Congenital Abnormality
arnold-chiari malformation
Subclass of:
Neural Tube Defects
Definitions related to arnold chiari malformation:
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(chiari malformation) Chiari malformations (CMs) are structural defects in the cerebellum. The cerebellum is the part of the brain that controls balance. With CM, brain tissue extends into the spinal canal. It can happen when part of the skull is too small, which pushes the brain tissue down. There are several types of CM. One type often happens in children who have neural tube defects. Some types cause no symptoms and don't need treatment. If you have symptoms, they may include Neck pain; Balance problems; Numbness or other abnormal feelings in the arms or legs; Dizziness; Vision problems; Difficulty swallowing; Poor hand coordination. Doctors diagnose CM using imaging tests. Medicines may ease some symptoms, such as pain. Surgery is the only treatment available to correct or stop the progression of nerve damage. NIH: National Institute of Neurological Disorders and StrokeMedlinePlusU.S. National Library of Medicine, 2021
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(arnold-chiari malformation) A group of congenital malformations involving the brainstem, cerebellum, upper spinal cord, and surrounding bony structures. Type II is the most common, and features compression of the medulla and cerebellar tonsils into the upper cervical spinal canal and an associated MENINGOMYELOCELE. Type I features similar, but less severe malformations and is without an associated meningomyelocele. Type III has the features of type II with an additional herniation of the entire cerebellum through the bony defect involving the foramen magnum, forming an ENCEPHALOCELE. Type IV is a form a cerebellar hypoplasia. Clinical manifestations of types I-III include TORTICOLLIS; opisthotonus; HEADACHE; VERTIGO; VOCAL CORD PARALYSIS; APNEA; NYSTAGMUS, CONGENITAL; swallowing difficulties; and ATAXIA. (From Menkes, Textbook of Child Neurology, 5th ed, p261; Davis, Textbook of Neuropathology, 2nd ed, pp236-46)NLM Medical Subject HeadingsU.S. National Library of Medicine, 2021
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(arnold-chiari malformation) A rare genetic brain malformation characterized by displacement of the brain stem and cerebellum through the foramen magnum. It may result in hydrocephalus.NCI ThesaurusU.S. National Cancer Institute, 2021
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(arnold-chiari malformation) Arnold-Chiari malformation consists of a downward displacement of the cerebellar tonsils and the medulla through the foramen magnum, sometimes causing hydrocephalus as a result of obstruction of CSF outflow.Human Phenotype Ontology (HPO)The Human Phenotype Ontology Project, 2021
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Chiari malformations, types I-IV, refer to a spectrum of congenital hindbrain abnormalities affecting the structural relationships between the cerebellum, brainstem, the upper cervical cord, and the bony cranial base. .WebMD, 2019
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Chiari malformation (kee-AH-ree mal-for-MAY-shun) is a condition in which brain tissue extends into your spinal canal. It occurs when part of your skull is abnormally small or misshapen, pressing on your brain and forcing it downward.Mayo Foundation for Medical Education and Research
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Chiari malformations are structural defects in the cerebellum, the part of the brain that controls balance. When the indented bony space at the lower rear of the skull is smaller than normal, the cerebellum and brainstem can be pushed downward. The resulting pressure on the cerebellum can block the flow of cerebrospinal fluid (the liquid...National Center for Advancing Translational Sciences
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