Ferdinando Aliberti

Chiari malformation in craniosynostosis

IntroductionChiari 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.DiscussionSince 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.ConclusionChiari 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

ObjectThe purpose of the present study is to assess the effectiveness of endoscopic third ventriculostomy (ETV) in children with hydrocephalus related to posterior fossa tumors.MethodsBetween 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.ResultsPreoperative 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.ConclusionsEndoscopic 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.

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.

Hydrocephalus in aqueductal stenosis.

IntroductionThe 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.MethodsAn extensive literature review concerning etiologic, pathogenetic, clinical, and neuroradiological aspects has been performed. Therapeutic options, prognosis, and intellectual outcome are also reviewed.ConclusionThe 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.

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

OBJECTIVETo 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. METHODSWe 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. RESULTSForty 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. CONCLUSIONA 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.

Hydrocephalus in Dandy–Walker malformation

IntroductionEven if the first description of Dandy–Walker dates back 1887, difficulty in the establishment of correct diagnosis, especially concerning differential diagnosis with other types of posterior fossa CSF collection, still persists. Further confusion is added by the inclusion, in some classification, of different malformations with different prognosis and therapeutic strategy under the same label of “Dandy–Walker”.MethodsAn extensive literature review concerning embryologic, etiologic, pathogenetic, clinical and neuroradiological aspects has been performed. Therapeutic options, prognosis and intellectual outcome are also reviewed.ConclusionThe correct interpretation of the modern neuroradiologic techniques, including CSF flow MR imaging, may help in identifying a “real” Dandy–Walker malformation. Among therapeutical strategies, single shunting (ventriculo-peritoneal or cyst-peritoneal shunts) appears effective in the control of both ventricle and cyst size. Endoscopic third ventriculostomy may be considered an acceptable alternative, especially in older children, with the aim to reduce the shunt-related problems. Prognosis and intellectual outcome mostly depend on the presence of associated malformations, the degree of vermian malformation and the adequate control of hydrocephalus.

Hydrocephalus and spinal cord tumors: a review

IntroductionHydrocephalus secondary to intraspinal tumors is a well-known but rare condition since about 1% of patients with spinal cord tumors have various degrees of hydrocephalus at initial presentation.DiscussionThe mechanism of development of intracranial hypertension and hydrocephalus in patients with spinal cord tumor is not exactly known. The problematic aspects of this condition, with regard to clinical presentation and pathophysiology, are discussed and the relevant literature is reviewed. This uncommon association should always be kept in mind in the differential diagnosis of hydrocephalus of unknown etiology for three main reasons: the possibility of neurological deterioration if the patient is shunted prior tumor removal, the possibility to treat the hydrocephalus without shunting by simply removing the tumor, and the possible role of hydrocephalus as an early sign of intracranial metastasis in patients previously operated upon for removal of intramedullary gliomas. Due to the very slow evolution of the disease, a careful and close clinical and neuroradiological follow-up are essential for many years afterward. The presence of intracranial hypertension in a patient previously operated for a spinal tumor should be considered and investigated as an early sign of neoplastic intracranial seeding.

Third Ventriculostomy in Shunt Malfunction

BACKGROUND Endoscopic third ventriculostomy (ETV) is the treatment of choice for noncommunicating hydrocephalus. In the last decade, its routine use also has taken place in patients who have previously undergone shunt placement (secondary ETV). METHODS This study reviews the specific anatomy of the ventricular system in patients presenting with shunt malfunction, the criteria for patient selection, and the results of ETV performed as an alternative to shunt revision in cases of shunt malfunction or infection. RESULTS The success rate of secondary ETV in well-selected cases is not different from that of primary ETV; it should be reasonable to offer all patients with blocked shunts and suitable anatomy indicating an obstructive cause the opportunity for shunt independence regardless of the original cause of the hydrocephalus. CONCLUSIONS Shunt infection should not be considered a contraindication to ETV, even if the success rate may be lower. Considering the higher complication rate and higher risk of intraoperative failure, secondary ETV should be performed by expert neuroendoscopists.

Eosinophilic granuloma of C4 causing spinal cord compression.

A rare case of vertebral eosinophilic granuloma (C4) causing spinal cord compression is reported. The clinical, histological and radiological features of this pathological entity are discussed. After surgery a complete neurological recovery was observed. The value, in selected cases, of surgical treatment with total removal of the tumour and reconstruction of the spine to ensure spinal stability and to prevent irreversible neurological deficit is emphasized.

Dislocation of a fractured mandibular condyle into the middle cranial fossa: a case treated by an extracranial approach

IntroductionPenetration of the mandibular condyle into the middle cranial fossa is a rare complication usually due to blunt traumas to the chin. Particular anatomical and dynamic conditions can lead to the intracranial dislocation of the condyle in spite of the fracture of the condylar neck that usually prevents this event from dissipating the kinetic force of the impact.DiscussionWe report the case of a 10-year-old female patient suffering from symphyseal and bilateral condilar fracture with intrusion of the left condyle into the middle cranial fossa. The diagnosis of intracranial dislocation was initially missed because of the nonspecific symptomatology and insufficient radiologic data provided by conventional investigations (plain X-rays and panoramic views). The persistence of the limitation of the mouth opening and the worsening of the preauricular pain with irradiation to the temporal region led us to perform further radiological investigations (computed tomography scan and magnetic resonance imaging) that revealed the intracranial complication. A successful removal of the displaced condyle was carried out through an extracranial approach, and at a 3-year follow-up temporomandibular joint function is satisfactory.ConclusionThe case is reported to emphasize the need for careful radiological investigation in case of condylar fractures and the effectiveness of the extracranial route to surgically treat these rare complications.