Infratentorial atypical choroid plexus papilloma in an adult: A case report and literature review

Atypical choroid plexus papilloma is classified as WHO (World Health Organization) Grade II subtype of choroid plexus tumor, and it has intermediate pathological features, prognosis, and clinical outcome rates between choroid plexus papilloma and choroid plexus carcinoma. These tumors are more common in children compared with adults and are usually located in the lateral ventricles. We present a case of an adult with atypical choroid plexus papilloma located in the infratentorial region. A 41?year?old woman underwent evaluation for headache and dull aching neck pain. Magnetic resonance imaging (MRI) of the brain revealed a well?defined intraventricular mass lesion in the fourth ventricle and foramen of Luschka. She underwent craniotomy and gross total excision of the lesion. Histopathological and immunohistochemical findings confirmed the diagnosis of atypical choroid plexus papilloma (WHO Grade II). We discuss the various treatment options for this condition and review the relevant literature.

Tumor pineal resuelto por Abordaje Infratentorial Supracerebeloso Endoscópico. Reporte de un caso y revisión de la literatura / Pineal tumor resolved by Endoscopic Supracerebellar Infratentorial Approach. Case report and literature review

Introducción: Los tumores de la región pineal constituyen un grupo heterogéneo de lesiones localizadas en la porción posterior del tercer ventrículo bajo el esplenio del cuerpo calloso y encima de la lámina cuadrigémina. Dentro de estos, los tumores del parénquima pineal constituyen un grupo frecuente. En estas lesiones no existe actualmente un protocolo establecido debido a la ausencia de grandes series. Se sugiere una combinación de cirugía y radioterapia con o sin quimioterapia. El tratamiento de elección es la resección total, sin embargo, muchas veces no es posible por dificultades técnicas. En este contexto, la cirugía con visualización endoscópica puede contribuir a lograr este objetivo. Descripción del caso: Se presenta un paciente masculino de 22 años de edad con lesión de región pineal e hidrocefalia obstructiva triventricular al que se le practicó una tercerventriculostomía endoscópica y un abordaje infratentorial supracerebeloso con total visualización endoscópica. Se describe la técnica quirúrgica y se realiza un análisis crítico de la literatura actualizada. Conclusiones: Los tumores de la región pineal constituyen un reto terapéutico. La resección total es el principal objetivo en lesiones de grado intermedio o bajo de malignidad. El abordaje infratentorial supracerebeloso con total visualización endoscópica es efectivo en la resección quirúrgica de estas lesiones al mejorar la visualización y minimizar la retracción cerebelosa

Introduction: Pineal region tumors are a variable group of lesions located in the posterior wall of the third ventricle under the corpus callous splenium and above the tectal plate. Pineal gland tumors are frequent. There is not a standard protocol in these lesions due the lack of large series. A combination of surgery and chemo therapy or radiotherapy are recommended. The complete surgical resection is the treatment of choice. However, usually it is not possible to accomplished this goal due to technical limitations. In this scenario, the endoscopic visualization could contribute to archive the goal. Patient characteristics: A 22 years old young male patient with a pineal region lesion and obstructive hydrocephalus is presented. A third ventriculostomy was performed and an infratentorial supracerebelous approach with fully endoscopic visualization. The surgical technique is described and a critical review of literature is performed. Conclusions: Pineal region tumors represents a therapeutic challenge. Total removal is the most important objective in intermediate or low-grade lesions. The infratentorial supracerebelous approach with full endoscopic visualization is effective and improve the visualization while reducing the cerebellar retraction.

Meningioma of the Fourth Ventricle: Literature Review

Meningiomas are among the most common central nervous system tumors, with an incidence that ranges from 15% to 40% of intracranial tumors. Of these, only 0.5% to 3% are intraventricular, and the rarest of them occurs in the fourth ventricle. Fourth-ventricle meningiomas originate generally fromthe choroid plexus and have no dural adhesions. Most often, they manifest in young patients, around 41 years of age, with a possible predominance in females, through intracranial hypertension and cerebellar syndromes. The treatment consists of surgical resection, which commonly presents good results due to the characteristics of the tumor. So, for better preoperative planning, the radiological differentiation of the most frequent tumors in this location is important. Themost common histologic subtypes are fibroblastic and meningothelial, both grade I according to the World Health Organization (WHO), although there are reports of tumors of grades II and III. We report a case ofmeningioma of the fourth ventricle operated in our institution, and we have conducted a literature review, through which we found that 57 cases have been reported so far, with the first one reported in 1938.

Epidemiological analysis of central nervous system tumors in pediatric patients from a tertiary care centre in India

Background: Tumors of the nervous system are the second most common childhood cancer after leukemia. The diagnosis of CNS tumors is challenging due to non-specific symptoms in children which mimic other less serious illness.Methods: This was a retrospective analysis of case records of patients from 0-18 years of age, who were diagnosed with CNS tumors for a period of 7 years.Results: Out of total 64 patients included in this study, 32 were females and 24 were males. The mean age was 13.2 years. The most common clinical presentation in patients with brain tumors was headache (92.3%) followed by visual symptoms in the form of blurring or loss of vision (42.3%) and swaying while walking (32.6%). The overall mean symptom interval for all patients was 274.8 days (approx. 9 months) ranging from 7-1820 days. In the present study out of total 64 patients, 54 were brain tumors (35 supratentorial and 19 infratentorial) and 10 were spinal tumors. The most common tumor location was cerebellum (21.8%) followed by cerebral cortex, spine and sellar area. Based on histopathology the most common tumor type in our study was astrocytoma. There was no significant correlation of symptom interval with age and gender but was significantly associated with location and tumor grade.Conclusions: Early referral to centers with appropriate facilities will help, as many pediatric CNS tumors are low grade with better survival.

Resección microquirúrgica de meningioma de la región pineal / Microsurgical resection of meningioma of the pineal region

Introducción: Los meningiomas de la región pineal son lesiones poco frecuentes, representando el 2 al 8% de los tumores localizados en esta área. Estos tumores son lesiones con comportamiento biológicamente benigno y potencialmente curables con la resección quirúrgica radical. A su vez representan un desafío quirúrgico debido a su profunda localización y la cercanía de estructuras anatómicas vitales. El abordaje supracerebeloso infratentorial, en posición semisentado (cuando las condiciones generales del paciente lo permiten), provee un corredor natural a la región pineal mediante la retracción cerebelosa gravitatoria. Objetivo: Presentación de la exéresis microquirúrgica completa de un meningioma de la región pineal. Descripción del caso: Paciente de 52 años que consulta por inestabilidad de la marcha y diplopía de 2 semanas de evolución. La resonancia magnética cerebral mostró una lesión expansiva, que realza con contraste, de 43 x 30 mm en la región pineal, con hidrocefalia obstructiva acompañante. Se realiza la exéresis microquirúrgica mediante abordaje supracerebeloso infratentorial con el paciente en posición semisentado. Resultado: Se realizó la exéresis completa de la lesión. La paciente cursó el primer día postoperatorio en Unidad de Terapia Intensiva y luego pasó a sala de internación general. Fue dada de alta al tercer día, sin déficit neurológico. La anatomía patológica de la lesión informó meningioma transicional (OMS grado I). El control imagenológico postquirúrgico mostró la resección de la lesión sin remanente tumoral. Conclusión: Los meningiomas de la región pineal presentan un desafío quirúrgico debido a la relación con estructuras anatómicas vitales. El abordaje supracerebeloso infratentorial ofrece un corredor anatómico natural mediante la retracción cerebelosa por la gravedad.

Background: Meningiomas of the pineal region are rare lesions representing 2 to 8% of the tumors located in this area. These tumors are lesions with biologically benign behavior and potentially curable by radical surgical resection. As well, they are a surgical challenge due to their deep location and the proximity to vital anatomical structures. The supracerebellar infratentorial approach, in a semisitting position (when the patient's general conditions allow it), provides a natural corridor to the pineal region through gravitational cerebellar retraction. Objetive: Presentation of a complete microsurgical resection of a meningioma of the pineal region. Case description: A 52-year-old patient who consulted due to gait instability and diplopia of 2 weeks of evolution. Brain magnetic resonance showed an expansive lesion, with contrast enhancement, 43 x 30 mm in the pineal region, with obstructive hydrocephalus. The microsurgical resection was performed by supracerebellar infratentorial approach with the patient in a semisitting position. Result: The complete microsurgical resection was achieved. The patient spent the first postoperative day in Intensive Care Unit, and then went to general room. He was discharged on the third postoperative day, without neurological deficit. The histopathology assessment of the lesion reported transitional meningioma (WHO grade I). Post-surgical imaging showed the resection of the lesion without remaining tumor. Conclusion: Meningiomas of the pineal region present a surgical challenge due to the relationship with vital anatomical structures. The supracerebellar infratentorial approach offers a natural anatomical corridor through cerebellar retraction by gravity.

Comparison of Dysphagia Between Infratentorial and Supratentorial Stroke Patients

OBJECTIVE: To compare dysphagia between infratentorial stroke patients and supratentorial stroke patients. METHODS: Subjects of this study were patients with post-stroke dysphagia (PSD) who were admitted to our medical institution between May 2014 and June 2017. We evaluated a total of 64 patients with PSD. A videofluoroscopic swallowing study (VFSS) was performed to determine dysphagia severity. We measured the following parameters: pharyngeal transit time (PTT), post-swallow pharyngeal remnant, Penetration Aspiration Scale (PAS) scores, and Functional Dysphagia Scale (FDS). We analyzed patient's results from VFSS performed at admission. All VFSS images were recorded using a camcorder running at 30 frames per second. An AutoCAD 2D screen was used to measure post-swallow pharyngeal remnant. RESULTS: In this study, PTT and FDS were similar (p>0.05) between infratentorial stroke patients and supratentorial stroke patients. However, there were significant differences in pharyngeal remnant and PAS scores between the two groups (p<0.01 and p<0.05, respectively). CONCLUSION: Both pharyngeal remnant and PAS score registered higher levels from VFSS test for infratentorial stroke patients than those for supratentorial stroke patients. This suggests greater chances of problems occurring with swallowing, the major functions of pons. Thus, clinicians should pay particular attention to active dysphagia evaluation and treatment in PSD of infratentorial stroke patients.

To assess the reliability of ICH score for predicting the mortality rate in acute intracerebral hemorrhage patients, in a rural based hospital, Jhalawar

Background: A simple clinical scale of intracerebral hemorrhage, comprising the Glasgow Coma Scale score, age, Infratentorial origin, ICH volume, and Intraventricular hemorrhage, was recently shown to predict 30-day mortality. We studied how well the original ICH Score would predict morbidity and mortality. Materials and methods: We did a retrospective study, in which records of all the patients with acute intracerebral hemorrhage were reviewed. Components of the ICH Score were recorded along with other clinical characteristics. Outcome was analyzed using modified ranking scale. Results: The mean age was 69  15 years with 45.4% males and 54.6% females. Common risk factors were smoking, diabetes mellitus and hypertension. Supratentorial lesions were 93.25% and Infratentorial lesions were 6.74 %. The overall 30 day mortality rate for ICH was 29.03%. Important predictors of mortality were, GCS score on admission (P<0.0001), hematoma volume >30ml (P <0.0001), Intraventricular extension (P <0.0001), and ICH score (P <0.0001). Conclusion: The study shows ICH score is very useful in prognostication. The overall mortality rate with ICH is similar to the previously published studies.

A clinical analysis of 5 patients with infratentorial primary angiitis of central nervous system / 中华内科杂志

Objective To explore the clinical characteristics of infratentorial primary angiitis in central nervous system (PACNS).Methods A total of 5 cases diagnosed as infratentorial PACNS in the neurology department of Navy General Hospital of PLA in 2015 were enrolled in the study.The clinical,imaging and pathological data were collected and analyzed.Results All the 5 cases were male with the median onset age of thirty-four.Five cases presented with dizziness,two with headache,three with walking unstable,two with facial numbness and one with dysarthria.Rising pressure of cerebrospinal fluid (CSF) (190-245 cmH2O,1 cmH2O =0.098 kPa) was found in 4 cases by the lumbar puncture,mildly increased number of leukocyte in 2 cases [(12-28) × 106/L],increased CSF protein in 3 cases(540-979 mg/L) and increased IgG index in 3 cases (0.84-1.45).Pons lesions were revealed by magnetic resonance imaging(MRI) in 4 cases,brachium pontis lesions in 2 cases,cerebellum lesions in 2 cases,one with midbrain lesion in 1 case,unilateral lesions in 4 cases and bilateral lesion in 1 case.Different degree of edema and mass effect were shown in all lesions by MRI.Patch like enhancement was found by contrast MRI in 5 cases and meningeal enhancement in 2 cases.Elevation of choline (Cho) peak was found by magnetic resonance spectroscopy (MRS) in 4 cases,reduction of N-acetyl aspartate (NAA) peak in 3 cases,appearance of lactate peak in 1 case and lipid peak in another case.Arterial spin labeling (ASL) was performed in 4 cases and no hyperperfusion was found.Susceptibility weighted imaging(SWI) was performed in 3 cases and microhemorrhage in the lesions was found in 2 cases and normal in 1 case.Magnetic resonance arteriography(MRA) was performed in 1 case and no stenosis was found.Digital subtraction arteriography(DSA) was performed in 1 case and multiple stenosis of the intracranial arteries was showed.Two cases had taken the stereotactic brain biopsy and the histopathologic diagnosis was angiitis.Five cases were treated with methylprednisolone and cyclophosphamide was added on in 1 case.Good prognosis was found in all cases.Conclusions Infratentorial PACNS mostly attacks middle-aged males.The lesions tend to locate in unilateral pons,brachium pontis,cerebellum and midbrain.Hemorrhage or microhemorrhage in lesions is often found by SWI and no hyperperfusion is shown by ASL,which would be useful to distinguish PACNS from malignant tumors.Given the limitations of brain biopsy in clinical practice,clinical and imaging features would be helpful to diagnose PACNS.

Abordaje supracerebeloso infratentorial a la región pineal. técnica, indicaciones y anatomía microquirúrgica en 3D / Supra-adventitious approach to the pineal región. technique, indications and 3D microsurgical anatomy

INTRODUCCIÓN: el abordaje supracerebeloso infratentorial fue descripto originalmente por Sir Victor Horsley, siendo posteriormente adaptado por Stein quien aplica la técnica microquirúrgica mejorando los resultados de las cirugías de la región pineal. OBJETIVOS: resaltar y sistematizar las indicaciones, detalles técnicos-anatómicos en el abordaje supracerebeloso infratentorial en base a nuestra experiencia quirúrgica y la revisión de la anatomía microquirúrgica de la región Pineal. MATERIAL Y MÉTODOS: se realizó un estudio descriptivo retrospectivo analizando las historias clínicas de 7 pacientes intervenidos quirúrgicamente a través de un abordaje supracerebeloso infratentorial, entre septiembre 2010 hasta septiembre 2013 en nuestro servicio. Las imágenes intraquirúrgicas y de preparados anatómicos fueron adquiridas en 3D. La revisión bibliográfica se realizó en Pub Med utilizando las palabras claves: Abordaje Supracerebeloso Infratentorial; Región Pineal; Craniectomía Suboccipital. RESULTADOS: durante el período 2010-2013 fueron intervenidos 7 pacientes. A todos se le practicó un abordaje supracerebeloso infratentorial. Fueron tratados 5 tumores de la región pineal, 1 glioma del culmen cerebeloso y 1 MAV de la fisura cerebelo mesencefálica. Se estandarizaron los siguientes pasos para la realización del abordaje supracerebeloso infratentorial de Stein: preparación prequirúrgica, posición sentado, posición de la cabeza, marcación y antisepsia cutánea, colocación de campos estériles, incisión de piel y tejido celular subcutáneo, disección de plano muscular, craneotomía, apertura dural, preparación del corredor supracerebeloso, disección intradural y anatomía microquirúrgica de la región pineal y consideraciones sobre elcierre. CONCLUSIONES: se sistematizó el abordaje supracerebeloso infratentorial con el que pudimos acceder a tumores pineales y también a lesiones vasculares en la región. En todos los casos la exposición anatómica fue suficiente para tratar en forma adecuada las patologías mencionadas, con mínima retracción de las estructuras del SNC

INTRODUCTION: even though Horsley was the first one to describe the supracerebellar infratentorial approach, it was Stein who adapted it to microsurgical techniques in an attempt to improve the results of surgical procedures on the pineal gland. OBJECTIVES: to enhance the indications and technical details of the supracerebellar infratentorial approach, based upon our experiences, we review the microsurgical anatomy of the pineal region that is exposed via this approach. MATERIALS AND METHODS: a retrospective descriptive study was conducted by analyzing the records of seven patients who had been operated on using this approach at our institution between September 2010 and September 2013. The images shown were obtained in 3D. RESULTS: the indications for surgery in these seven patients were a pineal gland tumor in five patients, and a culmen glioma and mesencephalic-fissure AVM in one patient each. The following steps were standardized according to Stein's description of the supracerebellar infratentorial approach: pre-surgical preparation, sitting position, head position, incision drawing and anti-sepsis, surgical field, collocation, skin and hypodermis incision, muscular dissection, hemostatic control, craniotomy, dural opening, supracerebellar corridor preparation, intradural dissection, microsurgical anatomy study, and considerations regarding closure. CONCLUSIONS: via this approach, we not only have been able to access pineal gland tumors but also vascular lesions in this region. The anatomical exposure achieved was enough to treat these lesions successfully, with minimal manipulation of the CNS

White Matter Hyperintensities and Cognitive Dysfunction in Patients With Infratentorial Stroke

OBJECTIVE: To determine whether cognitive function is associated with white matter hyperintensities (WMH) in patients with infratentorial stroke. METHODS: This was a retrospective, cross-sectional study. Twenty-four first-ever infratentorial stroke patients between 18 and 60 years of age were enrolled. WMH was evaluated by the Fazekas scale and the Scheltens scale. Cognitive functions were assessed using the Korean Mini-Mental Status Examination (K-MMSE), Rey-Osterrieth Complex Figure Test, and the Seoul Computerized Neuropsychological Test Battery (SCNT) at one month after stroke. All participants were divided into two groups based on the presence of WMH (no-WMH group and WMH group). General characteristics and cognitive functions were compared between the groups. RESULTS: There were no significant differences in general characteristics, such as age, stroke type, hypertension history, and education level between the two groups. However, K-MMSE in the WMH group was significantly lower compared to the no-WMH group (p<0.05). The verbal learning test score in SCNT was significantly higher in the no-WMH group compared to the WMH group (p<0.05). Executive function in the no-WMH group tended to be higher compared to the WMH group. CONCLUSION: Impairment of cognitive function in patients with infratentorial stroke appeared to be associated with WMH. WMH should be carefully evaluated during rehabilitation of infratentorial stroke patients.

Surgical Experience of Infratentorial Meningiomas : Clinical Series at a Single Institution during the 20-Year Period

OBJECTIVE: Based on surgical outcomes of patients with infratentorial meningiomas surgically treated at our institution, we analyzed the predictors for surgical resection, recurrence, complication, and survival. METHODS: Of surgically treated 782 patients with intracranial meningioma, 158 (20.2%) consecutive cases of infratentorial location operated on between April 1993 and May 2013 at out institute were reviewed retrospectively. The patients had a median age of 57.1 years (range, 16--77 years), a female predominance of 79.7%, and a mean follow-up duration of 48.4 months (range, 0.8--242.2 months). RESULTS: Gross total resection (Simpson's grade I & II) was achieved in 81.6% (129/158) of patients. Non-skull base location was an independent factor for complete resection. The recurrence rate was 13.3% (21/158) and the 5-, 10-, and 15-year recurrence rates were 8.2%, 12.0%, and 13.3%, respectively. Benign pathology, postoperative KPS over than 90, low peritumoral edema, and complete resection were significantly associated with longer recurrence-free survival rate. The 5-, 10-, and 15-year survival rates were 96.2%, 94.9%, and 94.9%, respectively. Benign pathology, postoperative KPS over than 90 and complete resection were significantly associated with a longer survival rate. The permanent complication rate was 13% (21/158). Skull base location and postoperative KPS less than 90 were independent factors for the occurrence of permanent complication. CONCLUSION: Our experience shows that infratentorial meningiomas represent a continuing challenge for contemporary neurosurgeons. Various factors are related with resection degree, complications, recurrence and survival.

Microanatomical study of the endoscopy-assisted extreme lateral supracerebellar infratentorial keyhole approach to the dorsolateral mesencephalon region / 中华显微外科杂志

Objective To explore the microanatomy technique of the endoscopy-assisted extreme lateral supracerebellar infratentorial keyhole approach and clinical significance.Methods The extreme lateral supracerebellar infratentorial keyhole approach was imitated in 10 vascular perfusion adult cadaveric heads fixed in formalin,the dorsolateral mesencephalon region was dissected and observed by microscopy and neuroendoscopy from December 2012 to March 2013.Results The extreme lateral supracerebellar infratentorial keyhole approach could be fully exposed the ambient cisterns,the posteromedial tentorial incisura,the dorsolateral mesencephalon region,the trochlear nerve,the root of the trigeminal nerve,the superior cerebellar artery,the posterior cerebral artery and other important anatomical structures.The temporal lobe and parahippocampal gyrus could be exposed when the tentorial was incised.The application of neuroendoscopy could clearly reveal the trigeminal nerve and surrounding structures.Conclusion The extreme lateral supracerebellar infratentorial keyhole approach is suitable for the surgical resection in dorsolateral mesencephalon region.The application of neuroendoscopy can make up for the lack of the trigeminal nerve observed under microscopy and expand the operative field.

Comparison of Swallowing Functions Between Brain Tumor and Stroke Patients

OBJECTIVE: To compare the swallowing functions according to the lesion locations between brain tumor and stroke patients. METHODS: Forty brain tumor patients and the same number of age-, lesion-, and functional status-matching stroke patients were enrolled in this study. Before beginning the swallowing therapy, swallowing function was evaluated in all subjects by videofluoroscopic swallowing study. Brain lesions were classified as either supratentorial or in-fratentorial. We evaluated the following: the American Speech-Language-Hearing Association (ASHA) National Outcome Measurement System (NOMS) swallowing scale, clinical dysphagia scale, functional dysphagia scale (FDS), penetration-aspiration scale (PAS), oral transit time, pharyngeal transit time, the presence of vallecular pouch residue, pyriform sinus residue, laryngopharyngeal incoordination, premature spillage, a decreased swal-lowing reflex, pneumonia, and the feeding method at discharge. RESULTS: The incidence of dysphagia was similar in brain tumor and stroke patients. There were no differences in the results of the various swallowing scales and other parameters between the two groups. When compared brain tumor patients with supratentorial lesions, brain tumor patients with infratentorial lesions showed higher propor-tion of dysphagia (p=0.01), residue (p<0.01), FDS (p<0.01), PAS (p<0.01), and lower ASHA NOMS (p=0.02) at initial evaluation. However, there was no significant difference for the swallowing functions between benign and malig-nant brain tumor patients. CONCLUSION: Swallowing function of brain tumor patients was not different from that of stroke patients according to matching age, location of lesion, and functional status. Similar to the stroke patients, brain tumor patients with infratentorial lesions present poor swallowing functions. However, the type of brain tumor as malignancy does not influence swallowing functions.

Gliosarcoma of the Cerebellar Hemisphere: a Case Report and Review of the Literature

Gliosarcoma is a rare central nervous system tumor usually located in the supratentorial area. Here we report a rare case of a gliosarcoma that developed in the cerebellar hemisphere in a 70-year-old woman. Computed tomography (CT) and magnetic resonance imaging (MRI) of the brain revealed an infratentorial mass of which radiological features were similar to those of glioblastoma. The tumor was diagnosed by pathology as a gliosarcoma. Though rare, gliosarcoma should be considered in the differential diagnosis of infratentorial tumors with radiological features of glioblastoma or metastasis in elderly patients.

Meduloblastoma: correlação entre ressonância magnética convencional, difusão e espectroscopia de prótons / Medulloblastoma: correlation among findings of conventional magnetic resonance imaging, diffusion-weighted imaging and proton magnetic resonance spectroscopy", "_i": "en

OBJETIVO: Correlacionar os achados de ressonância magnética convencional, difusão e espectroscopia de prótons nos meduloblastomas, e compará-los aos dados da literatura. MATERIAIS E MÉTODOS: Análise retrospectivade exames de ressonância magnética pré-operatórios de nove pacientes na faixa pediátrica com diagnóstico histológico de meduloblastoma (oito desmoplásicos e um de células gigantes). Foram considerados dados demográficos e características do tumor como localização, característica morfológica, intensidade de sinal, realce, disseminação e achados na difusão e espectroscopia. RESULTADOS: Na maioria dos casos os tumores apresentaram epicentro no vermis cerebelar (77,8%), sendo predominantemente sólido (88,9%), com hipossinal nas seqüências ponderadas em T1 e iso/hipersinal nas seqüências ponderadas em T2 e FLAIR, realce heterogêneo (100%), sinais de disseminação/extensão tumoral (77,8%) e restrição à movimentação das moléculas de água (100%). A espectroscopia de prótons pela técnica STEAM (n = 6) demonstrou redução da relação Naa/Cr (83,3%) e aumento de Co/Cr (100%) e mI/Cr (66,7%), e pela técnica PRESS (n = 7) evidenciou pico de lactato (57,1%). CONCLUSÃO: O conjunto dos achados macroscópicosobtidos pela ressonância magnética, somado às características bioquímicas dos meduloblastomas, têm sido úteis na tentativa de diferenciação entre os principais tumores da fossa posterior.

OBJECTIVE: To correlate imaging findings of medulloblastomas at conventional magnetic resonance imaging, diffusion-weighted imaging and proton magnetic resonance spectroscopy, comparing them with data in the literature. MATERIALS AND METHODS: Preoperative magnetic resonance imaging studies of nine pediatric patients with histologically confirmed medulloblastomas (eight desmoplastic medulloblastoma, and one giant cell medulloblastoma) were retrospectively reviewed, considering demographics as well as tumorscharacteristics such as localization, morphology, signal intensity, contrast-enhancement, dissemination, anddiffusion-weighted imaging and spectroscopy findings. RESULTS: In most of cases the tumors were centeredin the cerebellar vermis (77.8%), predominantly solid (88.9%), hypointense on T1-weighted images andintermediate/hyperintense on T2-FLAIR-weighted images, with heterogeneous enhancement (100%), tumor dissemination/extension (77.8%) and limited water molecule mobility (100%). Proton spectroscopy acquiredwith STEAM technique (n = 6) demonstrated decreased Naa/Cr ratio (83.3%) and increased Co/Cr (100%)and mI/Cr (66.7%) ratios; and with PRESS technique (n = 7) demonstrated lactate peak (57.1%). CONCLUSION: Macroscopic magnetic resonance imaging findings in association with biochemical features of medulloblastomas have been useful in the differentiation among the most frequent posterior fossa tumors. Keywords: Medulloblastoma; Infratentorial neoplasms; Pediatric brain tumors; Magnetic resonance imaging;Diffusion-weighted magnetic resonance imaging; Magnetic resonance spectroscopy.

Infratentorial-supracerebellar keyhole approach for microsurgical treatment of pineal region tumors / 中华显微外科杂志

Objective This study is to explore the infratentoriat-supracerebellar keyhole approach for microsurgical treatment of pineal region tumors and to evaluate its curative efficacy and safety.Methods According to hi-fi quality MRI images,individual operation schemes were designed.Microsurgical infratentori- al-supracerebellar keyhole approach was used to resect lesions in 7 consecutive patients with prone postition.A 2.0 cm?2.5 cm surgical bone window was performed with its superior margin reaching to the inferior margin of the transverse sinus and confluence sinus.Results Among the 7 pineal region tumors,there were 2 ger- minomas,2 pineocytomas,1 pineoblastoma,1 glioma and 1 chlesteatoma.All cases were re-examined with MRI after operation and it was found that 6 lesions were totally removed and 1 was subtotally removed.The outcome of the treatment was satisfying.There was no infection,bleeding or death after surgery.The follow-up result in the near future was good.Conclusion The infratentorial-supracerebellar keyhole approach for the excision of pineal region tumors was proved to be a satisfactory means with a total removal rate,an excellent curative effect and small surgical trauma.

Analysis of Factors Affecting Outcome in Infratentorial Tumor Surgery

OBJECT: It is well known that infratentorial surgery is more difficult to approach to the lesion and may result in poorer outcome than supratentorial surgery. The prognostic factors and outcome were analyzed for one hundred forty-five consecutive patients who underwent surgical treatment for infratentorial tumor between 1989 and 1997. METHODS: Neurilemmoma was the most common tumor(41 cases), followed by astrocytoma(19 cases), hemangioblastoma(19 cases), medulloblastoma(18 cases), meningioma(17 cases) respectively. We studied the relationship between postoperative outcome known various factors retrospectively: age at surgery, pathology, duration of symptoms, tumor size, location of tumor, presence of hydrocephalus, and extent of resection. A statistical analysis of clinical characteristics was conducted to evaluate the significance of associations by student t-test. Surgical results were evaluated by Ojemann's method. RESULTS: Of 145 cases, excellent were in 25 patients, good in 60 patients, fair in 41 patients, poor in 9 patients, and dead in 10 patients. Large size of tumor(p<0.01) and presence of hydrocephalus(p<0.05) were factors that indicate poor outcome. Surgical results of tumors in the cerebellopontine angle(CPA) or clival area were poorer than those in cerebellum(p<0.05). Age, duration of symptom, pathology, and extent of resection did not influence postoperative outcome significantly. The most common postoperative complication was facial palsy(21 cases). The operative mortality was 6.9% and sepsis was the leading cause of death. CONCLUSION:Large size(p<0.01), presence of hydrocephalus(p<0.05), and location in CPA and clival region(p<0.05) were factors that indicate poor outcome after infratentorial tumor surgery.

The Effect of Increased Infratentorial Intracranial Pressure and the Elevation of Blood Pressure on Frontal Cortical, Pontine Cerebral Blood Flow and Auditory Evoked Potentials

Patients with extra-axial mass lesions of the posterior fossa frequently demonstrate signs of brainstem dysfunction. These dysfunctions may be induced by the change of regional cerebral blood flow and electrophysiological status as well as mechanical compression and distortion of the brainstem. Frontal cortical regional cerebral blood flow(rCBF), pontine rCBF, brainstem autidory evoked potentials(AEPs), infratentorial intracranial pressure(infratentorial ICP) and mean arterial blood pressure(MABP) were recorded before and after expansion of an infratentorial epidural ballon in anesthetized experimental cat models. After the elevation of MABP during the increased infratentorial ICP, frontal cortical and potine rCBF, AEPs were recorded every 30 minutes. The results suggest that the elevating the MABP to improve cerebral perfusion pressure before irreversible change occurs in the brain may preserve cerebral function. We conclude that if the volume of the space in the posterior fossa that is occupied by the mass can be estimated, brain damage from low rCBF and brain compression due to intracranial hypertension can be prevented by the elevation of MABP before irreversible damage of the brain occurs.

A Case of Aneurysm Arising from the Marginal Branch of Superior Cerebellar Artery: A Case Report

The authors present a case of non-mycotic aneurysm arising from the marginal branch of the left superior cerebellar artery(SCA) in a 65-year-old female. Cerebral angiography disclosed a saccular aneurysm(3x3 mm) at the origin of marginal branch of the left SCA. The aneurysm was successfully clipped through the infratentorial-supracerebellar approach. Since the aneurysm from the marginal branch of the SCA is rare, we reported here briefly.

A Clinical Analysis of Brain Tumors in Children

The authors performed a clinical analysis of 80 cases of pediatric brain tumors which were verified by surgical operation during 10 years from Sept. 1978 to Aug. 1987 in the Department of Neurosurgery, Korea University, Seoul, Korea. These tumors were divided according to modified WHO classification. The results were as follows: 1) The male to female ratio was 1.42:1. 2) The most common pediatric brain tumor was gliomas(48.7%), and followed by medulloblastome(17.5%), germ cell tumor(7.5%), craniopharyngioma(6.2%), meningioma(5.0%). 3) Supratentorial tumors(57.5%) were more frequent than infratentorial tumors(42.5%). 4) Headache and vomiting were the most common presenting symptoms and papilledema was the most common sign. 5) Hydrocephalus was developed at supratentorial(58.7%) and infratentorial(73.5%) region. 6) Postoperative mortality was 7%.