Importance of Ophthalmological Evaluation in the Conservative Management of Increased Intracranial Pressure from a Ruptured Arachnoid Cyst.

Arachnoid cysts (ACs) are cerebrospinal fluid collections between the two layers of the normal arachnoid membrane. Although they are often asymptomatic with a stationary course, eventual complications may occur. Herein, we report the case of a 9-year-old boy who developed bilateral papilloedema secondary to spontaneous rupture of an AC in the left middle cranial fossa. Although the papilloedema worsened during follow-up, his visual field remained bilaterally stable, supporting the expectant management and obviating the potential morbidity associated with neurosurgical intervention. This case report highlights the importance of a multidisciplinary approach to patients with secondary intracranial hypertension, including serial ophthalmological examinations, which provide a useful guide to surgical decision-making.

Compressive Myelopathy Caused by Arachnoid Cyst and Extramedullary Hematopoietic Tissue in a Patient with Thalassemia Major / Mielopatia compressiva por cisto aracnóideo e tecido hematopoiético extramedular em paciente portador de talassemia maior

Thalassemias, inherited diseases of hemoglobin synthesis, are characterized by the presence of deficient hemoglobin chains that deposit in red blood cells, inducing hemolytic anemia. Extramedullary hematopoiesis represents a compensatory picture that usually affects the liver, the spleen, and lymph nodes. The involvement of the epidural space with spinal cord compression is extremely rare. Our objective was to describe the case of RMS, 31 years old, male, ß-thalassemia major carrier, admitted with 2-month progressive paraparesis and urinary retention due to medullary compression by extramedullary hematopoietic tissue and thoracic arachnoid cyst, and to discuss therapeutic options. Magnetic resonance imaging (MRI) showed an extensive intraspinal and extramedullary lesion with homogeneous contrast enhancement of T3- T11 in addition to a T1-T3 cystic lesion isointense to cerebrospinal fluid (CSF). After the presumed diagnosis of spinal cord compression by proliferative hematopoietic tissue, a 10-session fractional radiotherapy treatment was immediately performed. After the radiotherapy treatment, the neurological deficits of the patient persisted despite the excellent image response with almost complete disappearance of the intraspinal mass. However, the MRI showed a persistent T1-T3 cystic lesion with significant mass effect on the spinal cord. The patient was submitted to microsurgery for total resection of this cystic lesion. In the postoperative period, the patient improved his sphincter control and motor deficits. Medullary compression by extramedullary epidural hematopoiesis is a rare complication in thalassemic patients and may be treated with surgery and/or radiotherapy. There are successful cases with the exclusive use of radiotherapy, especially in extensive lesions.

As talassemias, desordens hereditárias da formação de hemoglobina, caracterizam-se pela síntese de cadeias deficientes de hemoglobina que se depositam nas hemácias e induzem a anemia hemolítica. A hematopoiese extramedular representa um quadro compensatório que habitualmente afeta o fígado, o baço e linfonodos, podendo também afetar outros tecidos. O envolvimento do espaço epidural com compressão medular é extremamente raro. No presente trabalho, objetivou-se descrever o caso do paciente RMS, 31 anos, sexo masculino, portador de talassemia ß maior, com paraparesia progressiva há 2 meses e retenção urinária devida à compressão medular por tecido hematopoiético extramedular e cisto aracnóideo torácicos, e discutir as opções terapêuticas. Ressonância magnética (RM) evidenciou extensa lesão expansiva intrarraquiana e extramedular com captação homogênea de contraste de T3-T11, além de lesão cística isointensa ao líquor de T1-T3. Devido à extensão da lesão e anemia grave do paciente, foi optado inicialmente pelo tratamento radioterápico fracionado em 10 sessões. Após o tratamento, o paciente manteve os déficits neurológicos apesar da excelente resposta imaginológica, com desaparecimento quase completo da massa intrarraquiana. Contudo, a RM de controle mostrou persistência da lesão cística T1-T3 com efeito de massa importante sobre a medula. O paciente foi submetido a microcirurgia com ressecção completa da lesão cística. No pós-operatório, houve melhora do controle esfincteriano e dos déficits motores. Compressão medular por hematopoiese extramedular epidural é uma complicação rara nos pacientes talassêmicos, e pode ser tratada com cirurgia e/ou radioterapia. Há casos de sucesso com uso de radioterapia exclusiva, especialmente quando as lesões são extensas.

Importance of Arachnoid Dissection in Arteriovenous Malformation Microsurgery: A Technical Note.

Intracranial arteriovenous malformations (AVMs) are congenital anomalies where arteries and veins connect without a capillary bed. AVMs are the leading cause of nontraumatic intracerebral hemorrhages in people younger than 35 years old.1 The leptomeninges (arachnoid and pia) form from the meninx primitiva.2,3 Endothelial channels produce a vascular plexus in the meninx connected by primitive arachnoid. Remodeling of the plexus in response to changing metabolic demands results in a recognizable pattern of arteries and veins.2,3 Defects at the level of capillaries during arteriovenous specification are most likely responsible for arteriovenous fistula formation.4-6 Interplay between the congenital dysfunction and flow-related maturation in adulthood, when vasculogenesis has stopped, produces the AVM.6,7 The relationship between the primitive arachnoid and aberrant AVM vessels is preserved and forms the basis of microsurgical disconnection discussed in Video 1. Several authors have described dissecting these natural planes to delineate the abnormal AVM vessels, relax the brain, and avoid morbidity during AVM surgery.8-10 We recommend sharp arachnoid dissection with a scalpel or microscissors, occasionally helped by blunt dissection with patties or bipolar forceps. We present a 2-dimensional video of the microsurgical resection of a right parietal AVM. The patient, a healthy 30-year-old female, presented with intermittent headaches and mild impairment of arithmetic and visuospatial ability. Magnetic resonance imaging and digital subtraction angiography showed a compact 3.5-cm supramarginal gyrus AVM supplied by the middle cerebral artery, with superficial drainage. Complete microsurgical resection was performed without morbidity. We demonstrate the principles of arachnoid dissection requisite to disentanglement of the nidus and safe resection of the AVM.

Quiste aracnoideo (Galassi Tipo II) y síntomas neuropsiquiátricos: a propósito de un caso / Arachnoid Cyst (Galassi Type II) and neuropsychiatry symptoms: about a case

INTRODUCCIÓN: un quiste aracnoideo es originado de la alteración de una de las membranas de la meninges (aracnoides), de predominio en la fosa craneal media; es una patología poco común que cause síntomas y si ocurren, se pueden presentar manifestaciones neuropsiquiatrías. OBJETIVO: exponer los datos clínicos; y la metodología diagnóstica y terapéutica. CASO: presentamos una paciente femenina de 24 años de edad; sin antecedentes personales médicos psiquiátricos y médicos no psiquiátricos conocidos, quien presenta una historia con un mes de evolución de síntomas psicóticos y cambios conductuales. Se le realizo CAT cerebral simple y luego una resonancia magnética cerebral contrastada para definir el tamaño del quiste aracnoideo, por los posibles síntomas neuropsiquiátricos encontrados. Por medio de exámenes de laboratorios, estudios electrofisiológicos (electroencefalograma), neuroimágenes y evaluación clínica. Se decide presentar las características clínicas encontradas de la paciente quien requirió manejo con antipsicóticos, benzodiacepinas y estabilizador del humor con gradual mejoría de sus sintomatologías de ingreso (agitación psicomotora y psicosis).

INTRODUCTION: an arachnoid cyst is caused by the alteration of one of the membranes of the meninges (arachnoid), predominantly in the middle cranial fossa; It is an uncommon pathology that causes symptoms and if they occur, neuropsychiatric manifestations may take place. OBJECTIVE: expose the clinical data; and the diagnostic and therapeutic methodology. CASE: we present a 24-year-old female patient; with no personal history of psychiatric and known non-psychiatric medical records, whom presents a story with a month of evolution of psychotic symptoms and behavioral changes. A simple cerebral CAT was performed and then a cerebral magnetic resonance imaging with contrast to define the size of the arachnoid cyst, due to the possible neuropsychiatric symptoms found. Through laboratory tests, electrophysiological studies (electroencephalogram), neuroimaging and clinical evaluation. It was decided to present the clinical characteristics of the patient who required management with antipsychotics, benzodiazepines and mood stabilizer with gradual improvement of her admission symptoms (psychomotor agitation and psychosis)

Approach to the Patient: Differential Diagnosis of Cystic Sellar Lesions.

Cystic lesions arising in the sellar region are not uncommon and encompass cystic pituitary adenomas, Rathke cleft cysts, craniopharyngiomas, and arachnoid cysts. Their clinical presentation may be similar, including headache, visual field defects, and anterior pituitary hormone deficits, which makes differential diagnosis challenging. On the other hand, imaging features may indicate certain pathologies. In this approach to the patient, we describe the case of a patient who presented with right temporal hemianopsia and a sellar/suprasellar cystic lesion, which was determined to be Rathke cleft cyst. We discuss the imaging characteristics that may suggest a particular diagnosis between Rathke cleft cyst, cystic pituitary adenoma, craniopharyngioma, and arachnoid cyst and propose a flowchart for aiding in the imaging differential diagnosis.

Probable Hydrocephalus Decompensation after Immunization with Pentavalent Vaccine: Case Report and Literature Review / Descompensação provável de hidrocefalia após imunização com vacina pentavalente: Relato de caso e revisão da literatura

There are several complications associated with immunization with the pentavalent vaccine. Most of them are mild reactions, of spontaneous resolution; however, though rare, serious and potentially-fatal adverse effects can occur. We report a case of acute intracranial hypertension syndrome in an infant with a previously-unknown suprasellar arachnoid cyst who developed acute obstructive hydrocephalus after immunization with the pentavalent vaccine. He underwent neuroendoscopic treatment, showing complete resolution of the condition. The present article aims to compare the activation of the immune system by the pertussis component of the vaccine and the mechanisms that hypothetically potentiated the pathological decompensation.

Várias são as complicações associadas à imunização com a vacina pentavalente (VP). Em geral, são reações leves, de resolução espontânea; entretanto, raramente podem ocorrer efeitos adversos graves, potencialmente fatais. Relatamos um caso de síndrome de hipertensão intracraniana aguda (HIA) em lactente portador de cisto aracnoide suprasselar até então desconhecido, que desenvolveu hidrocefalia obstrutiva aguda pós imunização com VP. Ele foi submetido a tratamento neuroendoscópico, e apresentou resolução completa do quadro. Este artigo pretende comparar a ativação do sistema imune pelo componente pertússis da vacina e os mecanismos que hipoteticamente potencializaram a descompensação patológica.

Primary Extra-axial Glioblastoma: Case Report and Literature Review

Glioblastoma multiforme (GBM) is the most frequent and most aggressive primary brain tumor in adults,mainly located in the cerebral hemispheres. In the literature, few cases of primary GBM have been reported to have radiographic and intraoperative features of extra-axial lesions, leading to a diagnostic dilemma. Despite the advances in imaging modalities, the diagnosis of GBM can be challenging, and it is mainly based on the histopathologic confirmation of the excised tumor. We describe the case of a 76- year-old previously healthy female patient who presented to our hospital due to speech disturbances and cognitive impairment. The diagnosis of the tumor type on magnetic resonance imaging (MRI) was difficult, as the findings were suggestive of a malignant meningioma due to the heterogeneous enhancement of a dural-based mass with a dural tail sign. Moreover, the intraoperative findings revealed an extra-axial mass attached to the dura. A histological examination confirmed the diagnosis of glioblastoma with arachnoid infiltration. The patient underwent adjuvant radiotherapy and concomitant temozolomide treatment, she had clinical improvement postoperatively, and was stable during the six months of follow-up. Glioblastoma should be considered in the differential diagnosis of primary extra-axial mass with atypical and malignant features, especially in elderly patients.

Surgical treatment of spinal arachnoid web: Report of two cases and literature review.

BACKGROUND: Arachnoid webs (AWs) can cause cord compression and syringomyelia in the thoracic spine. Here, we describe two patients who underwent operative treatment for AW and reviewed the literature. CASE DESCRIPTION: Two patients underwent surgical treatment for thoracic AW. Both presented with spastic gait and numbness in the lower extremities. On MR, these lesions exhibited the "scalpel" sign (i.e. due to the accumulation of cerebrospinal fluid on the dorsal aspect of the spinal cord). Operative intervention, consisting of fenestration and web resection, resulted in symptom resolution. CONCLUSION: Thoracic AWs are rare lesions that should be considered among the differential diagnosis of spinal compressive syndromes. Surgical fenestration and resection of the AW correct the flow dynamics allowing for full symptoms resolution.

Intradural Spinal Arachnoid Cyst in a Pediatric Patient: A Case Report

The present case reports a 13-year-old patient with an intradural arachnoid cyst, which manifested itself with a sudden loss of strength and sensitivity in the lower and upper limbs and a severe pain in the cervical and thoracic region. On examination, a lesion displayed as an intradural hematoma; however, a laminotomy was performed and it was realized that the lesion was an arachnoid spinal cyst of the cervical-dorsal spine.

Multiple extradural spinal arachnoid cysts: A case report.

BACKGROUND: Extradural spinal arachnoid cysts (SACs) rarely cause neural compression and disability. CASE DESCRIPTION: A 38-year-old female presented with a history of two episodes of falling due to transient weakness in the lower limbs. The neurological examination showed normal motor and sensory function, but hyperreflexia. The thoracic magnetic resonance imaging revealed multiple extradural SACs between the T3-L1 levels. Following complete surgical resection of the most symptomatic cyst, she did well. The histopathological examination confirmed a Type I extradural SAC. CONCLUSION: Here, we discussed one case and reviewed the literature on the diagnosis and treatment of multiple extradural SACs.

Quiste aracnoideo de la vaina del nervio óptico simulando defecto glaucomatoso en el campo visual / Optic nerve sheath arachnoid cyst simulating glaucomatous defect in the visual field

Resumen Introducción: el quiste aracnoideo es una colección benigna de fluido similar en composición al líquido cefalorraquídeo dentro de la aracnoides, circunscrita por tejido fibrovascular normal que comprime las leptomeninges que rodean el nervio óptico. Se describe el caso de una paciente con quiste aracnoideo de la vaina del nervio óptico con un defecto campimétrico típico de glaucoma, pero con un disco óptico sin características de glaucoma, con el fin de resaltar la necesidad de estudiar con neuroimágenes estos casos y detectar este tipo de alteraciones. El quiste aracnoideo de la vaina del nervio óptico es una entidad excepcional que generalmente tiene un comportamiento benigno, permaneciendo estable en el tiempo, aunque eventualmente puede producir una neuropatía óptica compresiva, afectando la agudeza o el campo visual por daño de la capa de fibras nerviosas. En el caso descrito, este daño se manifestó con un defecto de campo visual que simulaba neuropatía glaucomatosa.

Abstract Background: Arachnoid cyst is a benign fluid collection similar in composition to cerebrospinal fluid within the arachnoid, circumscribed by normal fibrovascular tissue that compresses the leptomeninges surrounding the optic nerve. Objective: To describe the case of a patient with an optic nerve sheath arachnoid cyst with a typical glaucoma campimetric defect, but with an optic disc without findings of glaucoma, to highlight the need to study these cases with neuroimaging to detect this type of changes. Conclusion: Optic nerve sheath arachnoid cyst is an exceptional entity that generally has a benign behavior remaining stable over time; but could eventually originate compressive optic neuropathy, affecting visual acuity or visual fields due to nerve fiber layer damage. In the patient´s case this damage was manifested with a visual field defect that simulated glaucomatous neuropathy.

Endoscopic Laser Fenestration to Treat a Bobble-Head Doll Syndrome Caused by Suprasellar Cyst.

The bobble-head doll syndrome (BHDS) is a rare acquired head movement disorder characterized by up and down or side-to-side movement, most commonly seen in the first decade of life. The syndrome occurs more often in lesions causing third ventricle dilatation such as suprasellar or third ventricle cyst, but it is also found in other pathologies associated with hydrocephalus like shunt dysfunctions, trapped fourth ventricle, congenital aqueductal stenosis, Dandy-Walker syndrome, and cerebellar malformations. The pathophysiology of this head movement has different origins theories; one states that this stereotyped movements empties the cyst and move the dome away from the foramina of Monro, which relieves the symptoms of hydrocephalus; the other suggests that the extrapyramidal tracts (rubrotegmentospinal and reticulospinal) are stimulated by the compression of dorsomedial nucleus of the thalamus by the cyst, whose tracts innervate the neck muscles resulting in the bobbling head movements. This video (Video 1) presents a clinical case of BHDS caused by suprasellar cyst in a 10- year-old boy treated by endoscopic procedure. A ventricular-cyst-cisternostomy was performed resulting in complete improvement of the head movements and uneventful recovery. Postoperative images demonstrate decreasing of the cyst lesion and resolution of the hydrocephalus.

Posttraumatic Arachnoid Cyst in the Thoracic Spine with Medullary Compression: Case Report.

Arachnoid cysts are rare; they can occur at all levels of the dural sac, and can have a congenital, traumatic, iatrogenic or inflammatory origin. In the present article, we report a patient presenting a compressive thoracic myelopathy due to an unusual intradural arachnoid cyst with posttraumatic manifestation and its resolution, in addition to a literature review on the subject. These cysts mainly occur at the thoracic spine, followed by the lumbar, lumbosacral and thoracolumbar spines. Traumatic cysts are caused by an injury to the inner dural layer. These lesions produce neurological deficits through a mass effect on the spinal cord. Concomitant compressive myelopathy is even rarer. In case of myelopathy, cyst resection or drainage is the treatment of choice, and it must be performed immediately. Although rare, arachnoid cysts can be a complication of spine fractures; as such, orthopedists and neurosurgeons, who commonly see these injuries, must be prepared for this unusual situation.

Non-neoplastic intracranial cystic lesions: not everything is an arachnoid cyst.

Intracranial cystic lesions are common findings on neuroimaging examinations, arachnoid cysts being the most common type of such lesions. However, various lesions of congenital, infectious, or vascular origin can present with cysts. In this pictorial essay, we illustrate the main causes of non-neoplastic intracranial cystic lesions, discussing their possible differential diagnoses as well as their most relevant imaging aspects.

Lesões císticas intracranianas são achados comuns nos exames de neuroimagem, sendo os cistos aracnoides os mais comuns. Porém, muitas outras lesões, de origem congênita, infecciosa e vascular, podem se apresentar com cistos. Neste ensaio ilustramos as principais causas de lesões císticas intracranianas não neoplásicas, discutindo seus possíveis diagnósticos diferenciais, bem como seus aspectos de imagem mais relevantes.

Posttraumatic Arachnoid Cyst in the Thoracic Spine with Medullary Compression: Case Report / Cisto aracnóide após trauma na coluna torácica com compressão medular: Relato de caso

Abstract Arachnoid cysts are rare; they can occur at all levels of the dural sac, and can have a congenital, traumatic, iatrogenic or inflammatory origin. In the present article, we report a patient presenting a compressive thoracic myelopathy due to an unusual intradural arachnoid cyst with posttraumatic manifestation and its resolution, in addition to a literature review on the subject. These cysts mainly occur at the thoracic spine, followed by the lumbar, lumbosacral and thoracolumbar spines. Traumatic cysts are caused by an injury to the inner dural layer. These lesions produce neurological deficits through a mass effect on the spinal cord. Concomitant compressive myelopathy is even rarer. In case of myelopathy, cyst resection or drainage is the treatment of choice, and it must be performed immediately. Although rare, arachnoid cysts can be a complication of spine fractures; as such, orthopedists and neurosurgeons, who commonly see these injuries, must be prepared for this unusual situation.

Resumo Cistos aracnóides são raros, podem ocorrer em todos os níveis do saco dural, e sua origem pode ser congênita, traumática, iatrogênica ou inflamatória. Neste artigo, relatamos o caso de uma paciente com mielopatia torácica compressiva decorrente de um cisto aracnóide intradural incomum, de manifestação pós-traumática, assim como sua resolução, além de realizar revisão da literatura sobre o tema. A principal localização é na coluna torácica, seguida das colunas lombar, lombossacra e toracolombar. O cisto com origem traumática é causado por lesão da camada interna da dura-máter. Essas lesões produzem déficit neurológico por meio de efeito de massa sobre a medula espinhal. A existência de mielopatia compressiva associada é mais rara ainda. A ressecção ou drenagem dos cistos na vigência de mielopatia deve ser imediata, sendo o tratamento de escolha. Apesar de raros, podem ser uma complicação de fraturas da coluna vertebral que são muito comuns na prática de ortopedistas e neurocirurgiões, que devem estar preparados para essa situação incomum.

Non-neoplastic intracranial cystic lesions: not everything is an arachnoid cyst / Lesões císticas intracranianas não neoplásicas: nem tudo são cistos aracnoides

Abstract Intracranial cystic lesions are common findings on neuroimaging examinations, arachnoid cysts being the most common type of such lesions. However, various lesions of congenital, infectious, or vascular origin can present with cysts. In this pictorial essay, we illustrate the main causes of non-neoplastic intracranial cystic lesions, discussing their possible differential diagnoses as well as their most relevant imaging aspects.

Resumo Lesões císticas intracranianas são achados comuns nos exames de neuroimagem, sendo os cistos aracnoides os mais comuns. Porém, muitas outras lesões, de origem congênita, infecciosa e vascular, podem se apresentar com cistos. Neste ensaio ilustramos as principais causas de lesões císticas intracranianas não neoplásicas, discutindo seus possíveis diagnósticos diferenciais, bem como seus aspectos de imagem mais relevantes.

Endoscope-Controlled Microsurgery of a Ruptured Middle Fossa Arachnoid Cyst.

Arachnoid cysts are responsible for 1% of expansive lesions in the central nervous system. Usually, they do not cause neurologic symptoms unless they have expansion or hemorrhage. Intracystic bleeding is caused by trauma or may be spontaneous. There are few cases in the literature of spontaneous hemorrhage of arachnoid cysts. This 2-dimensional video (Video 1) demonstrates the case of a 6-year-old boy who presented with headache and diplopia. At the physical examination, he exhibited right sixth nerve palsy. The complementary examinations revealed a left middle fossa arachnoid cyst classified as Galassi 2. An urgent procedure was planned to fenestrate the cyst. Informed written consent was obtained from the patient's family. Due to the team experience, endoscope-controlled microsurgery was performed. The patient experienced remission of the headache and the diplopia. A CT scan was performed on the first postoperative day and revealed a lamina of acute blood at the subdural space. It was an asymptomatic thin lamina of blood; we opted to watch and follow. One month later, a control MRI revealed a left frontoparietal subdural hematoma. Despite being asymptomatic, the hematoma was determined to have significant mass effect; thus, it was evacuated by a parietal burr-hole. After 1 month, another MRI showed resolution of the frontoparietal hematoma and significant reduction in the arachnoid cyst. There are few cases described of spontaneous rupture of arachnoid cyst; beyond that, we would like to illustrate a step-by-step procedure that is not widely available as a video article.

Quiste aracnoideo intraventricular asintomático: reporte de un caso / Asymptomatic intraventricular arachnoid cyst: a case report

Introducción: Los Quistes Aracnoideos son colecciones benignas de líquido cefalorraquídeo que representan el 1% de lesiones ocupantes de espacios intracraneales. Se detecta frecuentemente antes de los 20 años, entre 60 a 90% de los casos. La prevalencia estimada es de 1,4% en adultos, siendo la menos frecuente la ubicación intraventricular. Caso Clínico: Mujer de 60 años de edad, consultó por cefalea holocraneana de larga data y ocasionales mareos. Sin alteraciones al examen físico neurológico. Se le realizó tomografía axial computarizada donde llamó la atención una leve alteración de la densidad intraventricular por lo que se procedió a realizar resonancia magnética nuclear que demostró imágenes quísticas en atrio de ventrículos laterales, bilateral. No se requirió de una intervención quirúrgica debido a que la paciente no presentaba sintomatología significativa. Discusión: El tratamiento quirúrgico es recomendado en pacientes sintomáticos, en quistes de gran extensión y en los que cursan con complicaciones. Para los pacientes que cursen sólo con dolor de cabeza, sin hidrocefalia secundaria o un aumento evidente de la presión intracraneal se recomienda la observación con o sin repetición de las imágenes.

Introduction: Arachnoid cysts are benign collections of cerebrospinal fluid that represents 1% of lesions occupying intracranial spaces. It is frequently detected before the age of 20, between 60 to 90% of cases. The estimated prevalence is 1.4% in adults, the least frequent being intraventricular location. Clinical Case: A 60-year-old woman attended for a long-standing holocranial headache and occasional dizziness. No alteration in the neurological physical examination. A computerized axial tomography was performed, where a slight alteration in the intraventricular density drew attention, for which a nuclear magnetic resonance was carried out, which showed cystic images in the atrium of bilateral lateral ventricles. No surgical intervention was required because the patient did not present a significant symptomatology. Discussion: Surgical treatment is recommended in symptomatic patients, in cysts of great extension and in those with complications. For patients with only headache, without secondary hydrocephalus or an obvious increase in intracranial pressure, observation with or without repetition of the images is recommended.

Coexisting arachnoid cyst and tentorial sinus: A therapeutic dilemma.

A 4-year-old male presented with a large arachnoid cyst over the left temporal region causing displacement of adjacent structures. Cerebral angiography showed dilatation of the tentorial sinus without other apparent vascular alterations. The association of these two anomalies raises a therapeutic dilemma as no information is available about how the variants of the venous system can modify cerebrospinal fluid hydrodynamics and thus affect arachnoid cyst's prognosis. In this case, the patient was treated conservatively and has remained stable for 2 years.

Dysembryoplastic neuroepithelial tumor and temporal arachnoid cyst on a child with epilepsy. Which one to operate? Case report and literature review.

A 6 year-old male, with seizures characterized by abnormal epigastric sensation, behavioral arrest, upper extremities search automatisms and secondary tonic-clonic generalization. Magnetic resonance imaging showed a hypointense cystic extra-axial image with an increase in the thickness of the convolutions in the first and second gyri of the right frontal lobe. It was decided to resect the frontal lesion with transoperative motor mapping. Morphological and immunohistochemical findings corresponded to dysembryoplastic neuroepithelial tumor with focal cortical dysplasia. Adequate semiology, analysis of the electroencephalogram, and imaging studies allowed treating adequately the cortical dysplasia. At present, the patient is seizure-free without medication (Engel IA).

Niño de 6 años con crisis caracterizadas por sensación epigástrica, arresto conductual, automatismos de búsqueda y generalización tónico-clónica secundaria. La resonancia magnética mostró una imagen extraaxial quística y un aumento del grosor de las circunvoluciones del primer y segundo giros del lóbulo frontal derecho. Se decidió resecar primero la lesión frontal con guía por mapeo transcortical intraoperatorio. Los hallazgos morfológicos e inmunohistoquímicos mostraron un tumor neuroepitelial disembrioplásico con displasia cortical focal. La semiología, el análisis del electroencefalograma y la imagen permitieron orientar el tratamiento. Actualmente el paciente está libre de crisis y sin medicamentos (Engel IA).