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.

The roles of methylenetetrahydrofolate reductase 677C>T and 1298A>C polymorphisms in moyamoya disease patients

PURPOSE

The methylenetetrahydrofolate reductase (MTHFR) 677C>T and 1298A>C polymorphisms, which are associated with hyperhomocysteinemia and nitric oxide (NO) deficiency (which is related to atherothrombosis and cerebral ischemia), have not been studied in moyamoya disease. A case-control study was performed to investigate whether the MTHFR 677C>T and 1298A>C polymorphisms contribute to moyamoya disease (MMD).

METHODS

One hundred and seven Korean patients with MMD (mean age, 20.85 ± 15.89 years; 66.4 % female) and 232 healthy control subjects (mean age, 23.99 ± 16.16 years; 56.8 % female) were included. Genotyping for the MTHFR 677C>T and 1298A>C polymorphisms and measurements of homocysteine, folate, vitamin B12, and NO in the cerebrospinal fluid (CSF) were performed. The statistical analysis was performed by multivariate linear regression and logistic regression.

RESULT

The MTHFR 677CT+TT genotype frequency was significantly increased with early-onset MMD (<10 years) compared with late-onset MMD (≥10 years) (adjusted odds ratio, 3.392; 95 % confidence interval, 1.294-8.893, P = 0.013). The MTHFR 677C-1298C/677T-1298A diplotype (1.71 ± 1.23 arbitrary units) presented significantly lower NO levels in the CSF compared with the 677C-1298A/677C-1298A diplotype (11.40 ± 12.24 arbitrary units).

CONCLUSION

The MTHFR 677C>T and 1298A>C polymorphisms have restricted roles in the Korean MMD population. Therefore, further studies involving larger and more heterogeneous cohorts are needed to extend our understanding of the influence of polymorphisms in MTHFR and other thrombophilic genes on MMD.

The role of VEGF and KDR polymorphisms in moyamoya disease and collateral revascularization

We conducted a case-control study to investigate whether vascular endothelial growth factor (VEGF −2578, −1154, −634, and 936) and kinase insert domain containing receptor (KDR −604, 1192, and 1719) polymorphisms are associated with moyamoya disease. Korean patients with moyamoya disease (n = 107, mean age, 20.9±15.9 years; 66.4% female) and 243 healthy control subjects (mean age, 23.0±16.1 years; 56.8% female) were included. The subjects were divided into pediatric and adult groups. Among the 64 surgical patients, we evaluated collateral vessel formation after 2 years and divided patients into good (collateral grade A) or poor (collateral grade B and C) groups. The frequencies and distributions of four VEGF (−2578, −1154, −634, and 936) and KDR (−604, 1192, and 1719) polymorphisms were assessed from patients with moyamoya disease and compared to the control group. No differences were observed in VEGF −2578, −1154, −634, and 936 or KDR −604, 1192, and 1719 polymorphisms between the control group and moyamoya disease group. However, we found the −634CC genotype occurred less frequently in the pediatric moyamoya group (p = 0.040) whereas the KDR −604C/1192A/1719T haplotype increased the risk of pediatric moyamoya (p = 0.024). Patients with the CC genotype of VEGF −634 had better collateral vessel formation after surgery. Our results suggest that the VEGF −634G allele is associated with pediatric moyamoya disease and poor collateral vessel formation.

Natural history and progression factors of unilateral moyamoya disease in pediatric patients

PURPOSE

Thirty-four pediatric age patients with unilateral moyamoya disease (MMD) were reviewed to analyze the natural history and the predictive factors for progression to bilateral MMD.

METHODS

Forty out of 259 MMD patients cared for between January 2000 and June 2008 in the Severance Hospital had unilateral lesion. These patients were followed for a mean of 32.3 months for their symptoms and imaging studies. Thirty-four out of 40 patients were included in this study. Magnetic resonance angiography (MRA) and magnetic resonance perfusion (MR perfusion) images were taken for all patients for initial diagnosis and repeated at 6 months from the initial diagnosis and then at yearly basis. Clinical manifestations, the results of imaging studies, outcome of the indirect revascularization procedure, and the progression of the lesion were reviewed in this study.

RESULTS

Of these 34 patients, contralateral progression was identified in 20 patients (58.8%). Fourteen (70%) out of the 20 patients presented with anterior cerebral artery abnormalities at diagnosis progressed to bilateral disease as well as did 5 (83%) out of 6 patients with middle cerebral artery lesions at the initial examination. Among the 34 patients, six exhibited familial history of MMD and all of them progressed to bilateral disease (100%, p < 0.005).

CONCLUSION

Careful and long-term follow-up would be essential to evaluate the hemodynamic status and progression to bilateral disease in unilateral MMD patients to make prompt decision for a surgical revascularization.

Moyamoya syndrome after radiation therapy: case reports

Potentially harmful effects of irradiation on the developing central nervous system have been well documented. We report 2 pediatric patients with moyamoya syndrome developed after irradiation.

CASE

A 3-year-old girl had received 4,860 cGy of postoperative radiation for optic pathway glioma. Cerebral angiography 7 months after completion of the radiation therapy revealed progressive cerebral arterial occlusive disease, involving the internal carotid artery on either side of the circle of Willis, with abnormal netlike vessels. Another 5-year-old girl had received 3,600 cGy of postoperative radiation on the cerebrum for a medulloblastoma. Two years later, she was diagnosed with moyamoya syndrome and treated with indirect revascularization. She died due to further progressive obstruction of the right M1 and A1 on the unoperated hemisphere, in spite of well-developed collateral circulation from the superficial temporal artery and middle meningeal artery on the operated left hemisphere. We suggest that radiation therapy with portals typically including carotid siphon may particularly cause vascular damage, regardless of the tumor pathology and lead to radiation-induced moyamoya syndrome. The prognosis may be poorer in case of poor collateral flow and rapid progression. The radiation therapy may cause fatal vascular damage so it should be taken into consideration when a treatment plan is being formulated for young patients.

Are arachnoid cysts localized hydrocephali?

We report 2 cases of arachnoid cysts related to a head trauma. The first case involved a 1-year-old girl who developed an arachnoid cyst 7 months after suffering a head trauma due to a motor vehicle accident, and the second case involved a 1-year-old boy whose arachnoid cyst was first noted 2 months subsequent to his premature birth. We present the serial imaging for both cases. Choi and Kim [Pediatr Neurosurg 1998;29:260-266] postulated that head trauma in infancy may contribute to the pathogenesis of arachnoid cysts in some cases. In presenting our cases, we support this hypothesis, and further postulate that the arachnoid cysts may in fact be localized hydrocephali, triggered either by head trauma or by prematurity.

Treatment option for arachnoid cysts

OBJECTIVE

The objective of this study is to establish which treatment is the best operative intervention for arachnoid cyst.

MATERIALS AND METHODS

We reviewed a series of 209 cases with arachnoid cysts focusing on the effectiveness and safety. The cysts were treated with several surgical procedures including open surgery for fenestration, endoscopic fenestration, or cystoperitoneal shunting.

RESULTS

Follow-up imaging studies showed that 176 out of 209 arachnoid cysts (84.2%) reduced in size during a mean postoperative follow-up period of 6.9 years (range, 1 to 14 years). Although a cystoperitoneal shunt was the best method for early achieving an obliteration of the sylvian cyst (89%), it had the danger of shunt dependency (42%) in addition to four early complications. Although endoscopic fenestration tended to be less effective in reducing the size of a sylvian cyst, it was safe and particularly effective in completely obliterating a suprasellar, quadrigeminal, and prepontine cyst.

CONCLUSION

Although the shunt for arachnoid cyst can get the more rapid good radiological outcome, the shunt-related complication and dependency would be hazardous. We suggest that endoscopic or reduced open procedures offer the advantage of avoiding a large craniotomy or the known complications of a cystoperitoneal shunt in treatment of arachnoid cysts. We could get the nearly same surgical outcome without shunt complications with endoscopic or open procedures.

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.

The history of ependymoma management

INTRODUCTION

The ependymomas are relatively not a common tumor. However, most clinicians agree that the radical removal of the tumor is the most important prognostic factor.

MORBIDITY OF TREATMENT

Tumor removal was not sufficient before the era of magnetic resonance imaging (MRI) and resulted in a considerable operative morbidity and mortality. As the microneurosurgical techniques and microsurgical anatomy become popular and the MRI provide more detailed anatomical information preoperatively, radical removal of this complex and complicated tumor can be more feasible. In childhood ependymoma, the treatment-related morbidity and mortality can be the special issues, which can modify the policy of management safe tumor removal and minimal adjuvant treatment, which are extremely important.

RADIATION THERAPY

Radiation treatment has been the option for disseminated disease and residual tumor. With the advancement of detailed MR anatomical information, safer and more delicate radiation becomes possible with newer radiation modalities, three-dimensional conformal radiotherapy, intensity modulating radiotherapy, and tomotherapy.

PROGNOSTIC FACTORS

Although many clinicians believe that the ependymomas are inheritably chemoresistant, the new targets for the treatment are under investigation or clinically tried. Also, the genetic alterations of ependymoma are developing and might be a promising target.

CONCLUSION

The surgical techniques and assistant modalities for tumor removal are still advancing. So, the outcome of ependymoma is still improving. Unfortunately, newer treatment modalities, such as new chemotherapeutic agent and gene modification agent, are still not promising. The history of ependymoma management is still in progress.

Factors contributing improvement of syringomyelia and surgical outcome in type I Chiari malformation

OBJECTIVE

The aim of our study was to compare pre- and postoperative radiologic data of posterior fossa and the improvement of syringomyelia after posterior fossa decompression (PFD) with and without tonsillar management in Chiari type capital I, Ukrainian malformation (CM-I).

MATERIAL AND METHODS

A retrospective analysis was made of all patients who underwent PFD between Oct 1991 and March 2007 for CM-I. Fifty-seven patients treated for CM-I at a single institution were included in the study. Patients were divided into two groups according to the procedures used during their PFD: PFD vs. PFD with tonsillar management. To determine whether the tonsillar management or changes of posterior fossa volume relate with surgical outcome, we measure posterior fossa size and syringomyelia pre- and postoperatively using magnetic resonance imaging.

RESULTS

Forty patients (70.2%) received PFD and 17 patients (29.8%) received PFD with tonsillar management. The length of syringomyelia affected improvement of syringomyelia (alteration rate, A-rate). Clinical symptoms, craniectomy size, syringomyelia type, and the surgeon's specialty did not affect A-rate. Tonsillar management has no significant effect on improvement of syringomyelia. Four patients need repeated surgery due to recurrence.

CONCLUSION

We have shown that tonsillar management do not lead to improve A-rate, and the radiologic changes of posterior fossa volume do not relate with radiologic improvement of syringomyelia. PFD without tonsillar management is sufficient to improve syringomyelia. The longer syrinx, the more A-rate improve in our study. However, a wider craniectomy is unrelated to A-rate. In cases of recurrent patients, we obtained good results with tonsillar management or syringosubarachnoid shunt.

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.

Low-dose craniospinal irradiation as a definitive treatment for intracranial germinoma

PURPOSE

To determine the optimal radiotherapy (RT) dose and volume for treatment of intracranial germinoma.

MATERIALS AND METHODS

Eighty-one intracranial germinoma patients (33 pathologically-verified; 48 presumed by radiosensitivity testing) treated with RT alone between 1971 and 2002 were analyzed. The RT volume varied from focal (13) to whole brain (8), or to the entire neuraxis (60). All the cases after 1982 received craniospinal irradiation (CSI). Radiation dose was reduced gradually during the study period from 59 to 39.3 Gy for primary tumors, and from 34.2 to 19.5 Gy for the neuraxis. The median follow-up time was 120 months (48-260 months).

RESULTS

Five- and ten-year relapse-free survival rates were 98.8% and 94.1%, respectively. All the recurrences occurred in the patients who received local (4/13) or whole brain RT (1/8). None of the patients who received CSI suffered from a recurrence. Forty-six patients received 45 Gy or less to the primary site and 22 patients received less than 20 Gy to the spinal axis.

CONCLUSION

Low-dose CSI-based RT should remain the standard treatment for intracranial germinoma. The RT dose can be reduced to 39.3 Gy for primary tumor sites and to 19.5 Gy for the spinal axis.

Treatment modality for intractable epilepsy in hypothalamic hamartomatous lesions

OBJECTIVE

Hypothalamic hamartomas (HHs) are often associated with early-onset gelastic seizures, thus configuring a well recognized and usually severe case of childhood epilepsy syndrome. We present a treatment modality for intractable epilepsy in hypothalamic hamartomatous lesions.

METHODS

This study presents 14 patients with medically refractory seizure associated with HHs treated between 1995 and 2005. The HHs were diagnosed on the basis of magnetic resonance imaging, except in the case of one patient in whom hamartoma was confirmed histologically. There were seven boys and seven girls in this study. The most frequent clinical presentations were seizures. To identify the epileptic focus, we performed comprehensive epilepsy investigations, including electroencephalographic recording using a depth electrode into the hamartoma.

RESULTS

To control the seizure, we performed surgical resection in one patient, gamma knife radiosurgery in four patients, and endoscopic disconnection in 11 patients. Seizure outcome was scored according to Engel's classification throughout a mean follow-up period of 27.4 months (range, 3-54 mo). Of the 11 patients who underwent endoscopic disconnection, six were seizure-free immediately after surgery. Two patients were already diagnosed as having an HH and underwent gamma knife radiosurgery, but seizure control was not achieved. Their gelastic seizure disappeared after endoscopic disconnection.

CONCLUSION

We confirmed that HHs are intrinsically epileptogenic. Therefore, we suggest that HH-related seizures may be controlled by blocking the seizure propagation from epileptogenic HHs through simple disconnection, regardless of the treatment modality, and the endoscopic disconnection of HHs is safer and more effective than other modalities.

Changing the paradigm of 1-stage total callosotomy for the treatment of pediatric generalized epilepsy

OBJECT

The authors propose that anterior callosotomy -- thought to have some advantages over total callosotomy -- is not superior to total callosotomy for prevention of seizure propagation or other complications.

METHODS

The study comprised 34 patients in whom generalized epilepsy syndrome or frontal lobe seizures with a secondary generalization were diagnosed. Preoperatively, all patients suffered from disabling drop attacks or intense head-drop seizures, and some patients also experienced other types of seizures. The male/female ratio was 22:12, and patients ranged in age between 1 to 19 years (mean 8.7 years). The follow-up period ranged from 1.08 to 5.0 years (mean 2.58 years). Seizure outcome, parental assessment of daily function, and parental satisfaction with the outcome was assessed postoperatively.

RESULTS

After undergoing 1-stage total callosotomy, drop attacks disappeared completely in 25 patients during the follow-up period, and in 6 patients the frequency of drop attacks decreased to < 10% of baseline. With regard to other types of seizures, seizures resolved completely in 12 patients, and in another 18 seizure frequency decreased. Two patients experienced a transient disconnection syndrome for 2 and 4 weeks. One patient experienced ataxic hemiparesis for 3 weeks before it completely abated. The overall daily function of the patients improved, and all parents were satisfied with the surgical outcome.

CONCLUSIONS

For pediatric generalized epilepsy syndrome, 1-stage total callosotomy will be the first choice in treatment for controlling generalized seizures.

Factors contributing to resectability and seizure outcomes in 44 patients with ganglioglioma

OBJECTIVES

The purpose of this retrospective study was to evaluate causes contributing to surgical resectability and seizure outcomes depending on various clinical and surgical factors.

PATIENTS AND METHODS

The records of 44 patients with gangliogliomas surgically treated between April 1986 and March 2007, were retrospectively reviewed to assess presenting symptoms, resectability and seizure outcomes.

RESULTS

Tumors were located in the supratentorial areas in 33 cases, the infratentorial area in 9 cases and the spinal cord in 2 cases. Thirty-five cases underwent gross total removal and 9 cases underwent subtotal resection. Only 2 cases underwent postoperative radiotherapy and 2 cases underwent gamma knife surgery. Twenty-six patients presented seizure symptoms of which 22 cases were located in temporal lobe and 4 cases were located in the extratemporal lobe. Twenty-three patients (88.5%) were seizure-free after surgery. Two patients were Engel class II and another was Engel class III.

CONCLUSION

We concluded that tumor location and seizure-presenting symptoms are good predictors of gross total removal. Gross total removal of ganglioglioma had a better chance of leaving the patient seizure free after surgery rather incomplete resection. Our data do not support the concept that surgical methods, invasive monitoring and surrounding cortical malformation correlated with seizure-free outcome.

Prediction of prognosis in children with medulloblastoma by using immunohistochemical analysis and tissue microarray

OBJECTIVES

Medulloblastoma is the most common malignant neuroepithelial tumor found in children. Several reports have described efforts to identify the prognostic significance of various patterns of pathological and immunohistochemical features in medulloblastoma, but the published data appear to be controversial. The authors therefore attempted to demonstrate these prognostic factors convincingly in a retrospective study performed in patients with medulloblastoma.

METHODS

The data used were obtained in 58 patients with medulloblastoma who were > 3 years of age and in whom > 1 year of follow-up was available after the maximal resection, craniospinal irradiation, and chemotherapy treatments. These assessments were performed to compare the immunohistochemical features to cellular differentiation, the proliferation index (PI), the apoptotic index (AI), and oncogenesis revealed by TrkC and c-erbB-3. In addition, the authors tried to determine the prognostic utility of these results in this tumor category.

RESULTS

There was no statistically significant correlation between the prognosis and the degree of cell differentiation, but a positive correlation was noted between the PI and the AI in a tumor mass. The number of cases with a PI > 10% was significantly greater in the group of tumors in patients with recurrent medulloblastoma. A close association between the PI as a continuous variable and the progression-free and overall survival was also found. Most importantly, the PI is the only significant prognostic factor for the overall survival of patients with medulloblastoma.

CONCLUSIONS

Therefore, the authors suggest that the PI is directly linked to the prognostic factor for medulloblastoma and that immunohistochemical staining is a potentially powerful tool for predicting the prognosis of patients with medulloblastoma.

Management of intracranial cavernous malformation in pediatric patients

OBJECTIVE

Cavernous malformations (CMs) are vascular malformations affecting any part of the central nervous system. CMs in the pediatric age group are known to be different from those of adults both in origin and clinical characteristics. In this paper, we report our experience in managing CMs in pediatric patients.

MATERIALS AND METHODS

Between January 1994 and December 2006, 33 patients younger than 20 years of age with intracranial CMs were treated with microsurgery or radiosurgery. We retrospectively reviewed the presentation and treatment of these 33 patients (18 boys and 15 girls; average age 11.6 years).

RESULTS

The most common symptom at presentation was seizure (19 children, 57.6%). The most common type of CM, classified on the basis of magnetic resonance imaging, was type II (18, 54.5%). The supratentorial compartment was the most frequent location (27, 71.8%), and only six CMs (18.2%) were observed in the infratentorial compartment. Microsurgery was performed on 25 patients (75.8%), and radiosurgery was performed on eight patients (24.2%). The overall post-treatment results were positive. Only two children (6.1%) had persistent presurgical neurological signs, although the treatment ameliorated them. No progression of the preoperative neurological signs or onset of new neurological deficits was seen in any of the patients. In our patient group, the microsurgical removal of CMs resulted in the prevention of recurrent hemorrhage and the control of seizure disorders in all cases.

CONCLUSIONS

Our results suggest that pediatric patients with symptomatic CMs should be treated surgically because of the risk of recurrent hemorrhaging and the general benefits of CM removal.

Treatment failure in intracranial primary germinomas

OBJECT

A radiation dose of 40-50 Gy is able to produce a cure rate of more than 90% in intracranial pure germinoma. However, many attempts have been made to reduce the dose and volume of radiation without compromising the disease control rate because of the toxicity of irradiation. This retrospective study is intended to provide the physician with an appropriate therapeutic strategy.

MATERIALS AND METHODS

We reviewed a series of 10 recurrent germinomas among 117 germinomas diagnosed histologically or clinically between 1979 and 2002. These patients involved underwent three different treatment modalities; radiation alone (N = 71), chemotherapy alone (N = 9), and combined therapy (N = 37). The 10-year overall and relapse-free survival rates were 97 and 93% in the radiation alone group, 89 and 67% in the chemotherapy alone group, and 92 and 92% in the combined therapy group, respectively. As expected, both radiation therapy and combined therapy were effective in controlling the disease. Tumor recurrence was closely related to the volume of radiation but not to the dose of radiation. If the tumor bed and craniospinal axis were fully covered, the radiation dose might be reduced. Chemotherapy alone showed earlier recurrence and a higher tumor recurrence rate. In the case of combined therapy, chemotherapy was useful in reducing the radiation dose but revealed some toxicity (death of two patients).

CONCLUSIONS

The investigation of a possible further dose reduction seems worthwhile. Radiation therapy alone with a dose of less than 40 Gy should be compared with ongoing chemotherapeutic protocols combined with low-dose irradiation.

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 rotunda. 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.

Mixed or metachronous germ-cell tumor?

OBJECTIVE AND IMPORTANCE

We report the extremely rare occurrence of a second germ-cell tumor at a different site and with different histological types long after total resolution of a pineal germinoma.

CLINICAL PRESENTATION

A 21-year-old man who presented with headache and diplopia was admitted to our hospital. Neuroradiological studies revealed a tumor in the pineal region. The tumor was biopsied with endoscope, and third ventriculostomy was performed. Histologically, the tumor proved to be a germinoma. The patient received 3 cycles of combination chemotherapy consisting of carboplatin and etoposide with radiotherapy. The tumor was totally resolute. Twelve months later, he was readmitted with headache and diplopia. Neuroradiological studies showed a tumor in the right temporal lobe.

INTERVENTION

The second tumor was totally removed. Histologically, the tumor proved to be a mixed germ-cell tumor, which consisted a yolk-sac tumor and a germinoma. After the second course of chemotherapy, magnetic resonance image studies revealed no evidence of the tumor.

CONCLUSION

The second tumor was considered to be a metachronous neoplasm rather than a recurrence of the original mixed germ-cell tumor, which consisted a yolk-sac tumor and a germinoma.

Distraction vs remodeling surgery for craniosynostosis

OBJECTS

We designed several distraction devices and applied these instruments in 14 patients with varying types of craniosynostosis. The aim of this report is to clarify the advantages and disadvantages of these surgical methods and to discuss current concepts for the surgical strategy in the treatment of craniosynostosis.

METHODS

From January 2000 to July 2005, 28 patients with craniosynostosis were retrospectively analyzed. Surgical treatment was performed on 14 patients using the distraction method with internal distraction devices that we designed, in which 5 patients had plagiocephaly, 3 brachycephaly, and 6 scaphocephaly. All patients underwent preoperative and postoperative evaluations, which included the patient's neurological state, and three-dimensional CT.

RESULTS

With distraction devices, the time required for the surgery could be shortened almost 3 1/3 h; the bleeding during the surgery was decreased with reduced requirement of more than 200 ml of blood transfusion as compared with remodeling surgery. Postoperatively achieved distraction distances varied from 30.0 to 47.5 mm (mean, 42.99 mm). The average increased volume percent of cranium in distraction surgery group was 20.9% (range, -11.5 to 58.9%) after full distraction.

CONCLUSION

With distraction surgery, satisfactory cranial volume expansion and aesthetically pleasing morphological states were achieved in all cases, and the efficacy was statistically significantly high as compared with remodeling method.

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.

Risk factors for postoperative ischemic complications in patients with moyamoya disease

OBJECT

The aim of this study was to determine the risk factors associated with the development of postoperative ischemic complications after surgical revascularization used to treat pediatric patients with ischemic moyamoya disease.

METHODS

The clinical, imaging, and perioperative data from 170 procedures in 90 children who underwent indirect revascularization surgery were retrospectively reviewed. To clarify the risk factors, cases with identified ischemic complications and those without such events were compared. For this study, a postoperative ischemic complication was defined as a newly developed infarction within 2 weeks after surgery, which was confirmed by follow-up imaging studies.

CONCLUSIONS

The higher ischemic risks from surgical treatment should be considered for patients with moyamoya disease who are younger than 3 years of age and have a preoperative cerebral infarction. It is also recommended that the revascularization surgery be delayed for at least 6 weeks after the development of the previous cerebral infarction.

Endoscopic disconnection for hypothalamic hamartoma with intractable seizure. Report of four cases

Although intractable epilepsy associated with hypothalamic hamartoma (HH) can be controlled by microsurgical resection of the lesion, excision of deep-seated lesions is often associated with morbidity and mortality. Endoscopic disconnection is less invasive and seems to be well suited for this indication. The authors discuss the role of endoscopic-assisted surgery in the management of HH-induced seizures. Four patients with HH-related intractable gelastic seizure underwent endoscopic disconnection surgery. Postoperatively, all patients exhibited improvement. Two patients became seizure free immediately after endoscopic disconnection surgery, one patient with a widespread seizure focus involving the motor strip continued to experience rare complex partial seizures but gelastic seizures ceased, and one experienced a reduced frequency of seizures but persistence of some generalized seizures. Three patients suffered postoperative disconnection-like syndrome, which continued 3 to 7 days and spontaneously disappeared. The authors advocate the endoscopic disconnection surgery as a safe and effective treatment for HH-related epilepsy by blocking the spread of epileptic discharges from the lesion.

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.

Postoperative evaluation of moyamoya disease with perfusion-weighted MR imaging: initial experience

BACKGROUND AND PURPOSE

Encephaloduroarteriosynangiosis (EDAS) has become the main treatment for moyamoya disease, a chronically progressive cerebrovascular occlusive disease in children. We aimed to assess the utility of perfusion-weighted MR imaging for evaluating hemodynamic changes before and after EDAS.

METHODS

Thirteen patients with angiographically confirmed moyamoya disease who underwent EDAS were investigated, and results were compared with those of a control group (n = 5). Perfusion MR imaging was performed before and after EDAS by using a T2*-weighted contrast material-enhanced technique. Relative cerebral blood volume (rCBV) and time to peak enhancement (TTP) maps were calculated. Relative ratios of rCBV and TTP in the middle cerebral artery (MCA) and basal ganglia were measured and compared with those of the posterior cerebral artery (PCA). Changes in hemodynamic parameters between pre- and post-EDAS perfusion maps were investigated.

RESULTS

The mean rCBV ratio of MCA to PCA in the patient group was slightly higher than that in the control group, without statistical significance. All 13 patients showed a delayed TTP in the MCA before EDAS compared with the control group (P =.0006), and the TTP after EDAS was significantly reduced (P =.0002). In the basal ganglia, shortening of the TTP was demonstrated before EDAS, but no significant change was observed after EDAS.

CONCLUSION

Perfusion-weighted MR imaging can be applied for evaluating postoperative changes in cerebral blood flow in moyamoya disease. Shortening of the TTP in the MCA of the hemisphere operated on is a marker for the development of collateral circulation from the external carotid artery to the internal carotid artery.

The reversible focal MRI abnormalities in complex partial seizure: technical instruction

CASE REPORT

A 17-month-old infant girl was admitted with complex partial seizures and right side hemiparesis. Five days after the last seizure, MR signal changes were observed in the left hemisphere with a cavernous hemangioma in the middle temporal gyrus. However, these MR signal changes had normalized 11 days after the last seizure, except for the cavernous hemangioma. The scalp EEG findings revealed that the epileptic focus was on the mid-temporal gyrus. The patient underwent lesionectomy only. Two months after this operation the MR showed no signal abnormality. Throughout a 12-month follow-up after surgery the patient remained seizure free.

DISCUSSION

MR signal changes in seizure patients do not always indicate the structural region concerned, but can be transient signal changes. They may be due to the propagation of epileptic discharge along the association fiber from the seizure focus. However, transient signal changes after seizure must be followed up to allow exclusion of a tumor and other diseases.

Optic sheath schwannomas: report of two cases

INTRODUCTION

Schwannomas are benign tumors that arise from Schwann cells in the peripheral nervous system. The vestibular division of the VIIIth cranial nerve is the nerve segment most commonly affected, the trigeminal nerve root being the next most frequently affected. Although schwannomas of other cranial nerves are very rare, these nerves do have myelinated sheaths composed of Schwann cells and are potential sites for intracranial schwannomas. However, previous studies have suggested that the term 'schwannoma' should not be applied in the case of optic nerve pathology, although two cases of optic nerve sheath schwannoma have been reported to our knowledge.

PURPOSE

The purpose of this paper is to report two cases of the exceedingly rare entity of optic sheath schwannoma and to discuss its histopathogenesis.

Nestin and small heat shock protein expression on reactive astrocytes and endothelial cells in cerebral abscess

Cerebral abscess results in an extensive capsular formation, which is an important limiting barrier for the spread of microorganism. Reactive astrocytes and endothelial cells are major cellular components of the abscess capsule together with fibrocytes. Molecular pathogenesis that results in the migration and proliferation of these cells remain speculative. Intermediate filament (IF) nestin and small heat shock proteins (sHSP) are developmentally regulated protein. In this study, we found that nestin expression is re-induced in not only reactive astrocytes, but also in endothelial cells in the gliotic area of the capsule. These nestin expressing astrocytes and endothelial cells also expressed sHSPs, such as heat shock protein 27 (HSP27) and alphaB-crystalline. These results indicated that embryonic reversions of cytoskeletal proteins to nestin and the increased expression of sHSPs in in reactive astrocytes and endothelial cells are caused by pathogenic microorganism induced inflammatory stress.

Selective posterior rhizotomy for lower extremity spasticity: how much and which of the posterior rootlets should be cut?

BACKGROUND

It is well known that selective posterior rhizotomy is effective for relieving spasticity associated with cerebral palsy. However, there is significant variation between surgeons in terms of how much and which of the posterior rootlets should be cut for the improvement of ambulatory function without causing adverse effects.

METHODS

The study population was composed of 200 CP patients who underwent SPR more than 1 year before this study. The children were divided into 4 groups (Group A had their L1-S2 roots cut, Group B had the L2-S2 roots cut, Group C had the L2-S1 roots cut, and Group D had the L2-S1 roots and the unilateral S2 root cut). We assessed lower limb spasticity, passive range of motion, ambulatory function, and gait pattern in each group.

RESULTS

Inclusion of L1 and S2 in the lesioning process of SPR was more effective at relieving spasticity in terms of hip adduction and ankle dorsiflexion respectively and improving ambulatory function (p < 0.01). Although lesioning of S2 carried a greater risk of urinary dysfunction, resection of less than 50% of S2 significantly improved ambulatory function without urinary complications (p < 0.01). Unilateral lesioning of S2 was an alternative option in selected cases with different amounts of spasticity in the ankles for the same purpose.

CONCLUSIONS

We propose that L1 and S2 roots should be included in the lesioning process of SPR for effective improvement of gross motor function, but that resection of these roots should be less than 50% to prevent complications.

Ictal electrocorticographic findings related with surgical outcomes in nonlesional neocortical epilepsy

PURPOSE

To characterize ictal electrocorticographic features related to surgical outcomes in nonlesional neocortical epilepsy (NE).

METHODS

We analyzed 187 ictal electrocorticograms (ECoG) obtained from 18 patients who had undergone presurgical evaluation and subsequent neocortical resections (frontal: seven, parietal: one, occipital: four, multilobar: six). None of them had any MRI-detectable lesions. Various ECoG data sets recorded from eight patients who achieved a favorable surgical outcome (either seizure free or more than 90% reduction of seizure frequencies) were compared with that from ten patients with unfavorable outcome (less than 90% reduction of seizure frequencies) (follow up duration: 47+/-11 months).

RESULTS

Reproducible ictal onset zone (IOZ) in recurrent seizures (P=0.013) and persistent ictal discharges in IOZ from the onset to the end of seizure (P=0.004) were found more frequently in the patients with good outcome. Ictal onset patterns consisting of low voltage fast or high amplitude beta spikes predicted a good surgical outcome while rhythmic sinusoidal activity or rhythmic spike/sharp waves of slow frequency were predictive of poor outcome (P=0.01). The ictal onset rhythm consisting of gamma or beta frequencies was more prevalent in the favorable group (P=0.015).

CONCLUSIONS

The presence of stable ictal circuit suggested by the consistent earliest activation of specific electrodes in the repetitive seizures (reproducible IOZ) and the active participation of IOZ throughout the attack were valuable prognostic factors in addition to the morphology and frequency of ictal onset rhythm.

Transcolumellar approach in transsphenoidal pituitary surgery for patients with small nostril

OBJECTIVE

Sublabial approach has been widely used as the standard technique for transsphenoidal pituitary surgery. But it has several possible drawbacks, such as; postoperative flat nose deformity, hypesthesia of upper gum, and feeding difficulty until 2 to 3 weeks after surgery. As an alternative, an endonasal approach was adopted for patients who had large nostrils, such as white or acromegalic patients. In patients with small nostrils, especially oriental people, it requires an additional tension release incision that leaves a definitely visible scar at the base of nose.

STUDY DESIGN

We applied the transcolumellar approach, which modified the external rhinoplasty approach on the 136 cases of transsphenoidal pituitary surgery that were performed from 1994 to June 1999.

RESULTS

In all patients, we found we could reach the anterior portion of nasal septum in 7 to 8 mm in depth from the skin surface and eliminate the disadvantages of sublabial and endonasal approach. Also, this method can markedly reduce the surgical dissection time and blood loss.

CONCLUSIONS

We concluded that this technique was relatively simple and more than adequate in most transsphenoidal pituitary surgery, even in patients with small nostrils.

Neural phenotype expression of cultured human cord blood cells in vitro

Neural stem cells have been proposed as useful vectors for treating diseases in the CNS, but their utility is severely limited by lack of accessibility. Brain development is ongoing extensively in early postnatal life. However, it is unclear whether stem cells that differentiate into neurons exist in the blood during early postnatal life. We showed in this experiment that neural markers (NeuN, neurofilament, MAP2, GFAP) are expressed and long cytoplasmic processes are elaborated in the cultured human cord blood monocytes prepared from newborn umbilical blood. These results suggest that stem cells in human cord blood may be potential sources of neurons in early postnatal life. We suggest that the neonatal blood system functions as a circulating pool of different types of stem cell.

Selective posterior rhizotomy in children with cerebral palsy: a 10-year experience

We reviewed our 10-year experience of selective posterior rhizotomy (SPR), with an emphasis on surgical outcome concentrated on improvements in functional ability and adverse effects. We had performed SPR in 208 patients between 1990 and 1999. All patients showed an overall improvement (over 95%) in spasticity, passive range of motion, and gait pattern. Preoperative ambulatory functional level and age were very important predictive factors for further improvements in postoperative functional ability. Compared with the younger children, the older ones lacked a full range of motion preoperatively, and they continued to lack a full range of motion postoperatively, despite the decrease in tone achieved by SPR. Most postoperative complications such as hypotonia, urinary retention, spinal deformities, and sensory changes were temporary and not functionally important. We conclude that SPR is an effective method of alleviating spasticity and provides lasting functional benefits at acceptable complication levels in spastic children with cerebral palsy.

A co-operative study: clinical characteristics of 334 Korean patients with moyamoya disease treated at neurosurgical institutes (1976-1994). The Korean Society for Cerebrovascular Disease

A co-operative study was conducted to determine the clinical characteristics of patients with moyamoya disease who were diagnosed and treated at neurosurgical institutes in Korea before 1995. Twenty-six hospitals contributed 505 cases and among them, the clinical characteristics of 334 patients with definite moyamoya disease were evaluated. The number of patients began to increase from the late 1980s, and after that approximately 20 patients were treated each year. There were two age peaks: from six to 15 and from 31 to 40 years of age. Haemorrhagic manifestations occurred in approximately 43% of the patients. The major clinical manifestations were haemorrhage in adults (62.4%) and ischaemia in children (61.2%). Overall 54.5% of the patients experienced decreased consciousness levels, mainly due to intracranial haemorrhage or cerebral infarction. In the patients with ischemic manifestations, the adult patients were more likely to have cerebral infarction than the pediatric patients (80% vs. 39%) and the pediatric patients were more likely to have TIA (61% vs. 25%). Thirty eight percent of the patients underwent bypass surgery and 53% of these procedures were performed bilaterally. Treatment policies, including indications for bypass surgery and commonly used drugs, were somewhat different according to the institution. Overall favorable outcome was 73%, and the most significant factor affecting poor outcome was haemorrhagic manifestation. This article describes the characteristics of 334 patients with moyamoya disease, who were diagnosed and treated at neurosurgical institutes in Korea before 1995.

Endoscopic surgery for obstructive hydrocephalus

Endoscopic surgery is popular in the neurosurgical field. The purpose of this study was to determine the role of endoscopy in obstructive hydrocephalus. From 1989 to 1999, we performed 81 endoscopic third ventriculostomies and 10 septostomies. Seventy-one of 81 operations were performed with endoscopic third ventriculostomy alone and 10 patients had endoscopic third ventriculostomy and ventriculoperitoneal shunt simultaneously. Age distribution varied from 2 months to 62 years of age. Our selection criteria included aqueductal stenosis (39 patients) and obstructive hydrocephalus due to tumor or cyst (42 patients). The most common candidate for endoscopic septostomy was atresia of the foramen of Monro (4 patients). Endoscopic septostomy was also performed to simplify shunting in patient; with multiseptated ventricle due to shunt infection, germinoma, thalamic tumor, craniopharyngioma, cyst and brain abscess. Sixty-five of 71 patients who were treated with endoscopic third ventriculostomy alone showed successful results (91.5%). However, 6 patients had unsatisfactory results and they needed a ventriculoperitoneal shunt. With no mortality, transient surgical complications were observed in 7 patients: 2 transient diabetes insipidus from electrical injury to the pituitary stalk, 1 epidural hematoma from sudden drainage of CSF, 1 delayed intraventricular hemorrhage. 2 obstruction of fenestration site and 1 transient memory disturbance from injury to the fornix. Endoscopic septostomy was useful in simplifying shunting in all cases with complicated hydrocephalus. Endoscopic surgery is straightforward and effective in appropriately selected cases with obstructive by drocephalus.

Quantitative assessment of cerebrospinal fluid hydrodynamics using a phase-contrast cine MR image in hydrocephalus

This investigation was undertaken to characterize CSF flow at the level of the aqueduct of Sylvius with a phase-contrast cine MR pulse sequence in 28 healthy volunteers. Sixteen patients with obstructive hydrocephalus and 11 patients with normal pressure hydrocephalus (NPH) were investigated with the same sequence before and after CSF diversion. The peak CSF flow velocity and stroke volume in the aqueduct increased significantly in the NPH group and decreased significantly in the obstructive hydrocephalus group. After lumboperitoneal shunting in the NPH group, the retrograde flow of CSF was anterogradely converted and the peak flow velocities decreased somewhat. The clinical diagnosis of NPH was well correlated with the results of cine MRI. After endoscopic III ventriculostomy in the obstructive hydrocephalus group we noted increased CSF flow velocity with markedly increased stroke volume at the prepontine cistern. Phase-contrast cine MR is useful in evaluating CSF dynamics in patients with hyperdynamic aqueductal CSF or aqueductal obstruction.

Endoscopic approach to arachnoid cyst

A prospective study of 36 consecutive patients with congenital arachnoid cysts treated endoscopically is reported. There were 15 female and 21 male patients. The mean age at the time of diagnosis was 12.3 years (10 days to 38 years). Arachnoid cysts were located in the suprasellar region in 16 patients, the sylvian fissure in 11, the quadrigeminal cistern in 4 and the posterior fossa in 5. Endoscopic fenestration was combined with cysto-peritoneal shunting for 6 temporal cysts and with ventriculo-peritoneal shunting in 1 suprasellar cyst. Mean postoperative follow-up was 4.2 years (range 1-8 years). Follow-up imaging studies showed that 28 arachnoid cysts (77.8%) were obliterated after endoscopic procedures. Long-term clinical results were good in all patients, although the cysts of 8 patients were not reduced in size. There was no mortality or morbidity. We conclude that endoscopic procedures may be a promising alternative to microsurgical operations or shunting for the treatment of arachnoid cysts.

A new experimental model of obstructive hydrocephalus in the rat: the micro-balloon technique

We used three types of specialized micro-balloons 0.7-1.35 mm in outer diameter instead of kaolin to develop a reproducible rat model of hydrocephalus with a low experimental mortality. The micro-balloon was inserted 6 mm deep into the cisterna magna via a burr hole immediately behind the lambda. The angle of introduction was 50 degrees. We also set up kaolin-induced hydrocephalic models in 25 rats as controls. The kaolin model revealed 52% mortality with an 80% induction rate of hydrocephalus, while the balloon model showed 9% mortality with a 60% induction rate. Balloon-induced hydrocephalus was maximal at 1 week and tended to decrease after 2-3 weeks. The pathological findings were not different between the two models. We concluded that the micro-balloon model for hydrocephalus is an easily reproducible model with low experimental mortality.

Pathogenesis of arachnoid cyst: congenital or traumatic?

For clarifying the pathophysiology of arachnoid cysts and reestablishing therapeutic criteria for such cases, we reviewed a series of 90 cases with arachnoid cysts focusing on the traumatic origin. Arachnoid cysts of congenital origin have been well known. But we suspected that 14 out of 90 patients (15.6%) with arachnoid cyst were closely related to head trauma. Seven of them suffered from head traumas in infancy. The episodes of head trauma included falling down in 4 patients, slipping down in 2 patients, and a motor vehicle accident in 1 patient. Traumatic arachnoid cysts had a latent period from head trauma to initial clinical manifestation. The mean latent period was 2.2 years, ranging from 10 months to 6.2 years. Six of 7 arachnoid cysts were located in the suprasellar area and 1 at the posterior fossa. An other 7 patients had a history of perinatal trauma. We postulate that head trauma in infancy may contribute to the pathogenesis of arachnoid cyst in some cases.

Treatment of germ cell tumors in the pineal region

The authors retrospectively analyzed 107 patients with primary intracranial germ cell tumor (GCT), who were treated at the Department of Neurosurgery, Yonsei Medical Center between January 1986 and January 1996. The incidence of GCT was 2.8% in pediatric patients with intracranial tumor. Of the 107 tumors, 60 were located in the pineal region, 30 in the suprasellar region, 16 in basal ganglia or the thalamic region, and 1 in the posterior fossa. The 60 pineal GCT consisted of 39 germinomas (29 pure germinomas, 6 germinomas with STGC, 4 germinomas mixed with teratoma), 5 mature teratomas, and 16 nongerminomatous GCT. Thirty patients underwent surgery: their operations took the form of total resection in 14 cases, subtotal resection in 10, and biopsy in 6. Thirty patients (27 with germinomas, 3 with endodermal sinus tumors) were managed without surgery on the basis of radiological findings and tumor markers. The 5-year survival was 91% for 39 patients with germinomas, 80% for 5 with mature teratomas, and 49% for 16 with nongerminomatous GCT. Univariate analysis of prognostic factors with the Kaplan-Meier survival curve showed that histological tumor type, radiological findings, results of tumor marker studies, and response to trial radiation or chemotherapy were highly correlated with outcome. Chemotherapy was beneficial as the method of trial treatment in pineal GCT and treatment in recurrent tumors. The administration of trial chemotherapy or radiotherapy without tissue biopsy is well justified as a treatment modality in pineal GCT suspected on the basis of radiological findings and tumor marker studies. Aggressive multimodality approaches with surgery, radiotherapy, and chemotherapy are necessary to improve the outcome in these tumors. We propose new protocol for treatment of germ cell tumors in the pineal region, which is based on a minimally invasive approach.

Identical characteristics of the patient populations with pineal region tumors in Japan and in Korea and therapeutic modalities

The therapeutic modalities used for tumors of the pineal region in Western countries differ from those in Japan, mainly because of the different patient populations. An extensive survey was conducted to delineate the racial differences in Japan and in Korea in the epidemiology and recent therapeutic modalities for this tumor group. Among the members of International Society for Pediatric Neurosurgery (ISPN), 15 from Japan and 5 from Korea reported their recent findings in 118 (1-25 years of age, mean 7.38-year period) and 125 (1-12 years of age, mean 6.69-year period) histologically verified cases, respectively. The patient populations in the two countries were found to be almost identical, with an extremely high incidence of germ cell tumors representing 71.2% (in Japan) and 80.0% (in Korea) of all pineal region tumors and neuroectodermal tumors representing only 15.2% and 16.8%, respectively. The most common type of pineal region tumor was germinoma (46.6% in Japan and 47.2% in Korea). The majority of tumors were radio- and/or chemosensitive, and adjuvant therapy rather than extensive surgery played the major role in the treatment in both countries. Radical resection of the tumor was recommended as the initial procedure by only 22.2% of neurosurgeons in Japan and 16.6% in Korea. Biopsy was recommended by 38.9% and 50.0%, and radiation therapy by 38.9% and 37.5%, respectively. A minimally invasive procedure, by either a neuroendoscopic (33.3% of biopsies in Japan) or a stereotactic approach (33.3% of biopsies in Korea), was considered to be appropriate as the initial procedure. The study disclosed the almost identical epidemiology of this brain tumor in Japan and in Korea and clarified the consequent therapeutic modalities. The authors emphasize that minimally invasive tissue diagnosis with or without tumor debulking should be considered as the initial step for the treatment planning of the pineal region tumor, followed by the most commonly indicated major procedures, including radiation therapy, chemotherapy and/or radical resection with various methodologies.

Natural history of moyamoya disease: comparison of activity of daily living in surgery and non surgery groups

The present study was undertaken to reach a clearer understanding of the natural history of Moyamoya disease. Follow-up studies were performed in 88 patients with Moyamoya disease. They were divided into the ischemia group and the hemorrhage group. The activity of daily living (ADL) of each groups were followed up and compared between those who were surgically treated and conservatively managed. Ischemic manifestations were more common in the younger children and tended to be recurrent, whereas hemorrhagic manifestations were more common in the adults. Follow-up duration of the 36 patients, who were surgically treated, ranged from 6 to 86.4 months (mean: 28.8 months). During the follow-up period, ADL was improved in 17 of 31 ischemic Moyamoya patients (55%); the condition was unchanged in nine (29%); and aggravated in five (16%). Follow-up duration of the 52 patients who were managed without surgery ranged from 12 to 216 months (mean: 67.2 months). In 35 patients of the ischemia group, ADL was aggravated in 49% and improved in only 26% during the follow-up period. However, ADL was aggravated in 12% of 17 hemorrhagic patients, but improved in 53%. Our result suggest that indirect revascularization procedures are effective for prevention of recurrent ischemic attacks which is common in pediatric patients. However, the effectiveness of indirect revascularization for hemorrhagic Moyamoya disease is not clear and requires extended follow-up study.

An analysis of the natural history of cavernous malformations

BACKGROUND

The treatment of cavernous malformations has been controversial. Some reports suggest that surgical resection of the lesion for the prevention of recurrent hemorrhage should not be considered because of low hemorrhagic risk. However, the role of surgery in management of cavernous malformations is undergoing reevaluation. The decision for surgical resection should be based on a careful analysis of the natural history of this lesion, which is not well understood.

METHODS

We investigated, retrospectively, the natural history of 108 cavernous malformations in 62 patients. Individual cavernous malformations were divided into four categories on the basis of magnetic resonance (MR) findings. The pattern of clinical and radiologic presentation and outcomes of management were analyzed.

RESULTS

The age of the patients ranged from 4-63 years (mean: 32.2 years). Multiple lesions were found in 13 of 62 patients (21%) and two of these patients were siblings. Twenty-five out of 62 patients had suffered recurrent symptoms. The bleeding rate was 2.3%/person/year (1.4%/lesion/year) during 2509.6 patient years. There were no significant differences between the bleeding rates of each type of lesion. During the follow-up period of 12-48 months (mean: 22.4 months), two of 28 patients conservatively treated had recurrent hemorrhages (rebleeding rate: 3.8%/person/year). During the follow-up period of 12-66 months (mean: 21.7 months), recurrent hemorrhages were observed in two of 17 patients with radiosurgery (rebleeding rate: 7.8%/person/year).

CONCLUSION

Our study has provided a profile of the natural history of these lesions. Based on our results, we recommend surgical excision of cavernous malformations in those patients with recurrent symptoms or acute progressive symptoms.

Intradural extramedullary xanthoma of the spine: a rare lesion arising from the dura mater of the spine: case report

OBJECTIVE AND IMPORTANCE

Xanthomatous tumors of the central nervous system are occasionally found in several unrelated diseases such as Hand-Schüller-Christian disease, Weber-Christian disease, histiocytosis X, malignant fibrous histiocytoma, and a complication of metabolic or storage diseases. However, a solitary xanthoma without systemic disease is rare. We present an unusual case of a solitary and benign xanthoma arising in the spinal leptomeninges without systemic diseases or metabolic abnormality, including a lipid profile.

CLINICAL PRESENTATION

A 16-month-old male patient was admitted with a complaint of spastic paraparesis. His magnetic resonance images revealed an intradural extramedullary tumor that showed isosignal intensity on T1-weighted images and high signal intensity on T2-weighted images with homogenous gadolinium enhancement.

INTERVENTION

The tumor arising from the spinal meninges was totally removed. Histological findings and immunochemical studies positive for CD68 and lysozyme stain showed abundant histiocytic cells with foamy cytoplasm. Negative S-100 protein in the immunohistochemical study and the absence of Birbeck granules on an electromicroscopic study excluded the possibility of Langerhan's histiocytosis. These findings corresponded to xanthoma. The patient had no abnormality of lipid metabolism or familial history of xanthoma.

CONCLUSION

The patient improved enough to walk by himself 3 months after the operation.

Huge Langerhans cell histiocytosis granuloma of choroid plexus in a child with Hand-Schüller-Christian disease. Case report

In the literature, only two previous cases of presumed Langerhans cell histiocytosis (LCH) granuloma involving choroid plexus have been reported in patients with Hand-Schüller-Christian (HSC) disease, but those cases were not verified by immunohistochemistry or electron microscopy. The authors report a case of LCH granuloma of the choroid plexuses of bilateral lateral ventricles and the fourth ventricle in a child affected by HSC disease. This disease was confirmed by the presence of Birbeck granules on electron microscopy and positive reactivity to S-100 protein. Clinical, radiographic, and histological features are discussed. This case illustrates that LCH granuloma should be considered in the differential diagnosis of intraventricular masses.

Brain tumors diagnosed in the first year of life in five Far-Eastern countries. Statistical analysis of 307 cases

A statistical survey is presented of brain tumors diagnosed in the first year of life (from five Far-Eastern countries) in relation to the racial differences in tumor types, congenital factors, and general clinical features. Of the 307 cases collected, 262 were verified histologically, and astrocytomas comprised 23.3%, medulloblastomas 17.2%, ependymomas 11.1%, choroid plexus papillomas 10.7%, teratomas 8.4%, primitive neuroectodermal tumors 4.2%, meningiomas 2.3%, and others 22.9%. There were statistically significant racial differences in comparison with the worldwide survey done by the International Society for Pediatric Neurosurgery Education Committee (1987) on the same subject. In the Far-Eastern population, medulloblastoma and teratoma were more common (P less than 0.05), whereas astrocytoma was less frequent (P less than 0.01) than reported in the worldwide survey. The malformative factors were suggested in 18 cases in which various associated congenital anomalies were observed. Vascular anomalous lesions, mostly in the extracranial organs, were most common, comprising 61.1% of the associated malformations. Hereditary factors were less commonly demonstrated in these tumors than were anomalies in the major congenital central nervous system. Among the 307 cases, there was one instance (0.3%) of nearly identical tumors occurring in twin brothers. The specific clinical manifestations of brain tumors involving the immature brain were again apparent in this survey, as were the poor survival rates and poor functional prognosis.

Primary malignant lymphomas of the central nervous system: radiotherapy results in 12 cases

Twelve patients with primary lymphomas of the central nervous system were treated in the Department of Radiation Oncology, Yonsei University College of Medicine, between 1976 and 1987. There were seven males and five females ranging from 19 to 63 years of age. They had single (6 cases) or multiple (6 cases) discrete intracerebral nodules. All patients were treated with radiation therapy. Surgical resection was performed in five cases and intrathecal chemotherapy with methotrexate was performed in seven cases after radiotherapy. All patients except one had received whole brain irradiation with a median dose of 4000 cGy. The radiation dose for a primary tumor was 4800-6000 cGy (median 5560 cGy). Initial response to radiation was excellent with a 91.7% complete response rate, but late recurrences were noted and the median survival was 42.3 months. Intracranial recurrences were observed in two patients who received less than 4000 cGy to the whole brain without intrathecal chemotherapy. Although intracranial recurrence was not seen in the patients receiving intrathecal chemotherapy after radiation, a high incidence of necrotizing leukoencephalopathy was noted. High dose irradiation with a minimum of 4000 cGy to the whole brain and more than 5000 cGy to the primary tumor is recommended for the treatment of primary CNS lymphomas. Combined use of chemotherapy should be carefully attempted because of the increased toxicity.