June 30th, 2011 -- A group from the University of Alabama - Birmingham has published their experiences with one of the largest patient groups to date. Specifically, the research involves 500 surgical pediatric Chiari patients, spanning more than a decade. Interestingly, the authors state that in general they only operate on about 20% of the people they see who have an MRI indication of Chiari.

The children ranged in age from as young as just 2 months old to a more adult like 20 years, with the average age being 11. In contrast to many adult patient series where women are normally in the majority, the patient was comprised of 271 boys and 221 girls. Headache and neck and back pain were by far the most common presenting symptom (Table 1), although scoliosis and upper extremity issues were also fairly common. A couple of the more rare - but interesting - symptoms were chronic hiccups and rage attacks. Chronic hiccups have been associated with Chiari in published case studies, and Conquer Chiari has had questions from parents and teachers about rage attacks.

Table 1: Most Common Presenting Symptoms Among 500 Pediatric Chiari Patients (Most Patients Exhibited More Than One Symptom)

Symptom

Number With

Headache/neck/back pain 200
Scoliosis 90
Upper extremity pain/weakness 41
Apnea 25
Trouble swallowing 20
Ataxia 19
Irritability 19
Nasal speech 15

There were a number of common associated diagnoses (Table 2), including hydrocephalus of course and neurofibromatosis 1. Interestingly, the group had 21 children with growth hormone deficiency (the authors have previously published on growth hormone deficiency and Chiari). Highlighting the often confusing nature of Chiari, there were 25 associated diagnoses which affected only one patient in the group. The question of how many of these additional diagnoses were related to Chiari by more than just chance is difficult to say and was not addressed by the researchers. Slightly more than half of the group had syrinxes and there were six cases of syringobulbia.

Imaging studies showed that 22% of the group had herniations between the foramen magnum and the level of C1, 37% were at C1, 39% were at C2, and 1 % was at C2 (Table 3). Almost all of the children (97%) had pointed tonsils. The doctors routinely used cine MRI to assess CSF flow for a couple of years but stopped because they felt there was a high rate of false negatives.

Each member of the group underwent a posterior fossa decompression with laminectomy, and all but one had a duraplasty. The surgeons used different materials for the dural patch. About 10% of the group also had their cerebellar tonsils reduced using coagulation. The surgeries took 95 minutes on average and the children were generally in the hospital for 3 days and returned to school after 12 days. The complication rate was only 2.4% and thankfully there were no deaths associated with the surgery.

In terms of outcomes, the children were followed for an average of 5 years, with 83% experiencing good relief of symptoms. Fifteen children required further decompression, and two of that group also required a shunt. Twelve patients underwent cervical fusion and four had to have a transoral decompression to relieve brainstem pressure.

There have now been several very large patient series published which give a pretty good picture of both the average and extremes of the surgical experience. What is needed now is a structured effort to improve the outcomes and experiences of Chiari patients who undergo surgery.

-- Rick Labuda