Chiari malformation

Classification according to ICD-10
Q07.0	Arnold Chiari Syndrome
ICD-10 online (WHO version 2019)

As Chiari malformation is a group of developmental disorders with displacement of the cerebellum proportions through the foramen magnum ( foramen magnum ) into the spinal canal designated at the same time existing reduced-posterior fossa. It is named after the pathologist Hans Chiari (1851-1916), who first described this disorder. The names Arnold-Chiari malformation and Arnold-Chiari syndrome were propagated by the students of the pathologist Julius Arnold (1835-1915), but do not seem justified because this group of developmental disorders was only superficially described by him.

Classification

MRI of a Chiari-1 malformation. The arrow points to the cerebellar tonsils, which end well below the level of the foramen magnum (blue line).

Chiari malformation type 2 in a newborn on MRI

Four different types are divided based on their characteristics and localization:

• Type I: There is a displacement of the cerebellar tonsils . As a complication, it can lead to syringomyelia come. Bony malformations of the skull base and vertebral bodies are less common. Patients can be symptom-free. It is not uncommon for complaints to appear in young adulthood. In addition to head and neck pain, this can include: B. Signs of damage to the cerebellum (e.g. an unsteady gait known as ataxia ) or the brain stem (e.g. swallowing disorders).
• Type II: Here there is a more pronounced displacement of the cerebellar worm combined with compression and displacement of the brain stem as well as displacement of the fourth ventricle with the development of hydrocephalus . Normally there are bony malformations with the formation of a myelomeningiocele . The term Arnold-Chiari malformation only refers to this sub-form of the Chiari malformation.
• Type III: With this rarer sub-form there is a massive displacement of the cerebellum, with the formation of a bony defect also with the formation of a so-called encephalocele .
• Type IV: In this rarest sub-form, an underdevelopment ( hypoplasia ) of the cerebellum occurs.

The diagnosis is made by magnetic resonance imaging . In fetuses , the so-called lemon sign or banana sign can be used as a sonographic soft marker in prenatal diagnostic sonography, a possible indication of a Chiari malformation.

therapy

Computed tomography after surgical expansion of the foramen magnum, resection of the posterior atlas arch and the herniated parts of the cerebellar tonsils several decades ago.

In the event of a hydrocephalic build-up with a herniated cerebellar tonsil, decompression is carried out via a suboccipital access.

Web links

Commons : Chiari Malformation  - Collection of Images, Videos and Audio Files

• NINDS Chiari Malformation Information Page Resource of the National Institutes of Health with links to ongoing clinical studies

Individual evidence

1. ↑ H. Chiari: About changes in the cerebellum as a result of hydrocephaly of the cerebrum. In: Dtsch. Med. Wochenschr. 1891; 17, pp. 1172–1175 (first description) Textarchiv - Internet Archive
2. ^ PJ Koehler, SH Greenblatt: The Chiari Malformation. In: Koehler, Bruyn & Pearce (Eds.): Neurological Eponyms. Oxford University Press, 2000 (medical history work)
3. ↑ E. Schijman: History, anatomic forms, and pathogenesis of Chiari I malformations. In: Childs Nerv Syst. , 2004, 20, pp. 323-328. PMID 14762679 .
4. ^ Chiari Malformation Fact Sheet: National Institute of Neurological Disorders and Stroke (NINDS). Retrieved February 3, 2014 . 

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