Frederick A. Boop
Jean-François Hirsch and Christian Sainte-Rose
✓ A cortical incision performed with inflation of a balloon to create a channel has been used in an approach to deep lesions with minimal damage to cerebral tissue. The balloon is slipped over a blunt needle and, once in place, is inflated through the needle. Postoperative sealing of the incision with fibrin glue avoids the subdural collection of cerebrospinal fluid such as is sometimes observed when the ventricle is opened during surgery.
Christian Sainte-Rose, Michael D. Hooven, and Jean-François Hirsch
✓ To date, most patients suffering from hydrocephalus have been treated by insertion of differential-pressure valves that have fairly constant resistance. Since intracranial pressure (ICP) is a variable parameter (depending on such factors as patient's position and rapid eye movement sleep) and since cerebrospinal fluid (CSF) secretion is almost constant, it may be assumed that some shunt complications are related to too much or too little CSF drainage. The authors suggest a new approach to treating hydrocephalus, the aim of which is to provide CSF drainage at or below the CSF secretion rate within a physiological ICP range. This concept has led the authors to develop a three-stage valve system. The first stage consists of a medium-pressure low-resistance valve that operates as a conventional differential-pressure valve until the flow through the shunt reaches a mean value of 20 ml/hr. A second stage consists of a variable-resistance flow regulator that maintains flow between 20 and 30 ml/hr at differential pressures of 80 to 350 mm H2O. The third stage is a safety device that operates at differential pressures above 350 mm H2O (inducing a rapid increase in CSF flow rate) and therefore prevents hyper-elevated ICP. An in vitro study is described that demonstrates the capability of this system to maintain flow rates close to CSF production under a range of pressures similar to those observed under various human physiological and postural conditions. Promising clinical results in 19 patients shunted with this valve are summarized.
Dominique Renier, Christian Sainte-Rose, Daniel Marchac, and Jean-François Hirsch
✓ In this study, intracranial pressure (ICP) was recorded with an epidural ensor for periods of 12 to 24 hours in 92 cases of craniosynostosis. Pre- and postoperative recordings were performed in 23 patients, and 55 children underwent preoperative psychometric testing. The ICP was found to be normal in one-third of the cases, was obviously elevated in one-third, and was borderline in one-third. Waves of increased ICP were recorded during rapid eye movement (REM) sleep. After surgery, ICP decreased progressively and returned to normal in several weeks. A significant statistical relationship was found between the patients' ICP and their mental level: the higher the ICP the lower the mental level. The regression curve of ICP as a function of age shows that ICP is maximal at the age of 6 years and decreases later. The significance of these results is discussed. The authors recommend that ICP be recorded in cases of craniosynostosis since it is of some help in deciding whether patients should undergo surgery.
Raphael Guzman, Arjun V. Pendharkar, Michel Zerah, and Christian Sainte-Rose
Endoscopic third ventriculostomy (ETV) has become the procedure of choice for treatment of obstructive hydrocephalus. While patient selection is the most critical factor in determining the success of an ETV procedure, the technical challenge lies in the proper site of fenestration and the successful creation of a patent stoma. Positioning of a single balloon catheter at the level or below the floor of the third ventricle to achieve an optimal ventriculostomy can at times be challenging. Here, the authors describe the use of a double-barrel balloon catheter (NeuroBalloon catheter), which facilitates positioning across, as well as dilation of, the floor of the third ventricle. The surgical technique and nuances of using the NeuroBalloon catheter and the experience in more than 1000 cases are described. The occurrence of vascular injury was less than 0.1%, and the risk of balloon rupture was less than 2%. The authors found that the placement and deployment of this balloon catheter facilitate the creation of an adequate ventriculostomy in a few simple steps.
Anne-Laure Boch, Éric Hermelin, Christian Sainte-Rose, and Spiros Sgouros
Object. The authors studied new and calcified shunt catheters to identify the prevalence of failures caused by aging materials in the shunt. Complications associated with these devices have various origins. Among late complications, fracture or migration of the system is related to the subcutaneous adhesion of the distal tubing in a growing child. A review of a cohort of 64 children who underwent shunt placement in 1980 with barium-impregnated distal catheters showed that 10 of these patients underwent reoperation for complications related to aging of the shunt material. This group represents 15% of the whole series and 30% of those children who were followed for more than 3 years. The true impact of aging of materials on shunt function is probably underestimated.
Methods. The authors performed physical, chemical, and mechanical analyses of the retrieved aged catheters and also of new catheters, resulting in the following findings: 1) calcifications were observed only on the external surface of the catheter, predominantly in its subcutaneous segment at the level of the neck and anterior chest wall; 2) calcifications contained particles of free silicon and barium sulfate, signifying fragmentation of the polymer; 3) the microstructure of the silicone polymer was modified: microfractures and alteration of the polymeric network were observed; 4) silanol groups were observed on the external surface of the catheter; and 5) the mechanical properties of the silicone rubber were degraded, and the aged catheters were more brittle than the new ones, with ruptures at elongations and fracture energy much lower than that seen in new catheters.
Furthermore, in vitro testing with a metastable solution of simulated body fluid demonstrated the critical impact of pH variations in liquid media and surface degradation of the catheters on the precipitation of hydroxylapatite crystals.
Conclusions. Although most shunt complications can be addressed by better patient management and surgical technique, late complications appear to be partly related to aging of the material. Distal tubing calcifications have been observed in barium-impregnated catheters. The industry recently responded to these observations by introducing plain silicone-coated shunt tubing; further evaluation will show what improvement can be expected.
Anne Morice, Sylvie Fraitag, Catherine Miquel, Christian Sainte Rose, and Stéphanie Puget
Juvenile xanthogranuloma (JXG) is a rare disease that belongs to the non-Langerhans cell histiocytoses. It presents a wide clinical spectrum, usually occurs before 5 years of age, and is commonly confined to the skin; however, it can affect multiple sites, including the nervous system, and can lead to severe disorders. Although JXG is a benign disease that usually regresses spontaneously, several curative treatments have been proposed in cases of organ involvement. Treatment options include corticosteroids, chemotherapy, and radiotherapy; however, these can have severe, long-term adverse effects in children.
The authors here describe the first case of spontaneous resolution of an intramedullary spinal cord lesion of JXG associated with cerebral and cutaneous lesions in a young boy with 9 years of follow-up. The initial neurological symptoms resolved without any surgical or medical treatment. This case shows that extracutaneous lesions of JXG, including those with intramedullary spinal cord involvement, can regress without curative treatment—like cutaneous lesions—although both multidisciplinary care and close follow-up should be implemented.
Giuseppe Cinalli, Christian Sainte-Rose, Isabelle Simon, Guillaume Lot, and Spiros Sgouros
This study is a retrospective analysis of clinical data obtained in 28 patients affected by obstructive hydrocephalus who presented with signs of midbrain dysfunction during episodes of shunt malfunction.
All patients presented with an upward gaze palsy, sometimes associated with other signs of oculomotor dysfunction. In seven cases the ocular signs remained isolated and resolved rapidly after shunt revision. In 21 cases the ocular signs were variably associated with other clinical manifestations such as pyramidal and extrapyramidal deficits, memory disturbances, mutism, or alterations in consciousness. Resolution of these symptoms after shunt revision was usually slow. In four cases a transient paradoxical aggravation was observed at the time of shunt revision. In 11 cases ventriculocisternostomy allowed resolution of the symptoms and withdrawal of the shunt.
Simultaneous supratentorial and infratentorial intracranial pressure recordings performed in seven of the patients showed a pressure gradient between the supratentorial and infratentorial compartments with a higher supratentorial pressure before shunt revision. Inversion of this pressure gradient was observed after shunt revision and resolution of the gradient was observed in one case after third ventriculostomy. In six recent cases, a focal midbrain hyperintensity was evidenced on T2-weighted magnetic resonance imaging sequences at the time of shunt malfunction. This rapidly resolved after the patient underwent third ventriculostomy.
It is probable that in obstructive hydrocephalus at the time of shunt malfunction, the development of a transtentorial pressure gradient could initially induce a functional impairment of the upper midbrain, inducing upward gaze palsy. The persistence of the gradient could lead to a global dysfunction of the upper midbrain.
Third ventriculostomy contributes to equalization of cerebrospinal fluid pressure across the tentorium by restoring free communication between the infratentorial and supratentorial compartments, resulting in resolution of the patient's clinical symptoms.
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.