SDL 2- CNS Malformations Neural Tube Defects Failure of a portion
... Medulla elongated and may be folded dorsally, aqueduct and 4th ventricle are collapsed Associated aqueductal atresia Blocked CSF flow may lead to hydrocephalus (possible hydromyelia or syringomyelia) Type I: mild variant of type II, volume of posterior fossa is reduced overcrowding and herniation o ...
... Medulla elongated and may be folded dorsally, aqueduct and 4th ventricle are collapsed Associated aqueductal atresia Blocked CSF flow may lead to hydrocephalus (possible hydromyelia or syringomyelia) Type I: mild variant of type II, volume of posterior fossa is reduced overcrowding and herniation o ...
Cerebrospinal Fluid
... formed around blood vessels and along ventricular walls. It circulates from the lateral ventricles to the foramen of Monro , third ventricle, aqueduct of Sylvius , fourth ventricle, foramina of Magendie and foramina of Luschka ;subarachnoid space over brain and spinal cord; re absorption into venous ...
... formed around blood vessels and along ventricular walls. It circulates from the lateral ventricles to the foramen of Monro , third ventricle, aqueduct of Sylvius , fourth ventricle, foramina of Magendie and foramina of Luschka ;subarachnoid space over brain and spinal cord; re absorption into venous ...
Congenital Malformation & Hydrocephalus
... The volume of brain may be abnormally large (megalencephaly) or small (microencephaly). Microencephaly, by far the more common of the two, is usually associated with a small head as well It can occur in a wide range of clinical settings, including: ...
... The volume of brain may be abnormally large (megalencephaly) or small (microencephaly). Microencephaly, by far the more common of the two, is usually associated with a small head as well It can occur in a wide range of clinical settings, including: ...
Hydrocephalus
Hydrocephalus (from Greek hydro-, meaning ""water"", and kephalos, meaning ""head"") is a medical condition in which there is an abnormal accumulation of cerebrospinal fluid (CSF) in the brain. This causes increased intracranial pressure inside the skull and may cause progressive enlargement of the head if it occurs in childhood, potentially causing convulsion, tunnel vision, and mental disability. It was once informally called ""Water on the brain.""Hydrocephalus can be caused by congenital or acquired factors. Congenital causes include Spina Bifida, Arnold–Chiari malformation, craniosynostosis, Dandy–Walker syndrome, and Vein of Galen malformations. Acquired causes include hemorrhage, meningitis, head trauma, tumors, and cysts.Two types of hydrocephalus are commonly described non-communicating hydrocephalus and communicating hydrocephalus, although there is evidence that communicating forms can lead to obstruction of CSF flow in many instances.In non-communicating hydrocephalus, the CSF in the ventricles can not reach the subarachnoid space. This results from obstruction of interventricular foramina, cerebral aqueduct, or the outflow foramens of the fourth ventricle (median and lateral apertures). The most common obstruction is in the cerebral aqueduct. A block at any of these sites leads rapidly to dilatation of one or more ventricles. If the skull is still pliable, as it is in children younger than 2 years, the head may enlarge.In communicating hydrocephalus, the obstruction of CSF flow is in the subarachnoid space from prior bleeding or meningitis. This causes thickening of the arachnoid leading to blockage of the return-flow channels. In some patients, the spaces filled by CSF are uniformly enlarged without an increase in intercranial pressure. This special form of communicating hydrocephalus is called normal pressure hydrocephalus (NPH), which results specifically from impaired CSF reabsorption at the arachnoid granulations. NPH's clinical manifestations are gait abnormality, dementia, and involuntary urination. NPH usually occurs in elderly patients.