Joong-Uhn Choi

An analysis of the natural history of cavernous malformations.

BACKGROUNDnThe 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.nnnMETHODSnWe 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.nnnRESULTSnThe 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).nnnCONCLUSIONnOur 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.

Endoscopic approach to arachnoid cyst.

Abstractu2002A 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.

Pathogenesis of Arachnoid Cyst: Congenital or Traumatic?

For clarifying the pathophysiology of arachnoid cysts and restablishing 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.

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

Abstractu2002This 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.

Treatment option for arachnoid cysts

ObjectiveThe objective of this study is to establish which treatment is the best operative intervention for arachnoid cyst.Materials and methodsWe 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.ResultsFollow-up imaging studies showed that 176 out of 209 arachnoid cysts (84.2%) reduced in size during a mean postoperative follow-up period of 6.9xa0years (range, 1 to 14xa0years). 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.ConclusionAlthough 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.

Treatment of germ cell tumors in the pineal region

Abstract 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

Abstract 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.

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

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

Brain tumors diagnosed in the first year of life in five Far-Eastern countries

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<0.05), whereas astrocytoma was less frequent (P<0.01) than reported in the worldwide survey. The malformative factors were suggested in 18 cases in which various associated congential 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.

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

OBJECTIVESnThe purpose of this retrospective study was to evaluate causes contributing to surgical resectability and seizure outcomes depending on various clinical and surgical factors.nnnPATIENTS AND METHODSnThe 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.nnnRESULTSnTumors 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.nnnCONCLUSIONnWe 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.