Neurosurgery

  • Chiari Malformation in Children & Adolescents

    Chiari I malformation is defined as descent of the lower part of the brain, specifically the tonsils of the cerebellum, into the upper spinal canal. A person can be born with this condition or can acquire it at any point in life. This malformation can sometimes be detected in a child who is having no symptoms but has an imaging study such as a CT scan done for other reasons. Often, however, this malformation can lead to symptoms ranging from headaches and neck pain to trouble with swallowing, irregular breathing, noisy breathing, abnormal eye movements, clumsiness or drop attacks.

    At that point, the child’s primary care physician will often order an MRI of the brain that will show the typical findings of the Chiari I malformation, and a referral will be made to a pediatric neurosurgeon for evaluation. The MRI may show how low in the spinal canal the tonsils are (usually expressed in millimeters), the shape of the tonsils (whether they are pointed or rounded) and whether there is normal or abnormal (sometimes described as pistoning) movement of spinal fluid around the tonsils. These images will be reviewed with you by your child’s neurosurgeon and the significance of these findings discussed, which varies from patient to patient.

    In addition to the Chiari I malformation, some patients will be found to have an associated cavity filled with spinal fluid within the spinal cord called a syrinx, or syringomyelia. This is sometimes better seen on MRI images of the spine. This is caused by a disturbance of the flow of spinal fluid at the base of the skull by the Chiari malformation. It can be associated with symptoms such as scoliosis, incontinence, weakness, numbness or tingling in the hands, or, less commonly, the legs.

    Research efforts are under way at Cincinnati Children’s to study the genetics of familial cases of this condition as well as to better understand the different presentations and manifestations based on age of the patient at diagnosis. In addition, he has been at the forefront of tailoring the surgical approach for this condition to the unique pathophysiology found intraoperatively for each patient. Ongoing, rigorous monitoring of surgical outcomes data provides reassurance that we continue to be among the leaders in maintaining the highest standards of care for our patients with this condition.

    At Cincinnati Children’s, patients with Chiari malformations are evaluated by a comprehensive multidisciplinary approach utilizing a team of experts from many fields. If a decision for surgical intervention is made, surgery will involve removal of the bone compressing the tonsils in all cases. Intraoperative imaging, including ultrasound to look at the movement of the tonsils and surrounding spinal fluid, is then used to select those patients who will benefit from more extensive decompression of the tonsils by expanding the membranous sac (dura) surrounding the tonsils and possibly adding a small tube, or stent, to restore normal circulation of the spinal fluid. Sometimes a temporary external small drainage catheter is also placed into the lower spinal canal that remains in place for a few days following the operation. A typical hospital stay for this type of surgery is three to five days.

    Most symptoms respond very well to the surgery but long-term neurosurgical follow-up is necessary. Follow-up MRIs are usually obtained at varying intervals to look for the results of the decompression, the response of any associated syrinx to surgery, and to monitor for the development of scar tissue. A normal life without restrictions is the goal for most patients following surgery, and has been achievable for the majority of our patients.