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Notes: Abstract  The author reviews the progress made during the last 25 years in noninvasive diagnosis of brain tumours in children. MRI has replaced all other modalities available at that time. The diagnosis is still based on a precise anatomical analysis of the lesion rather than on other specific findings. New techniques, such as spectroscopy and diffusion, may help to characterise further brain tumours in children preoperatively.

Notes: Abstract A method of calculating intracranial volume from horizontal computerized tomography scan slices is presented. The accuracy of this technique was confirmed by applying it to 10 dry skulls and comparing the values obtained with the true intracranial volumes, as determined by filling the skulls with water. Values ranging between 98.14% and 102.6% of the true values were obtained, the mean error being 1.13%. This technique is now being used to study intracranial volume changes in children with craniostenosis.

Notes: Abstract Background. Prenatal diagnosis of fetal brain anomalies relies mainly upon ultrasonography. However, even in the most experienced hands, the technique has limitations for some difficult diagnoses. MRI is an excellent imaging modality for the paediatric and adult brain. Objective. To assess the value of prenatal MRI when a cerebral anomaly was detected by US and where the prognosis depended on the identification of other anomalies undetectable by US, or where fetuses were at risk for a CNS lesion even when the US was normal. Materials and methods. Four hundred prenatal MRI examinations were performed since 1988, and confirmed by postnatal follow-up or pathological examination. Two-thirds of the examinations were performed after 25 weeks of gestation, one-third between 21 and 26 weeks. Fetal immobilisation was obtained by maternal premedication with flunitrazepam, administered orally 1 h before the examination. The examinations were performed on 1.5 T scanners using one or two surface coils. Results. Prenatal MRI allowed the diagnosis of serious unsuspected lesions such as neuronal migration disorders, ischaemic and haemorrhagic lesions and the abnormalities observed in tuberous sclerosis. It helped to characterise ventricular dilatation and anomalies of the corpus callosum and of the posterior fossa. Conclusions. MRI is a valuable complementary tool when prenatal US is incomplete, doubtful or limited. Prenatal MRI is particularly useful for the detection of ischaemic and haemorrhagic lesions, neuronal migration disorders and tuberous sclerosis lesions. Detection of these associated anomalies worsens the fetal prognosis, has medico-legal implications and modifies obstetric management. Normal prenatal MRI does not exclude an anomaly.

Notes: Abstract Background. Patients with ataxia telangiectasia (AT), known to have an inherent increased susceptibility to the development of cancer, may present with malignancies that are unusual for the patient's age, are often difficult to diagnose clinically and radiographically and respond poorly to conventional therapy. Materials and methods. We reviewed the clinical presentation and imaging studies of 12 AT patients who developed malignancies. Results. Eight of the twelve patients developed non-Hodgkin's lymphoma (CNS, thorax, bone), two developed Hodgkin's disease, and two were diagnosed with gastrointestinal mucinous adenocarcinoma. Conclusion. The lymphomas were commonly extra nodal, and infiltrative rather than mass-like. The recognition of the tumors was often delayed due to confusion with the known infectious complications in AT patients.

Notes: Abstract Arteriovenous malformation of the vein of Galen (VGM) is a unique vascular anomaly in children. Its extra parenchymal location allows for aggressive endovascular treatment. Depending on the age of the child, the clinical presentation of VGM varies from congestive heart failure to hydrocephalus. The deleterious consequences to the brain depend on many factors, the most important of which is the volume of blood shunting through the malformation and away from the brain parenchyma (“steal” phenomenon). High flow in a fetus with a developing brain will lead not only to brain ischemia but also to multiple organ failure. At the other end of the spectrum, a small malformation can be well tolerated. Treatment should be tailored to each individual case.

Notes: Abstract Twenty percutaneous transluminal renal angioplasties were performed on 16 children (mean age 8.7 years) with hypertension secondary to renal artery stenosis (RAS). The aetiologies were neurofibromatosis (n = 1), Williams syndrome (n = 2), Takayasu arteritis (n = 1) and fibromuscular dysplasia (n = 12). The stenosis was isolated proximal or distal in 13 cases and multiple in 3 cases. Angioplasty resulted in a complete cure without medical treatment in 9 cases. Angioplasty allowed a reduction of medical treatment in two single stenoses, but was ineffective in all cases of multiple stenoses. Our findings show that angioplasty of RAS in children is an effective treatment when the stenosis is isolated, with a 69 % success rate. It seems ineffective in case of multiple stenoses (three cases).

Notes: Abstract We report a 51/2-year-old boy with juvenile rheumatoid arthritis (JRA) and lower-limb lymphoedema. US, MRI and lymphangiography were performed. Based on the lymphangiographic study, we propose a pathogenesis based on obstruction of normal superficial lymphatic vessels in the affected limb. This is discussed with other pathogenetic factors proposed in the 16 previously reported cases of lymphoedema complicating JRA.

Notes: 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.