Chiari Malformation Workup
- Author: Peyman Pakzaban, MD; Chief Editor: Brian H Kopell, MD more...
MRI is the most useful and most widely used imaging study for diagnosing Chiari malformation. In addition to depicting the anatomy of the craniocervical junction, it provides useful information about associated abnormalities, such as syringomyelia and hydrocephalus.
Patients who cannot undergo MRI can be evaluated with CT-myelography/cisternography. However, the increasing availability of high-resolution high-speed (eg, 64-slice) CT scanners allows for making the diagnosis with a noncontrast CT with sagittal reconstructions, obviating the need for myelography.
CSF flow analysis through foramen magnum with phase-contrast cine MRI helps distinguish symptomatic Chiari I from asymptomatic cerebellar ectopia and helps predict response to surgical decompression.
Lab studies are not applicable for diagnosing Chiari malformations.
Preparation for surgery for Chiari I decompression is the same as for any elective surgery and depends on the patient's general health. The author routinely obtains CBC, basal metabolic panel, PT, aPTT, chest radiograph, and ECG. Blood is typed and screened.
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|Characteristic||Chiari I||Chiari II|
|Usual age of diagnosis||Adults and older children||Infants and young children|
|Primary anatomical abnormalities||
|Hydrocephalus||Less than 10% of cases||Very common|
|Shared associated abnormalities||