Term
| Defects in neurulation (neural tube formation and neural pore closure) are known as what? |
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Definition
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Term
| Incidence of dysraphic defects may be reduces up to 70% by supplementation with what during pregnancy? |
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Definition
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Term
| Failure of neural tube closure occurs most often at what point? |
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Definition
| Anterior or posterior neuropore |
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Term
| The final anterior neuropore closure is located at what level? |
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Definition
| Lamina terminalis (anterior wall of the third ventricle below the anterior commissure) |
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Term
| Why does failure of the anterior neuropore to close properly often results in defects between the lamina terminalis and the cervical levels of the spinal cord? |
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Definition
| Once the neural tube is formed, it separates from the surface of the ectoderm which then proceeds to grow over the midline |
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Term
| Anencephaly is what kind of defect? |
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Definition
| Anterior neuropore closure defect |
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Term
| What characterizes anencephaly? |
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Definition
| Brain does not form, surrounding meninges and skull may not develop properuly, neonatal death |
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Term
| What are some associated causes of anencephaly? |
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Definition
| Maternal hyperthermia, maternal infection, sauna baths |
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Term
| Herniation of cranial contents that may accompany defects in the formation of the cranium is known as what? |
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Definition
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Term
| Encephaloceles are most common in what region of the brain? |
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Definition
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Term
| Herniation of solely the meninges and CSF is known as what? |
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Definition
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Term
| Herniation of both the meninges and the brain is known as what? |
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Definition
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Term
| Herniation of the meninges, brain, and part of the ventricles is known as what? |
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Definition
| Meningohydroencephalocele |
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Term
| Cystic defects resulting in the herniation of the cerebellar vermis through the foramen magnum and oftenc ausing pressure on the medulla and cervical spinal cord is known as what defect? |
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Definition
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Term
| Arnold-Chiari may be accompanied by a cavitation of the spinal cord or medulla. What are the names of these defects? |
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Definition
| Syringomyelia, syringobulbia |
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Term
| Syringomyelia or syringobulbia results in what other condition involving cerebrospinalfluid? |
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Definition
| Blockage of ventricles leading to hydrocephalus |
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Term
| Defects due to a failure of the posterior neuropore to close that affects the spinal cord and surrounding tissues are known as what? |
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Definition
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Term
| What general term is used for neural tube defects in the spinal region that may or may not involve neural tissue? |
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Definition
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Term
| Defects of vertebral arch fusion where skin is closed over the malformation are known as what? |
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Definition
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Term
| What usually marks a site of spina bifida occulta? |
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Definition
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Term
| Defects of vertebral arch fusion where skin is not closed over the malformation and a patent aperture is present are known as what? |
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Definition
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Term
| Spina bifida that are accompanied by a cystic mass are known as what? |
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Definition
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Term
| A cyst containing only meninges and cerebrospinal fluid is known as what? |
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Definition
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Term
| Cysts containing spinal neural tissue along with meninges and cerebrospinal fluid are known as what? |
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Definition
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Term
| What substances is usually found in elevated levels in cases of spinal bifida cystica? |
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Definition
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Term
| Spinal bifida cystica is usually accompanied by what other clinical symptoms? |
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Definition
| Hydrocephalus and Arnold Chiari malformation |
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Term
| Failure of posterior neural tube closer and exposure of bone or meninges is known as what? |
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Definition
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Term
| Malformations of the neural tube as part of secondary neurulation are called what? |
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Definition
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Term
| Myelodysplasias may be visible in what form? |
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Definition
| Dimpled or unusually pigmented skin, hair growth, and telangiectasias (large superficial capillaries/spider veins) |
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Term
| Myelodysplasias that cause abnormal adhesion of the spinal cord to the vertebral column is known as what? |
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Definition
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Term
| What are symptoms associated with tethered cord syndrome? |
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Definition
| Spinal cord placed under continued traction as vertebral column grows, may be damaged resulting in anesthesia in the legs and bladder control problems |
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Term
| How might tethered cord syndrom cause Arnold-Chiari? |
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Definition
| Growth of spinal column may also pull brainstem and cerebellum caudally into the foramen magnum, compressing the brainstem |
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Term
| What are the most common congenital malformations associated with peripheral nervous system development that result due to the failure of neural crest cells to properly differentiate or migrate? |
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Definition
| Congenital megacolon and familial dysautonomia |
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Term
| Failure of parasympathetic ganglia to form on portions of the colon due to mutations of the RET gene coding for receptors essential for cell migration is known as what? |
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Definition
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Term
| Hirschsprung disease is characterized by abnormal tonic contractions in parts of the colon and expansion in others which is known generally as what symptom? |
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Definition
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Term
| How is congenital megacolon treated? |
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Definition
| Removal of affected area of bowel |
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Term
| Failure of neural crest cells to develop in the formation of parasympathetic ganglia resulting in impaired pain, temperature sensation, and autonomic defects is known as what? |
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Definition
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Term
| Familial dysautonomia has thus far been exclusive to patients of what heritage? |
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Definition
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Term
| What prosencephalization defect results in an absence of lobes? |
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Definition
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Term
| What prosencephalization defect results in the presence of malformed, partly discernible lobes? |
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Definition
| Semilobar holoprosencephaly |
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Term
| What may be poorly developed other than the lobes in cases of holoprosencephaly? |
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Definition
| Thalamus, corpus callosum, olfactory structures, meningeal structures, may result in hypotelorism (cyclops) |
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Term
| What are some possible causes of hypoterlorism (cyclops) associated with holoprosencephaly? |
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Definition
| Defect in SHH gene or cholesterol biosynthesis, maternal alcohol abuse |
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Term
| What are possible consequences of hydrocephalus |
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Definition
| Expansion of the cranium during development due to ventricular enlargement |
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Term
| Cystic dilation of the fourth ventricle with aplasia of the cerebellar vermis is known as what? |
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Definition
| Dandy-Walker malformation |
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Term
| How are Dandy-Walker malformations treated? |
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Definition
| Placement of a cerebrospinal fluid shunt |
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Term
| A smooth cortical surface due to failure of gyri to form is known as what? |
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Definition
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Term
| Unusually large or small gyri are known as what? |
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Definition
| Pachygyria, microgyria respectively |
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