Peak systolic and diastolic CSF velocity in the foramen magnum in adult patients with Chiari I malformations and in normal control participants.
OBJECTIVE
Abnormal flow of CSF through the foramen magnum has been implicated in the pathogenesis of clinical deficits in association with Chiari I malformation. The purpose of this study was to test the hypothesis that peak CSF velocities in the foramen magnum are increased in patients with Chiari I malformations.


METHODS
Eight adult patients with symptomatic Chiari I malformations and 10 adult volunteers were studied with cardiac gated, phase-contrast MR imaging in the axial plane at the foramen magnum. The spatial uniformity of flow velocity in the foramen magnum was assessed at 14 time frames within the R-R interval. The velocity in each of the voxels at each of the time frames was calculated, and the peak systolic and diastolic velocities were tabulated for the patients and controls.


RESULTS
For the normal volunteers, the CSF velocities in the subarachnoid space were relatively uniform throughout the subarachnoid space at each of the time frames. Peak systolic velocity ranged from 1.2 to 3.3 cm/s, and peak diastolic velocity ranged from 1.6 to 4.5 cm/s. In symptomatic patients with Chiari I, velocities in the foramen magnum did not appear as uniform throughout the subarachnoid space in the phase-contrast images. Peak systolic velocities ranged from 1.8 to 4.8 cm/s, and peak diastolic velocities ranged from 2.5 to 5.3 cm/s. Peak systolic velocity was significantly higher (P =.01) in the patients than in the control volunteers.


CONCLUSIONS
Patients with Chiari I malformations have significant elevations of peak systolic velocity in the CSF in the foramen magnum.
Haughton
Victor M
VM
Department of Radiology, University of Wisconsin Hospitals and Clinics, 600 Highland Avenue, CSC E3/311, Madison, WI 53792, USA.
Korosec
Frank R
FR
Medow
Joshua E
JE
Dolar
Maria T
MT
Iskandar
Bermans J
BJ
D000328:Adult; D001139:Arnold-Chiari Malformation / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D016477:Artifacts; D002555:Cerebrospinal Fluid / Q000502:physiology*; D003971:Diastole / Q000502:physiology*; D005260:Female; D005539:Foramen Magnum / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012212:Rheology; D013346:Subarachnoid Space / Q000473:pathology; D013595:Syringomyelia / Q000134:cerebrospinal fluid / Q000175:diagnosis; D013599:Systole / Q000502:physiology*