Eduardo Castro-Sierra

Glioblastoma multiforme in children: experience at Hospital Infantil de Mexico Federico Gomez

ObjectiveTo evaluate clinical evolution of pediatric patients diagnosed with glioblastoma multiforme (GBM) at Hospital Infantil de México Federico Gómez.MethodsCases of patients treated from January to May, 2007, were included in this study. Variables analyzed were: age, diagnosis, size of tumor, histopathological description, degree of resection, time of stay in hospital, complications and outcome using Pearson’s chi-squared test and logistic regression.ConclusionSixteen patients were identified. Mean age of presentation was 8.8. An increased frequency of complications was observed in younger patients and longer survival rates in patients with greater resections; main mode of presentation was directly related to intracranial hypertension; size of tumor was not related to evolution or outcome. Modern histological classifications especially designed for children are deemed necessary to accurately diagnose GBM.

Preoperative and postoperative analysis of visual and auditory memory in children with cerebellar tumors

Motivated by the extensive clinical and experimental evidence that links the cerebellum to cognitive processes, we analyzed the auditory and visual memory of nine children with cerebellar tumors. Five patients had midline lesions and four had cerebellar hemispheric tumors. The patients were tested before and after surgery. One of the patients was also tested at 4 and 24 months after surgery. A third group constituted by four children, sibling of some of the patients, served as control. Statistically significant differences (P< 0.05) were found in the test of auditory memory, in which children with cerebellar tumors made a higher number of errors than their normal counterparts. Surgery performed according standard techniques did not increase significantly the number of errors in any of the tested categories. Location of the tumor (hemispheric vs midline) was not a determinant of the performance of the children. The patient tested up to 2 years after surgery demonstrated a progressive improvement in the performance of visual and auditory memory tasks. Our results provide further evidence that the cerebellum plays a role in the integration of auditory stimuli.

Cerebellar abscesses caused by dog bite: a case report

IntroductionBites by house pets can be lethal or cause a series of catastrophic events with severe sequels, such as the loss of a limb or a systemic infection which may be life-endangering, especially in the case of children being bitten.PresentationA 2-year-old girl was attacked by a dog, causing lesions at the occipital region. This was treated initially as a superficial wound that became further complicated with two cerebellar abscesses. These abscesses required neurosurgical and antimicrobial treatment, with a satisfactory outcome.ConclusionThe precise and diligent evaluation of a lesion caused by an animal bite may prevent further life-endangering complications. To the best of our knowledge, there are no reports about cerebellar abscess caused by a dog bite. When cranial lesions are penetrating, an abscess must to be considered. We insist on the importance of medical evaluation and adequate treatment of such lesions.

Brachmann-Cornelia de Lange syndrome with a papilloma of the choroid plexus: analyses of molecular genetic characteristics of the patient and the tumor. A single-case study.

PurposeA 10-month-old girl with a Brachmann-Cornelia de Lange syndrome and a choroid plexus papilloma of the brain was studied at the Hospital Infantil de México Federico Gómez (HIMFG) in Mexico City.Methods and resultsPresumptive papilloma of the third ventricle was evidenced on CT and MR images and removed. Pathological analysis confirmed its origin. A posterior radiosurgery was required due to a tumor relapse. Karyotypes (GTG bands) of the patient and her parents undertaken at HIMFG were normal. Array comparative genomic hybridization (array CGH) analyses of blood DNA of the patient and her parents carried out at BlueGnome’s Laboratory in Cambridge, UK, set in evidence amplification of genes SPNS2, GGT6, SMTNL2, PELP1, MYBBP1A, and ALOX15 in chromosome 17p of the patient. Since MYBBP1A is a proto-oncogene and ALOX15 participates in the development of cancer and metastases of tumors, further fluorescent in situ hybridization (FISH) analyses of these two genes were implemented at HIMFG. Amplification of the two genes was found in the tumor of the case under study but not in an unrelated papilloma of the choroid plexus.DiscussionFurther analyses of the association of choroid plexus papillomas with disorders of psycho-neural development and its relationship to molecular genetic modifications at chromosome 17p are now under way at HIMFG.

The first neuroanatomical text published on the American continent: Mexico City, 1579

Details of publicationThe first neuroanatomy text published on the American continent was included in the Tractado de Anothomia y Chirugia by Fr. Agustín Farfán, O.S.A., who received his M.D. in 1569 from the Royal and Pontifical University of Mexico. It was printed in 1579 by Antonio Ricardo, a Piedmontese who had settled in Mexico City, capital of New Spain.ContentThis text encompasses a very correct and complete neuroanatomy of an eminently Galenic type.

Lexical tonal discrimination in Zapotec children. A study of the theta rhythm

El zapoteco es un lenguaje hablado principalmente en el estado de Oaxaca, en Mexico, que tiene la caracteristica de ser tonal; es decir, las palabras homofonas que difieren en la altura del fundamental tienen diferente significado. El objetivo de este trabajo fue analizar los cambios del ritmo theta del electroencefalograma en el curso de la discriminacion de palabras bisilabicas homofonas en zapoteco. Metodo: Se empleo el analisis espectral del electroencefalograma durante la discriminacion tonal lexica del lenguaje zapoteco en 12 ninos sanos de 9-16 anos. Resultados: Se observo una mayor potencia relativa theta en la region temporal derecha durante la discriminacion lexica en comparacion con el registro de reposo-ojos abiertos. Tambien se observaron varias correlaciones significativas intra e interhemisfericas con predominio entre la region frontotemporal izquierda y temporal derecha mientras se realizaba la discriminacion tonal lexica. Conclusion: Estos resultados sugieren que hay un mayor compromiso de las redes neuronales en el hemisferio derecho que participan en la discriminacion del lenguaje zapoteco

Discriminación tonal léxica en niños zapotecas. Un estudio del ritmo theta

BACKGROUND Zapotec is a language used mainly in the state of Oaxaca in Mexico of tonal characteristic; homophone words with difference in fundamental frequency with different meanings. Our objective was to analyze changes in the electroencephalographic (EEG) theta rhythm during word discrimination of lexical tonal bi-syllabic homophone word samples of Zapotec. METHODS We employed electroencephalography analysis during lexical tonal discrimination in 12 healthy subjects 9-16 years of age. RESULTS We observed an increase in theta relative power between lexical discrimination and at rest eyes-open state in right temporal site. We also observed several significant intra- and inter-hemispheric correlations in several scalp sites, mainly in left fronto-temporal and right temporal areas when subjects were performing lexical discrimination. CONCLUSIONS Our data suggest more engagement of neural networks of the right hemisphere are involved in Zapotec language discrimination.

Intramedullary Spinal Cord Tumors in Children: Part II

Skin Incision The patient undergoing surgery is pretreated with dexamethasone, 0.25 to 0.50 mg/kg/day. In our experience, ISCTs should always be approached from the back by opening the posterior vertebral arc. Tumor extension should be marked on the patient’s back. Involved spinal levels should be established clearly by use of MRI scans, and the incision should be designed so that it extends for one vertebral segment above and below the lesion. These steps allow the surgeon to approach the tumor without manipulating nontumoral spinal cord tissue. If this precaution is not taken, widening the working trench becomes complicated by open dura mater and the potential danger of harming sensitive structures when cutting the bone. It is important, whenever possible, to operate on a patient with healthy and clean skin. If the surgical problem permits, it is better to wait for a few days until skin conditions improve. A skin infection may cause neurological infections.

Intramedullary Spinal Cord Tumors in Children: Part I

Epidemiology In adults, intramedullary spinal cord tumors (ISCTs) account for 30% of all spinal tumors; in children, they represent from 35% to 45% of spinal lesions. The incidence of these tumors has been reported to be 1 per 100,000 in children, with a slight predominance in boys. Tumors of the spinal cord constitute between 4% and 10% of all tumors of the central nervous system (CNS) in people of all ages. ISCTs account for approximately 6% of tumors of the CNS in children and 20% of spinal tumors among all age groups. However, as many as 35% of spinal tumors in children may be ISCTs (Table 1). The most common locations and histological types of ISCTs are shown in Tables 2 and 3.