Benign cerebellar astrocytomas in children

OBJECT

Cerebellar astrocytomas are benign tumors of childhood known to be associated with excellent long-term survival in patients in whom complete surgical resection is possible. However, the roles of other factors--clinical, radiological, histological, and therapeutic--in the survival of the patient, tumor recurrence, and long-term patient outcome remain imprecise. The goal of this study was to examine these factors and their relationships.

METHODS

To clarify these issues a retrospective review was conducted of 168 children who were surgically treated for a cerebellar astrocytoma at Hôpital Necker-Enfants Malades between 1955 and 1995. These patients' clinical files were examined, the histological characteristics of their tumors were reviewed, and their outcomes were assessed according to Bloom's scale and the Wechsler intelligence quotient test. Of the 168 patients in the study, 91 were male and 77 were female with a mean age of 6.9 years and a mean follow up lasting 7.7 years. Tumors were identified as being strictly located in the cerebellum in 76.2% of the patients and as involving the brainstem (referred to as the "transitional form") in 23.8% of the patients. Complete surgical excision was possible in 88.7% of cases. There was a total mortality rate of 4.2% and a tumor recurrence rate of 9.5%. Fifty-eight percent of the patients had no neurological sequelae at follow-up evaluation. Pejorative factors that were discovered by multivariate analysis to be important included: a long preoperative duration of symptoms and the transitional form of tumor with respect to survival; incomplete tumor excision with respect to an increased risk of recurrence; and a long preoperative duration of symptoms, an early epoch during which surgery was performed (1955-1974), severe ventricular dilation, and the transitional form of tumor with respect to a poorer long-term patient outcome.

CONCLUSIONS

The presence of brainstem involvement (tumor in the transitional form) emerged as a significant negative prognostic factor and should be treated as a distinct nosological entity. The extent of surgical excision has a significant bearing on the risk of tumor recurrence.

Epilepsy in children with shunted hydrocephalus

OBJECT

The incidence of epilepsy among children with hydrocephalus and its relation to shunts and their complications, raised intracranial pressure (ICP), and developmental outcome are explored in a retrospective study.

METHODS

The authors studied a series of 802 children with hydrocephalus due to varying causes, who were treated by ventriculoperitoneal shunt placement between 1980 and 1990, with a mean follow-up period of 8 years. Patients who had tumoral hydrocephalus and those whose files lacked significant data were excluded. Data extracted from medical records, including history of the hydrocephalus and history of seizures, if any, were analyzed. Thirty-two percent of the children had epilepsy, the onset of which frequently occurred at approximately the same time that the diagnosis of hydrocephalus was made. The majority of the affected children had severe uncontrolled epilepsy. The incidence of epilepsy was significantly affected by the original cause of the hydrocephalus. The presence of radiological abnormalities was also found to be a significant predictor of epilepsy. Similarly, shunt complications predisposed to epilepsy. Episodes of raised ICP related to hydrocephalus or in association with shunt malfunction may also predispose to epileptic seizures. Furthermore, the presence of a shunt by itself seems able to promote an epileptogenic focus. Finally, epilepsy appears to be an important predictor of poor intellectual outcome in hydrocephalic children with shunts.

CONCLUSIONS

A prospective study is needed to identify clearly and confirm avoidable factors predisposing to seizures in these children so that we can strive to reduce the incidence of these seizures and, subsequently, improve these children's quality of life.

Late outcome of the surgical treatment of hydrocephalus

The purpose of this report is to analyze the long-term outcome in hydrocephalic children treated by shunt placement and in particular their psycho-intellectual development. In the case of shunt placement postoperative mortality is virtually nil, and the overall mortality rate after 10 years of follow-up has been reduced to less than 5%. Morbidity, in contrast, is far from satisfactory. This study was conducted in 129 consecutive children with nontumorous hydrocephalus who underwent a first shunt insertion before the age of 2 years between 1979 and 1982 and who were followed up for at least 10 years. The final neurological examination revealed a motor deficit in 60%, visual or auditory deficits in 25%, and epilepsy in 30%. The final IQs were above 90 in 32% of the children, between 70 and 90 in 28%, between 50 and 70 in 19%, and lower than 50 in 21%. Integration into the normal school system was possible for 60% of the children, but half of them were 1-2 years behind their age group or having difficulties; 31% were attending special classes or were in institutions; and 9% were considered ineducable. The presence of behavioral disorders was a determinant factor for scholastic and social integration. Such disorders were frequent, and were characterized as severe in 30%. A relationship between final outcome and etiology, initial ventricular size, and epilepsy was observed. These results are used as the basis of a discussion on how morbidity might be improved.

Medical abortion: ethics, laws and religious points of view, A study by the 1994-1995 Ethics and Morals Committee of the ISPN

Central nervous system malformations are now frequently detected prenatally. Unfortunately, the progress in diagnosis having far outstripped that in therapeutics, the only question to answer is usually whether the pregnancy should be continued or terminated. Pediatric neurosurgeons have to deal with such problems more and more often. They are asked to give an opinion on the prognosis. In many cases the law requires their involvement in the decision about the possibility of a "therapeutic", or more correctly a medical, abortion. The final decision is based on the religious attitutes of the family and the neurosurgeon and on the law of the country in which the medical abortion would be performed. This article reviews the points of view of the main religions and also the laws in different countries. This knowledge may be of some help to neurosurgeons, especially when the religious attitudes of those involved are different or when their final decision is not in accordance with the law of the country.

Intellectual outcome in children with malignant tumors of the posterior fossa: influence of the field of irradiation and quality of surgery

The purpose of this study was to determine the respective parts played by cerebral hemisphere irradiation, posterior fossa irradiation, and surgery in the poor late functional results often observed in children treated for medulloblastoma. To do this we compared the intellectual outcome in a series of 59 children operated on for medulloblastoma, who had received whole-brain irradiation, to that observed in a series of 37 children operated on for ependymoma of the posterior fossa, who had received radiotherapy only on the posterior fossa. Only patients who had survived for more than 2 years without recurrence were included. At the assessment 1 year after treatment, intellectual outcome was somewhat better in the ependymoma group, but the difference was not statistically significant. At the long-term follow-ups at 5 and 10 years the results remained stable in the children treated for ependymoma, around 60% having an IQ above 90, whereas the intellectual level of the children treated for medulloblastoma was seen to have deteriorated progressively: 20% had an IQ above 90 5 years after treatment and only 10% at the 10-year follow-up. This progressive degradation is most likely due to the irradiation of the cerebral hemispheres, as this prophylactic irradiation constituted the only difference between the two groups. Moreover, irradiation to the posterior fossa did not seem to affect intellectual functions, since in the group of children with ependymomas the proportion of IQs above 90 was high and remained stable over the years. Surgery was certainly responsible for some poor results. The percentage of IQs above 90 observed 1-2 years after treatment was between 70 and 80 when no postoperative complications occurred, and only between 20-40% in the presence of postoperative complications. Postoperative aggravation was in most cases related to a brain-stem lesion. These results encourage the reduction, when possible, of irradiation to the cerebral hemispheres and underline the importance of the quality of surgery.

Malignant hemispheric tumors in childhood

Sixty-four malignant hemispheric tumors in children less than 15 years old were treated in the pediatric neurosurgical department of the Hôpital des Enfants Malades between 1970 and 1989. (1) These tumors evolved rapidly in most cases. However the pre-operative evolution in 20% of the patients had a duration of more than 6 months, which favors the hypothesis that at least one-fifth of these tumors result from malignant transformation of a benign lesion. This observation should prompt neurosurgeons to operate on all benign hemispheric tumors as soon as they are diagnosed. (2) Five of the 64 patients had two successive malignant diseases. In four cases the other malignant disease was an acute lymphoblastic leukemia. (3) Among the malignant hemispheric tumors, the grade III and IV astrocytomas had a dismal prognosis. As it is known from previous studies that grade I and II astrocytomas have a good prognosis in children, it can be concluded that grading these tumors is essential. By contrast, almost one out of two patients with malignant ependymoma was alive 5 years after treatment. This implies that the grading of ependymomas is of modest prognostic values. (4) The harmful effect of radiotherapy was evaluated by comparing the functional outcome of children operated for a benign hemispheric tumor to that of children operated and irradiated for a malignant hemispheric tumor.

[Malignant tumors of the cerebral hemisphere in children. A series of 64 cases]

BACKGROUND

Cerebral hemisphere tumors in children represent about 15% of all tumors of central nervous system. 30 to 40% of them are malignant and have a poor prognosis.

PATIENTS AND METHODS

The files of 64 children (30 boys and 34 girls, less than 15 years old) treated between 1970 and 1989 for malignant cerebral hemisphere tumor were analysed. There were 27 astrocytomas, 20 ependymomas, 7 oligodendroblastomas, 6 sarcomas, 2 neuroblastomas, 1 medulloepithelioma and 1 teratoma. The tumor was located in the frontal area in 18 patients; it was temporal in 9, parietal in 8 and occipital in 2 patients. The tumor infiltrated 2 or several lobes in 27 children. The tumor was excised in 58 patients (completely in 36). Radiotherapy was given in 42 children; 18 of them also received chemotherapy.

RESULTS

The time between the first clinical manifestation and diagnosis was longer than 6 months in 20% of cases. Symptoms of increased intracranial pressure were present at onset of the disease in 56% of patients and at admission in 73%. Convulsions revealed the tumor in only 30% of cases. Nine children died during the first post-operative month. The actuarial survival rate was 39 +/- 13% at 5 years and 29 +/- 13% at 10 years. This rate was better for ependymomas (48 +/- 23% at 5 years and 41 +/- 23% at 10 years) than for astrocytomas (25 +/- 18% and 13 +/- 16%). Three of the 27 astrocytomas developed in children who had been treated 6 to 7 years earlier for acute lymphoblastic leukemia. One infant developed acute lymphoblastic leukemia 2 years after surgery and chemotherapy for astrocytoma and one patient, treated at 5 months of age for retinoblastoma, developed an astrocytoma 13 years later.

CONCLUSIONS

Increased intracranial pressure is more frequently the first symptom than are convulsions in malignant cerebral hemisphere tumors. The long interval between the first manifestations and diagnosis suggests degeneration of benign tumors in 20% of cases. The development of a second malignant neoplasm is not exceptional in children. The better prognosis for ependymomas than for astrocytomas indicates that cerebral ependymomas should be excised and irradiated regardless of their grade.

Neurosurgery with craniotomy and CT stereotactic guidance in the treatment of intracerebral space-occupying lesions

When intracerebral space-occupying lesions are small or located deeply within the brain parenchyma, it is sometimes difficult to localize them at surgery or to design the most direct and least hazardous surgical approach. Therefore, we have developed a method that combines conventional neurosurgical techniques with craniotomy using stereotactic guidance. We have used the Brown-Roberts-Wells (BRW) stereotactic system, which allows for computed tomography (CT) or magnetic resonance imaging (MRI) guidance and does not interfere with the absolute sterility mandatory each time a flap is created. Eleven patients were operated on using this method. The deep tumors were approached through a linear incision of the cerebral cortex. Then a needle, fixed in the right position on the arc system of the BRW, was inserted toward the surface of the lesion; the exposure was finally widened by inflation of a rubber balloon set on the stereotactic needle. This technique allows the two lips of the cortical incision to be glued at the end of the operation. Gluing with a fibrin glue avoids the postoperative subdural collections that often develop when the ventricle has been opened. Except for one case, the postoperative course was uncomplicated in these patients. No permanent postoperative neurological worsening was observed even after the removal of an intrathalamic tumor.

Medulloblastoma in childhood: progressive intellectual deterioration

A series of 120 medulloblastomas in children operated on between 1967 and 1987 at the Hôpital des Enfants-Malades has been reviewed in order to check whether the conclusions of our study published 10 years ago have remained valid and, in particular, to verify whether the quality of life of these patients, which had been found to be poor at the time, had improved or worsened over the years. The postoperative mortality for the whole series was 6.5%; there have been no deaths in the 35 patients operated on after 1980. The overall survival rate for the 120 children was 60% at 5 years and 53% at 10 years; for the patients who completed radiotherapy, the survival rate was 73% at 5 years and 64% at 10 years. Survival rates were surprisingly better in patients treated when under 6 years of age than in older children. They were also better in girls than in boys, and in desmoplastic compared with other medulloblastomas; however, the differences were not significant. When comparing the groups after total or subtotal resection of tumors, survival rates were not significantly different, but were lower in the small group of partial resections. Cell differentiation did not influence the prognosis. Psychological sequelae were significant and worsened over the years. Five years after treatment 58% of the children showed an IQ above 80; 5 years later this group included only 15% of the patients. These psychological sequelae were related to age at the time of radiotherapy: the younger the child, the lower the final IQ.(ABSTRACT TRUNCATED AT 250 WORDS)

Benign astrocytic and oligodendrocytic tumors of the cerebral hemispheres in children

The authors review 42 consecutive cases of benign astrocytic and oligodendrocytic tumors of the cerebral hemispheres in children undergoing surgery in the pediatric service of the Hôpital des Enfants Malades between 1975 and 1987. Epilepsy was the presenting sign in 76% of the children and remained the only clinical sign at diagnosis in 62%. Partial or complex partial seizures were observed in half of the cases, but other seizure types were also frequent. Diagnosis of the tumor as the etiological agent rested upon the results of computerized tomography or magnetic resonance imaging. Postoperative mortality (5%) and morbidity (16%) rates were low. The postoperative intelligence quotient was above 80 in 71% of the patients, and 77% of the children had no major problem in school. Although only two of the 42 patients were given postoperative radiotherapy, there were no recurrences in 82% of the survivors. The actuarial probability of nonrecurrence of the tumor was 95% at 5 years. Three patients with recurrent tumor underwent further surgery and are, at the present time, recurrence-free. The incidence of epilepsy fell from 76% before surgery to 19% after removal of the tumor alone; therefore, intraoperative electrocorticography and resection of the electrically abnormal cortex at the time of the first surgical procedure do not appear necessary. It is possible that tumor removal restores a mechanism that limits the spread of seizures and, thus, the clinical manifestations of epilepsy. Benign astrocytic and oligodendrocytic tumors of the cerebral hemispheres in children should not be treated with adjuvant radiotherapy, at least initially.

Pericerebral collections after shunting

Nineteen pericerebral collections (18 subdural and 1 epidural) occurred in a series of 682 consecutive initial shunt insertions for hydrocephalus in children, performed between 1976 and 1984. No collections were observed in 358 reoperations performed in the same patients during the same period. The incidence rate of this complication is nearly four times higher after 2 years of age than in younger children (6.5% versus 1.7%). The rate is also higher, regardless of age, in noncommunicating than in communicating hydrocephalus. Pericerebral collections are observed with high- as well as low-closing pressure valves. Pericerebral collections after shunting were diagnosed in 80% of the cases less than 2 months after surgery. They were asymptomatic in nearly 60% of the cases but could become symptomatic later when they were not treated. At the onset at least, these pericerebral collections are compensated by the outflow of an equal quantity of intraventricular CSF so that ICP is only moderately elevated. Postshunt pericerebral collections may be the consequence of CSF loss at the time of surgery. In most cases, however, they are due to a CSF overdrainage by the valve. This overdrainage, together with the reversal of CSF flow in the highly resistant CSF pathways of hydrocephalus, establishes a pressure lower in the ventricles than in the subarachnoid space and tends to open up the subdural space. The treatment of postshunt subdural collections is the insertion of a simple tubing without valve between the subdural space and the peritoneum, the ventriculoperitoneal shunt being left in place. With this treatment, more than 80% of the collections disappeared or were improved.(ABSTRACT TRUNCATED AT 250 WORDS)

The Dandy-Walker malformation. A review of 40 cases

Forty cases of Dandy-Walker malformation referred to the Hôpital Necker Enfants-Malades between 1969 and 1982 have been reviewed. The incidence of the malformation in hydrocephalus was 2.4%. There was a slight, statistically insignificant, female prevalence. Hydrocephalus should not be included in the definition of the syndrome. In 80% of the cases, it was actually a post-natal complication of the malformation and most often developed within 3 months after birth. In 80% of the cases, a communication, although insufficient, was found between the dilated 4th ventricle and the subarachnoid space. Since this communication is probably established through the foramina of Luschka, the definition of the Dandy-Walker malformation should only include atresia of the foramen of Magendie. Associated brain and systemic malformations were numerous. Among facial anomalies, facial angiomas were found in 10% of our cases. The association of facial and cardiovascular anomalies favors the hypothesis that the onset of the malformation occurs between the formation and the migration of the cells of the neural crest (that is, between the 3rd and the 4th post-ovulatory week, earlier than previously thought). Except in selected patients, membrane excision has a high rate of failure and should be abandoned. Cyst-peritoneal shunting avoids the risk of an entrapped fourth ventricle and is presently the best surgical procedure. The overall mortality in this series was 12.5%. Intelligence quotients were over 80 in 60% of the patients. Other studies will be necessary to understand why the communication between the fourth ventricle and the subarachnoid spaces, sufficient in utero, usually becomes insufficient for a normal cerebrospinal fluid (CSF) circulation in the first months following birth. Two hypotheses are discussed: a change in CSF circulation, or bleeding in the dilated fourth ventricle during delivery.