1. Neurosurgical Considerations in Spina Bifida Debbie K. Song, M.D. Gillette Children’s Specialty Healthcare St. Paul, MN Spina Bifida Association of Iowa Education Day 2015 March 28, 2015

2. Neurosurgical Issues in Spina Bifida  Spina bifida / myelomeningocele  Closure of myelomeningocele  Hydrocephalus  Chiari II Malformation  Tethered Spinal Cord  Syringomyelia

3. Spina Bifida

4. Myelomeningocele  Incidence: ~1-2/1000 live births  Genetic risk  2-3% risk of having child with myelomenigocele after having a prior pregnancy affected by myelomeningocele  6-8% if 2 affected siblings  Increased risk when close relatives have pregnancies affected by myelomeningocele  Risk factors  Prior pregnancy affected by myelomeningocele  Maternal folic acid deficiency  0.4 mg/day if no history of neural tube defect  4 mg/day if prior pregnancy with neural tube defect  Pregestational maternal diabetes mellitus  Certain antiseizure medications: valproic acid, carbemazepime

5. Myelomeningocele closure

6. Adzick NS et al, N Engl J Med. 2011 March 17; 364 (11):993-1004

7. Hydrocephalus

8. Hydrocephalus  Affects 85% of people with myelomeningocele  5-10% of babies with MMC have overt hydrocephalus at birth  If it occurs, hydrocephalus usually does so by 6 months of age  May become clinically evident after closure of back at birth  Shunt to treat hydrocephalus in myelomeningocele  Some work looking at endoscopic third ventriculostomy (ETV) as an alternative

9.  Catheter in ventricle through burr hole in skull  Reservoir/valve (separate or in combination)  Distal catheter draining into:  Peritoneal cavity  Pleural cavity  Right atrium  Gallbladder, sagittal sinus, fallopian tube…  Antibiotic impregnated catheter  Anti-siphon devices  Programmable valves Shunts – basic configuration

10. Ventriculoperitoneal shunt for hydrocephalus

11.  Neurosurgery follow-up important  Why was the shunt placed?  What kind of valve (programmable? Setting?)  History of shunt surgeries – malfunctions, infections?  What does child look like during a shunt malfunction?  Copies of scans on file for local ER/future comparison  Do ventricles get larger when shunt malfunctions? Managing a child with hydrocephalus

12. Chiari II malformation

13.  Present in 75-90% of patients with myelomeningocele  Constellation of anomalies:  Hindbrain herniation (downward displacement of parts of the medulla, cerebellum, 4 th ventricle into spinal canal)  Brainstem abnormalities  Low-lying venous sinuses  Small posterior fossa  Chiari II related to hydrocephalus development  Intrauterine repair of myelomeningocele reduces incidence of Chiari II (MOMS trial)

15. Chiari II malformation  Leading cause of mortality in infants with myelomeningocele  15-30% of patients symptomatic, requiring surgery  Presentation in infants:  Apnea, swallowing problems, stridor, lower cranial neuropathies  High-pitched, hoarse, weak cry  Vocal cord palsy, hypotonia  Recurrent aspiration pneumonia, nasal regurgitation  Presentation in older patients:  Headache, neck pain  Balance/coordination problems  Increased upper extremity spasticity, weakness  Make sure shunt is working!

17. Tethered Spinal Cord

20.  Everyone with repaired myelomeningocele will have radiographic tethered cord  ~1/3 of patients with spina bifida will require tethered cord release surgery  Assess for symptoms: neurologic, orthopedic, urologic  Clinical symptoms often driven by growth spurt  Make sure shunt is working!

21. Syringomyelia

22. Syringomyelia  CSF within the spinal cord  Present in 40-80% of patients with myelomeningocele  Symptomatic in 2-5% of patients; assess for clinical change!  Presentation overlaps with tethered cord and Chiari II symptoms:  Upper extremity weakness, loss of function  Hand deformity  neck or back pain  Worsening scoliosis  Spasticity  Ascending motor loss in the legs  Treatment options: syrinx shunt, Chiari decompression, tethered cord release  Make sure shunt is working!

24. Final Thoughts  Shunt care is important  Clinical deterioration warrants investigation…starting with shunt function  Overall clinical picture is more important than imaging  Be proactive and accountable for you/your child’s healthcare  DEBBIEKSONG@GILLETTECHILDRENS.COM