Introduction: Chiari Malformation (CM) is a condition in which ectopy or herniation of components of the posterior cranial fossa to theforamen magnum are present, and can be divided into four types. Type I (CM-I) occurs when there is protrusion of only the cerebellartonsils into the cervical spinal canal. One of the available therapeutic options is subpial aspiration. Previous anatomopathologicalstudies showed that the main alterations in the aspirated tonsils were the loss of Purkinje cells, Bergmann gliosis, cortical atrophyand neuronal changes due to hypoxia; all of them secondary to the aggression to the nervous tissue over time. These changes leadto gradual loss of function of the tissue, with compensation by other structures. Therefore, when subpial aspiration of the herniatedtonsil is performed in adults, there are no negative consequences to the patient in the future, as concluded by many studies targetingadults with CM. However, studies in children with CM are scarce, which means that we cannot affirm in which age the histologicalchanges occur. Hence, we cannot determine whether or not the surgical removal of this tissue in childhood leads to future losses tothe patient. Objective: To analyze the main histological aspects of cerebellar tonsils in children with Chiari I Malformation whounderwent subpial aspiration, to help clarify the natural history of this pathology, as well as to help determine the prognosis of thispopulation when treated with this technique. Method: We analyzed the histopathology of the tonsils removed with subpial aspirationtechnique, in several hospitals of João Pessoa, Brazil, from children diagnosed with Chiari I malformation. Results: The slides of alltonsils showed the same histological changes: Bergmann gliosis, loss of Purkinje cells, atrophy of the cerebellar cortex and meningealfibrosis. The obtained results were similar to the ones found in previous studies carried out in adults. Conclusion: The cerebellaranatomopathological alterations secondary to Chiari I Malformation, which leads to loss of tissue function, seem to appear early inlife, suggesting the safety of the subpial aspiration in pediatric patients. However, more extensive studies and long-term follow-up ofpatients are needed to establish with more precision the natural history of the disease.

Introdução: As malformações da junção craniovertebral são patologias frequentes no nordeste brasileiro, predominando a impressãobasilar (IB) e a malformação de Chiari (MC), por vezes associadas à siringomielia (SM). Objetivo: Analisar a prevalência, o padrão decefaleia e os fatores associados em 65 casos de IB e MC operados entre os anos de 1994 e 2015. Método: Trata-se de um estudo retrospectivorealizado a partir da análise de prontuários médicos de pacientes diagnosticados com malformações da junção craniovertebral por meiode ressonância magnética e cujo quadro clínico refratário era indicativo de cirurgia. A amostra foi composta por pacientes operadospela mesma equipe neurocirúrgica no município de João Pessoa, Paraíba, Brasil, entre agosto de 1994 e maio de 2015. Tabularam-se osdados relacionados ao padrão e prevalência de cefaleia, além de seus fatores associados. A inserção, processamento e análise dos dadosobtidos foi efetuada por meio do software estatístico Statistical Package for Social Sciences (SPSS) versão 21.0. Resultados: A amostrafinal foi composta por 65 pacientes. Observamos que 29 deles (44,6%) eram portadores de IB e MC, 26 (40%) eram portadores de IB, MCe SM, sete, apenas IB, dois, somente MC e em um paciente a associação de MC e SM. Do total de pacientes, 32 (49,2%) apresentavamcefaleia e 43 (66,1%) dor nucal. Houve presença de braquicefalia em 44 casos (67,7%) e brevis collis em 42 (64,6%). Quando cruzadasas variáveis cefaleia, dor nucal, braquicefalia e brevis collis, observamos presença em 9 pacientes (31%) do grupo que possuía IBe MC, e em 8 (30,8%) do grupo com IB, MC e SM. Conclusão: Diante dos resultados, recomendamos que para todos os pacientesportadores de cefaleia e dor nucal advindos de regiões em que epidemiologicamente as malformações da junção craniovertebral sãofrequentes, excluindo-se cefaleia tensional, sejam levantadas a hipótese diagnóstica de IB ou MC, principalmente quando apresentaremalterações no exame físico, como braquicefalia e brevis collis. Neste estudo, ressaltamos a relevância de se evitar a falha diagnóstica ouo diagnóstico tardio em pacientes sintomáticos, realizando-se tratamento cirúrgico oportuno nos que apresentam sintomas refratários eincapacitantes ou déficit neurológico, prevenindo sequelas permanentes.

Introduction Ventriculoperitoneal (VP) shunt is commonly used in the treatment of hydrocephalus and may present complications in up to 30% of patients. The present report addresses an uncommon complication in the abdominal cavity, in which the catheter caused extrinsic compression of the gastric wall. Case report A 30-year-old man presented a decreased level of consciousness, associated with severe headache and vomiting. He had a history of congenital neurotoxoplasmosis and VP shunt insertion at 7 years of age. Imaging exams demonstrated the formation of an encapsulated retrogastric pseudocyst and extrinsic compression of the gastric wall by a VP shunt catheter. Through videolaparoscopy, decompression of the gastric wall and removal of the pseudocyst were performed, with the reestablishment of the drainage of cerebrospinal fluid. An analysis of the distal fragment of the removed catheter revealed obstruction by fibrotic material. The patient was discharged with a reestablished baseline after four days of hospitalization. Comments The literature shows that ∼ 47% of the complications presented by patients are related to the distal end of the catheter, and 8.2% of these come from migration to the abdominal cavity. However, there is an extreme paucity of studies that demonstrate extrinsic compression of the gastric wall by a VP shunt catheter. Therefore, we suggest that further studies on complications involving the VP shunt be performed to improve diagnostic and therapeutic results, in addition to complementing the literature on this complication.