Hydrocephalus in aqueductal stenosis.

INTRODUCTION: The sylvian aqueduct is the most common site of intraventricular blockage of the cerebro-spinal fluid. Clinical aspects, neuroradiological appearance, and treatment of hydrocephalus secondary to aqueductal stenosis are specific. METHODS: An extensive literature review concerning etiologic, pathogenetic, clinical, and neuroradiological aspects has been performed. Therapeutic options, prognosis, and intellectual outcome are also reviewed. CONCLUSION: The correct interpretation of the modern neuroradiologic techniques may help in selecting adequate treatment between the two main options (third ventriculostomy or shunting). In the last decades, endoscopic third ventriculostomy has become the first-line treatment of aqueductal stenosis; however, some issues, such as the cause of failures in well selected patients, long-term outcome in infant treated with ETV, and effect of persistent ventriculomegaly on neuropsychological developmental, remain unanswered.

Pseudotumor cerebri.

INTRODUCTION: Pseudotumor cerebri is a condition characterized by raised intracranial pressure, normal CSF contents, and normal brain with normal or small ventricles on imaging studies. It affects predominantly obese women of childbearing age; however, its incidence seems to be increasing among adolescent and children. While among older children the clinical picture is similar to that of adults, younger children present demographic and clinical peculiarities. Different diagnostic criteria for adults and pre-pubertal children have been proposed. Etiology and pathogenesis are still unclear, particular concerning the role of obstruction to venous outflow. METHODS: An extensive literature review concerning all the aspects of pseudotumor cerebri has been performed, both among adults and pre-pubertal children. CONCLUSION: Pseudotumor cerebri is an avoidable cause of visual loss, both in adults and children. Few diagnostic measures are usually sufficient to determine the correct diagnosis. Since pseudotumor cerebri is a diagnosis of exclusion, the differential diagnosis work out is of special importance. Modern neuroimaging techniques, especially magnetic resonance imaging and magnetic resonance venography may clarify the role of obstruction to venous outflow in each case. Various therapeutic options are available: medical, surgical, and endovascular procedures may be used to prevent irreversible visual loss. Treatment is usually effective, and most patients will experience complete resolution of symptoms without persistent deficits.

Neuroendoscopic treatment of arachnoid cysts of the quadrigeminal cistern: a series of 14 cases.

OBJECT: In this paper, the authors' goal was to evaluate the role of neuroendoscopy in the treatment of arachnoid cysts of the quadrigeminal cistern. METHODS: Between March 1995 and February 2008, 14 patients affected by arachnoid cysts of the quadrigeminal cistern were treated endoscopically. The cysts were classified according to their anatomical and radiological appearance. The most frequent form (Type I) extended infratentorially and supratentorially with a dumbbell shape. Type II cysts were confined to the infratentorial space and were associated with the most severe and acute form of hydrocephalus. Type III cysts presented a significant asymmetric expansion toward the temporal fossa. Ten patients underwent an endoscopic procedure as primary treatment and 4 as an alternative to shunt revision. In 6 cases, the first endoscopic procedure was ventriculocystostomy (VC) together with endoscopic third ventriculostomy (ETV). In the other 8 cases, the first endoscopic procedure was VC alone. RESULTS: In the 6 cases in which VC was performed with an ETV, the procedure was successful, and the patients did not require further surgery. Of the 8 cases in which the first endoscopic procedure performed was VC without ETV, 7 underwent reoperation. Four of these patients underwent endoscopic procedures (by reopening the obstructed VC and performing ETV or cystocisternostomy) 2, 4, 4, and 5 months later with final success in all cases. Three patients (all of whom were previously treated using ventriculo- or cystoperitoneal shunts) required shunt reimplantation (complete failure). Subdural collection developed in 1 case, which was managed by transient insertion of a subduroperitoneal shunt. Neurological and developmental outcomes were good except for 1 patient who did not show improvement in preoperative developmental delay. No transient or permanent morbidity or mortality was observed. CONCLUSIONS: The analysis of this series suggests that arachnoid cysts of the quadrigeminal cistern and the associated hydrocephalus can be effectively treated by endoscopy; this approach allows the patient to be shunt independent in more than 78% of the cases. If endoscopy is used as first option, the success rate of endoscopic procedures observed in this series was 90%. Endoscopic third ventriculostomy should be associated with a VC to offer the highest success rate with a single procedure.

Central nervous system complications during treatment of acute lymphoblastic leukemia in a single pediatric institution.

Central nervous system (CNS) complications during treatment of childhood acute lymphoblastic leukemia (ALL) remain a challenging clinical problem. Outcome improvement with more intensive chemotherapy has significantly increased the incidence and severity of adverse events. This study analyzed the incidence of neurological complications during ALL treatment in a single pediatric institution, focusing on clinical, radiological, and electrophysiological findings. Exclusion criteria included CNS leukemic infiltration at diagnosis, therapy-related peripheral neuropathy, late-onset encephalopathy, or long-term neurocognitive defects. During a 9-year period, we retrospectively collected 27 neurological events (11%) in as many patients, from 253 children enrolled in the ALL front-line protocol. CNS complications included posterior reversible leukoencephalopathy syndrome (n = 10), stroke (n = 5), temporal lobe epilepsy (n = 2), high-dose methotrexate toxicity (n = 2), syndrome of inappropriate antidiuretic hormone secretion (n = 1), and other unclassified events (n = 7). In conclusion, CNS complications are frequent events during ALL therapy, and require rapid detection and prompt treatment to limit permanent damage.

Long-term results of a second endoscopic third ventriculostomy in children: retrospective analysis of 40 cases.

OBJECTIVE: To evaluate retrospectively the operative findings and long-term results of a repeat endoscopic third ventriculostomy (ETV) in pediatric hydrocephalic patients readmitted after the first procedure with symptoms and/or signs of intracranial hypertension and/or radiological evidence of increased ventricular dilation and/or occluded stoma on follow-up radiological examinations. METHODS: We analyzed a series of 482 ETVs in pediatric patients from 2 Italian departments of pediatric neurosurgery. The clinical charts of 40 patients undergoing a second ETV were selected and reviewed retrospectively. The pre- and postoperative radiological findings and operative films were analyzed retrospectively. RESULTS: Forty patients underwent a total of 82 ETVs. Thirty-eight patients were operated on twice and 2 were operated on 3 times. During the second procedure, the stoma was found to be closed in 28 patients without underlying adhesions, to be open but with significant arachnoid adhesions in the prepontine cistern in 8 patients, to be open without adhesions in 2 patients, to have a pinhole orifice in 1 patient, and to be closed with underlying adhesions in 1 patient. The second procedure allowed reopening of the stoma or lysis of the arachnoid adhesions in 35 patients and was abandoned in 3 patients because of extensive arachnoid adhesions or because the stoma was found to be wide open (2 patients). In 30 patients (75%), the second ETV was effective, and the 2 patients who underwent a third ETV remained shunt free. In 10 patients (25%), a ventriculoperitoneal shunt was eventually placed. Age younger than 2 years at the time of the first procedure and arachnoid adhesions in the subarachnoid cisterns observed during the second procedure are the main negative prognostic factors for the success of a second ETV. CONCLUSION: A second ETV can be performed with a reasonable chance of restoring patency of the stoma and avoiding placement of an extrathecal shunt. Every effort should be made to detect subarachnoid adhesions in the cistern on preoperative imaging study to select potential candidates and avoid unnecessary procedures.

Complications following endoscopic intracranial procedures in children.

BACKGROUND: The significant technological improvement of endoscopic instrumentation has allowed, in the last 10 years, a widespread diffusion of neuroendoscopic procedures. Nevertheless, severe, sometimes life-threatening, complications may occur during neuroendoscopic surgery, and the incidence and age specificity of complications in children have been underdescribed so far. MATERIALS AND METHODS: Complications recorded in a prospectively collected database of pediatric patients undergoing neuroendoscopic procedures were analysed; the medical histories of the patients and the surgical procedures were reviewed. RESULTS: Complications occurred in 32 out of 231 (13.8%) procedures performed for the management of obstructive hydrocephalus (137), multiloculated hydrocephalus (53), arachnoid cysts (29) and intraventricular tumors (12). Subdural hygroma occurred in 11 cases, seven requiring subdural shunting. In one of these cases, infection of the subdural space occurred and required a craniotomy. Cerebrospinal fluid (CSF) infection occurred in 11 cases. In one case, a frontal abscess developed and was managed with craniotomy. CSF leak occurred in nine cases, intraventricular haemorrhages in two, technical failures in seven, subcutaneous CSF collection (managed with lumbo-peritoneal shunt) in one, thalamic contusion and post-operative transient akinetic mutism in one. This patient suddenly died 6 months later, probably as a consequence of closure of the stoma. Two patients developed secondary compartmentalisation of the ventricles after complicated endoscopic third ventriculostomy. In nine cases, these complications were associated. Overall, no patient died after the procedure (operative mortality 0), one patient died 6 months after the procedure for unexplained events (sudden death rate 0.4%), and three patients presented permanent disability as a consequence of surgical complication (permanent morbidity 1.3%). CONCLUSIONS: Complication rate of neuro-endoscopic procedures is not negligible even in experienced hands. The majority are minor complications which do not affect the final outcome, but sporadically major events may occur, leading to significant problems in surgical management and, occasionally, to permanent disabilities. Careful selection of patients on pre-operative imaging studies and intensive training of surgeons are mandatory to improve results.

Neuroendoscopic treatment of multiloculated hydrocephalus in children.

OBJECT: The authors performed a retrospective analysis of data obtained in a series of 30 patients suffering from multiloculated hydrocephalus and treated endoscopically. The goal of the study was to evaluate the effectiveness of neuroendoscopic treatment as an alternative to the placement of multiple shunts to relieve intracranial hypertension, to simplify the shunt system, and to reduce the high rate of shunt revision. METHODS: The endoscopic procedures included intraventricular septum fenestration, aqueductoplasty, Monro foraminoplasty, and third ventriculostomy. The patients were divided into two groups: Group A included 23 children in whom a shunt was already in place at the time of endoscopy, and Group B included seven children in whom a shunt had never been placed. The control of hydrocephalus by a single shunt placement or the absence of a shunt was achieved in 25 (83.3%) of 30 children. In Group A, five children no longer had shunts, 14 needed a single shunt, three required two shunts, and one required three shunts. The mean preendoscopy shunt revision rate in this group decreased from 2.07/year to 0.35/ year following the endoscopic procedure. Seven patients required endoscopic reoperations (endoscopic reoperation rate 0.31/year, total reoperation rate [shunt revisions plus endoscopic reoperation] 0.66/year). In Group B, three children did not require shunts, three needed a single shunt, and one required two shunts. Two patients required repeated endoscopic surgery (endoscopic reoperation rate 0.19/year), and two patients required shunt revisions (shunt revision rate 0.07/year) (total operation rate 0.26/year). CONCLUSIONS: Neuroendoscopic procedures are a valid alternative to shunt revision in the management of multiloculated hydrocephalus. Early diagnosis comprising close monitoring with high-resolution magnetic resonance imaging and early treatment are the keys of success.

Neuroendoscopic management of interhemispheric cysts in children.

OBJECT: Interhemispheric arachnoid cysts are very rare, and they are often associated with complex brain malformations such as corpus callosum agenesis and hydrocephalus. Debate remains concerning the proper management of these lesions. Placement of shunts and microsurgical marsupialization of the cyst are the traditional options. Using endoscopic methods to create areas of communication between the cyst, the ventricular system, and/or the subarachnoid space is an attractive alternative to the use of shunts and microsurgery. METHODS: Between 2000 and 2005, seven consecutive pediatric patients with interhemispheric arachnoid cysts underwent neuroendoscopic treatment involving cystoventriculostomy in two patients, cystocisternostomy in two, and cystoventriculocisternostomy in three. There were three cases of associated hydrocephalus, six cases of corpus callosum agenesis, and one case of corpus callosum hypogenesis. The follow-up period ranged from 12 to 49 months (mean 31.6 months). Endoscopic procedures were completely successful in all but two patients. In one of the remaining two patients, a repeated endoscopic cystocisternostomy was performed with success because of closure of the previous stoma. In the other, a subcutaneous collection of cerebrospinal fluid (CSF) was managed by insertion of an lumboperitoneal shunt. A subdural collection of CSF developed in three patients; it was treated with insertion of a subduroperitoneal shunt in one patient and managed conservatively in the other two patients, resolving spontaneously without further treatment. Neurodevelopmental evaluation performed in six patients showed normal intelligence (total intelligence quotient [IQ] > 80) in three patients, mild developmental delay (total IQ 50-80) in two, and severe developmental delay (total IQ < 50) in one. CONCLUSIONS: Endoscopic treatment of interhemispheric cysts can be considered a useful alternative to traditional treatments, even if some complications are to be expected, such as subdural or subcutaneous CSF collections and CSF leaks due to thinness of cerebral mantle and to the often-associated multifactorial hydrocephalus.

The role of transventricular neuroendoscopy in the management of craniopharyngiomas: three patient reports and review of the literature.

BACKGROUND: Management of craniopharyngiomas is problematic and often requires multimodal protocols. In the last decade neuroendoscopy has been increasingly used in the management of these lesions. PATIENT REPORTS: We report three cases of craniopharyngiomas in which various endsocopic procedures were performed. In the first case the endoscopic approach alone allowed the gross total removal of an intraventricular craniopharyngioma; in the second case the endoscopic fenestration of a cystic intraventricular craniopharyngioma allowed long-term control of the tumor with no further treatment; in the third case endoscopic fenestration and drainage of the cystic part allowed collapse of the cyst with resolution of mass effect on the visual pathway and control of hydrocephalus. The patient later underwent microsurgical removal of the solid portion of the tumor. CONCLUSIONS: Neuroendoscopy has shown great versatility in the management of intra/paraventricular craniopharyngiomas. It can be used alone to achieve gross total removal or marsupialization of cystic tumors, or, more often, in association with additional therapies, such as microsurgery, radiosurgery or intracavitary drug administration.

Endoscopic aqueductoplasty and placement of a stent in the cerebral aqueduct in the management of isolated fourth ventricle in children.

OBJECT: In this study the authors conducted a retrospective evaluation of the effectiveness of endoscopic aqueductoplasty, performed alone or accompanied by placement of a stent, in the treatment of an isolated fourth ventricle (IFV) in seven patients afflicted with loculated hydrocephalus after a hemorrhage or infection. METHODS: Seven children with symptomatic IFV and membranous aqueductal stenosis underwent endoscopic aqueductoplasty alone or combined with placement of a stent in the cerebral aqueduct. The mean age of the patients at the time of surgery was 10 months. The mean duration of follow up was 26 months. In all patients a supratentorial shunt had already been implanted, and in five patients neuroendoscopy had already been performed because other isolated compartments had been present inside the ventricular system. Aqueductoplasty alone was performed in three patients and aqueductoplasty and aqueductal stent placement in four. A precoronal approach was performed in five patients and a suboccipital approach in two. Signs and symptoms of intracranial hypertension resolved in all cases. Stent placement was successful in all five cases, resulting in clinical and neuroimaging-confirmed improvements in the IFV. Restenosis of the aqueduct occurred in two patients in whom stents had not been placed. In one of these patients restenosis was managed by an endoscopic procedure, during which the aqueduct was reopened and a stent implanted; in the other patient a shunt was placed in the fourth ventricle. Hydrocephalus was controlled by a single shunt in six cases (86%) and by a double shunt in one case. CONCLUSIONS: Endoscopic placement of a stent in the aqueduct is more effective in preventing the repeated occlusion of the aqueduct than aqueductoplasty alone and should be indicated as the initial treatment in each case of compatible anatomy.

Intracranial pressure monitoring and lumbar puncture after endoscopic third ventriculostomy in children.

OBJECTIVE: The aim of this study is to analyze changes in intracranial pressure (ICP) after endoscopic third ventriculostomy (ETV) performed in children affected by noncommunicating hydrocephalus. METHODS: ICP was continuously recorded for an average of 7 days in 64 children who underwent 68 ETVs for obstructive triventricular hydrocephalus of various etiology. In the first group (44 children), ETV was performed as the primary treatment; in the second group (20 children), the patients presented with shunt malfunction and underwent ETV and shunt removal. Three of the patients in the second group were reoperated for obstruction of the stoma: two were reoperated once and one was reoperated twice. RESULTS: ICP changes after ETV were not homogeneous and varied according to etiology: the highest values were observed in patients affected by posterior fossa tumors and the lowest values were seen in patients operated on during shunt malfunction and who had their shunt removed. After 31 procedures (45.6%), ICP remained normal (< 20 mmHg) for the entire duration of the monitoring. After 37 procedures (54.5%), ICP was persistently high on Day 1 (mean, 29.7) and decreased very slowly in the subsequent days, remaining high for 2-9 days (mean, 4.5). After 20 of the 37 procedures with high postoperative ICP, patients presented symptoms of intracranial hypertension that resolved, in most of the cases, with one or two lumbar punctures. Lumbar puncture was noted to be effective in bringing about fast normalization of the ICP and resolution of the symptoms. In 13 patients (19.1%), ETV failed and a ventriculoperitoneal shunt was implanted. After four procedures, the stoma obstructed and the patients were treated, reopening the stoma. Postoperative ICP was not statistically significant higher in the patients in whom ETV failed. CONCLUSION: The high ICP observed in a group of patients in the early postoperative days is probably related to the slow permeation of the subarachnoid spaces by the cerebrospinal fluid flowing out of the third ventriculostomy. Management of intracranial hypertension after ETV remains a matter of controversy. The role of the lumbar puncture in the faster normalization of the ICP is examined in this article. By increasing the compliance and the buffering capacities of the spinal subarachnoid spaces, it probably decreases the cerebrospinal fluid outflow resistance from the ventricular system, facilitating the decrease of the ventricular volume and allowing faster permeation of the intracranial subarachnoid spaces. High postoperative ICP can account for persistent symptoms of intracranial hypertension and ventricular dilatation on computed tomographic scans after third ventriculostomy. A cycle of one to three lumbar punctures should always be performed in patients who remain symptomatic and who show increasing ventricular dilatation after ETV, before ETV is assumed to have failed and an extracranial cerebrospinal fluid shunt is implanted.

Current state and future development of intracranial neuroendoscopic surgery.

Since the introduction of the modern, smaller endoscopes in the 1960s, neuroendoscopy has become an expanding field of neurosurgery. Neuroendoscopy reflects the tendency of modern neurosurgery to aim towards minimalism; that is, access and visualization through the narrowest practical corridor and maximum effective action at the target point with minimal disruption of normal tissue. Transventricular neuroendoscopy allows the treatment of several pathologies inside the ventricular system, such as obstructive hydrocephalus and intra-/paraventricular tumors or cysts, often avoiding the implantation of extracranial shunts or more invasive craniotomic approaches. Endoscopic endonasal transphenoidal surgery allows the treatment of pathologies of the sellar and parasellar region, with the advantage of a wider vision of the surgical field, less traumatism of the nasal structures, greater facility in the treatment of possible recurrences and reduced complications. However, an endoscope may be used to assist microsurgery in virtually any kind of neurosurgical procedures (endoscope-assisted microsurgery), particularly in aneurysm and tumor surgery. Basic principles of optical imaging and the physics of optic fibers are discussed, focusing on the neuroendoscope. The three main chapters of neuroendoscopy (transventricular, endonasal transphenoidal and endoscope-assisted microsurgery) are reviewed, concerning operative instruments, surgical procedures, main indications and results.

Chiari malformation in craniosynostosis.

INTRODUCTION: Chiari malformation (CM) is a frequent finding in multisutural and syndromic craniosynostosis, occurring in 70% of patients with Crouzon's syndrome, 75% with oxycephaly, 50% with Pfeiffer's syndrome and 100% with the Kleeblattschädel deformity. The pathogenesis of this condition and rationale for treatment are still controversial. DISCUSSION: Since its first description in 1972, several factors have been cited to play a role in inducing CM. In the light of recent publications, the roles of premature fusion of cranial vault and cranial base sutures, of congenital anomalies of the cerebellum and brain stem, of raised intracranial pressure, of venous hypertension and of hydrocephalus are reviewed. Evaluation and management of CM are also discussed. CONCLUSION: Chiari malformation appears to be an acquired and progressive condition that develops in the first months of life, because of a disproportion between hindbrain growth and an abnormally small posterior fossa, a consequence of the premature fusion of lambdoid and cranial base sutures. Venous hypertension caused by stenosis of the jugular foramen can also be present in these patients, resulting in intracranial hypertension and/or hydrocephalus. Careful MRI evaluation is recommended for the forms of craniosynostosis at a high risk of developing hindbrain herniation. The selection of posterior cranial vault expansion as the first surgical procedure is advocated. In selected cases, treatment of the posterior cranial deformity by occipital vault remodelling and treatment of the Chiari-like deformity by suboccipital decompression can be carried out using the same surgical procedure.

Endoscopic third ventriculostomy in the treatment of hydrocephalus in posterior fossa tumors in children.

OBJECT: The purpose of the present study is to assess the effectiveness of endoscopic third ventriculostomy (ETV) in children with hydrocephalus related to posterior fossa tumors. METHODS: Between September 1999 and December 2002, 63 children with posterior fossa tumors were treated at Santobono Hospital in Naples, Italy. Twenty-six patients had severe hydrocephalus. In order to relieve intracranial hypertension before tumor removal, 20 were treated with ETV, and 6 with ventriculo-peritoneal (VP) shunts. Twenty patients with mild hydrocephalus were treated with diuretics, corticosteroid agents, and early posterior fossa surgery, and 17 patients who did not have hydrocephalus were treated by elective posterior fossa surgery. Another 4 ETV were performed in the management of postoperative hydrocephalus. RESULTS: Preoperative ETV procedures were technically successful. One was complicated by intraventricular bleeding. The successful 19 preoperative ETV resolved intracranial hypertension before posterior fossa surgery in all cases. Three of these 19 patients developed postoperative hydrocephalus and were treated by VP shunt insertion after posterior fossa surgery. Out of the 4 ETV performed after posterior fossa surgery, only 2 were successful, both when the shunt malfunctioned. CONCLUSIONS: Endoscopic third ventriculostomy should be considered as an alternative procedure to ventriculo-peritoneal shunting and external ventricular draining for the emergency control of severe hydrocephalus caused by posterior fossa tumors, since it can quickly eliminate symptoms, and hence, can delay surgery scheduling if required. Even though ETV does not prevent postoperative hydrocephalus in all cases, it does protect against acute postoperative hydrocephalus due to cerebellar swelling. In addition, it eliminates the risks of cerebrospinal fluid (CSF) infection related to external drainage and minimizes the risk of overdrainage because it provides more physiological CSF drainage than the other procedures. Since postoperative hydrocephalus is very often physically obstructive, ETV should always be considered a possible treatment procedure.