Chiari malformation | |
---|---|
Other names | Hindbrain herniation |
![]() | |
A sagittal FLAIR MRI scan, from a patient with an Arnold–Chiari malformation, demonstrating tonsillar herniation of 7 mm. | |
Pronunciation | |
Specialty | Neurosurgery |
Complications | Hydrocephalus, spina bifida, syringomyelia, tethered cord syndrome.[3] |
Types | I, II, III, IV[4] |
Treatment | Decompressive surgery[5] |
Prognosis | varies by type-see below |
Frequency | 1 in 100 (type I)[a] |
Named after |
In neurology, the Chiari malformation (/kiˈɑːri/ kee-AR-ee; CM) is a structural defect in the cerebellum, characterized by a downward displacement of one or both cerebellar tonsils through the foramen magnum (the opening at the base of the skull).
CMs can cause headaches, difficulty swallowing, vomiting, dizziness, neck pain, unsteady gait, poor hand coordination, numbness and tingling of the hands and feet, and speech problems.[7] Less often, people may experience ringing or buzzing in the ears, weakness, slow heart rhythm, or fast heart rhythm, curvature of the spine (scoliosis) related to spinal cord impairment, abnormal breathing, such as central sleep apnea, characterized by periods of breathing cessation during sleep, and, in severe cases, paralysis.[7] CM can sometimes lead to non-communicating hydrocephalus[8] as a result of obstruction of cerebrospinal fluid (CSF) outflow.[9] The CSF outflow is caused by phase difference in outflow and influx of blood in the vasculature of the brain.
The malformation is named after the Austrian pathologist Hans Chiari. A type II CM is also known as an Arnold–Chiari malformation in honor of Chiari and German pathologist Julius Arnold.
Types of Chiari
was invoked but never defined (see the help page).
Cite error: There are <ref group=lower-alpha>
tags or {{efn}}
templates on this page, but the references will not show without a {{reflist|group=lower-alpha}}
template or {{notelist}}
template (see the help page).