Arnold-Chiari deformity

9.6

A birth condition where part of the brain pushes through an opening at the back of the skull

noun
/ɑrnəld ˈkiːɑri dɪˈfɔːrmɪti/

Specialized

: deformidad de Arnold-Chiari

MRI scans revealed an Arnold-Chiari deformity at the base of the patient's skull.

Examples

Many patients with Arnold-Chiari deformities experience headaches.
The neurosurgeon explained that the symptoms were caused by an Arnold-Chiari deformity.
Early diagnosis of Arnold-Chiari deformity can help prevent serious complications.
The doctor diagnosed her with an Arnold-Chiari deformity.
Early diagnosis of Arnold-Chiari deformity can help prevent serious complications.
MRI scans revealed an Arnold-Chiari deformity at the base of the patient's skull.
The neurosurgeon explained that the symptoms were caused by an Arnold-Chiari deformity.

Surface Forms

Arnold-Chiari deformity singular

Arnold-Chiari deformities plural

Morphology

Arnold-Chiari + deformity

The element 'Arnold-Chiari' is an eponym/proper name with no lexical meaning that a learner can compose, while 'deformity' only indicates a generic abnormality. A B1 learner who knows the constituent words would at best infer that it is some named abnormal condition but could not derive the specific medical meaning (cerebellar protrusion), so the expression is not compositionally transparent.

Etymology

Arnold-Chiari deformity is named after two doctors, Arnold and Chiari, who first described the condition. Imagine the small back part of the brain, the cerebellum, 'slipping' down through a hole at the base of the skull, and that picture explains why the name refers to a condition where parts of the brain are pushed down.