The purpose of this study is to decide which position of the neck affects cerebral spinal fluid (CSF) flow between the spinal cord and the brain. CSF is a fluid that flows up and down your spinal cord, around the brain and into the ventricles of the brain.

This study will be done with patients who have abnormalities of the neck, including Chiari 1 malformations.

In this study, subjects will have a dynamic cervical magnetic resonance imaging (MRI) of the craniovertebral junction (CVJ) coupled with CSF flow studies. The studies will assess changes in CSF flow velocities that are associated with with changing position of the neck at the CVJ and aqueduct of Sylvius.

Eligible patients include those with Chiari 1 malformations and similar malformations to the CVJ. This malformation lead to inherent instability in this region and symptoms such as headaches, dizziness, neck pain and other neurological problems. This study will determine if there is any correlation of these MRI findings to clinical outcome.

Inclusion Criteria:

• Healthy volunteers must be 18 yrs of age or older.
• Patients w/Chiari 1 or CVJ malformations aged 12 yrs or older,
• Able to cooperate in flexing and extending their neck within the cervical spine coil used for MR Imaging.
• Pediatric patients will be included only if they can cooperate for additional sequences done for the study who don't require sedation or any form of anesthesia.

Exclusion Criteria:

• Patients who are medically unstable or cannot voluntarily flex or extend their necks.
• Patients who have hardware in the head or necks which are incompatible with MR imaging.
• Patient requiring any form of sedation which can lead to compromise of the airway with maneuvers described above.
• History of prior head trauma or history of neurological conditions which can result in altered CSF dynamics.

Pilot group consisting of 10 healthy volunteers. Patients recruited w/incidental findings of Chiari 1 malformations and Patients recruited with known Chiari and other CVJ malformations (prior to surgery)