lissencephaly definition
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Lissencephaly MRI scan showing the characteristic smooth brain of an individual with lissencephaly. Lissencephaly is a set of rare brain disorders where the whole or parts of the surface of the brain appear smooth. The word lissencephaly is derived from the Greek λισσός lissos meaning smooth and encephalos meaning brain. It is caused by defective neuronal migration during the 12th to 24th weeks of gestation resulting in a lack of development of brain folds (gyri) and grooves (sulci). It is a form of cephalic disorder.
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Definitions &Translations Encephalocele, sometimes known by the Latin name cranium bifidum, is a neural tube defect characterized by sac-like protrusions of the brain and the membranes that cover it through openings in the skull.
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- By Mayo Clinic Staff. Microcephaly usually is the result of abnormal brain development, which can occur in the womb (congenital) or during infancy. Microcephaly may be genetic. Other causes may include: Craniosynostosis.
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Hydrocephalus Hydrocephalus is a condition in which there is an accumulation of cerebrospinal fluid within the brain. This typically causes increased pressure inside the skull. Older people may have headaches, double vision, poor balance, urinary incontinence, personality changes, or mental impairment. In babies there may be a rapid increase in head size. Other symptoms may include vomiting, sleepiness, seizures, and downward pointing of the eyes. Hydrocephalus can occur due to birth defects or be acquired la
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Encephalitis Encephalitis is a term used to describe inflammation of the brain. This condition causes problems with the brain and spinal cord function. The inflammation causes the brain to swell, which leads to changes in the child's neurologic condition, including mental confusion and seizures.
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Pachygyria Pachygyria (from the Greek pachy meaning thick or fat gyri) is a congenital malformation of the cerebral hemisphere.It results in unusually thick convolutions of the cerebral cortex.ne of the best known and most common types of neuronal migration disorders is lissencephaly, a diffuse cortical malformation relating directly to agyria and pachygyria. Incomplete neuronal migration during the early fetal brain development is the precursor to lissencephaly.
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- Anencephaly is a defect in the closure of the neural tube during fetal development. The neural tube is a narrow channel that folds and closes between the 3rd and 4th weeks of pregnancy to form the brain and spinal cord of the embryo.nencephaly is a defect in the closure of the neural tube during fetal development. The neural tube is a narrow channel that folds and closes between the 3rd and 4th weeks of pregnancy to form the brain and spinal cord of the embryo.
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- Description. Cephalocaudal means head to toe. As such, the cephalocaudal principle refers to the general pattern of development seen in the earliest years of postnatal development specifically ranging from infancy into toddlerhood. The cephalocaudal principle applies to both physical and functional development. Regarding the prior (i.e., physical development), physical growth in size, weight, and feature differentiation follows this pattern of development [ 1 ].
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- Spina bifida is a birth defect that happens when a baby's backbone (spine) does not form normally. As a result, the spinal cord and the nerves that branch out of it may be damaged. The term spina bifida comes from Latin and literally means split or open spine.
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Microcephaly Microcephaly is a descriptive term meaning a small head and is associated with numerous disorders of diverse aetiology.icrocephaly can be divided into primary (or true) or secondary microcephaly. In primary microcephaly the brain never forms normally whereas in secondary microcephaly normal continued brain development is arrested by some defined insult / event.
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- Porencephaly: A disorder of the central nervous system involving a cyst or cavity in a cerebral hemisphere of the brain.The cysts or cavities are usually the remnants of destructive lesions, but are sometimes the result of abnormal development.orencephaly has a number of different causes including absence of brain development and destruction of brain tissue. The presence of porencephalic cysts can sometimes be detected by transillumination of the skull in infancy (when a strong light is shined through the head).
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Encephalitis Encephalitis Overview. Encephalitis is defined as inflammation of the brain. This definition means encephalitis is different from meningitis, which is defined as inflammation of the layers of tissue, or membranes, covering the brain.
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WELCOME!Letâs Stay Connected. Sign-Up to receive breaking rare disease information, news and stories right to your inbox! (We value your privacy. Your email address will not be shared.)SIGN ME UP Holoprosencephaly is a birth defect that arises during the first few weeks of the pregnancy. Diabetes in the mother during the pregnancy can increase the risk of holoprosencephaly in the fetus. However, for most children, there is no known intrauterine exposure that can be related to holoprosencephaly.
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What is Schizencephaly? Top 10 facts about the world. Schizencephaly is a very rare congenital abnormality of the brain in which the brain is interrupted with one or more clefts which are filled with cerebrospinal fluid.op 10 facts about the world. Schizencephaly is a very rare congenital abnormality of the brain in which the brain is interrupted with one or more clefts which are filled with cerebrospinal fluid.
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Gyrus A cerebral cortex without surface convolutions is lissencephalic, meaning 'smooth-brained'. As development continues, gyri and sulci begin to take shape on the fetal brain, with deepening indentations and ridges developing on the surface of the cortex.
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Anencephaly Anencephaly is a condition that prevents the normal development of the brain and the bones of the skull. This condition results when a structure called the neural tube fails to close during the first few weeks of embryonic development.
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- Porencephaly: Porencephaly is an extremely rare disorder of the central nervous system involving cysts or cavities in a cerebral hemisphere.The cysts or cavities ...more about Porencephaly.rticle Excerpts about Porencephaly. Porencephaly is an extremely rare disorder of the central nervous system involving cysts or cavities in a cerebral hemisphere. The cysts or cavities are usually the remnants of destructive lesions, but are sometimes the result of abnormal development.
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Hydranencephaly: Definition, Information, Diagnosis & Prognosis Definition: Hydranencephaly. Hydranencephaly is defined as the congenital absence of the cerebral hemispheres in which the space in the cranium that they normally occupy is filled with fluid. Hydranencephaly is a neurologic disorder in which the cerebral hemispheres are lacking although the cerebellum, brainstem, and other central nervous system tissues may be intact. The newborn with hydranencephaly may have normal neurologic functions but does not develop, and computed tomographic scans indicate an absence of cerebral tissue.
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Overview Microcephaly usually is the result of abnormal brain development, which can occur in the womb (congenital) or during infancy. Microcephaly may be genetic. Other causes may include: Craniosynostosis.
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Encephalomalacia Encephalomalacia means cerebral softening. It is an extremely serious medical condition that causes damage to the brain a person can suffer. It can occur in anyone regardless of race, age, or gender, including infants and the embryo during development.
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Hydranencephaly Hydranencephaly is a condition in which the brain's cerebral hemispheres are absent to varying degrees and the remaining cranial cavity is filled with cerebrospinal fluid. Hydranencephaly is a type of cephalic disorder. These disorders are congenital conditions that derive from either damage to, or abnormal development of, the fetal nervous system in the earliest stages of development in utero. Cephalic is the medical term for “head” or “head end of body.” These conditions do not ...
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Microcephaly A homozygous mutation in one of the microcephalin genes causes primary microcephaly. It serves as an important neurological indication or warning sign, but no uniformity exists in its definition. It is usually defined as a head circumference (HC) more than two standard deviations below the mean for age and sex.
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- Medical Definition of MICROCEPHALY. : a condition of abnormal smallness of the head usually associated with mental retardation.edical Definition of MICROCEPHALY. : a condition of abnormal smallness of the head usually associated with mental retardation.
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- Microcephaly is rare, generally occurring in... nervous system disease, human any of the diseases or disorders that affect the functioning of the human nervous system. Everything that humans sense, consider, and effect and all the unlearned reflexes of the body depend on the functioning of the nervous system.
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Introduction to Research Finding background information. Once you have identified the main topic and keywords for your research, find one or more sources of background information to read. These sources will help you understand the broader context of your research and tell you in general terms what is known about your topic.
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- Locked-in syndrome (LIS) is a condition in which a patient is aware but cannot move or communicate verbally due to complete paralysis of nearly all voluntary muscles in the body except for the eyes.