Bruce B. Storrs

Analysis of 153 Patients with Myelomeningocele or Spinal Lipoma Reoperated upon for a Tethered Cord

After primary repair of myelomeningoceles or lipomyelomeningoceles, late progressive neurologic deterioration commonly occurs due to a treatable cause. In our experience many of these patients have a tethered cord. With early untethering, most patients are stabilized and a significant percent of the patients show improvement in their clinical status. Of 341 tethered cord releases done from 1981 to 1988, we report on 153 patients reoperated upon following primary repair. One hundred were performed after primary closure of a myelomeningocele and 53 after repair of a lipomyelomeningocele. The average age of the patients with a myelomeningocele was 6 years old, and for the spinal lipoma patients, 8 years old. The presenting symptoms were similar; weakness, deterioration in gait, scoliosis, orthopedic deformities, and urinary incontinence represented the most common complaints. All 153 patients were noted to have a tethered cord at operation. Additional pathology (dermoid tumors, hydromyelia, tight filum and diastematomyelia) was present in 30% of the cases. With the use of the CO2 laser for dissection, all but 10 patients could be untethered. Follow-up over an average of 4 years revealed 93% of the patients with a myelomeningocele had stabilization or improvement of their presenting complaints, and 7% had progression of their presenting complaints. All of the lipomyelomeningocele patients had either stabilization or improvement of their presenting complaints. There were no mortalities. Close follow-up and early treatment of this patient population is indicated. With release of the cord a significant portion of the population will have relief or improvement of their presenting complaints.

Intracranial Aneurysms in the Pediatric Age-Group

29 cases of intracranial aneurysms in children under 16 years of age are reviewed. The prodrome, presentation, location of aneurysm, and outcome are discussed. Evidence is presented to encourage a more aggressive evaluation of suspected subarachnoid hemorrhage in children.

Management of the Dandy-Walker syndrome

The charts of 50 patients with the Dandy-Walker Syndrome were reviewed. Initial therapy was cystoperitoneal (CP) shunt in 21 (42%), ventriculoperitoneal (VP) shunt in 13 (26%), and both (CPVP) in 7 (14%), with the remaining 9 (18%) requiring no shunting procedure. Conversion from single to double shunt secondary to expansion of the unshunted compartment occurred in 9 (42%) of CP only and 4 (30%) of VP only patients. Final therapy was CP in 12 (24%), VP in 9 (18%), CPVP in 20 (40%) and none in 9 (18%). Patients who were unshunted remained shunt-free. When CPVP shunts were present, there was a statistically significant probability that shunt malfunction was due to the CP component only or both components, but not the VP component only. However, there was no statistical difference in malfunction or complication rates between patients with CP only or VP only shunts. Associated anomalies, intellectual outcome, and mortality were also analyzed. Seizures, hearing or visual problems, various CNS abnormalities, and systemic abnormalities were associated with poor intellectual development and could be used to predict intellectual outcome.

Occipital Meningoceles in Patients with the Dandy-Walker Syndrome

Occipital cephaloceles in the Dandy-Walker syndrome are not rare. To date, 28 cases have been reported. We report on 8 cases of associated occipital meningocele, totalling 16% of all patients with the Dandy-Walker syndrome in our series. In all patients, communication existed between the posterior fossa cyst and the occipital meningocele. In 2 patients, the occipital meningocele disappeared after cerebrospinal fluid shunting and never required surgical repair. It appears that the cranial defect had ossified and resulted in self-closure. Poor intellectual development in persons with the Dandy-Walker syndrome is associated with the presence of other central nervous system and systemic abnormalities and not with occipital meningoceles alone.

Anatomical progression of the Chiari II malformation.

To evaluate whether anatomic change of the relationship of the Chiari II malformation and the cranial base was occurring, 22 children with meningomyelocele had serial MRI scans reviewed. A ratio (B/A) was established between the distance from the foramen magnum to the caudalmost portion of herniated cerebellum (B) and the diameter of the foramen magnum (A) and this ratio was compared on serial MRI scans. Eighteen children had an increase in the B/A ratio, two children had a decrease, and two had no change. This indicates that continuous anatomic change of the Chiari II malformation and the skull base is occurring. Clinical deterioration in the older child may be explained by a combination of compressive and traction forces due to this change.

Selective Posterior Rhizotomy for Treatment of Progressive Spasticity in Patients with Myelomeningocele

This preliminary report describes two cases of progressive spasticity and scoliosis in children with myelomeningocele. Both patients had evidence of tethered spinal cord. Untethering of the spinal cord was successful in arresting the scoliosis but not the spasticity. Selective posterior rhizotomy was successful in resolving the spasticity in both cases. The technique of selective posterior rhizotomy is reviewed.

Posterior fossa cysts: supratentorial shunt placement with ultrasound guidance

A technique is presented for posterior fossa cyst shunt placement from a supratentorial location utilizing intraoperative ultrasonography.

Radiation Exposure to the Ocular Lens during CT Scanning

Measurements of radiation exposure during routine CT scanning were found to average 4.2 R at the level of the ocular lens. This data was combined with CT scanning rate data from a sample of 100 patients followed in the myelomeningocele clinic. The number of scans averaged 7.75/patient with a range of 0-34 scans. Cumulative radiation exposure to date ranged from 0 to 143 R. Radiation dosage nomenclature and acceptable limits are discussed and recommendations for reduction of dosage are presented.

Medical Management of Head Injuries in Neonates and Infants

The medical management of children with head injuries is often the most important aspect of their treatment. Children have a much lower incidence of surgical mass lesions (25%)4,5,19,20 than adults (50%)1,2,9 They also suffer an 80% incidence of increased intracranial pressure following severe head injuries.15 Thus, the medical management of their injuries has an increased importance. The age of the patient has a profound influence on the type of injury sustained and the ultimate outcome. It appears that a child under 2 years old is at the highest risk for significant complications and sequelae following a severe head injury. Many of these complications are related to the secondary injury of the brain6,19,20 such as edema, hyperemia, hypoxia, and so on, and thus are managed medically.