Expansión del espacio subaracnoideo en el niño / Enlargement of subarachnoid space in child

Se presentan dos casos de niños referidos a consulta de neurocirugía por macrocranea y dilatación de los espacios subaracnoideos en la convexidad y cisternas basales. Ambos evolucionan con resolución espontánea de esta anomalía, demostrada y seguida con tomografía computarizada (TC) y resonancia magnética (RM). Sin alteraciones significativas en su desarrollo psicosomático

Hipertrofia ou alargamento benigno do espaço subaracnóide / Hyphertrophy or benign lenghtening of subaracnoidal space

Relata-se caso de macrocefalia relacionada ao alargamento benigno do espaço subaracnóide. Discutem-se os achados clínicos, etiopatogenia e manuseio dessa condiçäo. Salienta-se a importância do diagnóstico radiológico (tomografia computadorizada) e evoluçäo caracteristicamente favorável dos pacientes

Experimentally induced Chiari-like malformation with myeloschisis in chick embryos

Though several pathogenetic theories concerning the frequent association of Chiari malformation and hydrocephalus with myeloschisis have been suggested, none of them explains all the aspects of the disorder. To investigate whether myeloschisis is the direct cause of Chiari malformation and hydrocephalus or these conditions are the results of another basic event, we observed the morphological changes of the posterior cranial fossa and its components in the chick embryos with surgically induced myeloschisis. To make myeloschistic lesions, we opened the neural tube for a length of 9-11 somites in Hamburger and Hamilton stage 16-19 chick embryos. They were divided into cervicothoracic (C-T) and lumbosacral(L-S) groups according to the area of incision. The embryos were re-incubated until postoperative day 11. In the control group, embryos were incubated with the eggshell window open as their experimental counterparts. The survival rates of each group were as follows; 11% (9 survivors/85 operated embryos), 8% (7/83), and 17% (10/60) in the C-T, L-S and control groups, respectively. Myeloschisis positive rates were 100% in the operated groups and 0% in the control group. The heads of embryos were sectioned along the sagittal plane to observe the morphological changes in the posterior cranial fossa and its components. Of the survivors, five in the C-T group, two in the L-S group and six in the control group were available for light microscopic inspection. In the majority of embryos with myeloschisis, without difference between the C-T and L-S groups, the fourth ventricles were smaller than those of the control group and the subarachnoid spaces in the posterior cranial fossa were also narrower. In embryos with severe changes, the cerebellum displaced downward comparing with that of the control embryos. No evidence of hydrocephalus was present Though not always typical, morphological changes similar to Chiari malformation were observed in chick embryos with surgically induced myeloschisis. It suggests a strong direct causal relationship between the two conditions and supports the theories of derangements in cerebrospinal fluid dynamics rather than those of primary mesenchymal or neural origin as a pathogenetic mechanism of Chiari malformation.

Experimentally induced Chiari-like malformation with myeloschisis in chick embryos

Though several pathogenetic theories concerning the frequent association of Chiari malformation and hydrocephalus with myeloschisis have been suggested, none of them explains all the aspects of the disorder. To investigate whether myeloschisis is the direct cause of Chiari malformation and hydrocephalus or these conditions are the results of another basic event, we observed the morphological changes of the posterior cranial fossa and its components in the chick embryos with surgically induced myeloschisis. To make myeloschistic lesions, we opened the neural tube for a length of 9-11 somites in Hamburger and Hamilton stage 16-19 chick embryos. They were divided into cervicothoracic (C-T) and lumbosacral(L-S) groups according to the area of incision. The embryos were re-incubated until postoperative day 11. In the control group, embryos were incubated with the eggshell window open as their experimental counterparts. The survival rates of each group were as follows; 11% (9 survivors/85 operated embryos), 8% (7/83), and 17% (10/60) in the C-T, L-S and control groups, respectively. Myeloschisis positive rates were 100% in the operated groups and 0% in the control group. The heads of embryos were sectioned along the sagittal plane to observe the morphological changes in the posterior cranial fossa and its components. Of the survivors, five in the C-T group, two in the L-S group and six in the control group were available for light microscopic inspection. In the majority of embryos with myeloschisis, without difference between the C-T and L-S groups, the fourth ventricles were smaller than those of the control group and the subarachnoid spaces in the posterior cranial fossa were also narrower. In embryos with severe changes, the cerebellum displaced downward comparing with that of the control embryos. No evidence of hydrocephalus was present Though not always typical, morphological changes similar to Chiari malformation were observed in chick embryos with surgically induced myeloschisis. It suggests a strong direct causal relationship between the two conditions and supports the theories of derangements in cerebrospinal fluid dynamics rather than those of primary mesenchymal or neural origin as a pathogenetic mechanism of Chiari malformation.

Follow-up study of macrocephalic children with enlargement of the subarachnoid space

Trata-se de estudo prospectivo de 18 crianças com macrocefalia por aumento do espaço sub-aracnóideo, com ou sem dilataçäo ventricular, seguidas até idade em média de 56 meses. Todas nasceram a termo, sem intercorrências perinatais e com testes negativos para TORCH. O tempo médio de seguimento foi 46 meses. Havia 17 meninos e apenas uma menina no grupo estudado. A porcentagem de anormalidades neurológicas no seguimento foi de 11%. Durante o seguimento, o perímetro cefálico retornou aos níveis da normalidade em 45% das crianças. Nenhum caso desenvolveu hipertensäo intracraniana durante o estudo. Todas as crianças realizaram TAC de crânio como parte da avaliaçäo inicial e, além do aumento do espaço sub-encefálico, 77% delas apresentavam discreta dilataçäo ventricular. No seguimento, 11 realizaram TAC de controle que revelaram resoluçäo completa do processo em 3 casos, melhora em 2 e permaneceram inalteradas em 6. Concluimos que o aumento do espaço sub-aracnóideo em crianças macrocefálicas é entidade que apresenta bom prognóstico neurológico na maioria dos casos e que a macrocefalia e o aumento do sub-aracnódeo continuaräo presentes, na maioria das crianças, no seguimento a longo prazo

Perfil neuroevolutivo del lactante con macrocefalia y ensanchamiento benigno del espacio subaracnoideo / Neuroevolutionary profile of nursing with macrocephalia and benign widening of the subarachnoid space

Con la finalidad de estudiar el pronóstico neuroevolutivo de los niños con macrocefalia (percentil>95) y ensanchamiento del espacio subaacnoideo identificados por TAC del cráneo, se seleccionaron cinco casos atendidos en el consultorio de Neurología Pediátrica del Hospital Regional Docente de Trujillo, Perú, entre enero de 1983 a enero de 1988 y cuyo seguimiento alcanzó entre 1.5 a 3 años. Todos los lactantes mostraron en la TAC, separación anormal del espacio subaracnoideo frontal, fisura interhemisférica y cisura de Silvio sin ventriculomegalia o mínima dilatación del sistema ventricular. Mediante la evaluación neurológica y la prueba de Desarrollo de Denver se observó en todos los casos, excepto uno, un patrón caracterizado por hipotonía y retardo motor grueso durante el primer año de vida, el cual fue modificándose hacia la normalidad los controles secuenciales hasta la edad de 25 a 40 meses. Estos hallazgos sugieren el buen pronóstico y la benignidad de esta condición que se resuelve espontáneamente y relacionada al parecer con macrocefalia familiar benigna