patients

OBJECTIVE: Aneurysmal rebleeding is a major cause of death and disability. The aim of this study is to investigate the incidence of rebleeding, and the factors related with patient's outcome. METHODS: During a period of 12 years, from September 1995 to August 2007, 492 consecutive patients with aneurysmal subarachnoid hemorrhage (SAH) underwent surgery at our institution. We reviewed the patient's clinical records, radiologic findings, and possible factors inducing rebleeding. Also, we statistically analyzed various factors between favorable outcome group (FG) and unfavorable outcome group (UG) in the rebleeding patients. RESULTS: Rebleeding occurred in 38 (7.7%) of 492 patients. Male gender, location of aneurysm (anterior communicating artery) were statistically significant between rebleeding group and non-rebleeding group (p = 0.01 and p = 0.04, respectively). Rebleeding occurred in 26 patients (74.3%) within 2 hours from initial attack. There were no statistically significant factors between FG and UG. However, time interval between initial SAH to rebleeding was shorter in the UG compared to FG (FG = 28.71 hrs, UG = 2.9 hrs). CONCLUSION: Rebleeding occurs more frequently in the earlier period after initial SAH. Thus, careful management in the earlier period after SAH and early obliteration of aneurysm will be necessary.

Brain Injuries during Intraoperative Ventriculostomy in the Aneurysmal Subarachnoid Hemorrhage Patients

OBJECTIVE: Intraoperative ventriculostomy is widely adopted to make the slack brain. However, there are few reports about hemorrhagic or parenchymal injuries after ventriculostomy. We tried to analyze and investigate the incidence of these complications in a consecutive series of patients with aneurysmal subarachnoid hemorrhage (SAH). METHODS: From September 2006 to June 2007, 43 patients underwent surgical clipping for aneurysmal SAH at our hospital. Among 43 patients, we investigated hemorrhagic or parenchymal injuries after intraoperative ventriculostomy using postoperative computed tomographic scan in 26 patients. After standard pterional craniotomy, ventriculostomy catheter was inserted perpendicular to the cortical surface along the bisectional imaginary line from Paine's point. RESULTS: Hemorrhagic injuries were detected in 12 of 26 patients (46.2%). Mean systolic blood pressure during anesthesia was with in statistically significant parameter related to hemorrhage (p = 0.006). On the other hand, parenchymal injuries were detected in 11 of 26 patients (42.3%). Female and the amount of infused mannitol during anesthesia showed statistically significant parameters related to parenchymal injury (p = 0.005, 0.04, respectively). However, there were no ventriculostomy-related severe complications. CONCLUSION: In our series, hemorrhagic or parenchymal injuries after intraoperative ventriculostomy occurred more commonly than previously reported series in aneurysmal SAH patients. Although the clinical outcomes of complications are generally favorable, neurosurgeon must keep in mind the frequent occurrence of brain injury after intraoperative ventriculostomy in the acute stage of aneurysmal SAH.

Is Transcranial Doppler Ultrasonography Old-fashioned?: One Institutional Validity Study

Objective: The purpose of this study is to investigate the correlation between various transcranial Doppler (TCD) ultrasonography parameters and clinical vasospasm after aneurysmal subarachnoid hemorrhage (SAH). Methods: This study enrolled 40 patients presented with aneurysmal SAH between September 2006 and August 2007. We measured differences of mean blood flow velocity (BFVm), highest systolic blood flow velocity (BFVh), and Lindegaard ratio (LR) in the middle cerebral artery on TCD examination. These parameters were evaluated for correlation with clinical vasospasm by univariate analysis and the receiver operating characteristic analysis. Results: Twelve patients (30%) developed clinical vasospasm. The best TCD parameters for the detection of clinical vasospasm were revealed to be differences of BFVm, BFVh, and LR values between 1st TCD test and 3rd TCD (7 cm/s, 11.5 cm/s, 0.45 respectively). The positive predictive value of any one of three parameters was 60% and the negative predictive value was 100%. Conclusion: TCD is still considered a useful tool for screening clinical vasospasm. To confirm the predictive value of the above parameters, further prospective study will be needed.

Cervical Spondylodiscitis Caused by Candida Albicans in Non-Immunocompromised Patient

Fungal infections of the spine are relatively uncommon. Moreover, cervical spondylodiscitis due to Candida albicans in non-immunocompromised patient is very rare. We report a case of Candida spondylodiscitis in a 64-year-old woman who complained of neck pain. The clinical feature and treatment option are presented with a review of pertinent literatures.

"Syndrome of the Sinking Skin-Flap" Secondary to the Ventriculoperitoneal Shunt after Craniectomy

The syndrome of the sinking skin flap was introduced to explain the phenomenon of neurological deterioration after decompressive craniectomy. A 37-year-old man was admitted with acute subdural hematoma and traumatic intraparenchymal hematoma. After decompressive craniectomy, the patient suffered from hydrocephalus for which a ventriculoperitoneal (V-P) shunt was inserted. Following this procedure, the depression of the skin flap became remarkable and his mentation was deteriorated. The patient recovered uneventfully after temporary elevating of valve pressure and cranioplasty. We present a patient who was successfully managed with elevation of valve pressure and cranioplasty for the syndrome of the sinking scalp flap with review of a pertinent literature.

Epidermoid Cyst Arising from the Corpus Callosum

Most of intradural epidermoid cyst arise as slowly growing extraaxial lesions but purely intracerebral epidermoid cysts are rare. A 39-year-old female presented with a headache during several months. Brain computed tomography (CT) scan showed a mass lesion in the both frontal lobe with heterogenous density approximately 5x5cm in size. Magnetic resonance imaging (MRI) revealed a mass of heterogenous signal intensity on T1, T2-weighted image and faint enhancement with gadolinium (Gd). Through the both interhemispheric approach, mass was removed subtotally except the calcified portion tightly attached to the corpus callosum. The patient discharged without neurological deficit. The authors report a case of epidermoid cyst in the corpus callosum and discuss the pathogenesis of the intraparenchymal epidermoid cyst.

Subsidence Ratio after Anterior Cervical Interbody Fusion Using an Intraoperative Custom-made Cervical Cage

OBJECTIVE: The postoperative subsidence of anterior cervical interbody fusion for cervical degenerative diseases gives rise to segmental kyphotic collapse, screw loosening, and chronic neck pain. So, intraoperative custom-made polymethylmethacrylate (PMMA) C-cage has been developed to prevent subsidence following anterior cervical fusion. METHODS: A total of patients who underwent anterior cervical interbody fusion with a intraoperative custom - made cervical cage filled with local bone and demineralized bone matrix (group A) were analyzed prospectively from June 2004 to June 2005. These were compared with 40 patients who were treated with iliac bone graft (group B). We evaluated subsidence ratio, change of segmental angle, distraction length and segmental angle. Statistical analysis was performed using independent sample t-test and Pearson correlation coefficient. RESULTS: Group A had a statistically significant decrease in subsidence ratio (0.64+/-0.43%, p=0.00), distraction length (2.42+/-1.25 mm, p=0.02), and follow angle change (1.78+/-1.69degrees, p=0.01) as compared with Group B. However, there was no statistically significant difference in postoperative segmental angle change (p=0.66). On the analysis of the correlation coefficient, the parameters showed no interrelationships in the group A. On the other hand, subsidence ratio was affected by distraction length in the group B (Pearson correlation=0.448). CONCLUSION: This operative technique would be contributed for the reduction of a postoperative subsidence after the anterior cervical interbody fusion procedure for cervical disc disease with moderate to severe osteoporotic condition and segmental loss of lordosis.

Validity of Paramedian Tangential Approach to L5-S1 Far-Lateral Lesions

OBJECTIVE: There are various surgical approaches to far-lateral lesions in the L5-S1 intervertebral space. Of these is the validity of a paramedian tangential approach is being investigated in this study. METHODS: A retrospective study was conducted on 25 patients who had been diagnosed as having a far-lateral L5-S1 disc herniations, osteophyte, costal process hypertrophy, and had undergone a paramedian tangential approach from November 1999 through December 2003. The degree of symptoms and improvement were compared via the visual analog pain scale, before and after surgery. RESULTS: This study included 4 males and 21 females with a mean age of 62+/-11.8 years old. The average follow-up period after surgery was 8.2+/-2.7 months. The visual analog pain scale taken before surgery was 6.7+/-1.1 points, while the post-surgical scale was 2.4+/-0.9 points showing a significant decrease (p<0.05). There were no complications that developed during surgery. CONCLUSION: A paramedian tangential approach is less invasive in the soft tissue than that of the median approach. This approach may effectively reduce nerve root compression and expand intervertebral foramens, and is devoid of the risk of spinal instability after surgery. The authors suppose that a paramedian tangential approach is quite an effective technique to relieve compression in the far-lateral L5-S1 intervertebral space.