Neuroendoscopy: Current and Future Perspectives

Neuroendoscopic surgery is performed because it causes minimal damage to normal structures, carries a lower rate of complications, and achieves excellent outcomes. Surgeons using an endoscope and related instruments can perform complex operations through very small incisions, which is especially useful for minimally invasive procedures for the brain and spine. Neuroendoscopic surgery is now performed in cases of obstructive hydrocephalus, various intraventricular lesions, hypothalamic hamartomas, craniosynostosis, skull base tumors, and spinal lesions. This review discusses the brief history of neuroendoscopy and the current state and future perspectives of endoscopic surgery.

A Great Teacher of Neurosurgery in Korea: Hun Jae Lee (1921-1983)

No abstract available.

Reduced-dose craniospinal radiotherapy followed by high-dose chemotherapy and autologous stem cell rescue for children with newly diagnosed high-risk medulloblastoma or supratentorial primitive neuroectodermal tumor

BACKGROUND: In this study, we investigated the effects of reduced-dose craniospinal radiotherapy (CSRT) followed by tandem high-dose chemotherapy (HDCT) with autologous stem cell rescue (ASCR) in children with a newly diagnosed high-risk medulloblastoma (MB) or supratentorial primitive neuroectodermal tumor (sPNET). METHODS: Between March 2005 and April 2007, patients older than 3 years with a newly diagnosed high-risk MB or sPNET were enrolled. The patients received two cycles of pre-RT chemotherapy consisting of cisplatin, etoposide, vincristine, and cyclophosphamide (cycle A), and carboplatin, etoposide, vincristine, and ifosphamide (cycle B), followed by CSRT with 23.4 Gy and local RT with 30.6 Gy. After four cycles of post-RT chemotherapy (cycles A, B, A, and B), tandem double HDCT with ASCR was performed. RESULTS: A total of 13 patients (MB=11, sPNET=2) were enrolled. Of these, one patient progressed, one patient died of septic shock after the second cycle of B, and one patient relapsed after the third cycle of B. The 3-year event-free survival (EFS) rate of the patients intended for HDCT was 76.9%, whereas the 3-year EFS rate of the patients who received HDCT was 100%. No treatment-related mortality occurred during HDCT. CONCLUSION: Although the follow-up period was short and the patient cohort was small in size, the results of this study are encouraging. The limited toxicity and favorable EFS rate observed in children treated with reduced-dose CSRT followed by HDCT and ASCR warrant further exploration in a larger study population.

Intraventricular Hemorrhage Long after Successful Encephaloduroarterio Synangiosis in Moyamoya Patient

Intraventricular hemorrhage long after successful encephaloduroarterio synangiosis (EDAS) is very rare. The effect of revascularization surgery for preventing hemorrhagic event of moyamoya disease remains controversial. We report a 17-year-old female with intracerebral hemorrhage and intraventricular hemorrahge 10 years after successful EDAS. Even though cerebral vessels angiography showed good collateral circulations without specific weak points, a cerebral hemorrhage could occur in patient with ischemic type of moyamoya disease long after successful indirect bypass operations. Good collateralization of cerebral angiography or magnetic resonance perfusion image after indirect bypass surgery would ensure against ischemic symptoms, not a hemorrhage. And, thus a life-time follow-up strategy might be necessary even if a good collateral circulation has been established.

Proposal for the Promotion of Korean Neurosurgery

The author conducted a survey on the current status of neurosurgery around the world in preparation for Presidential Address at the International Society for Pediatric Neurosurgery (ISPN). The addresses and findings from the survey were presented at ISPN in 2006 and Child's Nervous System in 2007. After reviewing the current status of neurosurgery of various countries, the author would like to share this information with members of the Korean Neurosurgical Society, as well as offer a proposal to promote Korean neurosurgery around the world.

Congenital Cavernous Sinus Cystic Teratoma

Teratomas represent 0.5% of all intracranial tumors. These benign tumors contain tissue representative of the three germinal layers. Most teratomas are midline tumors located predominantly in the sellar and pineal regions. The presence of a teratoma in the cavernous sinus is very rare. Congenital teratomas are also rare, especially those of a cystic nature. To our knowledge, this would be the first case report of a congenital, rapidly growing cystic teratoma within the cavernous sinus. A three-month-old boy presented with a past medical history of easy irritability and poor oral intake. A magnetic resonance image (MRI) scan of the head disclosed a large expanding cystic tumor filling the right cavernous sinus and extending into the pterygopalatine fossa through the foramen rotundum. These scans also demonstrated a small area of mixed signal intensity, the result of the different tissue types conforming to the tumor. Heterogeneous enhancement was seen after the infusion of contrast medium. However, this was a cystic tumor with a large cystic portion. Thus, a presumptive diagnosis of cystic glioma was made. With the use of a right frontotemporal approach, extradural dissection of the tumor was performed. The lesion entirely occupied the cavernous sinus, medially displacing the Gasserian ganglion and trigeminal branches (predominantly V1 and V2). The lesion was composed of different tissues, including fat, muscle and mature, brain-like tissue. The tumor was completely removed, and the pathological report confirmed the diagnosis of a mature teratoma. There was no evidence of recurrence. Despite the location of the lesion in the cavernous sinus, total removal can be achieved with the use of standard microsurgical techniques.

Long Term Magnetic Resonance Angiography Follow-up in Moyamoya Disease / 대한뇌혈관외과학회지

OBJECTIVE: Revascularization is an effective treatment for the ischemic symptom of moyamoya disease. Indirect revascularization is also effective. Magnetic resonance angiography (MRA) has the ability for collateral formation that is equivalent to conventional angiography. This study analyzed the results of indirect revascularization by MRA. METHODS: A total of 25 patients underwent bilateral EDAS for the management of moyamoya disease. All patients underwent MRA after surgery more than 24 months later. The collateral formation was graded as Good, Fair, and Poor. The clinical outcome was assessed as Excellent, Good, Fair, and Poor. RESULTS: Good collateral formation was 32 sides of the EDAS, and fair was 18. An excellent clinical outcome was obtained in 15 patients, Good in 8, Fair in 1, and Poor in 1. There was a significant correlation between the preoperative symptom, gender, and the clinical outcome. CONCLUSION: In the management of ischemic moyamoya disease, indirect revascularization has been the golden standard with remarkably low morbidity and mortality. Moreover, and MRA can replace conventional angiography in the follow-up of moyamoya patients.

The Results of One stage Total Callosotomy in Pediatric Epilepsy / 대한간질학회지

PURPOSE: In the pediatric patients who have medically intractable epilepsy the callosotomy is useful to prevent the propagation of seizure from one hemisphere to the other. The indications of callosotomy are drop attack, life threatening primarily or secondarily generalized seizure, medically refractory mixed seizure types such as Lennox-Gastaut syndrome. In addition, the retarded children are not contraindicated. The anterior callosotomy is used to perform to control medically intractable epilepsy which is believed to have some advantages to total callosotomy. But, we propose that the anterior callosotomy does not seem to be superior to total callosotomy for the prevention of the propagation of seizure or complication. We describe a series of 21 patients with medically intractable epilepsy who underwent total callosotomy in one stage. METHODS: The diagnoses in these patients included Lennox-Gastaut syndrome, atonic seizure, infantile hemiplegia, and no obvious solitary seizure focus on chronic video/EEG monitoring to characterize seizures, electrographic activity, and postictal behaviors. Preoperatively 16 patients suffered from disabling drop attacks or intense head drop seizures which caused frequent physical injuries. Other types of seizures are 12 generalized tonic-clonic seizures, 7 complex partial seizures, 1 absence seizure, and 7 myoclonic seizures. Male:Female=14:7, Age: 2-22 years (Mean: 9.4 years). The follow-up period ranged from 0.8 to 3.8 years (median 2.4 years). Seizure outcome, parental assessment of daily function, and parental satisfaction with outcome were assessed postoperatively. RESULTS: Drop attacks disappeared completely during the entire follow-up period in 13 patients and decreased to less than 10% of baseline in five. The corpus callosum of the one patient were not completely sectioned in Diffusion Tensor Image, tractography. Other types of seizures resolved completely in 14 patients and decreased in 7. 2 patients experienced a transient disconnection syndrome, but completely resolved within four weeks. Overall daily function improved and parents were satisfied with the surgical outcome in all patients except three who experienced recurrent of drop attacks after operation. There was no sign of significant and persistent neurological deficits in any case. CONCLUSION: Results of total callosotomy in patients with medically intractable epilepsy with diffuse epileptic foci were favorable in most cases. The procedure was particularly effective against drop attacks causing physical injuries and impaired quality of life in these patients.

Effects of Methylprednisolone on the Neural Conduction of the Motor Evoked Potentials in Spinal Cord Injured Rats

Methylprednisolone (MP), a glucocorticoid steroid, has an anti-inflammatory action and seems to inhibit the formation of oxygen free radicals produced during lipid peroxidation in a spinal cord injury (SCI). However, the effects of MP on the functional recovery after a SCI is controversial. The present study was conducted to determine the effects of MP on the recovery of neural conduction following a SCI. A SCI was produced using the NYU spinal cord impactor. A behavioral test was conducted to measure neurological disorders, and motor evoked potentials (MEPs) were recorded. According to the behavioral test, using BBB locomotor scaling, MP-treated animals showed improved functional recoveries when compared to salinetreated animals. MEP latencies in the MP-treated group were shortened when compared to those in the control group. Peak amplitudes of MEPs were larger in the MP-treated group than those in the control group. The thresholds of MEPs tended to be lower in the MP-treated group than those in the control group. These results suggest that MP may improve functional recovery after a SCI.

Surgical Treatment of Cavernous Malformation of Pineal Region

The main causes of pineal apoplexy are hemorrhage associated with pineal region tumors, vascular malformations, and pineal cysts. Cavernous malformations rarely occur in the pineal region, with only fifteen cases reported previously. Hemorrhage associated with cavernous malformation causes apoplectic event in the pineal region. We report two surgically treated cases of pineal hemorrhage associated with cavernous malformation and discuss the consideration in management of the pineal apoplexy.

Surgical Treatment of Cavernous Malformation of Pineal Region

The main causes of pineal apoplexy are hemorrhage associated with pineal region tumors, vascular malformations, and pineal cysts. Cavernous malformations rarely occur in the pineal region, with only fifteen cases reported previously. Hemorrhage associated with cavernous malformation causes apoplectic event in the pineal region. We report two surgically treated cases of pineal hemorrhage associated with cavernous malformation and discuss the consideration in management of the pineal apoplexy.

Pineal Cavernous Malformations: Report of Two Cases

Pineal hemorrhage only occurs in rare cases, and this known to have several different causes such as germ cell tumors, pineal cysts and vascular malformations, including the cavernous malformations. Pineal cavernous malformations are extremely rare: to date only fifteen cases have been reported worldwide. Although the diagnosis of pineal cavernous malformation is not easy because of the extreme rareness of this condition, the presence of this lesion can be suspected based on its typical radiological findings. Case 1. A 42-year- old man presented with a limitation in his upward gazing. Radiologic examinations showed acute hemorrhage in the pineal region. He underwent ventriculo-peritoneal (VP) shunting but the patient's condition deteriorated after the shunting surgery. We operated and totally removed the tumor and the hemorrhages via an occipital-transtentorial approach. Case 2. A 37-year-old man presented with diplopia. Radiologic examinations showed acute hemorrhage in the third ventricle. He underwent VP shunting, and after this procedure the diplopia was aggravated. We operated and totally removed the tumor and the hemorrhages via an occipital-transtentorial approach. If there is no doubt about the pineal cavernous malformation on MR imaging, we strongly recommend early surgical intervention without performing a risky biopsy. In this study, we describe our experiences for the diagnosis of cavernous malformations in the pineal region with special emphasis on the radiological aspects and the clinical course of this disease.

Analysis of the Causes of Subfrontal Recurrence in Medulloblastoma and Its Salvage Treatment / 대한방사선종양학회지

PURPOSE: Firstly, to analyze factors in terms of radiation treatment that might potentially cause subfrontal relapse in two patients who had been treated by craniospinal irradiation (CSI) for medulloblastoma. Secondly, to explore an effective salvage treatment for these relapses. MATERIALS AND METHODS: Two patients who had high-risk disease (T3bM1, T3bM3) were treated with combined chemoradiotherapy. CT-simulation based radiation-treatment planning (RTP) was performed. One patient who experienced relapse at 16 months after CSI was treated with salvage surgery followed by a 30.6 Gy IMRT (intensity modulated radiotherapy). The other patient whose tumor relapsed at 12 months after CSI was treated by surgery alone for the recurrence. To investigate factors that might potentially cause subfrontal relapse, we evaluated thoroughly the charts and treatment planning process including portal films, and tried to find out a method to give help for placing blocks appropriately between subfrotal-cribrifrom plate region and both eyes. To salvage subfrontal relapse in a patient, re-irradiation was planned after subtotal tumor removal. We have decided to treat this patient with IMRT because of the proximity of critical normal tissues and large burden of re-irradiation. With seven beam directions, the prescribed mean dose to PTV was 30.6 Gy (1.8 Gy fraction) and the doses to the optic nerves and eyes were limited to 25 Gy and 10 Gy, respectively. RESULTS: Review of radiotherapy portals clearly indicated that the subfrontal-cribriform plate region was excluded from the therapy beam by eye blocks in both cases, resulting in cold spot within the target volume. When the whole brain was rendered in 3-D after organ drawing in each slice, it was easier to judge appropriateness of the blocks in port film. IMRT planning showed excellent dose distributions (Mean doses to PTV, right and left optic nerves, right and left eyes: 31.1 Gy, 14.7 Gy, 13.9 Gy, 6.9 Gy, and 5.5 Gy, respectively. Maximum dose to PTV: 36 Gy). The patient who received IMRT is still alive with no evidence of recurrence and any neurologic complications for 1 year. CONCLUSION: To prevent recurrence of medulloblastoma in subfrontal-cribriform plate region, we need to pay close attention to the placement of eye blocks during the treatment. Once subfrontal recurrence has happened, IMRT may be a good choice for re-irradiation as a salvage treatment to maximize the differences of dose distributions between the normal tissues and target volume.

The Interaction between GFAP and Fascin in U343 Glioma Cell Line

No abstract available.

The Surgical Effect of Callosotomy in the Treatment of Intractable Seizure

We evaluated the surgical effects of the callosotomy, particularly with respect to the effect of callosotomy in some seizure types and the extent of surgery. Twenty-one patients with a minimum follow-up of two year were enrolled. The most significant effect of callosotomy was the complete suppression of the generalized seizures associated with drop attack in 12 of 21 patients and seizure reduction of more than 75% in 6 of 21 patients. The surgical effect on the partial seizures was very variable. Transient disconnection syndrome appeared in 4 patients after anterior callosotomy. Total callosotomy by staged operation significantly suppressed generalized seizures associated with drop attack without any disconnection syndrome. Our data show that callosotomy is quite a good approach to the surgical treatment of drop attacks accompanied by disabling generalized seizures.

Letters to the Editor: The Interaction between GFAP and Fascin in U343 Glioma Cell Line. J Korean Neurosurg Soc 35 : 507-513, 2004

No abstract available.

Influence of Prognostic Factors on Survival Rate of Medulloblastoma Patient with Chemotherapy

PURPOSE: Brain tumors are the second most common tumor in childhood, and medulloblastomas comprise 15-25% of brain tumors. The well known prognostic factors are age at diagnosis, stage of disease, and extent of surgical excision. In this study, we analysed the prognostic factors in patients who received chemotherapy after excision. METHODS: We reviewed the medical records of 61 patients who received chemotherapy among the 94 patients who were diagnosed and treated between Jan 1985 and Sep 2001 in the Department of Pediatrics and Neurosurgery at Severance Hospital. RESULTS: Among the total survival rate of patients who underwent chemotherapy, the 3-yr progression-free survival rate was 66.5+/-6.3% and the 15-yr progression-free survival rate was 60.3+/-6.7%. The progression-free survival rate for patients with age at diagnosis over 3 yrs old and under 3 yrs old, was 64.5+/-7.7% and 48.2+/-12.9% respectively and there was no statistically significant difference. The survival rate of the high vs low risk group by staging was 72.7+/-10.5% and 54.6+/-8.3% respectively, and there was no significant difference. The survival rate of patients with total removal vs subtotal removal was 65.8+/-11.8% and 56.8+/-8.2% respectively, showing no statistical difference. CONCLUSION: The reason there is no difference in survival rate according to the traditional prognostic factors is that chemotherapy has improved not only the total survival rate but also the survival rate in patients with poor traditional prognostic factors. So, sufficient removal of tumor followed by proper chemotherapy and radiotherapy is an important factor which influences the survival rate of medulloblastoma patients.

Expression of the DNA Repair Gene, N-Methylpurine-DNA Glycosylase in Astrocytic Tumors

OBJECTIVE: This study is designed to investigate the association of tumorigenesis with DNA repair gene, N-methylpurine-DNA-glycosylase(MPG) in astrocytic tumors. METHODS: MPG mRNA expression and localization in the 30 astrocytic tumors and 7 tumor-adjacent brain tissues was examined by reverse transcriptase-polymerase chain reaction(RT-PCR) and RNA in situ hybridization. Expression and intracellular localization of MPG protein was determined by immunohistochemistry. Statistical analysis was performed by ANOVA with a p value<0.05 considered statistically significant. RESULTS: MPG mRNA expression in RT-PCR was significantly higher in grade IV tumor tissues than in brain tissues adjacent to tumor or in grade II-III astrocytic tumor tissues(p<0.05). MPG mRNA in in situ hybridization was detected both in brain tissues adjacent to tumor and in astrocytic tumor tissues, regardless of the tumor grades. However, MPG protein localization in immunohistochemical study was detected only in the nucleus of all tumor tissues. In brain tissues adjacent to tumor, immunohistochemical study for MPG was not stained both in the nucleus and in cytoplasm. CONCLUSION: These results suggest MPG's role in human astrocytic tumors and raise the possibility that the increased mRNA level and intracellular localization could be associated with astrocytic tumorigenesis. Further studies about control of MPG gene expression in astrocytic tumors are warranted.

Significance of Chronic Epilepsy in Glial Tumors

OBJECTIVE: The aim of this study is to compare the frequency of postoperative epilepsies of patients with chronic as opposed to recent onset epilepsy due to glial tumors in the frontal or temporal lobe with the hypothesis that patients with chronic epilepsy do worse. METHODS: We compared the clinical and diagnostic characteristics of the patients(n=73) who had seizures preoperatively to those of the patients(n=153) who did not. Among those who have had seizures preoperatively, we compared those(n=32, chronic seizure group) who had seizures a year or more prior to surgery to those(n=41, acute seizure group) who had seizures within a year prior to surgery. RESULTS: Among the various factors, the frequency of benign pathology and favorable neurological state were higher in seizure group than in non-seizure group(p<0.05). Complex partial seizure and low-grade tumors were frequent in chronic seizure group, whereas simple partial seizure and high-grade tumors were frequent in acute seizure group. Seizure-free rate was significantly higher in acute seizure group than in chronic one(p<0.05). Also, the difference of seizure control rate between surgical strategies were statistically significant(p<0.05). CONCLUSION: This study indicates that preoperative seizure durations and frequencies have a close relationship with the frequency of postoperative epilepsy of glial tumors. A longer lapse may allow the formation of epileptogenic foci, leading to chronic epilepsy, and eventually having a negative effect on the prognosis of the patients. Factors including histopathological characteristics of the tumor, its location, seizure duration/frequency, and semiology should be taken account of deciding on surgical strategies.

Management of Intracranial Cavernous Malformation: A Retrospective Analysis of 76 Consecutive Cases

OBJECTIVE: To establish a treatment guideline for intracranial cavernous malformation, the authors analyzed the clinical features, treatment modality, complications, and late outcomes in 76 consecutive cases (45 microsurgical resections, 30 stereotactic radiosurgeries, one microsurgery followed by radiosurgery) managed at the Yonsei University Medical Center from 1985 to 1998. RESULTS: Among 104 lesions in 76 patients, 64(61.5%) lesions were supratentorial and 40(38.5%) infratentorial. Hemorrhage was the most common presentation(31 patients, 40.8%), followed by generalized seizure(15 patients, 19.7%). Fifteen(19.7%) patients had mixed presentation with generalized seizure and hemorrhage, while 9(11.9%) patients presented focal deficits. The remaining 6(7.9%) patients had headache or incidental lesion. Almost all infratentorial lesions(92.5%) were managed with radiosurgery, and 65.6% of supratentorial lesions with microsurgery. The average follow-up period was 14.6 months for the microsurgery group and 32 months for the radiosurgery group. The overall outcome was good in 68(89.5%), fair in 6(7.9%), poor in 1(1.3%), and dead in 1(1.3%). Total microsurgical resection and symptomatic cure rate was 95.6%. Two lesion were incompletely resected. One lesion was followed by radiosurgery and the other was followed by reoperation. Only 38.5% of lesions with radiosurgery were shrunken. CONCLUSION: Microsurgical removal is effective for lesions in the non-eloquent area, or with recurrent hemorrhages and seizures. Although radiosurgery could be considered for lesions with multiplicity in the eloquent or deep-seated area, further study for the radiosurgical effect on cavernous malformations is required.