Resultado a largo plazo de una serie de fetos con agenesia aislada del septum pellucidum / Long-term postnatal outcome of fetuses with isolated agenesis of the septum pellucidum

Objetivo: Reportar el resultado a largo plazo de una serie de fetos con agenesia del septum pellucidum aislada (ASP), con medición de su quiasma óptico mediante neurosonografía fetal (NSG). Método: Se incluyeron todas las pacientes con ASP y NSG evaluadas desde el año 2008 a la fecha y con seguimiento hasta su edad escolar. En todos los casos se consignaron los datos clínicos de NSG y de resonancia magnética (RM), cuando esta se realizó. Se entrevistó telefónicamente a los padres. Resultados: Nueve pacientes cumplieron los criterios: cuatro con displasia septo-óptica (DSO) (rango de seguimiento: 5-14 años) y cinco sin DSO (rango de seguimiento: 7-10 años). Un décimo caso se excluyó por tener solo 6 meses de seguimiento. Ninguna de las ASP tuvo otra anomalía detectada en su seguimiento. Ninguno de los casos con DSO tuvo alteración del tamaño de su quiasma óptico en la NSG ni anormalidad en la vía óptica en la RM. Conclusiones: En nuestra población, el riesgo residual de DSO frente a ASP es del 44,4%. En el seguimiento, nuestra definición de ASP por NSG no tuvo falsos negativos con relación a otras anomalías de aparición posnatal, a excepción de la DSO.

Objective: To report the long-term outcome of a series of fetuses with isolated septum pellucidum agenesis (ASP) with measurement of their optic chiasm by fetal neurosonography (NSG). Method: All patients with ASP and NSG evaluated from 2008 to date and with follow-up until their school age were included. In all cases, clinical, NSG and magnetic resonance imaging (MRI) data were recorded. Parents were interviewed by telephone. Results: Nine patients met the criteria: four with septo-optic dysplasia (SOD) (follow-up range: 5-14 years) and five without SOD (follow-up range: 7-10 years). A tenth case was excluded because only 6 months of follow-up. None of the ASP cases had another anomaly detected in their follow-up. None of the cases with DSO had anomaly of the size of their optic chiasm on NSG or abnormality in the optical pathway in the MRI. Conclusions: In our population, the residual risk of DSO versus ASP is 44.4%. At follow-up, our NSG definition of ASP had no false negatives in relation to other postnatal-onset anomalies, except for SOD.

Tumor de hipófise em paciente com hidrocefalia: um desafio diagnóstico / Pituitary tumor in a patient with hydrocephalus: a diagnostic challenge

RESUMO A hidrocefalia é definida como a dilatação ventricular pelo aumento da pressão intraventricular e intracraniana quando não tratada ou por insucesso do tratamento. Muitas vezes, leva ao dano das vias ópticas, podendo causar atrofia óptica, devido à proximidade dessas vias com o ventrículo lateral quando ocorre a dilatação. Assim como a hidrocefalia pode levar à atrofia óptica, outras patologias também podem. Tumores hipofisários compartilham desse mesmo sinal, além de causar hemianospsia bitemporal quando o tumor comprime quiasma óptico. Ademais, a hemianopsia bitemporal é o distúrbio visual mais comum encontrado em pacientes com tumor de hipófise. Os tumores de hipófise, por exemplo, geram manifestações clínicas que podem estar relacionadas à disfunção da glândula ou aos efeitos mecânicos da expansão tumoral. Sinais e sintomas visuais estão mais ligados ao efeito mecânico do tumor. Assim, muitas vezes, o paciente procura o oftalmologista antes do endocrinologista. Neste caso, analisaremos uma paciente portadora de hidrocefalia que apresentava, concomitantemente, um tumor hipofisário, e a investigação oftalmológica fez toda a diferença no tratamento da paciente.

ABSTRACT Hydrocephalus is defined as ventricular dilation caused by increased intraventricular and intracranial pressure when untreated or due to treatment failure. Optical pathways can often cause optic atrophy due to the proximity to the lateral hazard when dilation occurs. Hydrocephalus can lead to optic atrophy, as well as other pathologies. Pituitary tumors share this same sign, in addition to causing bitemporal hemianopia when it compresses the optic chiasm. In addition, bitemporal hemianopia is the visual disturbance most commonly found in patients with pituitary tumors. Pituitary tumors, for example, have clinical manifestations that may be related to gland dysfunction, or to mechanisms of tumor expansion. Visual signs and symptoms are more linked to the mechanical effect of the tumor. Therefore, the patient usually seeks the ophthalmologist before the endocrinologist. In this case, we analyzed a patient with hydrocephalus who presented, at the same time, a pituitary tumor, and the ophthalmological investigation made all the difference in the treatment of the patient.

Traumatic chiasmal syndrome. Case report / Síndrome quiasmática traumática. Relato de caso

ABSTRACT Traumatic chiasmal syndrome is one of the rare etiologies of chiasmal syndrome, characterized by optic chiasm injury following head trauma. The main visual defect associated is bitemporal hemianopia with macular splitting; however, it can present with a variety of other visual defects and neurologic signs. The authors report a case of complete bitemporal hemianopia after head trauma, with multiple frontal and skull base fractures and no other neurologic deficits, or hypothalamic-pituitary abnormality. Most cases of traumatic chiasmal syndrome are caused by mechanical stretch or compression of the chiasma. Nevertheless, in this case, the radiologic findings excluded macroscopic disruption or external compression of the chiasma, raising the possibility of a contusion necrosis associated with functional impairment of the optic chiasma. Traumatic chiasmal syndrome must be considered in the differential diagnosis of patients presenting with complete bitemporal hemianopia after head injury caused by frontal and skull base fracture.

RESUMO A síndrome quiasmática traumática é uma das raras etiologias da síndrome do quiasma óptico, que se caracteriza pela presença de lesão do quiasma óptico causada por traumatismo craniencefálico. O principal defeito visual associado é a hemianopsia bitemporal com macular splitting. No entanto, pode se manifestar por uma variedade de outros defeitos visuais e sinais neurológicos. Os autores relatam um caso de hemianopsia bitemporal completa após traumatismo craniencefálico com múltiplas fraturas frontais e da base do crânio na ausência de outros défices neurológicos ou alterações do eixo hipotálamo-hipofisário. A maioria dos casos de síndrome quiasmática traumática é causada por estiramento mecânico ou compressão do quiasma. No entanto, no caso apresentado, os achados radiológicos excluíram lesão macroscópica ou compressiva do quiasma, levantando a possibilidade de uma necrose após contusão associada ao compromisso funcional do quiasma óptico. A síndrome quiasmática traumática deve ser considerada no diagnóstico diferencial de doentes que apresentam hemianopsia bitemporal completa após traumatismo craniencefálico, especialmente em casos de fratura do osso frontal e da base do crânio.

As consequências irreversíveis do diagnóstico tardio de macroadenoma de hipófise em paciente jovem / The irreversible consequences of late diagnosis of pituitary macroadenoma in a young patient

Resumo Os tumores de hipófise representam aproximadamente 15% de todos os tumores cerebrais e dependendo do tamanho, pressionam o quiasma óptico, resultando em comprometimento da função visual que se manifesta como defeitos no campo visual, diminuição da acuidade visual e da visão das cores. O objetivo do presente estudo foi relatar um caso de macroadenoma de hipófise com compressão do quiasma óptico e defeito no campo visual, tratado inicialmente como glaucoma, levando a um diagnóstico e tratamento tardio.

Abstract Pituitary tumors represent approximately 15% of all brain tumors and depending on size, pressure optic chiasma, resulting in impaired visual func-tion that manifests itself as defective in the visual field, decreased acuity visual and color vision. The ob-jetive of the present study was to report a case of pitui-tary macroadenoma with compression of optical chiasma and visual field de-fect, initially treated as glaucoma, leading to a late diagnosis and treatment.

Quiste de la bolsa de Rathke / Rathke pouch cyst

Es una lesión quística que surge del remanente epitelial de la bolsa de Rathke, casi siempre su diagnóstico es un hallazgo incidental ya que en la mayoría de los casos es asintomático. Cuando se manifiesta se debe a que ha aumentado lo suficiente su volumen hasta comprimir estructuras vecinas causando cefalea, alteraciones visuales y disfunción pituitaria. En su mayoría ocurre en adultos entre la cuarta y quinta década de vida. Presentamos el caso de una paciente femenina de 9 años de edad que consultó por talla baja al servicio de endocrinología, por lo cual se inició tratamiento con hormona de crecimiento y se solicitó una resonancia magnética nuclear (RMN) la cual reportó quiste de la bolsa de Rathke versus adenoma hipofisario.

Rathke pouch cysts are epithelium-lined cysts arising from the embryological remnants of Rathke ́s pouch. They are usually incidentally identified since the majority are asymptomatic. They become symptomatic when they enlarge enough to compress neighbor structures causing headache, visual disturbances and pituitary dysfunction. They occur mostly in adults in the fourth to fifth decades of life. A case is presented in a 9-year-old female patient who consulted for growth retardation to the endocrinology service. She was treated with growth hormone and a magnetic resonance imaging (MRI) scan reported Rathke ́s pouch cyst versus pituitary adenoma.

Quiste de la bolsa de Rathke / Rathke pouch cyst

Es una lesión quística que surge del remanente epitelial de la bolsa de Rathke, casi siempre su diagnóstico es un hallazgo incidental ya que en la mayoría de los casos es asintomático. Cuando se manifiesta se debe a que ha aumentado lo suficiente su volumen hasta comprimir estructuras vecinas causando cefalea, alteraciones visuales y disfunción pituitaria. En su mayoría ocurre en adultos entre la cuarta y quinta década de vida. Presentamos el caso de una paciente femenina de 9 años de edad que consultó por talla baja al servicio de endocrinología, por lo cual se inició tratamiento con hormona de crecimiento y se solicitó una resonancia magnética nuclear (RMN) la cual reportó quiste de la bolsa de Rathke versus adenoma hipofisario.

Rathke pouch cysts are epithelium-lined cysts arising from the embryological remnants of Rathke ́s pouch. They are usually incidentally identified since the majority are asymptomatic. They become symptomatic when they enlarge enough to compress neighbor structures causing headache, visual disturbances and pituitary dysfunction. They occur mostly in adults in the fourth to fifth decades of life. A case is presented in a 9-year-old female patient who consulted for growth retardation to the endocrinology service. She was treated with growth hormone and a magnetic resonance imaging (MRI) scan reported Rathke ́s pouch cyst versus pituitary adenoma.

Bilateral Occipital Lobe Infarction Presenting as Bilateral Inferior Altitudinal Defects

PURPOSE: Horizontal visual field defects are generally caused by lesions before the optic chiasm, but we report a case with bilateral inferior altitudinal defects secondary to bilateral occipital lobe infarction. CASE SUMMARY: A 57-year-old male with a history of diabetes and hypertension presented with a month of blurring in the inferior visual field. His corrected visual acuity was 1.0 in the right eye and 0.63 in the left eye, and the intraocular pressure was normal in each eye. Pupillary response, ocular movement, and color vision tests were normal in both eyes. There was no specific finding of the optic disc and macula on fundus examination. Visual field examination revealed an inferior congruous homonymous hemianopia with horizontal meridian sparing and a left incongruous homonymous quadrantanopia. Optical coherence tomography for peripapillary retinal nerve fiber layer thickness revealed a mild decrease in the inferior disc of both eyes. Brain magnetic resonance imaging confirmed the presence of an acute infarction confined with upper medial calcarine fissures of bilateral occipital lobe and the right splenium of the corpus callosum, which were consistent with inferior altitudinal hemianopia and left superior incongruous quadrantanopia, respectively. Brain magnetic resonance angiography showed multiple stenosis of bilateral posterior cerebral arteries. CONCLUSIONS: The altitudinal visual field defects could be caused by the occipital lesion medial to the calcarine fissure, and unusual visual defects could be due to a combination of multiple lesions.

Intraoperative monitoring of flash visual evoked potential under general anesthesia / 대한마취과학회지

In neurosurgical procedures that may cause visual impairment in the intraoperative period, the monitoring of flash visual evoked potential (VEP) is clinically used to evaluate visual function. Patients are unconscious during surgery under general anesthesia, making flash VEP monitoring useful as it can objectively evaluate visual function. The flash stimulus input to the retina is transmitted to the optic nerve, optic chiasm, optic tract, lateral geniculate body, optic radiation (geniculocalcarine tract), and visual cortical area, and the VEP waveform is recorded from the occipital region. Intraoperative flash VEP monitoring allows detection of dysfunction arising anywhere in the optic pathway, from the retina to the visual cortex. Particularly important steps to obtain reproducible intraoperative flash VEP waveforms under general anesthesia are total intravenous anesthesia with propofol, use of retinal flash stimulation devices using high-intensity light-emitting diodes, and a combination of electroretinography to confirm that the flash stimulus has reached the retina. Relatively major postoperative visual impairment can be detected by intraoperative decreases in the flash VEP amplitude.

An Unruptured Anterior Communicating Artery Aneurysm Presenting with Left Homonymous Hemianopsia: A Case Report

Unruptured cerebral aneurysms sometimes present with visual symptomsdue to compression of the visual pathways. However, until now, unruptured anterior communicating artery (ACoA) aneurysms presenting visual field defects have been extremely rare. The authors report the case of a 51-year-old woman who presented with left homonymous hemianopsia. Radiological findings demonstrated an ACoA aneurysm filled with thrombus, that was compressing the optic chiasm and post-chiasmal tract. The patient underwent clipping of the aneurysm, which resolved the visual field defect. In cases of visual field defects, an ACoA aneurysm should be included in the differential diagnosis.

Spontaneous Involution of Rathke’s Cleft Cysts without Visual Symptoms

BACKGROUND: There have been various reports in the literature regarding the conservative management of pituitary apoplexy, pituitary incidentalomas and Rathke cleft cysts (RCCs). However, to the best of our knowledge, spontaneous involution of cystic sellar mass has rarely been reported. We report 14 cases of cystic sellar masses with spontaneous involution. METHODS: A total of 14 patients with spontaneous regression of cystic sellar masses in our hospital were included. The median age was 35 years (range, 5–67), and 8 patients were male. Clinical symptoms, hormone study and MRI were evaluated for all patients. The initial MRI showed all 14 patients with RCCs. Eight patients were presented with sudden onset of headache, and 1 patient with dizziness. Another patient, a 5-year-old child, was presented with delayed growth. Three patients had no symptoms via regular medical work up. All 14 patients had no visual symptoms. The follow-up period ranged from 5.7 to 42.8 months, with the mean of 17.3 months. RESULTS: The mean initial tumor size was 1.29 cm³ (range, 0.05 to 3.23). After involution, the tumor size decreased to 0.23 cm³ (range, 0 to 0.68) without any treatments. Repeated MRI showed a spontaneous decrease in tumor volume by 78% (range, 34 to 99). The initial MRI showed that the tumor was in contact with the optic chiasm in 7 patients, while compressing on the optic chiasm in 3 patients. Five patients were initially treated with hormone replacement therapy due to hormone abnormality. After the follow-up period, only 2 patients needed a long-term hormone replacement therapy. CONCLUSION: The spontaneous involution of RCCs is not well quantified before. Their incidence has not been well demonstrated, but this phenomenon might be underreported. Conservative management can be a treatment option in some RCCs without visual symptoms, even in those that are large in size and in contact with the optic nerve via imaging study.

Expanded Endoscopic Transnasal Approach to the Chordoid Glioma of the Third Ventricle : The First Case Ever Reported

Chordoid glioma of the third ventricle is a rare and challenging tumor to surgery because of its unique anatomical location and its close juxtaposition to the neurovascular structures and hypothalamus. The authors report a case of chordoid glioma of the third ventricle in a 43-year-old woman, who presented with headache and somnolence. The tumor was approached by endoscopic transnasal technique with a favorable result. Histopathologic examination disclosed a neoplastic tissue composed of eosinophilic epithelioid cells, mucinous, periodic acid Schiff-diastase positive, extracellular matrix, and scattered lymphoplasmacytic infiltrates. The best treatment option remains controversial. Customarily, the surgical route to remove chordoid glioma is transcranial; however, the undersurface of the optic chiasm and optic nerves preclude an adequate surgical visualization. In contrast, an expanded endoscopic transnasal approach provides a direct midline corridor to this region without any brain retraction.

The Application of a New Maximum Color Contrast Sensitivity Test to the Early Prediction of Chiasma Damage in Cases of Pituitary Adenoma: The Pilot Study

PURPOSE: Our objective was to estimate the maximum color contrast sensitivity (MCCS) thresholds in individuals with chiasma opticum damage. METHODS: The pilot study tested 41 people with pituitary adenoma (PA) and 100 age- and gender-matched controls. Patients were divided into two groups according to PA size, PA ≤1 cm or PA >1 cm. A new MCCS test program was used for color discrimination. RESULTS: The mean total error score (TES) of MCCS was 1.8 in the PA ≤1 cm group (standard deviation [SD], 0.38), 3.5 in the PA >1 cm group (SD, 0.96), and 1.4 in the control group (SD, 0.31; p 1 cm (p < 0.01). In PA patients with normal VA, the TES was 2.35 times worse than that of healthy persons (p < 0.01).

Dosimetric comparison of intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) in total scalp irradiation: a single institutional experience

PURPOSE: Total scalp irradiation (TSI) is a rare but challenging indication. We previously reported that non-coplanar intensity-modulated radiotherapy (IMRT) was superior to coplanar IMRT in organ-at-risk (OAR) protection and target dose distribution. This consecutive treatment planning study compared IMRT with volumetric-modulated arc therapy (VMAT). MATERIALS AND METHODS: A retrospective treatment plan databank search was performed and 5 patient cases were randomly selected. Cranial imaging was restored from the initial planning computed tomography (CT) and target volumes and OAR were redelineated. For each patients, three treatment plans were calculated (coplanar/non-coplanar IMRT, VMAT; prescribed dose 50 Gy, single dose 2 Gy). Conformity, homogeneity and dose volume histograms were used for plan. RESULTS: VMAT featured the lowest monitor units and the sharpest dose gradient (1.6 Gy/mm). Planning target volume (PTV) coverage and homogeneity was better in VMAT (coverage, 0.95; homogeneity index [HI], 0.118) compared to IMRT (coverage, 0.94; HI, 0.119) but coplanar IMRT produced the most conformal plans (conformity index [CI], 0.43). Minimum PTV dose range was 66.8% –88.4% in coplanar, 77.5%–88.2% in non-coplanar IMRT and 82.8%–90.3% in VMAT. Mean dose to the brain, brain stem, optic system (maximum dose) and lenses were 18.6, 13.2, 9.1, and 5.2 Gy for VMAT, 21.9, 13.4, 14.5, and 6.3 Gy for non-coplanar and 22.8, 16.5, 11.5, and 5.9 Gy for coplanar IMRT. Maximum optic chiasm dose was 7.7, 8.4, and 11.1 Gy (non-coplanar IMRT, VMAT, and coplanar IMRT). CONCLUSION: Target coverage, homogeneity and OAR protection, was slightly superior in VMAT plans which also produced the sharpest dose gradient towards healthy tissue.

Bitemporal Hemianopsia in Ethambutol-Induced Optic Neuropathy

PURPOSE: To report three cases with bitemporal hemianopsia after using ethambutol to treat tuberculosis. CASE SUMMARY: A 50-year-old male with chronic renal failure and tuberculous pleurisy, a 57-year-old male with diabetic retinopathy and pulmonary tuberculosis, and a 59-year-old male with diabetes and pulmonary tuberculosis were referred for evaluation due to decreased visual acuity for several months after taking ethambutol to treat tuberculosis. All 3 patients had abnormal color vision and visual evoked potential in both eyes. Visual field showed bitemporal hemianopsia with or without central scotoma. Brain imaging tests were normal. Although ethambutol was discontinued in all three patients, one patient with renal disease showed further decrease in visual acuity and visual field worsened to total field defect. CONCLUSIONS: Ethambutol-induced optic neuropathy is a wide spectrum disorder and based on our cases, can present as bitemporal hemianopsia mimicking compressive chiasmal lesions. A thorough history should be taken and immediate discontinuation of ethambutol is recommended in cases when bitemporal hemianopia occurs.

A Large Ruptured Anterior Communicating Artery Aneurysm Presenting with Bitemporal Hemianopsia

Anterior communicating artery (ACoA) aneurysms sometimes present with visual symptoms when they rupture or directly compress the optic nerve. Giant or large ACoA aneurysms producing bitemporal hemianopsia are extremely rare. Here we present an unusual case of bitemporal hemianopsia caused by a large intracranial aneurysm of the ACoA. A 41-year-old woman was admitted to our neurosurgical department with a sudden-onset bursting headache and visual impairment. On admission, her vision was decreased to finger counting at 30 cm in the left eye and 50 cm in the right eye, and a severe bitemporal hemianopsia was demonstrated on visual field testing. A brain computed tomography scan revealed a subarachnoid hemorrhage at the basal cistern, and conventional cerebral catheter angiography of the left internal carotid artery demonstrated an 18x8 mm dumbbell-shaped aneurysm at the ACoA. Microscopic aneurysmal clipping was performed. An ACoA aneurysm can produce visual field defects by compressing the optic chiasm or nerves. We emphasize that it is important to diagnose an aneurysm through cerebrovascular study to prevent confusing it with pituitary apoplexy.

Chordoid Glioma Originating in the Intrasellar and Suprasellar Regions: Case Report

Chordoid glioma is a rare, low-grade brain neoplasm typically located in the third ventricle. Herein, we report an unusual case of histologically confirmed chordoid glioma located in the pituitary fossa and suprasellar region, not attached to the third ventricle. A 57-year-old woman presented with a 2-month history of headache and visual disturbance. Magnetic resonance imaging revealed an ovoid mass in the pituitary fossa and suprasellar region, compressing the optic chiasm without involvement of the third ventricle. The tumor showed low signal intensity on T1-weighted images and iso- to high signal intensity on T2-weighted images, with strong and homogenous contrast enhancement. Subtotal resection was performed via the transcranial approach, and the patient subsequently received adjuvant gamma knife radiosurgery. However, the residual mass showed disease progression 5 months after the initial surgery.

The Influence of Pituitary Adenoma Size on Vision and Visual Outcomes after Trans-Sphenoidal Adenectomy: A Report of 78 Cases

OBJECTIVE: The aims of this study were to investigate the quantitative relationship between pituitary macroadenoma size and degree of visual impairment, and assess visual improvement after surgical resection of the tumor. METHODS: The medical records of patients with pituitary adenoma, who had undergone trans-sphenoidal adenectomy between January 2009 and January 2011, were reviewed. Patients underwent an ocular examination and brain MRI before and after surgery. The visual impairment score (VIS) was derived by combining the scores of best-corrected visual acuity and visual field. The relationship between VIS and tumor size/tumor type/position of the optic chiasm was assessed. RESULTS: Seventy-eight patients were included (41 male, 37 female). Thirty-two (41%) patients experienced blurred vision or visual field defect as an initial symptom. Receiver operating characteristic curve analysis showed that tumors <2.2 cm tended to cause minimal or no visual impairment. Statistical analysis showed that 1) poor preoperative vision is related to tumor size, displacement of the optic chiasm in the sagittal view on MRI and optic atrophy, and 2) poorer visual prognosis is associated with greater preoperative VIS. In multivariate analysis the only factor significantly related to VIS improvement was increasing pituitary adenoma size, which predicted decreased improvement. CONCLUSION: Results from this study show that pituitary adenomas larger than 2 cm cause defects in vision while adenomas 2 cm or smaller do not cause significant visual impairment. Patients with a large macroadenoma or giant adenoma should undergo surgical resection as soon as possible to prevent permanent visual loss.

Primary Granulomatous Hypophysitis Presenting with Panhypopituitarism and Central Diabetes Insipidus / 대한내과학회지

Primary granulomatous hypophysitis is a rare inflammatory disorder of the pituitary gland and patients commonly present with symptoms of sellar compression and hypopituitarism. A 48-year-old woman was admitted due to headache and fatigue. Magnetic resonance imaging showed a 21 x 18 x 13-mm round sellar mass with a thickened pituitary stalk. The endocrinological examination revealed panhypopituitarism and diabetes insipidus. Suspecting hypophysitis, the patient was given steroid and hormone replacement therapy. Six months later, she continued to complain of severe headaches and nausea. Computed tomography showed no significant change in the sellar mass. Subsequently, transsphenoidal surgery was performed. The pathological examination revealed granulomatous changes with multinucleated giant cells and primary granulomatous hypophysitis was diagnosed. Her headache resolved, but the pituitary functions did not improve. This is the first reported case in Korea of primary granulomatous hypophysitis with dysfunction of anterior and posterior pituitary gland, including the stalk, without optic chiasm compression.

Evaluation of organs at risk's dose in external radiotherapy of brain tumors

Radiotherapy plays an important role in the management of most malignant and many benign primary central nervous system [CNS] tumors. Radiotherapy affects both tumor cells and uninvolved normal cells; so, it is important to estimate absorbed dose to organs at risk in this kind of treatment. The aim of this study was to determine the absorbed dose to chiasma, lens, optic nerve, retina, parotid, thyroid and submandibular gland in frontal lobe brain tumors radiotherapy based on treatment planning system [TPS] calculation and direct measurement on the phantom. A head and neck phantom was constructed using natural human bone and combination of paraffin wax and Sodium Chloride [NaCl] as tissue-equivalent material. Six cylinders were made of phantom material which had cavities to insert Thermoluminescent Dosimeters [TLDs] at several depths in order to measure absorbed dose to chiasma, lens, optic nerve, retina, parotid, thyroid and submandibular gland. Three routine conventional plans associated with tumors of this region and a new purposed technique were performed on the phantom and dose distribution and absorbed dose to critical organs were compared using treatment planning system [TPS] calculation and direct measurement on the phantom. Absorbed doses were measured with calibrated TLDs and are expressed in centigray [cGy]. In all techniques absorbed dose to all organs except the lenses were at their tolerance dose levels and in the new purposed technique, absorbed dose to chiasma was significantly reduced. Our findings showed differences in the range of 1-5% in all techniques between TPS calculation and direct measurements for all organs except submandibular glands and thyroid. Because submandibular glands and thyroid are far from primary radiation field, TLD reading in these regions although small but differs from TPS calculation which shows very smaller doses. This might be due to scattered radiation which is not well considered in the TPS. In the new technique, because the chiasma is out of the radiation field, absorbed dose was reduced significantly

Bilateral acute visual loss from Rathke's cleft cyst apoplexy in a patient with dengue fever / Perda visual aguda secundária a apoplexia de cisto de Rathke em paciente com dengue

Hemorrhagic complications of optic pathway diseases are extremely rare causes of acute visual loss associated with dengue fever. In this paper we report a patient presenting with dengue fever and bilateral acute visual loss caused by chiasmal compression due to Rathke's cleft cyst apoplexy. Considering the importance of early diagnosis and treatment to visual recovery, apoplexy of sellar and suprasellar tumors should be considered in the differential diagnosis of patients with acute visual loss and dengue fever.

Complicações hemorrágicas de doenças da via óptica são causas extremamente raras de perda aguda de visão em pacientes com dengue. Nesse trabalho, documentamos um caso de paciente com dengue apresentando perda de visão bilateral aguda secundária a compressão quiasmática por quadro hemorrágico em cisto de Rathke. Considerando a importância do diagnóstico e tratamento precoces para um bom prognóstico visual, a apoplexia de tumores da região selar e suprasselar deve ser incluída como um raro, porém importante, diagnóstico diferencial de perda visual aguda nesses pacientes.