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Notizen: Abstract We assessed the normal movement of the lumbar spinal cord using phase-contrast MR imaging, and also the movement of the spinal cord in patients with spinal lipoma pre- and postoperatively. Phase-contrast MR imaging proved to be a valuable tool in this context.

Notizen: Abstract Sixty-four malignant hemispheric tumors in children less than 15 years old were treated in the pediatric neurosurgical department of the H ôpital 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.

Notizen: Summary The authors report on a series of 57 medulloblastomas in children operated upon between 1964 and 1976. Among these children, 44 completed the treatment with radiotherapy to the whole central nervous system. The postoperative mortality rate is 10.5%. Postoperative deaths occurred mainly in infants or when a tumour involved the brain stem. The five-year survival rate is 54% in the whole series. It rose to 71% in the patients who completed the treatment with radiotherapy. The study shows that the life of survivals is frequently impaired by mental or behavioural disturbances. IQ varies from 70 to 90 in 58% of the children; it is below 70 in 31%. Behavioural disturbances are found in 93% of cases. 82% have defective spatial orientation, dysphasia, or dysgraphia. In order to evaluate the responsibility of X-ray therapy for the development of these sequelae, the results have been compared to those of a series of cerebellar astrocytomas surgically removed, but not irradiated. The comparison shows that radiotherapy is at least partially responsible for the mental and behavioural disturbances. No relation was found between these disturbances and a persistent ventricular dilatation or an endocrine dysfunction. However the endocrine assessment showed growth hormone deficiency in 65% of the children, short stature in 55%, and compensated hypothyroïdism in 58%.

Notizen: Summary In the removal of tumours that develop within the third ventricle, most approaches are not entirely satisfactory. Therefore, a new approach has been devised: transfrontal exposure of the anterior portion of the frontal horn; coagulation and section of the striothalamic vein in order to open up the roof of the third ventricle; use of a blunt spatula introduced in the foramen of Monro and pushed backwards under the choroïd plexus. This approach has been used in ten cases. Postoperative mortality has been nil; the surgical approach has not apparently been responsible for any sequelae. It is simple and gives a good view of the third ventricle.

Notizen: Abstract The authors report 16 cases of lumbosacral lipoma in children studied by MRI. The exact position of the cord and its relationship to the lipoma were well demonstrated in all cases but one. There was as high incidence (25%) of syringomyelia in the terminal conus. Arnold Chiari malformation was never associated, which differentiates lumbosacral lipomas from myelomeningoceles. However, the nerve roots and their relationship to the lipoma were rarely visualized. Despite these drawbacks, MRI is the examination of choice if lumbosacral lipoma is suspected in children.

Notizen: Abstract Hypothalamo-pituitary function in children with optic glioma may be impaired by the tumour itself and by the high cranial radiation doses used in treatment. This study evaluates the effect of optic glioma and its treatment on patient growth and pubertal development. Twenty-one patients (13 boys, 8 girls), treated for optic glioma by cranial irradiation (45–55 Grays) at a mean age of 5.4 years, were evaluated before (n=10) and/or after (n=21) irradiation. Growth hormone (GH) deficiency was present in only 1 patient tested before irradiation and in all patients after irradiation. Precocious puberty occurred in 7/21 cases, before irradiation in 5 patients and after irradiation in 2 patients. The cumulative height loss during the 2 years after irradiation was 0.2±0.2 SD (m±SEM) in 7 patients with precocious puberty and 1.1±0.2 SD in 14 prepubertal patients (P〈0.01). The corresponding bone age advance over chronological age, evaluated 1–3 years after irradiation, was 1.1±0.5 and −0.7±0.3 year in the two groups (P〈0.01). The mean height loss between time of irradiation and the final height was 2.3±0.6 SD (n=6). Primary amenorrhoea, associated with low oestradiol levels, occurred in two of the three girls of pubertal age. These data indicate that the high dose of cranial radiation used to treat optic glioma invariably results in GH deficiency within 2 years and that hGH therapy is required when GH deficiency is documented. Precocious puberty, resulting in apparently normal growth velocity in spite of GH deficiency, should be treated with luteinizing hormone-releasing hormone analogues because of the risk of accelerated bone maturation and reduced final height.

Notizen: Conclusions There is no need for demonstrating the necessity of multidisciplinary care units to take care of patients presenting with spina bifida. These patients have so many troubles and their troubles are sometimes so complex that coordination of treatments and determination of proper treatments needs close and long-lasting collaboration between various pediatric specialists. Such a collaboration cannot be set up, or only with great difficulties, outside large pediatric hospitals. In these multidisciplinary units, the role of the neurosurgeon is always important. For lipomas it lasts as long as the follow-up itself, because neurological deterioration in these patients is life-threatening. Theoretically, systematic removal of lipomas and untethering of the spinal cord should prevent these complications. However, in all studies, the length of follo-up is insufficient for drawing definite conclusions, especially since in this pathology the first neurological deficits may occur late in life.

Notizen: Abstract  This review evaluates the contribution of prenatal diagnosis to the understanding of intracranial cysts. We describe the outcome of 54 fetuses in which prenatal investigations indicated the presence of such lesions. The cysts were diagnosed between 20 and 30 weeks of gestation. Most (63%) were supratentorial and interhemispheric. There was only a single sylvian cyst. In the infratentorial compartment, median retrocerebellar cysts were predominant. Incisural cysts accounted for 14.8% of the series. Nine pregnancies were interrupted because of the presence of associated brain disorders. Forty-five children are alive. Thirty-four had neuropsychological tests. Cysts rarely progressed, most frequently stabilized and often regressed postnatally. Hydrocephalus was rare. In two cases delivery was precipitated at 36 weeks to allow urgent treatment of rapidly evolving cysts. Thirteen children (28.2%) were treated postnatally, in general for developing cysts. The median follow-up for the whole series exceeds 4 years. Behavior, neurological development, and intelligence are normal in 88% of the cases, and 91% have a normal neurological status. Prognosis at the time of the prenatal consultation was correct in 89% of the cases. We emphasize the value of prenatal magnetic resonance imaging and karyotype studies to limit risks of incorrect prognosis.

Notizen: Abstract Congenital lumbosacral lipomas can be responsible for progressive defects. The general feeling is that tethering of roots, filum, or cord probably explains this evolution, and that untethering of these structures could prevent late deterioration. Like the vast majority of neurosurgeons, we too have routinely and systematically operated on lumbosacral lipomas, even in the absence of neurological deficits. This policy stemmed from our belief that spontaneous neurological deterioration was frequent, recovery from preoperative deficits rare, and surgery both efficient and benign in nature. After 22 years of experience, we felt that it was necessary to review our series of 291 lipomas (38 lipomas of the filum and 253 of the conus) operated on from 1972 to 1994. To reassess the value of pro-phylactic surgery, we attempted an accurate evaluation of (1) the risk of pathology, (2) the risks involved in surgery, (3) the postoperative outcome with respect to preoperative deficits, and (4) the postoperative outcome in asymptomatic patients at 1 year and at maximum follow-up. Special attention was paid to 93 patients whose postoperative follow-up was more than 5 years (average 8.7, median 8, range 5–23 years). Of these 93 patients, 39 were asymptomatic preoperatively (7 with lipoma of the filum and 32 with lipoma of the conus). Lipomas of the filum and of the conus are entirely different lesions and were studied separately. In 6 cases prenatal diagnosis had been possible. The mean age at surgery was 6.4 years. Low back skin stigmata were present in 89.4% of cases. Preoperative neurological deficits existed in 57% of the patients and were congenital in 22%. Clinical signs and symptoms recorded were pain in 13.3% of the patients and/or neurological deficits affecting sphincter (52%), motor (27.6%) and sensory (22.4%) functions. Deficits were progressive in 22.4% of cases, slowly progressive in 58.8% of these and rapidly progressive in the remaining 41.2%. In 36 patients (13.2%) the lipomas were seen to grow either subcutaneously or intraspinally. Among these patients, 21 were infants, 2 were obese adolescents, and 10 were pregnant women. The metabolism of the fat within the lipomas was studied in 11 patients and found to be similar to that at other sites. Lipomas were associated with various other malformations, either intra- or extraspinal. These associated anomalies were rare in the case of lipomatous filum (5.2%) but frequent with lipomas of the conus, except for intracranial malformations (3.6%). Therapeutic objectives were spinal cord untethering and decompression, sparing of functional neural tissue and prevention of retethering. Procedures used to achieve these goals were subtotal removal of the lipoma, intraoperative monitoring, duroplasty, and sometimes closure of the placode. Histologically, lipomas consisted of normal mature fat. However, 77% of them also included a wide variety of other tissues, originating from ectoderm, mesoderm, or entoderm. This indicates that lipomas are either simple or complex teratomas. The results of the study are as follows. (1) Surgery was easy and safe when performed for treatment of lipomas of the filum (no complications), but difficult and hazardous in the case of lipomas of the conus (20% local, 3.9% neurological complications). (2) All types of deficit could be improved by surgery, which was beneficial in all cases of lipoma of the filum and 50% of cases of lipoma of the conus. (3) In asymptomatic patients long-term surgical results depended on the anatomical type of the lipoma. They were excellent in lipomas of the filum. In lipomas of the conus they were good in the short term but eroded with time. At more than 5 years of follow-up only 53.1% of the patients were still free of symptoms. (4) Reoperations were performed in 16 patients (5.5%), 5 (31.2%) of whom improved postoperatively, while in 7 (43.7%) progression stopped, in 3 (18.7%) deterioration continued and in 1 (6.2%) the condition was worse after surgery. (5) The natural history of the malformation, that is to say the risk of spontaneous aggravation, has only been evaluated in hospital in-patients, so that the true level of risk remains unknown. This means we cannot interpret the actuarial curve following surgery for asymptomatic lipoma of the conus. In conclusion, there are two different types of lipoma: lipoma of the filum, for which surgery is harmless and beneficial in both the short and the long term, and lipoma of the conus, for which surgery involves considerable risks and is of questionable benefit in the long term. This raises the question as to whether prophylactic surgery is indicated for patients with asymptomatic lipomas of the conus, and whether the outcome is any better than it would be if the lipoma were left to take its natural course. The lack of basic information remains a stumbling block to management of these patients. Until this is remedied, we are unable to recommend prophylactic surgery in patients with asymptomatic lipomas of the conus.

Notizen: Abstract Congenital intraspinal lipomas are frequently responsible for progressive neurological deficits caused by distortion or compression of the nervous system. Since fat metabolism in these lesions has not been previously studied, the aim of this study was to determine whether intraspinal lipoma cells behave like lipomas or like normal adipocytes. In 11 patients, intraspinal lipoma cells were compared with normal adipocytes isolated from adjacent subcutaneous adipose tissue for the following parameters: lipoprotein lipase (LPL), lipogenesis from U14C glucose, ß-receptor number, adenylate cyclase activity, cyclic AMP production, and lipolysis in response to ß- and α2-adrenergic agonists. No significant difference between these two cell populations was found, suggesting that intraspinal lipomas are not lipomatous tumors, but hamartomatous lesions capable of growth and regression along with the changes in the rest of the fatty pool. This emphasizes the danger of an abnormal weight gain, as well as the possible usefulness of an hypocaloric diet in patients who worsen in spite of previous surgery.