A review of 40 cases
Jean-François Hirsch, Alain Pierre-Kahn, Dominique Renier, Christian Sainte-Rose, and Elizabeth Hoppe-Hirsch
✓ 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. Cystperitoneal 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.
Giuseppe Cinalli, Dominique Renier, Guy Sebag, Christian Sainte-Rose, Eric Arnaud, and Alain Pierre-Kahn
✓ The incidence of chronic tonsillar herniation (CTH) was evaluated with magnetic resonance imaging in 44 patients with Crouzon's syndrome and 51 with Apert's syndrome; the incidence was 72.7% in Crouzon's syndrome and 1.9% in Apert's syndrome. All the patients with Crouzon's syndrome and progressive hydrocephalus had CTH, but of 32 individuals with Crouzon's syndrome and CTH, only 15 had progressive hydrocephalus. Five patients with Apert's syndrome were treated for progressive hydrocephalus; none had CTH.
The patterns of suture closure in these two groups of patients were studied, and significant differences in coronal, sagittal, and lambdoid sutures were found between patients with Crouzon's and Apert's syndromes. In Crouzon's syndrome, significant differences in the pattern of lambdoid suture closure were found between the groups with and without CTH; in the group with CTH, the lambdoid closure appeared earlier. The authors propose that the high incidence of individuals with CTH who have Crouzon's syndrome is related to the premature synostosis of the lambdoid suture in the first 24 months of age.
Report of two cases
Abhaya V. Kulkarni, Alain Pierre-Kahn, and Michel Zerah
✓ Spinal lipomas of the conus (SLCs) are relatively common closed neural tube defects. Many of these lesions are treated surgically at the time of diagnosis and, therefore, little has been documented about their true natural progression. In addition, the changes, if any, of SLCs in pediatric patients have not been widely studied or documented using magnetic resonance (MR) imaging. In this report, the authors describe two asymptomatic infants in whom serial MR imaging revealed substantial spontaneous regression of SLCs, a phenomenon that has been very rarely reported in the literature. These are the first MR imaging—documented cases of near-complete spontaneous regression of SLCs in infants.
Christian Sainte-Rose, Jacques LaCombe, Alain Pierre-Kahn, Dominique Renier, and Jean-François Hirsch
✓ From a previous study of achondroplasia as well as from the observation of patients with hydrocephalus associated with craniostenosis, the authors have concluded that an increased superior sagittal sinus venous pressure (SSVP) could be the cause of the enlarged ventricles. However, other workers have demonstrated that an increased SSVP could be the consequence of increased intracranial pressure (ICP). Therefore, the authors undertook a study to determine if there was a physiological test that could distinguish between rare instances of increased SSVP caused by structural and irreversible narrowing of the sinus and those caused by increased ICP.
In 20 hydrocephalic infants and children, pressure was simultaneously measured in the lateral ventricle, the superior sagittal sinus, and the jugular vein. Stable baseline pressures were recorded, as well as the variations observed after the withdrawal of an amount of cerebrospinal fluid (CSF) sufficient to lower ICP to zero. Similar recordings were taken after reinjection of an equal quantity of CSF. In all of the patients, SSVP was increased, but not as much as the ICP. In the cases of hydrocephalus without any associated cranial malformation, and therefore without any likely anatomical interruption of the sinus, CSF withdrawal induced a simultaneous decrease of ICP and SSVP. However, whereas ICP could be lowered to zero, SSVP never fell below the jugular venous pressure, which remained stable (around 5 mm Hg) throughout the recording session. Results were different when sinography demonstrated an anatomical interruption of the sinus, as in cases of hydrocephalus associated with achondroplasia or craniostenosis. In these cases, although ICP was normally lowered by CSF withdrawal, SSVP remained nearly unchanged, usually greater than the jugular venous pressure.
The present study demonstrated that SSVP recording during ICP variations induced by CSF withdrawal permits differentiation between a reversible collapse of the sigmoid sinus due to increased ICP and a fixed obstructive lesion of the sinuses. Based upon this test and the results of sinography, the authors inserted a venous bypass between the lateral sinus and a jugular vein in three patients.
Darach William Crimmins, Alain Pierre-Kahn, Christian Sainte-Rose, and Michel Zerah
The authors sought to determine the natural history of and optimal treatment for suprasellar cysts (SSCs).
Three hundred forty-two patients harboring intracranial cysts presented to the authors’ neurosurgery unit between January 1986 and August 2004. The patients’ records were reviewed to assess symptomatology, results of imaging studies, and outcome according to mode of treatment.
Thirty-three patients (9.6%) were eligible for this study. Nine SSCs were diagnosed prenatally and 24 were identified postnatally (range 0 months–18.2 years, mean 5.6 years). The mean follow-up period was 66.8 ± 44.6 months (standard deviation). Seven cysts were left untreated, six (66%) detected before birth and one (4.5%) after birth. Of the 26 patients who required surgery, three were admitted elsewhere for complications of shunt surgery. A ventriculocystostomy (VC) was performed in all three of these patients, but the treatment failed in two. The primary treatment in the remaining 23 children was: open fenestration in two patients, VC in seven, ventriculocystocisternostomy (VCC) in 13, and cystoperitoneal (CP) shunt in one patient. Both open fenestration procedures were successful, as was the CP shunt insertion. The success rate of primary endoscopic surgery, although not statistically significant, was higher for VCCs (11 [85%] of 13 patients) than for VCs (four [57%] of seven patients). None of the patients’ preoperative endocrine disorders resolved postoperatively. The distribution of intellectual and developmental quotients paralleled the normal range. Intellectual performance was unrelated to patient-specific factors or to treatment modalities.
Most SSCs are of moderate size, are stable and asymptomatic, and have a favorable outcome. Treatment is required when the cyst evolves or the patient is symptomatic, but endocrine disturbances alone are not an indication for surgery. When hydrocephalus is present, endoscopic fenestration is the primary treatment of choice. The goal of the procedure should be to open the cyst into both the ventricles and the cisterns. Intellectual capability after treatment at outcome is not related to age at diagnosis, initial or final cyst size, presence or absence of hydrocephalus, or type of endoscopic treatment.
Computer analysis of 1174 operations
Dominique Renier, Jacques Lacombe, Alain Pierre-Kahn, Christian Sainte-Rose, and Jean-François Hirsch
✓ A series of 1174 operations performed on 802 hydrocephalic children was analyzed in an effort to find the factors causing acute postoperative infection. Culture of the cerebrospinal fluid (CSF) samples during the operation was positive in 33 cases. These cases were excluded from the series. Ninety infections were observed in the remaining 1141 operations, an overall rate of 7.9%. Most of these infections were meningitis (56 cases). Staphylococcus epidermidis was the bacterium most frequent identified (44%).
Statistically significant relationships were found between shunt infection and the following factors: 1) age: infection was 2.6 times as frequent before 6 months than after 1 year of age (p = 0.03); 2) poor condition of the skin; 3) presence of intercurrent seats of infection at the time of surgery; 4) type of operation: the rate of infection was 8.4% in primary shunt insertions, 5% in shunt revisions, and 17.5% in reinsertions following shunt removal for infection (p = 0.0001); 5) end of the shunt requiring revision: an infection rate of 7.7% followed revision of the ventricular catheter alone, and 2.6% followed revision of the other end alone (p = 0.012); and 6) postoperative wound dehiscence or scalp necrosis. The surgical team involved was poorly correlated with the rate of infection (p = 0.12).
No statistically significant relationships have been found between infection and 1) etiology of hydrocephalus; 2) sex; 3) recent neurosurgical operation before the shunt procedure; 4) preoperative presence of an external drainage tube or CSF fistula; 5) lumbar or ventricular taps, or ventriculography; 6) number of previous operations performed on the shunt; 7) time (month and year) of operation; or 8) sugar level and cell count in the CSF.
Ricardo Santos de Oliveira, Giuseppe Cinalli, Thomas Roujeau, Christian Sainte-Rose, Alain Pierre-Kahn, and Michel Zerah
The authors of this retrospective review and analysis of the literature cover an institutional series of neurenteric cysts of the central nervous system in children treated in the magnetic resonance imaging era during a 14-year period.
Sixteen patients 20 days to 14 years of age are described. The most frequent signs and symptoms at presentation were acute spinal cord compression (11 patients), paresis of a cranial nerve (two patients), meningitis or infection (two patients), and intracranial hypertension (one patient). The locations of the cysts were as follows: in the spinal canal in 12 patients (75%), the clivus in two (12.5%), the cavernous sinus in one (6%), and the craniocervical junction in one (6%). The most common location was the ventral aspect of the spinal canal (seven patients). Associated spinal deformities were found in five patients. All patients underwent surgery, with a posterior approach used in all of the spinal cases. Total resection was achieved in 12 of the 16 cases and partial resection in four. Of the four patients who underwent subtotal resection, the cyst recurred in three, requiring further surgery.
Neurenteric cysts are uncommon congenital anomalies that can present acutely in the pediatric population. Total removal is usually possible and is associated with a good prognosis.
Illustrative cases and review of the literature
Giuseppe Cinalli, Christian Sainte-Rose, Arielle Lellouch-Tubiana, Guy Sebag, Dominique Renier, and Alain Pierre-Kahn
✓ Over the past 15 years, eight children affected by intramedullary low-grade gliomas associated with hydrocephalus were treated at l'Hôpital des Enfants Malades. In all cases the diagnosis of hydrocephalus was made prior to that of the spinal tumor. Neuroradiological examination of all patients revealed contrast enhancement of the intracranial subarachnoid spaces. In six cases this was progressive, suggesting subarachnoid spread of the tumor, which was confirmed in two cases by histological examination.
The authors analyzed 38 cases of intramedullary low-grade glioma associated with hydrocephalus that were reported in the literature. Fifteen of the cases had intracranial leptomeningeal seeding. Several hypotheses have been proposed to explain this unusual association, such as 1) increase in cerebrospinal fluid (CSF) viscosity because of elevated fluid protein content; 2) obliteration of the cisterna magna due to a rostral extension of the tumor; and 3) blockage of the spinal subarachnoid pathways of CSF resorption. Two other theories seem of particular interest. Bamford and Labadie suggested that the abnormal presence of fibrinogen in the CSF and its transformation into fibrin at the level of the basal cisterns and Pacchioni's granulation may alter CSF hydrodynamics. This mechanism alone is sufficient to induce hydrocephalus of the communicating type. In addition, as suggested by Maurice-Williams and Lucey, the resulting leptomeningeal fibrosis might predispose secondary implantation of neoplastic elements in the subarachnoid spaces of the intracranial compartment.