ABSTRACT
PURPOSE: Knowledge of anatomy of the IV ventricle is basic to surgical approach of any kind of lesion in its compartment as well as for those located in its neighborhood. The purpose of this study is to demonstrate the surgical approach options for the IV ventricle, based on the step by step dissection of anatomical specimens. METHODS: Fifty formalin-fixed specimens provided were the material for this study. The dissections were performed in the microsurgical laboratory in Gainesville, Florida, USA. RESULTS: The IV ventricle in a midline sagittal cut shows a tent-shaped cavity with its roofs pointing posteriorly and the floor formed by the pons and the medulla. The superior roof is formed by the superior cerebellar peduncles laterally and the superior medullary velum on the midline. The inferior roof is formed by the tela choroidea, the velum medullary inferior, and the nodule. The floor of the IV ventricle has a rhomboid shape. The rostral two thirds are related to the pons, and the caudal one third is posterior to the medulla. The median sulcus divides the floor in symmetrical halves. The sulcus limitans runs laterally to the median sulcus, and the area between the two sulci is called the median eminence. The median eminence contains rounded prominence related to the cranial nucleus of facial, hypoglossal, and vagal nerves. The lateral recesses are extensions of the IV ventricle that opens into the cerebellopontine cistern. The cerebellomedullary fissure is a space between the cerebellum and the medulla and can be used as a surgical corridor to the IV ventricle. CONCLUSIONS: We obtained in this study a didactic dissection of the different anatomical structures, whose recognition is important for addressing the IV ventricle lesions.
Subject(s)
Cerebellum/anatomy & histology , Fourth Ventricle/surgery , Medulla Oblongata/anatomy & histology , Neurosurgery/methods , Pons/anatomy & histology , Cerebellum/blood supply , Humans , Medulla Oblongata/blood supply , Pons/blood supplySubject(s)
Brain Neoplasms/diagnosis , Calcinosis/diagnosis , Central Nervous System Cysts/diagnosis , Leukoencephalopathies/diagnosis , Adult , Calcinosis/complications , Central Nervous System Cysts/complications , Diagnosis, Differential , Humans , Leukoencephalopathies/complications , Magnetic Resonance Imaging , MaleSubject(s)
Adult , Humans , Male , Brain Neoplasms/diagnosis , Calcinosis/diagnosis , Central Nervous System Cysts/diagnosis , Leukoencephalopathies/diagnosis , Calcinosis/complications , Central Nervous System Cysts/complications , Diagnosis, Differential , Leukoencephalopathies/complications , Magnetic Resonance ImagingABSTRACT
Uma paciente epiléptica jovem foi vítima de queda de certa altura após crise tônico-clônica generalizada. Foi admitida em coma no Setor de Emergência. Sua investigaçäo clínico-radiológica mostrou presença de hematomas interhemisféricos, extensa secçäo traumática do corpo caloso e contusöes fronto-basais. A despeito de hemiparesia residual, sua investigaçäo neuropsicológica näo mostrou sinais de desconexäo hemisférica, compatível à integridade da regiäo do esplênio ao exame de RMN. Após o trauma, a paciente apresentou grande melhora da síndrome epiléptica. O papel relativo de cada uma das lesöes traumáticas é difícil de ser inferido, em se tratando de lesäo cerebral múltipla. O provável mecanismo fisiolpatológico deve incluir impacto direto do corpo caloso contra a foice, além de mecanismos de aceleraçäo/desaceleraçäo
