External ventricular drainage in pediatric patients: indications, management, and shunt conversion rates.

PURPOSE: Placement of an external ventricular drainage (EVD) is one of the most frequent procedures in neurosurgery, but it has specific challenges and risks in the pediatric population. We here investigate the indications, management, and shunt conversion rates of an EVD. METHODS: We retrospectively analyzed the data of a consecutive series of pediatric patients who had an EVD placement in the Department of Neurosurgery at Hannover Medical School over a 12-year period. A bundle approach was introduced to reduce infections. Patients were categorized according to the underlying pathology in three groups: tumor, hemorrhage, and infection. RESULTS: A total of 126 patients were included in this study. Seventy-two were male, and 54 were female. The mean age at the time of EVD placement was 5.2 ± 5.0 years (range 0-17 years). The largest subgroup was the tumor group (n = 54, 42.9%), followed by the infection group (n = 47, 37.3%), including shunt infection (n = 36), infected Rickham reservoir (n = 4), and bacterial or viral cerebral infection (n = 7), and the hemorrhage group (n = 25, 19.8%). The overall complication rate was 19.8% (n = 25/126), and the total number of complications was 30. Complications during EVD placement were noted in 5/126 (4%) instances. Complications during drainage time were infection in 9.5% (12 patients), dysfunction in 7.1% (9 patients), and EVD dislocation in 3.2% (4 patients). The highest rate of complications was seen in the hemorrhage group. There were no long-term complications. Conversion rates into a permanent shunt system were 100% in previously shunt-dependent patients. Conversion rates were comparable in the tumor group (27.7%) and in the hemorrhage group (32.0%). CONCLUSION: EVD placement in children is an overall safe and effective option in children. In order to make further progress, carefully planned prospective and if possible randomized studies are needed controlling for multivariable aspects.

The semi-sitting position in patients with indwelling CSF shunts: perioperative management and avoidance of complications.

OBJECTIVE: Posterior fossa or midline tumors are often associated with hydrocephalus and primary tumor removal with or without perioperative placement of an external ventricular drain (EVD) is commonly accepted as first-line treatment. Shunting prior to posterior fossa surgery (PFS) is mostly reserved for symptomatic cases or special circumstances. There are limited data regarding the anticipated risk for symptomatic pneumocephalus and the perioperative management using the semi-sitting position (SSP) in such a scenario. Here, we therefore assessed the safety of performing PFS in a consecutive series of patients over a period of 15 years to allow the elaboration of recommendations for perioperative management. METHODS: According to specific inclusion and exclusion criteria a total of 13 patients who underwent 17 operations was identified. Supratentorial pneumocephalus was evaluated with semiautomatic-volumetric segmentation. The volume of pneumocephalus was evaluated according to age and ventricular size. RESULTS: Ten of the 13 patients had a programmable valve (preoperative valve setting range 6-14 cmH20; mean 7.5 cmH20) while 3 patients had non programmable valves. A variable amount of supratentorial air collection was evident in all patients postoperatively (range 3.2-331 ml; mean 122.32 ml). Positive predictors for the volume of postoperative pneumocephalus were higher age and a preoperative Evans ratio > 0.3. In our series, we encountered no cases of tension pneumocephalus necessitating an air replacement procedure as well as no obstruction, disconnection, infection or hardware malfunction of the shunt system. CONCLUSIONS: Our findings indicate that a CSF shunt in situ is not a contraindication for performing PFS in the semi-sitting position and it does not increase the pre-existing risk for postoperative tension pneumocephalus. In cases of primary shunting for hydrocephalus associated with posterior fossa tumors a programmable valve set at a medium opening pressure with a gravitational device is a valid option when PFS in the semi-sitting position is opted. In patients with an indwelling shunt diversion system special caution is indicated in order to prevent and detect overdrainage especially in not adjustable valves or shunts without antisiphon devices.

Resection of posterior fossa tumors in the semi-sitting position in children younger than 4 years of age.

PURPOSE: The semi-sitting position for resection of posterior fossa tumors is a matter of ongoing debate. Here we report about our experience with this approach in children younger than 4 years of age. METHODS: We retrospectively analyzed data of children younger than 4 years of age operated on in our institution in the semi-sitting position over a 15-year period. Patients were intraoperatively monitored for venous air embolism (VAE) by transthoracic Doppler (TTD) or transesophageal echocardiography (TEE). The severity of VAE was classified according to the Tübingen grading scale. Intraoperative incidents of VAE were recorded and the patients' course was followed postoperatively with a special focus on possible complications. RESULTS: Twenty-four children (18 boys, 6 girls) were operated on in the semi-sitting position (26 operations). Mean age was 2.2 years (± 1.0), range between 0.4 and 3.9 years. External ventricular drains were inserted in 18 children with hydrocephalus preoperatively. VAE was detected in 6 instances during surgery (6/26 (23.1%)). In 3 patients with grade 1 VAE, no additional treatment was necessary. In one patient with grade 2 VAE, intracardiac air suction via the central venous catheter was performed, and in two patients with grade 4 VAE, additional cathecholamine-infusion was administered. No major intraoperative complications occurred. Postoperative CT images showed pneumocephalus in all children. In two children, small asymptomatic impression skull fractures at the site of the Mayfield pin occurred. Revision surgery was necessary in one child with a suboccipital CSF fistula. CONCLUSION: The semi-sitting position for resection of tumors in the posterior fossa in children younger than 4 years of age can be safely performed in experienced centers taking special caution to detect and treat potential complications in an interdisciplinary setting.

Effect of mannitol on platelet function during elective craniotomy in adult patients with brain tumor.

BACKGROUND: Mannitol is used in the treatment of raised intracranial pressure (ICP). The aim of this study was to investigate whether mannitol (MAN) leads to a relevant deterioration in platelet function in routine neurosurgical procedures. METHODS: Thirty-eight patients undergoing elective craniotomy due to a brain tumor with elevated ICP were included. After induction of anaesthesia a blood sample was taken (T1). The patients then received 1 g-kg-1 MAN within 30 minutes. The second blood sample (T2) was obtained 60 minutes after T1. Blood samples were examined by means of aggregometry (Multiplate®) and PFA-100® tests. RESULTS: No patient had clinical signs of increased bleeding. We could not find any deterioration in the aggregometry using Multiplate®, neither in the adenosinediphosphate (ADP), the arachidonic acid (ASPI), or the thrombin receptor activating protein (TRAP) test. PFA-100® closing times (cT) showed a significant prolongation between T1 and T2: collagen/adenosindiphosphate (COL/ADP) test 79s [70/99] and 91s [81/109]; p=0.002); collagen/epinephrine (COL/EPI) test 109s [92/129] and 122s [94/159]; p=0.0004). A subgroup analysis showed that the patients who received isotonic balanced infusions only, had no prolongation of cT, whereas the patients who received additionally gelatine solution had a significant prolongation. COL/ADP: 78s [70/98] and 91s [82/133]; p=0.0004). COL/EPI: test 111s [92/128] and 127s [103/146]; p=0.0026). Except for individual outliers, the measured values were in the normal range. CONCLUSIONS: In this study, we found no clinically relevant deterioration of platelet function in neurosurgical patients with increased ICP after administration of MAN. Changes that occurred were all within normal ranges.

Analysis of risk factors for venous air embolism in the semisitting position and its impact on outcome in a consecutive series of 740 patients.

OBJECTIVE: Routine use of the semisitting position, which offers several advantages, remains a matter of debate. Venous air embolism (VAE) is a potentially serious complication associated with the semisitting position. In this study, the authors aimed to investigate the safety of the semisitting position by analyzing data over a 20-year period. METHODS: The incidence of VAE and its perioperative management were analyzed retrospectively in a consecutive series of 740 patients who underwent surgery between 1996 and 2016. The occurrence of VAE was defined by detection of bubbles on transthoracic Doppler echocardiography (TTDE) or transesophageal echocardiography (TEE) studies, a decrease of end-tidal CO2 (ETCO2) by 4 mm Hg or more, and/or an unexplained drop in systolic arterial blood pressure (≥ 10 mm Hg). From 1996 until 2013 TTDE was used, and from 2013 on TEE was used. The possible risk factors for VAE and its impact on surgical performance were analyzed. RESULTS: There were 404 women and 336 men with a mean age at surgery of 49 years (range 1-87 years). Surgery was performed for infratentorial lesions in 709 patients (95.8%), supratentorial lesions in 17 (2.3%), and cervical lesions in 14 (1.9%). The most frequent pathology was vestibular schwannoma. TEE had a higher sensitivity than TTDE. While TEE detected VAE in 40.5% of patients, TTDE had a detection rate of 11.8%. Overall, VAE was detected in 119 patients (16.1%) intraoperatively. In all of these patients, VAE was apparent on TTDE or TEE. Of those, 23 patients also had a decrease of ETCO2, 18 had a drop in blood pressure, and 23 had combined decreases in ETCO2 and blood pressure. VAE was detected in 24% of patients during craniotomy before opening the dura mater, in 67% during tumor resection, and in 9% during wound closure. No risk factors were identified for the occurrence of VAE. Two patients had serious complications due to VAE. Surgical performance in vestibular schwannoma surgery was not affected by the presence of VAE. CONCLUSIONS: This study shows that the semisitting position is overall safe and that VAE can be managed effectively. Persistent morbidity is very rare. The authors suggest that the semisitting position should continue to have a place in the standard armamentarium of neurological surgery.

Epigenetic Regulation of Neural Transmission after Cerebellar Fastigial Nucleus Lesions in Juvenile Rats.

Structural and functional abnormalities in the cerebellar midline region, including the fastigial nucleus, have been reported in neuropsychiatric disorders, also comprising the cerebellar cognitive affecting syndrome. In rats, early fastigial lesions reduce social interaction during development and lead to cognitive and emotional deficits in adults, accompanied by compromised neuronal network activity. Since epigenetic mechanisms are implicated in the etiology of neuropsychiatric disorders, we investigated whether fastigial nucleus lesions in juvenile rats would impact epigenetic regulation of neural transmission. The fastigial nucleus was lesioned bilaterally in 23-day-old male rats. Sham-lesion and naïve rats served as controls. DNA methylation was investigated for target genes of the GABAergic, dopaminergic, glutamatergic and oxytocinergic systems in brain regions with anatomic connections to the fastigial nucleus, i.e., medial prefrontal cortex, nucleus accumbens, striatum, thalamus, and sensorimotor cortex. Protein expression was examined for the respective target genes in case of altered DNA methylation between lesion and control groups. Lesioning of the fastigial nucleus led to significant differences in the epigenetic regulation of glutamate decarboxylase 1 and the oxytocin receptor in the nucleus accumbens and the prefrontal cortex. No differences were found for the other target genes and brain regions. Our findings indicate that epigenetic dysregulation after lesioning of the fastigial nucleus may influence long-term recovery and the emergence of behavioral changes. Together with previous behavioral and electrophysiological investigations of this rat model, these observations can play a role in the cerebellar cognitive affective syndrome and other neuropsychiatric disorders.

Pseudotumor cerebri syndrome in a child with Alagille syndrome: intracranial pressure dynamics and treatment outcome after ventriculoperitoneal shunting.

Alagille syndrome (AS) is a rare multisystem disease of the liver, heart, eyes, face, skeleton, kidneys, and vascular system. The occurrence of pseudotumor cerebri syndrome (PTCS) in patients with AS has been reported only exceptionally. Owning to its rarity and a mostly atypical presentation, the diagnosis and natural history of affected patients remain uncertain. We report an atypical case of PTCS in a 4-year-old boy with a known history of AS who presented with bilateral papilledema (PE) on a routine ophthalmological examination. Visual findings deteriorated after treatment with acetazolamide. Continuous intracranial pressure (ICP) monitoring was then utilized to investigate ICP dynamics. Successful treatment with resolution of PE was achieved after ventriculoperitoneal shunting but relapsed due to growth-related dislocation of the ventricular catheter. This report brings new insights into the ICP dynamics and the resulting treatment in this possibly underdiagnosed subgroup of PTCS patients. It also demonstrates that ventriculoperitoneal shunting can provide long-term improvement of symptoms for more than 10 years.

Lesion of the Fastigial Nucleus in Juvenile Rats Deteriorates Rat Behavior in Adulthood, Accompanied by Altered Neuronal Activity in the Medial Prefrontal Cortex.

The cerebellar cognitive affective syndrome may result from various cerebellar injuries. Although it is not exactly known which anatomical structures are involved, the fastigial nucleus has been thought to play a pivotal role according to recent studies. Here we investigate whether bilateral fastigial nucleus lesions in juvenile rats affect cognitive-associative and limbic related functions in adulthood. Furthermore, potential effects on the neuronal activity in the medial prefrontal cortex (mPFC) and local field coherence with the sensorimotor cortex (SMCtx) were evaluated. The fastigial nucleus was lesioned bilaterally by thermocoagulation via stereotaxically inserted electrodes in 23-day old male Sprague Dawley rats. Naïve and sham-lesioned rats (electrodes inserted above the nucleus and no electrical current applied) served as controls. As adults, all groups were tested for cognitive-associative function, social behavior, and anxiety. Thereafter, electrophysiological recordings were obtained under urethane anesthesia. Finally, lesions and recording sites were histologically verified. Spatial learning in a radial maze test and learning in an operant learning paradigm was disturbed in rats with fastigial lesions. Furthermore, in the elevated plus maze anxiety was enhanced, whereas social behavior was not affected. Electrophysiological recordings showed enhanced local field coherence between mPFC and SMCtx across all frequency bands. Impaired cognitive and affective functions together with enhanced coherence between mPFC and SMCtx after bilateral fastigial nucleus lesions indicate that the fastigial nucleus contribute to the development of the cerebellar cognitive affective syndrome and associated motor behavior.

Intracranial emergencies during pregnancy requiring urgent neurosurgical treatment.

OBJECTIVE: Despite contemporary diagnostic and therapeutic techniques intracranial emergencies in the obstetric setting pose still a major challenge for the clinicians. There are limited guidelines and differing ethical views. Multidisciplinary teams are needed to support the pregnant woman in a way that she can deliver a viable and healthy child. The aim of the present study was to scrutinize the management of intracranial emergencies during pregnancy which needed urgent neurosurgical treatment. PATIENTS AND METHODS: Data of all pregnant women who presented with newly diagnosed intracranial pathologies and neurological symptoms caused by these pathologies in an emergency setting were collected over a 10-year period (2008-2018). Patient characteristics including maternal age, gestational age, and preoperative work-up of both mother and fetus were recorded. Furthermore, the surgical treatment, mode of delivery, and neonatal and maternal outcomes were analysed. RESULTS: The mean maternal age was 32.7 years and most patients were in their third trimester. There was one twin pregnancy (total of 12 fetuses). Five out of eleven pregnant women suffered from intracerebral haemorrhage (epidural haematoma (1), arteriovenous malformation (1), subarachnoid haemorrhage (2) and intracerebral haemorrhage (1)) and the other six patients had intracranial neoplasms (primary meningeal sarcoma (1), trigeminal schwannoma (1), anaplastic astrocytoma (2), glioblastoma (1) and sphenoid wing meningioma (1)).Neurosurgical procedures were performed via craniotomies in eight patients. A stereotactic biopsy via a frontal burr hole was achieved one patient. The two other patients with subarachnoid haemorrhage due to rupture of PICA aneurysms were treated with coil embolization. Depending on the gestational age and the clinical condition of the pregnant women it was decided to perform an emergency Caesarean section prior to further therapeutic measures in seven patients. Two out of 12 fetuses were unviable. Six women survived, while five women succumbed to the intracranial pathology. CONCLUSION: The individualized treatment approach in this peculiar obstetric scenario needs to consider various issues such as the clinical condition of the pregnant woman, prognosis of the disease, gestational age and the status of the pregnancy. The primary concern in this context must be the mother`s health and safety. Caesarean section is the primary mode of delivery in most cases. While contemporary care can insure survival for the majority of infants, maternal mortality still poses an extraordinary challenge. Interdisciplinary consulting of the patient and/or her family is necessary to develop a treatment strategy for both the expectant woman and her offspring.

Spinal Emergency Surgery During Pregnancy: Contemporary Strategies and Outcome.

BACKGROUND: Low back pain is a common complaint during pregnancy. However, spinal pathologies, which manifest with severe pain, radiculopathy, and acute neurologic deficits because of disk herniation or mass lesions require special attention. Here, we present our interdisciplinary experience in the surgical management of spinal emergencies during pregnancy. METHODS: The data of pregnant women who underwent surgery for spinal pathologies over a 10-year period were collected. Patient-related characteristics such as maternal age, gestational age, preoperative workup, signs and symptoms of mothers, and diagnostic procedures were evaluated. After an interdisciplinary conference, individualized treatment plans regarding available options were developed. Fetal Doppler and cardiotocography were obtained before and after surgery. RESULTS: Nine pregnant women presented with spinal disorders and underwent spinal emergency surgery within the study period. The mean maternal age was 32.2 years. Six women presented with lumbar disk herniations manifesting as severe sciatica or foot drop and 3 patients had thoracic mass lesions resulting in cauda equine syndrome and/or ataxia. The mean gestational age at the time of presentation was 26.5 weeks. Caesarean sections were performed in 3 women prior to the neurosurgical procedure, whereas the pregnancies were maintained in the 6 other patients. Eight infants who were healthy at birth had an unremarkable development. CONCLUSIONS: Surgery for spinal emergencies in pregnancy can be performed safely according to individual treatment plans developed by an interdisciplinary team taking into account the expectant mother's decision. Maintenance of pregnancy is possible and feasible in most patients.

Pediatric rosette-forming glioneuronal tumor of the septum pellucidum.

Rosette-forming glioneuronal tumor (RGNT) is a rare tumor entity which has been reported mainly occurring in the fourth ventricle. It has been described as a benign lesion with limited extension into surrounding structures, including the cerebellar vermis, midbrain, and cerebral aqueduct. More recently, few cases involving also other midline structures have been documented as well. Here, we report about diagnosis and treatment of RGNT in the septum pellucidum in a pediatric patient which has not been described previously. A 7-year-old boy had a 3-week history of headache. Magnetic resonance imaging showed a solid mass in the septum pellucidum accompanied by hydrocephalus. The tumor was resected via a transcortical approach. Histological examination revealed the typical findings of a RGNT. At 2-year follow-up, there was no tumor recurrence, and clinical outcome was unremarkable. RGNT has to be considered in the differential diagnosis of pediatric midline tumors also outside of the fourth ventricle. Surgical resection is the first-line therapy which may result in beneficial outcome in the long term. The role of adjuvant therapy needs further definition since due to the rarity of this tumor entity, available data is very limited.

Long-term impairment of social behavior, vocalizations and motor activity induced by bilateral lesions of the fastigial nucleus in juvenile rats.

The cerebellum is increasingly recognized to be involved in limbic and cognitive-associative functioning. Cerebellar cognitive affective syndromes may result from various types of injuries. Cerebellar mutism may occur in children after resection of midline tumors in the posterior fossa, which has been thought to be related to damage to the cerebellar vermis. Here, we investigated whether bilateral lesions of the fastigial nucleus, which is located within the upper vermis, would affect social behavior in a rat model. Juvenile male Sprague-Dawley rats, aged 23 days, underwent bilateral thermocoagulation of the fastigial nucleus via stereotaxically implanted electrodes under general anesthesia. Electrodes were inserted without application of electric current in a sham-lesion group and naïve rats served as additional controls. All groups underwent standardized examination before surgery and on specific time points up to 49 days after surgery to investigate locomotor activity, motor coordination, social behavior, and ultrasound vocalizations during social interaction. Finally, lesions were verified histologically. Playing behavior and vocalizations were reduced up to 4 weeks after surgery in rats of the lesion group compared to rats with sham-lesions and controls. After surgery in rats of the lesion group, locomotor activity was disturbed for 3 days as compared to sham-lesion rats, but for 4 weeks as compared to controls. Motor coordination measured by the rotarod and balance beam test was compromised until adulthood. Bilateral lesions of the fastigial nucleus in juvenile rats cause a severe and long-lasting reduction of social interaction and motor coordination in juvenile rats, which has some similarities to cerebellar cognitive affective syndromes in the human context. This indicates a modulating role of the fastigial nucleus with regard to neural circuitries relevant for social behavior, such as the limbic system and the prefrontal cortex.

Glial tumors and deep brain stimulation: An increasingly recognized association?

Occurrence of gliomas in patients with chronic deep brain stimulation (DBS) has been reported few. It has been speculated whether there could be a causal relationship. Here, we report the development of a pilocytic astrocytoma in close vicinity of a DBS electrode during the course of chronic DBS. A 38-year-old man with refractory dystonic head tremor underwent bilateral implantation of quadripolar DBS electrodes in the thalamic ventral intermediate nucleus. He benefited markedly from chronic DBS. At age 46 he was admitted with head and neck pain, attention deficits and sensory disturbances. Cranial computed tomography and magnetic resonance imaging (MRI) showed a subcortical tumor originating from the right pulvinar. Surgery was performed with neuronavigation guidance and the tumor was subtotally removed. The neuropathological examination revealed a pilocytic astrocytoma WHO Grade I. Postoperative MRI demonstrated a small remnant tumor without increase in size during 1 year follow-up after adjuvant radiation therapy. He had ongoing benefit of his tremor with continued DBS. To our knowledge, there have been only three case reports published before indicating such a co-occurrence. In all of these reports, the tumors were high-grade gliomas. It is estimated that about 160.000 patients have been treated with DBS worldwide to date. Even if one would take into account that glial tumors would develop only with chronic DBS after several years and that a significant number of patients didn't reach such long term follow-up the resulting probability of brain tumor development most likely wouldn't be higher as the expectation of mere coincidence.

Secondary extradural spinal manifestation of esthesioneuroblastoma.

Secondary spinal manifestations of esthesioneuroblastoma are rare. A 67-year-old woman was presented with an extradural spinal manifestation at the vertebra Th7 within 8 weeks after resection of an esthesioneuroblastoma. Subtotal removal of the epidural tumour was achieved combined with dorsal transpedicular stabilization. Early screening for distant metastases may be considered in patients with esthesioneuroblastoma.

Severe Subarachnoid Hemorrhage Due to Fusiform Lateral Anterior (A1) Artery Perforator Aneurysm with "Spontaneous Resolution".

Perforating arteries are thin and long vessels which originate from the main cerebral arteries. Subarachnoidal hemorrhage from a perforator aneurysm is rare. Here, we report on a 70-year-old woman who presented with severe subarachnoid hemorrhage from a fusiform lateral anterior (A1) artery perforator aneurysm. Unexpectedly, digital subtraction angiography was non-diagnostic. MR imaging, however, demonstrated occlusion of the aneurysm secondary to thrombosis. Surgery was performed to remove the associated hematoma, and histopathological examination verified intraaneurysmal thrombosis.

Severe Cerebral Complications Secondary to Perforation Injury of the Anterior Skull Base During Sinonasal Surgery: An Underappreciated Problem?

OBJECTIVE: Functional endonasal sinus surgery (FESS) is widely practiced and is considered a generally safe procedure. Skull base injuries occur in <1% of procedures and are typically associated with cerebrospinal fluid leaks. Rarely, skull base injuries might result in cerebral lesions. Here we present a series of 4 patients with iatrogenic perforating injuries of the anterior skull base and cerebral lesions after routine FESS. METHODS: Four patients with iatrogenic perforating cerebral lesions after routine FESS, performed at other institutions, were referred to a tertiary neurosurgery department. Within a 10-year period these procedures were performed in 3 patients as endoscopic FESS and as a microscopic FESS in 1 patient. RESULTS: There were 3 men and 1 woman. Mean age at the time of surgery was 50 years. In 3 instances (in which an endoscope was used), the ear, nose, and throat physician had noted perforation of the skull base during surgery, but it went unnoticed in 1 patient operated with the microscope. Frontal lobe hematoma occurred in all patients, and in 3 of them cerebral infarction developed secondary to injury of branches of the anterior cerebral artery. Three patients developed acute hydrocephalus. Two had rapid global brain swelling and they succumbed within days. The other 2 patients survived without apparent neurological deficits. CONCLUSIONS: Cerebral lesions during FESS still occur in contemporary surgery and they are possibly underreported. Even with prompt conservative and surgical measures, these lesions may result in catastrophic outcome. Associated vascular injuries have a worse prognosis. The only risk factor associated with lethal outcome in our series was younger age.

Idiopathic Intracranial Hypertension in Monozygotic Female Twins: Intracranial Pressure Dynamics and Treatment Outcome.

BACKGROUND: Familial cases of idiopathic intracranial hypertension (IIH) are exceedingly rare, and its occurrence in monozygotic twins has not been reported previously. CASE DESCRIPTION: We report monozygotic female twins who developed IIH, one at age 25 years and the other at age 28 years. Continuous intracranial pressure (ICP) monitoring confirmed elevated ICP as measured initially by lumbar puncture. In both cases, successful treatment with resolution of papilledema and symptoms relief was achieved after ventriculoperitoneal shunting. CONCLUSIONS: This report documents the first case of IIH in monozygotic twins and the associated changes in ICP dynamics. Interestingly, almost equivalent alterations in ICP dynamics were found in the 2 patients.

Shunt Surgery in Idiopathic Intracranial Hypertension Aided by Electromagnetic Navigation.

BACKGROUND: Idiopathic intracranial hypertension (IIH) is characterized by increased cerebrospinal fluid (CSF) pressure and normal or slit ventricles. Lumboperitoneal shunting had been favored by many investigators for CSF diversion in IIH for decades; however, it has been associated with various side effects. Because of the small ventricular size adequate positioning of a ventricular catheter is challenging. OBJECTIVES: Here, we investigated the usefulness of electromagnetic (EM)-guided ventricular catheter placement for ventriculoperitoneal shunting in IIH. METHODS: Eighteen patients with IIH were included in this study. The age of patients ranged from 5 to 58 years at the time of surgery (mean age: 31.8 years; median: 29 years). There were 2 children (5 and 11 years old) and 16 adults. Inclusion criteria for the study were an established clinical diagnosis of IIH, lack of improvement with medication, and the presence of small ventricles. In all patients EM-navigated placement of the ventricular catheter was performed using real-time tracking of the catheter tip for exact positioning close to the foramen of Monro. Postoperative CT scans were correlated with intraoperative screen shots to validate the position of the catheter. RESULTS: In all patients EM-navigated ventricular catheter placement was achieved with a single pass. There were no intraoperative or postoperative complications. Postoperative imaging confirmed satisfactory positioning of the ventricular catheter. No proximal shunt failure was observed during the follow-up at a mean of 41.5 months (range: 7-90 months, median: 40.5 months). CONCLUSIONS: EM-navigated ventricular catheter placement in shunting for IIH is a safe and straightforward technique. It obviates the need for sharp head fixation, the head of the patient can be moved during surgery, and it may reduce the revision rate during follow-up.