A retrospective study of quadrigeminal arachnoid cysts diagnosed by Magnetic Resonance Imaging and Computed Tomography in 26 dogs / Estudo retrospectivo de cistos aracnoides da cisterna quadrigeminal diagnosticados pela ressonância magnética e tomografia computadorizada em 26 cães

Arachnoid cysts are accumulations of cerebrospinal fluid that occur within the arachnoid membrane due to the splitting or duplication of this structure. The aim of this retrospective study is to report the occurrence of this condition in 26 dogs, as well as to describe the findings of computed tomography imaging and magnetic resonance image scans and to correlate these with the clinical signs. A prevalence of the condition was observed in males, predominantly in the small breeds Miniature Pinscher and Shih Tzu, with age raging from 2 months to 9 years. The mainly clinical signs observed in these dogs were seizures and cerebellar ataxia. The study concluded that in 17 dogs the quadrigeminal arachnoid cyst was regarded as an incidental finding, in 6 dogs this condition was regarded as the determinant cause of the clinical signs, and in 3 dogs some clinical signs were associated with arachnoid cyst, but they also presented clinical signs involving others sites of intracranial lesion. (AU)

Cistos aracnoide são acúmulos de líquido cefalorraquidiano que ocorre dentro da membrana aracnoide devido à divisão ou duplicação desta estrutura. O objetivo desse estudo retrospectivo é relatar a ocorrência dessa condição em 26 cães, assim como descrever os aspectos de imagem pela tomografia computadorizada e ressonância magnética e correlacionar com os sinais clínicos. No estudo observamos a prevalência em machos, em raças de pequeno porte, com predomínio de Pinscher miniatura e Shih Tzu, com idade variando de dois meses a nove anos. Os principais sinais neurológicos observados nestes animais foram crises epiléticas e ataxia cerebelar. Foi possível concluir que em 17 cães o cisto aracnoide quadrigeminal foi considerado um achado incidental, em seis cães essa condição foi considerada a causa determinante dos sinais clínicos, e em três cães alguns sinais estavam associados com o cisto aracnoide, porém esses animais apresentaram sinais clínicos relacionados a outros sítios de lesão intracraniana.

Quadrigeminal cisterna lipoma: report of two cases and literature review / Lipoma da cisterna quadrigeminal: relato de dois casos e revisão da literatura

Intracranial lipomas are congenital, benign and slow-growing tumors. The incidence were 0.1 to 0.5 percent of all primary brain tumors and are often diagnosed in incidental findings of neuroradiological investigation. Lipoma in quadrigeminal region occurs in 25 percent of intracranial lipomas and has been reported as lipomas in quadrigeminal cistern (perimesencephalic cistern), quadrigeminal plate, ambiens cistern or superior medullary velum. MRI is the most major exam. The treatment is conservative in most cases, surgical removal is hampered by their deep location and contiguous with adjacent neurovascular structures. The authors report two cases of lipoma in the quadrigeminal region, incidental findings and discuss the clinical findings, neuroimaging and treatment.

Lipomas intracranianos são tumores congênito, benigno e de crescimento lento. Sua incidência é de 0.1 a 0.5 por cento de todos os tumores cerebrais primários e são frequentemente diagnosticados em achados incidental de investigação neuroradiológica. Lipoma na região quadrigeminal ocorre em 25 por cento dos lipomas intracranianos e tem sido relatados como lipomas na cisterna quadrigeminal (cisterna perimesencefálica), placa quadrigeminal, cisterna ambiens ou véu medular superior. O exame de eleição é ressonância magnética. O tratamento é conservador na maioria dos casos, a remoção cirúrgica é dificultada pela sua localização profunda e da contiguidade com estruturas neurovasculares adjacentes. Os autores relatam dois casos de lipoma na região quadrigeminal achados incidentalmente e discutem os achados clínicos, imagem e tratamento.

Lesión como malformación de Chiari secundaria a quiste aracnoidal de la cisterna cuadrigémina / Chiari malformation-like lesion secondary to arachnoid cyst of the quadrigeminal cistern

Se presenta el caso de una mujer de 31 años de edad con cefalea y cervicalgia que se agravaba con la maniobra de Valsalva, presentando además mareos, encontrándose una malformación de Chiari secundario a un quiste aracnoideo cuadrigeminal. Después de efectuada la resonancia magnética diagnóstica, la paciente fue sometida a descompresión del agujero magno y extirpación del quiste cuadrigeminal, seguido por la resolución tanto de la malformación de Chiari y el quiste. Los síntomas desaparecieron después de la cirugía y han permanecido completamente resuelto hasta la actualidad. En pacientes adultos que presentan signos y síntomas de una malformación de Chiari debido a la compresión de la médula por las las amígdalas cerebelosas, la presencia de un quiste aracnoideo de cisterna cuadrigéminal es una rara patología asociada que puede ser tratada quirúrgicamente.

We report a rare case of a 31-year-old woman with headache and pain manifested by cervicalgia that worsened with the Valsalva maneuver and dizziness, who was found to have a Chiari malformation secondary to a posterior fossa arachnoid cyst. After magnetic resonance imagining (MRI), the patient was submitted to foramen magnum decompression and arachnoid cyst removal that were followed by resolution of both the Chiari malformation and the cyst. The symptoms disappeared after surgery and have remained completely resolved to the present day. In adult patients who present with signs and symptoms of Chiari malformation due to direct medulla compression by the tonsils, a quadrigeminal cistern arachnoid cyst is a rare associated pathology that can be treated surgically.

[Tectal lipoma: a case report and review of literature]

Intracranial lipomas are rare benign neoplasms that comprise 1% of all primary brain tumors. Generally, occur in midline structure and usually identified incidentally on CT scans or in autopsies. The incidence of intracranial lipomas is about 0.08 to 0.46% on autopsies. These benign lesions are slow-growing, usually asymptomatic and rarely require surgery. We report a 20 years old male who complained of headache since two years ago. On CT examination, a quadrigeminal cistern lipoma without any pressure effect on neural structures demonstrated. His headache remitted with conservative measures. Here, we have a review on the literature and explain CT scan and MRI findings. According to the literature and present case, it seems that direct surgical excision of tumor is not justified in the majority of cases and symptoms of patients greatly respond to conservative measures and, at most, in cases of hydrocephalus, CSF shunting relieves their symptoms

A administração de hCG incrementa a incidência de ovulações duplas e múltiplas em éguas da raça Campolina apresentando folículos codominantes? / Does hCG administration increase the incidence of double and multiple ovulations in Campolina mares with co-dominant follicles?

A gonadotrofina coriônica humana (hCG) é rotineiramente empregada na indução de ovulação em éguas. A incidência de duplas ovulações é variável, sendo comum em determinadas raças brasileiras, como Brasileiro de Hipismo e Campolina. O objetivo deste trabalho foi avaliar se a administração de hCG em éguas da raça Campolina incrementa a incidência de ovulações duplas e múltiplas. Através de palpação retal e ultrassonografia, foram avaliados dois ciclos estrais de 104 éguas, divididas em dois grupos. À detecção de um ou mais folículos ³35 mm e edema endometrial grau 2, 2.500 IU de hCG (IV) eram administrados às éguas do grupo I. O grupo II serviu como controle. Os resultados obtidos foram analisados pelo Qui-quadrado. A incidência de ovulações duplas nos grupos I e II foi de, respectivamente, 32,7% (34/104) versus 30,8% (32/ 104). Ambos os grupos obtiveram incidência semelhante de ovulações triplas (1,9% - 2/104). Apenas uma ovulação quádrupla (1,0% - 1/104) foi detectada, no grupo controle. A incidência de duplas e múltiplas ovulações foi similar entre os grupos (p > 0,05). Pelo fato das éguas da raça Campolina apresentarem, fisiologicamente, considerável incidência de ovulações duplas e múltiplas, é possível que a administração de hCG não tenha influenciado estes padrões ovulatórios.

The human chorionic gonadotrophin (hCG) has been routinely used in the equine species to induce ovulations for more than four decades. The incidence of multiple ovulations in horses is variable, being double ovulations a common occurrence in some Brazilian breeds, such as Brasileiro de Hipismo and Campolina. The aim of this work was to evaluate the role of hCG administration to increase, in Campolina mares, the incidence of double and multiple ovulations, which are desirable in embryo transfer programs. One hundred and four (104) mares had their estrous cycles recorded through rectal palpation and ultrasonographic evaluation during the breeding season of 2003 - 2004, in a total of two hundred and eight (208) cycles (two cycles per mare). Animals were allocated in two groups, with fifty two (52) horses each. In Group I mares, once one or more = 35 mm follicles and grade 2 uterine edema were present, 2.500 IU of hCG were intravenously administered. The untreated mares in Group II served as control. The Chi-Square test was used to analyze obtained results. The incidence of double ovulations in groups I and II was, respectively, of 32.7% (34/104) versus 30.8% (32/104). The incidence of triple ovulations was low in both groups, of 1.9% (2/104). Only once in the control group (1.0% - 1/104) was a quadruple ovulation detected. There was no difference in the incidence of double and multiple ovulations between both groups (p > 0.05). Possibly, hCG administration did not influence ovulation patterns in this work due to the fact that Campolina breed mares physiologically show a considerable incidence of double and multiple ovulations.

Tectal glioblastoma

Brain stem gliomas are a heterogeneous group of neoplasms arising mostly in paediatric patients. Tectal plate gliomas represent a particular type of brain stem tumours usually with a benign, indolent clinical course, presenting with signs of raised intracranial hipertension due to supra-tentorialhydrocephalous caused by aqueductal stenosis. Seldom high-grade lesions arise in this location with tremendous therapeutic implications. When a malignant tumour is clinically and radiographically suspected a biopsy should be performed to obtain histhological confirmation. Treatment is then planned in a case-by-case basis. We present the case of a glioblastoma of the tectal plate in a 22 years-old woman operated upon by a supracerebellar-infratentorial approach.

Os gliomas do tronco cerebral são um grupo heterogêneo de neoplasias que acometem habitualmente crianças. Os gliomas da placa quadrigeminal representam um tipo particular de tumores do tronco cerebral, habitualmente com um curso benigno e indolente, surgindo com sinais de hipertensão intracraniana devido a hidrocefalia supra-tentorial provocada por compressão do aqueduto cerebral. Raramente surgem lesões de alto grau nesta região, mas as implicações terapêuticas são tremendas. Quando existe suspeita clínica e imagiológica de que se trata de lesão maligna, esta deve ser biopsada para se obter confirmação histológica. O tratamento deve então ser planejado caso a caso. Apresentamos o caso de glioblastoma da placa quadrigeminal em uma paciente de 22 anos intervencionado por via supracerebelar-infratentorial.

Tectal plate tumors

Tumores na região do teto mesencefálico são raros. Vários tipos de lesões como tumores, lesões vasculares, inflamatórias e infecciosas localizam-se nesta região. Nós revimos o tratamento adotado em sete pacientes com diferentes tipos de lesões tectais: cinco pacientes apresentando gliomas de baixo grau, um paciente com lesão metastática proveniente de câncer de pulmão e um com cavernoma. O tratamento cirúrgico com abordagem direta da lesão foi realizado em três casos (devido ao aumento do volume tumoral ou quando houve necessidade da confirmação diagnóstica). Nos demais casos o tratamento para a hidrocefalia não-comunicante foi o método empregado. O prognóstico dessas lesões é baseado no tipo de patologia em questão. Em nossa série, com exceção do caso de metástase e do paciente com cavernoma, as demais lesões foram gliomas de baixo grau. Estas lesões representam um subgrupo diferenciado de tumores de tronco encefálico, apresentando bom prognóstico e tendo comportamento benigno com sobrevida elevada. Acreditamos que tumores da região tectal devam ser avaliados caso a caso. Na hipótese diagnóstica de uma lesão benigna, o tratamento do principal complexo sindrômico – hidrocefalia não-comunicante – é provavelmente a melhor conduta a ser empregada.

Ultrasonografía transfontanelar en las malformaciones del desarrollo del SNC en neonatos / Transfontanelar ultrasound in CNS malformations

Propósito. Demostrar el valor de la Ultrasonografía (US) en el diagnóstico precoz de las malformaciones del desarrollo del sistema nervioso central y determinar la incidencia de las mismas en la población estudiada. Material y métodos. Desde abril de 1999 a abril de 2003 fueron realizadas por el mismo operador 5726 ecografías cerebrales de primera vez con transductores microconvex de 5 y 6 MHz por vía trans-fontanelar. Presentamos un análisis retrospectivo de las mismas referidas solamente a la detección de malformaciones del desarrollo cerebral en niños de 0 solicitadas por diferentes motivos. Se excluyeron las alteraciones cerebrales secundarias a patologías que no inciden en el desarrollo del SNC. (Hipoxia, encefalopatía, atrofia, etc.). Resultados. Se detectaron 118 malformaciones estructurales del desarrollo cerebral (2 por ciento). Siendo su frecuencia la siguiente: Hidrocefalia, 40 casos (34 por ciento); Agenesia parcial o total de cuerpo calloso, 19 (16 por ciento); Hidranencefalia, 13 (11 por ciento); Encefalocele, 12 (10 por ciento); Holoprosencefalia, 11 (9,3 por ciento); Complejo Dandy Walker, 10 (8,5 por ciento); Agenesia de Septum, 5 (4,2 por ciento); Esquisencefalia, 3 (2,5 por ciento); Lipomas intracraneanos, 2 (1,6 por ciento); Malformación Vascular de la fosa posterior, 1 (0,8 por ciento); Quiste aracnoideo, 1 (0,8 por ciento) y la asociación de Dandy Walker con Holoprosencefalia en un paciente, 1 (0,8 por ciento)...

Two Cases of Methyl Bromide Intoxication with Seizures and Altered Mental State / 대한간질학회지

Methyl bromide is presently used as a fumigant for insects in soil, grains or fruit in storage or transport. It is a neurotoxic agent and has been responsible a number of deaths or acute poisonings among occupationally exposed persons. We report 2 patients, who had worked fumigation warehouse, presented with seizures and altered mental state. The serum concentrations of bromide were elevated 32.9 and 42.5 mg/l, respectively. Brain MRI showed bilateral symmetric high signal intensities in the splenium of corpus callosum, the globus pallidus, the quadrigeminal plate, the periaqueductal gray matter, the red nucleus, the substantia nigra, the medial lemniscus, the pontine tegmentum, the dentate nucleus, and the medulla. There was no brain lesion in the other patient. Appropriate and supervised handling of the chemical and regular education to workers are important to avoid the risk of methyl bromide poisoning.

Clinical and Neuroradiologic Evaluations of Intracranial Lipoma

BACKGROUND: Intracranial lipomas are uncommon benign lesions of the central nervous system. They preferentially occur near the midline, most frequently in the pericallosal cistern, and are often associated with various neurologic and systemic anomalies. Since the advent of CT scanning and MR imaging, unexpected findings of intracralial lipomas have increased. We identified 11 cases of intracranial lipomas diagnosed by CT and MR and analyzed their characteristic clinical and radiologic findings. METHODS: We retrospectively reviewed 11 cases of intracranial lipomas. MR was used in all cases and CT in three. RESULTS: There were seven men and four women whose ages ranged from six months to 76 years, with a mean of 39 years. Six (55%) lipomas were located in the quadrigeminal plate and five (45%) in the pericallosal area. The pericallosal lipomas were divided into three cases of curvilinear type and two cases of tubulonodular type. Of the six quadrigeminal lipomas, five cases (83%) were associated with either hypoplasia of the unilateral (four) or bilateral (one) superior and/or inferior colliculus. One case of quadrigeminal lipoma was associated with hypoplasia of the cerebellar vermis, agenesis of the septum pellucidum, and glioblastoma multiforme. All cases of pericallosal tubulonodular type were associated with dysgenesis of the corpus callosum and enlarged ventricles. However, all cases of pericallosal curvilinear type were not associated with other anomalies. Four (36%) cases found incidentally were asymptomatic. Seizure was the most frequent clinical presentation in five (45%) cases, followed by headaches in three (27%) and mental retardation in one (9%). Of five seizures cases, three had secondary generalized seizures and two had generalized tonic clonic seizures. CONCLUSIONS: Quadrigeminal and pericallosal lipomas were the most common types of intracranial lipomas. Sixty-three percent of the lesions were associated with adjacent brain malformations of varying degrees. Four cases were asymptomatic, while the others presented with seizures, headache, and mental retardation. (J Korean Neurol Assoc 19(2):149~154, 2001)

Clinical and Neuroradiologic Evaluations of Intracranial Lipoma

BACKGROUND: Intracranial lipomas are uncommon benign lesions of the central nervous system. They preferentially occur near the midline, most frequently in the pericallosal cistern, and are often associated with various neurologic and systemic anomalies. Since the advent of CT scanning and MR imaging, unexpected findings of intracralial lipomas have increased. We identified 11 cases of intracranial lipomas diagnosed by CT and MR and analyzed their characteristic clinical and radiologic findings. METHODS: We retrospectively reviewed 11 cases of intracranial lipomas. MR was used in all cases and CT in three. RESULTS: There were seven men and four women whose ages ranged from six months to 76 years, with a mean of 39 years. Six (55%) lipomas were located in the quadrigeminal plate and five (45%) in the pericallosal area. The pericallosal lipomas were divided into three cases of curvilinear type and two cases of tubulonodular type. Of the six quadrigeminal lipomas, five cases (83%) were associated with either hypoplasia of the unilateral (four) or bilateral (one) superior and/or inferior colliculus. One case of quadrigeminal lipoma was associated with hypoplasia of the cerebellar vermis, agenesis of the septum pellucidum, and glioblastoma multiforme. All cases of pericallosal tubulonodular type were associated with dysgenesis of the corpus callosum and enlarged ventricles. However, all cases of pericallosal curvilinear type were not associated with other anomalies. Four (36%) cases found incidentally were asymptomatic. Seizure was the most frequent clinical presentation in five (45%) cases, followed by headaches in three (27%) and mental retardation in one (9%). Of five seizures cases, three had secondary generalized seizures and two had generalized tonic clonic seizures. CONCLUSIONS: Quadrigeminal and pericallosal lipomas were the most common types of intracranial lipomas. Sixty-three percent of the lesions were associated with adjacent brain malformations of varying degrees. Four cases were asymptomatic, while the others presented with seizures, headache, and mental retardation. (J Korean Neurol Assoc 19(2):149~154, 2001)

Cyst of Pineal Gland

With advances in MR imaging, reports of pineal cyst have become more common. In contrast to pineal neoplasm, a pineal cyst is usually asymptomatic and is detected incidentally. We reviewed six cases of pineal cyst diagnosed between 1991 and 1996. Only one patient presented with syncopal attack due to compression of the midbrain. MRI typically reveals a cystic mass with a mean diameter of 1.66cm and shows faint rim-like contrast enhancement. Since it shows the anatomic relationship of the cyst to the aquedect, sagittal MRI is the most useful diagnost test. In the one symptomatic patient, we performed suboccipital cramiectomy and removed the cyst. It contained clear fluid and was easily removed. Surgery can be considered only when the lesion produces symptoms due to compression of the quadrigeminal plate, aqueduct, or midbrain. The long term behavior of these lesions is, however, unknown, so only with follow-up for long time will appropriate management techniques become apparent.

Congenital quadrigeminal lipoma with osteocartilagenous element: A case report

A case of congenital tectal lipoma found incidentally at an autopsy is reported. This female fetus was a product of pregnancy termination at 24 weeks of gestational age after sonographic detection of hydrocephalus. Autopsy revealed a small mass in the periaqueductal portion. The mass was composed of adipose tissue, cartilage, and mature bony tissue with hematopoiesis. The resultant diagnosis was tectal lipoma with osteocartilagenous element. It is uncertain whether the lesion represents a teratoma or hamartoma or mesenchymal metaplasia. The osteocartilagenous component suggests the latter.

Tumores da lâmina quadrigêmea na infância / Tumours of the quadrigeminal plate in the childhood

Os autores apresentam os dados clínicos e neurorradiológicos de 6 crianças portadoras de tumores da regiäo tectal e periaquedutal. Todos os casos foram tratados inicialmente com derivaçäo liquórica e apresentaram boa evoluçäo em intervalos de acompanhamento que väo de 10 meses a 5 anos. Säo discutidos, à luz da literatura, os aspectos específicos destes tumores bem como as dificuldades diagnósticas.

Involvement of adrenergic & cholinergic mechanisms in analgesia electrically induced from pretectal nucleus of rat.

Analgesia induced by pretectal stimulation in rat was analysed using suitable antagonists. Mild electrical stimulation of sites in the pretectal nucleus (PTN) caused analgesia of long duration, without signs of aversion and unassociated with motor deficit. Pretreatment of animals with ip atropine sulphate (1 mg/kg), phenoxybenzamine (5 mg/kg), sotalol (2 mg/kg) and haloperidol (1 mg/kg) but not with saline, markedly reduced the antinociceptive response to PTN stimulation. Mild PTN stimulation thus seems to induce potent and long lasting analgesia in rats probably involving multisynaptic antinociceptive pathway(s).

MRI Findings in Wernicke's Encephalopathy with Hyperemesis Gravidarum

A 25 year old female patient with hyperemesis gravidarum developed mental confusion, gait disturbance and diplopia. MRI of this patient showed high-signal lesions in thalamus, floor of the fourth ventricle, periaqueductal gray matter, mammillary body, and corpora quadrigemina, The high signal areas correlated well with the anatomical distribution of pathologic lesions in wernicke's encephalopathy previously described.

Telencephalic and pretectal modulation of the directional selectivity of accessory optic neurons in the pigeon

Direction-selective units within the accessory optic system of the pigeon were shown to respond more strongly to motion along two main directions, downward-nasal and upward-temporal. Following ipsilateral telencephalic or pretectal lesions, these directions were modified in a systematic way. In the former, the principal response directions were downward-nasal and temporal and in the latter, downward-temporal and upward-temporal. These data indicate that the non-retinal afferents play an important role in the functional organization of the accessory optic system

Cardiovascular regulation in the acute decerebrate rat

Male Wistar rats were decerebrated at precollicular level, by aspiration under ether anaesthesia. The experiments employed rats instrumented for chronic electrocardiogram (ECG) recordings or mean blood pressure (MBP) and heart rate (Hr) determination. Immediately after surgery, decerebrate (D) and sham operated (SO) animals presented a small and ismilar increase in their HR. Three and a half hours after surgery, SO group presented a normal HR, whilst D animals continued to show an increas ein their HR up to 4.5 h, when it stabilized. Twenty four hours after surgery both groups presented similar MBP (D:110ñ6; SO:108ñ11; SO:335ñ5 beats/min). The blockade of parasympathetic tonus induced significant increases in the HR of both groups, withou major changes in their MBP. Beta-adrenergic blockade reduced HR of both groups, bringin HR of D almost to control level. Simultaneously there was a reduction in MBP of D but not of SO animals. When parasympathetic blockade was superimposed to beta-adrenergic blockade, there was a significant increase in HR of SO, but not of D or in MBP of both groups. Thus we conclude that the decerebrate rat presents normal MBP with simultaneous tachycardia mainly caused by increased sympathetic outflow to the heart

CT Findings of Primary Brainstem Injury: Case Report

Computerized tomography has been proven to be of particular value in patients with head trauma. Neverthless, primary traumatic brainstem lesions are not always revealing even by the advent of brain CT. In two cases of head trauma, we identified midbrain hemorrhage by CT scan. One of them was hemorrhage in the quadrigeminal plate, the quadrigeminal cistern, and the vermis; the other small round isolated hemorrhage in the quadrigeminal plate. They were well correlated with the clinical findings. Those two patients got well with conservative treatment.