Marcelo Volpon Santos

Extradural arachnoid cysts in children

BackgroundExtradural arachnoid cysts in the spine are uncommon causes of spinal cord compression in the pediatric population that are thought to arise from congenital defects in the dura mater. Most reports describe such cysts as communicating with the intrathecal subarachnoid space through a small defect in the dura. Excision of the cyst with obliteration of the communicating dural defect is the mainstay of treatment in symptomatic patients. Solitary extradural arachnoid cysts have been reported in several studies, but multiple extradural arachnoid cysts are very rarely reported in children.Materials and methodsThe authors report a case of multiple extradural spinal arachnoid cysts in a 14-year-old boy who presented progressive lower extremity weakness, myelopathy, and severe gait ataxia. Magnetic resonance (MR) of the spine demonstrated four extradural arachnoid cysts extending from T-1 to T-9. The patient underwent a thoracic laminoplasty for en bloc resection of the spinal extradural arachnoid cysts. Postoperatively, the patient’s motor strength and ambulation improved immediately.ConclusionsMultiple spinal extradural arachnoid cysts are rarely reported in the literature. Excision of the cysts at the spinal cord level leads to a favorable outcome.

The Success of Endoscopic Third Ventriculostomy in Children: Analysis of Prognostic Factors

Objective: The treatment of hydrocephalus in children with endoscopic third ventriculostomy (ETV) has particular features and is associated with different success rates (SR). The aim of this study was to identify putative factors that could influence the outcome of ETV in children. Methods: Clinical data of 114 consecutive patients under 18 years of age who underwent 116 consecutive ETVs from January 2000 to January 2010 were reviewed. Data were analyzed with regards to clinical and radiological SR. The actual long-term SR was compared to that predicted by the ETV Success Score (ETVSS) model. Results: The study group included 49 males (43%) and 65 females (57%) with a mean age of 6.17 ± 1.02 years (ranging from 11 days to 18 years) at surgery. Concerning the etiology of hydrocephalus, tumors and aqueductal stenosis (AS) were the most frequently observed, with each occurring in 33 cases (29%), followed by malformations in 24 (21%), cystic lesions in 6 (5%) and other etiologies in 18 patients (16%). The overall SR at the first ETV attempt was 80% (91/114), compared to 74.8% (variance 14.35, 95% CI 69.37-78.22) predicted by the ETVSS. Regarding age, SR was 58% in patients under 6 months of age, 65% in children between 6 months and 1 year, and 86% in children older than 1 year. SR for AS and hydrocephalus associated with posterior fossa tumors were 88 and 90%, respectively. Unsatisfactory results were related to previous intraventricular hemorrhage and infection. The overall complication rate in this series was 13%. Conclusion: ETV is safe and effective in children. In this series, the age of the patient and etiology of hydrocephalus were related to SR. Also, the ETVSS was accurate to predict outcome. In a long-term follow-up, surgical experience was statistically significant in reducing complications.

Approach to cortical dysplasia associated with glial and glioneuronal tumors (FCD type IIIb)

IntroductionBrain tumors are a frequent cause of epilepsy in the pediatric population. The last International League Against Epilepsy (ILAE) classification of focal cortical dysplasias (FCDs) includes a subgroup consisting of tumors with surrounding dysplastic abnormalities (FCD type IIIb). Although its pathogenesis is still unclear, it has several clinical and therapeutic (surgical) implications.BackgroundA number of benign tumors (such as dysembryoplastic neuroepithelial tumors and gangliogliomas) frequently present with medically refractory epilepsy associated with cortical dysplasia. In such cases, planning of surgical resection needs to take into consideration not only the tumor but also the whole area of epileptogenicity. The use of intraoperative electrocorticography recordings is reported to result in better postoperative outcomes, since they help delineate the abnormal cerebral cortex that needs to be resected to provide seizure freedom to patients. Clinical, radiological, and pathological features are also discussed herein.

Inter-institutional protocol describing the use of three-dimensional printing for surgical planning in a patient with childhood epilepsy: From 3D modeling to neuronavigation

This study is the first step in an effort to develop three-dimensional (3D) printing for use in pediatric surgical planning. In order to accomplish this, we established an effective collaboration between Ribeirao Preto Clinics Hospital (HCRP) and Renato Archer Center for Information Technology (CTI). Printed biomodels can be used to support discussions, decision-making, and neuronavigation before surgery. The main purpose of 3D printing for specific case handling is to reduce damage by enhancing knowledge of orientation during surgical planning and personnel training before surgery. Here, we produced an object that represented the brain and face segment of a patient via additive manufacturing technology based on magnetic resonance imaging (MRI) data. Specific landmarks were measured by three distinct methods: manual caliper, an InVesalius software measurement tool, and neuronavigation coordinate detection. The mean coefficient of variation was 7.17% between all methods and landmarks measured. Our results validate the combined use of biomodels with InVesalius software tools for the assessment of individual brain anatomy facilitating manual handling and visualization of 3D models. The establishment of communication protocols between the teams involved, as well as navigation protocols for quality control, presents the possibility of developing long term training programs, and promotes the congregation of individuals from research areas in Medical Physics, Medical Sciences, and Neuroscience.

Metachronous occurrence of nonradiation-induced brain cavernous hemangioma and medulloblastoma in a child with neurofibromatosis type I phenotype

Cavernous hemangioma (CH) is a sporadic vascular malformation occurring either as an autosomal dominant condition or as a well-known complication of radiation exposure. Medulloblastoma is a primitive neuroectodermal tumor common in children and currently treated with surgical resection, chemotherapy, and radiotherapy. Neurofibromatosis is the most common single-gene disorder of the central nervous system. Posterior fossa malignant tumors in the context of neurofibromatosis type I (NF1) are very infrequent. This is the first documented case of an unusual metachronous occurrence of non-radiation-induced CH and medulloblastoma in a child with NF1 phenotype. We report the case of a 13-month-old boy with café-au-lait skin lesions associated with NF1-like phenotype who underwent surgical resection of a single CH in the temporal lobe due to recurrent seizures. Four years later he presented with signs of raised intracranial pressure associated with a posterior fossa tumor and hydrocephalus, thus requiring gross total resection of the lesion. Histological analysis revealed a medulloblastoma. After being treated with radiotherapy and chemotherapy, he achieved total remission. Six years later a massive recurrence of the tumor was observed and the child eventually died. The interest in this case lies in the rarity of NF1-like phenotype associated with a non-radiation-induced brain CH and medulloblastoma in a child.

Combined pre- and subtemporal transtentorial approach for epidermoid cysts of the cerebellopontine angle

ObjectiveEpidermoid cysts of the cerebellopontine angle (CPA) can be a surgical challenge for the pediatric neurosurgeon. Ideally, total removal must be achieved; however, occasional adhesions of these tumors to vital neurovascular structures and extension far beyond the midline may preclude their total removal. The aims of this article are to present an alternative surgical approach to these lesions and to provide the rationale for this technique.Material and methodsA 16-year-old boy was admitted to our pediatric neurosurgery department with a 1-year history of nonspecific headaches. His neurological examination showed right-sided dysmetria and gait ataxia. Magnetic resonance scans showed a space-occupying lesion on the right CPA with low intensity on T1-weighted images and high intensity on T2-weighted images.ResultsCraniotomy for tumor excision via pre- and subtemporal transtentorial approach was performed disclosing a 3.5 × 3 × 2.8-cm3 well-encapsulated tumor, which was confirmed to be an epidermoid cyst. The postoperative course was uneventful.ConclusionsA combined pre- and subtemporal approach utilizes a wide opening of the tentorium and the option of supratentorial retraction of the cerebellum to provide an excellent angle of approach to CPA lesions involving the anterolateral aspect of the brain stem in children.

Epidermoid cyst mimicking an intrinsic brainstem tumor

OBJECTIVE To describe an atypical clinical and radiological presentation of a brainstem epidermoid cyst in a child and to provide a review of the medical literature on brainstem epidermoid cysts in children. MATERIAL AND METHOD Review of medical records and operative notes of an unusual case of a patient with a brainstem epidermoid cyst. MEDLINE literature search using the terms brainstem, epidermoid cyst and children. RESULTS Gross total resection of the cyst was achieved. The patient had an uneventful recovery. CONCLUSION Epidermoid cysts are rare tumors of the brain and children. The management of these tumors can be quite challenging. A good clinical and neuroradiological evaluation pre-operatively is fundamental for a successful surgical treatment. Surgical resection should be as radical as possible without putting the patients neurological status into risk.

Neurosurgical Management of Pott’s Puffy Tumor in an Obese Adolescent with Asthma: Case Report with a Brief Review of the Literature

Pott’s puffy tumor is a rare and severe complication of frontal sinusitis, characterized by the progressive swelling of the frontal soft tissues secondary to a subperiosteal abscess. Radiological imaging with ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) are important diagnostic tools in establishing diagnosis and treatment planning. Early surgery along with intravenous antibiotics are required in order to achieve a good recovery. The authors report a case of Pott’s puffy tumor in an obese 14-year-old male, with a previous history of asthma and a chronic use of steroids, treated with neurosurgical debridement followed by a combined course of intravenous (IV) and oral antibiotics, who had a favorable outcome upon long-term follow-up. In addition, a brief review of the current medical literature was performed for a discussion on the diagnostic and therapeutic features of this pathology.

Cranial morcellation decompression for refractory idiopathic intracranial hypertension in children

BackgroundPrimary idiopathic intracranial hypertension (PIIH) in children is rare and has a poorly understood pathophysiology. It is characterized by raised intracranial pressure (ICP) in the absence of an identified brain lesion. Diagnosis is usually confirmed by the measurement of a high cerebrospinal fluid (CSF) opening pressure and exclusion of secondary causes of intracranial hypertension. Refractory PIIH may lead to severe visual impairment. The purpose of this study was to evaluate a cranial morcellation decompression (CMD) technique as a new surgical alternative to stabilize intracranial pressure in PIIH.Materials and methodsA literature review was carried out, disclosing only 7 pediatric cases of PIIH treated with surgical skull expansion. In addition, we describe here one case of our own experience treated by CMD.ConclusionsCMD surgery is a safe and effective option to control refractory PIIH in selected patients.

Hypertrophic olivary degeneration in children after posterior fossa surgery. An underdiagnosed condition

BackgroundHypertrophic olivary degeneration (HOD) is a rare transsynaptic form of degeneration occurring after injury to the dentato-rubro-olivary pathway (“Guillain-Mollaret triangle”). The majority of studies have described HOD resulting from posterior fossa (PF) hemorrhage or infarction. HOD in patients undergoing PF surgery has not been well characterized. These lesions are rare and symptomatic children with HOD are even more uncommon. The purpose of this study was to evaluate HOD that develops after PF operations in children.Materials and methodsA literature review was carried out describing 37 pediatric cases of HOD in 13 articles. In addition, two new cases of our own experience were included.ConclusionsHOD is a rare complication related after PF tumors surgery and symptoms may be misdiagnosed with pediatric cerebellar mutism syndrome. Children with HOD usually do not develop palatal tremor but ataxia is common.