Palliative Surgical Techniques (VNS, Callosotomy)

Living reference work entry


Epilepsy management has experienced a drastic change over the last few decades, with earlier intervention and comprehensive epilepsy evaluation resulting in improved outcomes. Curative resective epilepsy surgery is an option in only a subgroup of pharmacoresistant patients, where an epileptogenic focus is localized and amenable to surgical intervention. In the remaining patients with medically refractory epilepsy, palliative epilepsy surgery can be offered. Palliative procedures include corpus callosotomy and vagus nerve stimulation. All patients undergoing palliative neurosurgical intervention should undergo complete preoperative evaluation. This entails a comprehensive epilepsy evaluation involving history, examination, prolonged video-electroencaphalogram, extensive tailored neuroimaging, antiepileptic medication management, and genetic/metabolic evaluation when applicable. The decision on which palliative procedure would be most successful must be based on individual factors of each patient. Recent evidence supports the earlier the surgical intervention in the course of intractable epilepsy, the better the outcome in terms of seizure burden, quality of life and development. In addition, there is a reported reduced risk of postoperative complications with early surgical intervention. We discuss in this chapter the indications, patient selection, anatomic considerations, surgical technique and complications, and outcomes observed in corpus callosotomy and vagus nerve stimulation therapy. We summarize experience with palliative neurosurgical techniques in adult and pediatric patients and discuss the beneficial effects, as well as risks of each procedure.


Eepilepsy Mmedically refractory Iintractable Ppalliative Ccorpus callosotomy Vvagus nerve stimulation therapy Nneurosurgery Ppediatric Sseizure Ddisconnection Nneurocyberonics 


  1. Aalbers MW (2009) Horner’s syndrome: a complication of experimental carotid artery surgery in rats. Auton Neurosci 147(1–2):64–69CrossRefPubMedGoogle Scholar
  2. Agostini E, Chinnock JE, Daly MS, Murray JG (1957) Functional and histological studies of the vagus nerve and its branches to the heart, lungs and abdominal viscera in the cat. J Physiol 135:182–205CrossRefGoogle Scholar
  3. Amar AP, Apuzzo ML, Liu LY (2008) Vagus nerve stimulation therapy after failed cranial surgery for intractable epilepsy; results from the vagus nerve stimulation therapy patient outcome registry. Neurosurgery 62(2):506–513PubMedGoogle Scholar
  4. Andermann F (1992) Clinical indications for hemispherectomy and callosotomy. Epilepsy Res Suppl 5:189–199PubMedGoogle Scholar
  5. Andermann F, Olivier A, Gotman J (1987) Callosotomy for the treatment of patients with intractable epilepsy and the Lennox-Gastaut syndrome. In: Liss A, Niedermeyer E, Degen R (eds) The Lennox-Gastaut syndrome. Alan Liss, New York, pp 361–376Google Scholar
  6. Asadi-Pooya AA (2008) Corpus callosotomy. Epilepsy Behav 13:271–278CrossRefPubMedGoogle Scholar
  7. Ascapone JJ et al (1998) Early experience with vagus nerve stimulation for treatment of epilepsy: cardiac complications. Epilepsia 39(6):193Google Scholar
  8. Bailey P, Bremer F (1938) A sensory cortical representation of the vagus nerve: with a note on the effects of low blood pressure on the cortical electrogram. J Neurophysiol 1(5):405–412CrossRefGoogle Scholar
  9. Baumgartner JE, Von Allmen GK (2011) Chapter 67: vagus nerve stimulation for intractable epilepsy. In: Winn H (ed) Youmans neurosurgical surgery, 6th edn. Elsevier Saunders, Philadelphia, pp 806–812Google Scholar
  10. Bower RS et al (2013) Seizure outcomes after courpus callosotomy for drop attacks. Neurosurgery 73(6):993–1000CrossRefPubMedGoogle Scholar
  11. Chandra PS et al (2006) FDG-PET/MRI coregistration and diffusion-tensor imaging distinguish epileptogenic tubers and cortex in patients with tuberous sclerosis complex: a preliminary report. Epilepsia 47(9):1543–1549CrossRefPubMedGoogle Scholar
  12. Chen PC et al (2015) Bilateral intracranial EEG with corpus callosotomy may uncover seizure focus in nonlocalizing focal epilepsy. Seizure: Eur J Epilepsy 24:63–69CrossRefGoogle Scholar
  13. Cuckiert A et al (2006) Extended, one-stage callosal section for treatment of regractory secondarily generalized epilepsy in patients with Lennox-Gastaut and Lennox-like syndromes. Epilepsia 47:371–374CrossRefGoogle Scholar
  14. Cyberonics Inc (2016) VNS therapy system physician’s manual (US). pp 2–20. Available at: Accessed 16 July 2016
  15. DeGiorgio CM et al (2000) Prospective long-term study of vagus nerve stimulation for the treatment of refractory seizures. Epilepsia 41:1195–1200CrossRefPubMedGoogle Scholar
  16. Elliot RE et al (2011) Vagus nerve stimulation in 436 consecutive patients with treatment-resistant epilepsy: long-term outcomes and predictors of response. Epilepsy Behav 20:57–63CrossRefGoogle Scholar
  17. Englot DJ, Chang EF, Auguste KL (2011) Vagus nerve stimulation for epilepsy: a meta-analysis of efficacy and predictors of response. J Neurosurg 115:1248–1255CrossRefPubMedGoogle Scholar
  18. Erickson TC (1940) Spread of the epileptic discharge. An experimental study of the after0discharge induced by electrical stimulation of the cerebral cortex. Arch NeuroPsych 43(3):429–452CrossRefGoogle Scholar
  19. Fernándes IS, An S, Loddenkemper T (2015) Pediatric refractory epilepsy: a decision analysis comparing medical versus surgical treatment. Epilepsia 56:263–272CrossRefGoogle Scholar
  20. Fernando DA, Lord RS (1994) The blood supply of vagus nerve I nthe human: its implication in carotid endarterectomy, thyroidectomy and carotid arch aneurectomy. Ann Anat 176:333–337CrossRefPubMedGoogle Scholar
  21. Funnell MG et al (2000) Cortical and subcortical interhemispheric interactions following partial and complete callosotomy. Arch Neurol 57:185–189CrossRefPubMedGoogle Scholar
  22. Graham D, Tisdall MM, Gill D (2016) Corpus callosotomy outcomes in pediatric patients: a systematic review. Epilepsia 57(7):1053–1068CrossRefPubMedGoogle Scholar
  23. Greiner HM et al (2012) Case report: corpus callosotomy for treatment of pediatric refractory status epilepticus. Seizure 21(4):307–309CrossRefPubMedPubMedCentralGoogle Scholar
  24. Handforth A et al (1998) Vagus nerve stimulation therapy for partial-onset seizures: a randomized active-control trial. Neurology 51:48–55CrossRefGoogle Scholar
  25. Helmers SL et al (2002) Observations on the use of vagal nerve stimulation earlier in the course of pharmacoresistant epilepsy: patients with seizures for six years or less. Neurologist 9:160–164CrossRefGoogle Scholar
  26. Helmers SL et al (2011) Clinical and econoic impact of vagus nerve stimulation therapy in patients with drug-resistant epilepsy. Epilepsy Behav 22:370–375CrossRefPubMedGoogle Scholar
  27. Hemb M et al (2010) Improved outcomes in pediatric epilepsy surgery: the UCLA experience, 1986-2008. Neurology 74(22):1768–1775CrossRefPubMedPubMedCentralGoogle Scholar
  28. Hornig GW et al (1997) Left vagus nerve stimulation in children with refractory epilepsy: an update. South Med J 90:484–488CrossRefPubMedGoogle Scholar
  29. Ishizaki M et al (2012) Crossed aphasia following an infarction in the right corpus callosum. Clin Neurol Neurosurg 114(2):161–165CrossRefPubMedGoogle Scholar
  30. Iwasaki M et al (2016) Clinical profiles for seizure remission and developmental gains after total corpus callosotomy. Brain Dev 38(1):47–53CrossRefPubMedGoogle Scholar
  31. Jadhav T (2012) Surgical approaches to treating epilepsy in children. Curr Treat Options Neurol 14:620–629CrossRefPubMedGoogle Scholar
  32. Jalilian L et al (2010) Complete versus anterior two-thirds corpus callosotomy in children: analysis of outcome. J Neurosurg Pediatr 6(3):257–266CrossRefPubMedGoogle Scholar
  33. Kabir SM, Rajaraman C, Rittey C, Zaki HS, Kemeny AA, McMullan J (2009) Vagus nerve stimulation in children with intractable epilepsy: indication, complications and outcome. Childs Nerv Syst 25:1097–1100CrossRefPubMedGoogle Scholar
  34. Kahlow H, Olivecrona M (2013) Complications of vagal nerve stimulation for drug-resistant epilepsy: a single center longitudinal study of 143 patients. Seizure 22(10):827–833CrossRefPubMedGoogle Scholar
  35. Kasasbeh AS et al (2014) Outcomes after anterior or complete corpus callosotomy in children. Neurosurgery 74(1):17–28CrossRefPubMedGoogle Scholar
  36. Kirse DJ et al (2002) Vagus nerve stimulator implantation in children. JAMA Otolaryngol Head Neck Surg 128:1263–1268Google Scholar
  37. Kwan P, Brodie MJ (2002) Refractory epilepsy: a progressive, intractable but preventable condition? Seizure 11:77–84CrossRefPubMedGoogle Scholar
  38. Lanska DJ (2002) Corning and vagal nerve stimulation for seizures in the 1880s. Neurology 58:452–459CrossRefPubMedGoogle Scholar
  39. Lin JS et al (2011) Corpus callosotomy in multistage epilepsy surgery in the pediatric population. J Neurosurg Pediatr 7:189–200CrossRefPubMedGoogle Scholar
  40. Lötvall J et al (1994) Airway effects of direct left-sided cervical vagal stimulation in patients with comple partial seizures. Epilepsy Res 18:149–154CrossRefPubMedGoogle Scholar
  41. MacLachlan RS (1993) Suppression of interictal spikes and seizures by stimulation of the vagus nerve. Epilepsia 34:918–923CrossRefGoogle Scholar
  42. Maehara T, Shimizu H (2001) Surgical outcome of corpus callosotomy in patients with drop attacks. Epilepsia 42(1):67–71CrossRefPubMedGoogle Scholar
  43. Matsuzaka T et al (1999) Quantitative EEG analyses and surgical outcome after corpus callosotomy. Epilepsia 40(9):1269–1278CrossRefPubMedGoogle Scholar
  44. McGregor A, Wheless J, Baumgartner J, Bettis D (2005) Right-sided vagus nerve stimulation as a treatment for refractory epilepsy in humans. Epilepsia 46(1):91–96CrossRefPubMedGoogle Scholar
  45. Morris GL, Mueller WM (1999) Vagus nerve stimulation study group E01-EO5: long-term treatment with vagus nerve stimualtion in patients with refractory epilepsy. Neurology 53:1731–1735CrossRefGoogle Scholar
  46. Morris GL III et al (2013) Evidence-based guideline update: vagus nerve stimulation for the treatment of epilepsy. Neurology 81(16):1453–1459CrossRefPubMedPubMedCentralGoogle Scholar
  47. Navas M et al (2010) Treatment of refractory epilepsy in adult patients with right-sided vagus nerve stimulation. Epilepsy Res 90:1–7CrossRefPubMedGoogle Scholar
  48. Oguni H et al (1994) Effect of anterior callosotomy on bilaterally synchronous spike and wave and other EEG discharges. Epilepsia 35(3):505–513CrossRefPubMedGoogle Scholar
  49. Orosz I et al (2014) Vagus nerve stimulation for drug-resistant epilepsy: a European long-term study up to 24 months in 347 children. Epilepsia 55:1576–1584CrossRefPubMedGoogle Scholar
  50. Palliative (2016) Def. 1. Merriam-Webster’s online dictionary. Retrieved 21 July 2016, from
  51. Park YD (2003) The effects of vagus nerve stimulation therapy on patients with intractable seizures and either landau-Kleffner syndrome or autism. Epilepsy Behav 4(3):286–290CrossRefPubMedGoogle Scholar
  52. Parker AP et al (1999) Vagal nerve stimulation in epileptic encephalopathies. Pediatrics 103:778–782CrossRefPubMedGoogle Scholar
  53. Penry JK, Dean JC (1990) Prevention of intractable partial seizures by intermittent vagal stimulation in humans: preliminary results. Epilepsia 31(2):S40–S43CrossRefPubMedGoogle Scholar
  54. Pinard JM et al (1999) Callosotomy for epilepsy after west syndrome. Epilepsia 40(12):1727–1734CrossRefPubMedGoogle Scholar
  55. Pitkӓnen A, Sutula TP (2002) Is epilepsy a progressive disorder? Prospects for new therapeutic approaches in temporal-lobe epilepsy. Lancet Neurol 1(3):173–181CrossRefGoogle Scholar
  56. Rathore C et al (2007) Outcome after corpus callosotomy in children with injurious drop attacks and severe mental retardation. Brain Dev 29(9):577–585CrossRefPubMedGoogle Scholar
  57. Rayport M, Ferguson SM, Corrie WS (1983) Outcomes and indications of corpus callosum section for intractable seizure control. Appl Neurophysiol 46(1–4):47–51PubMedGoogle Scholar
  58. Renfro JB, Wheless JB (2002) Earlier use of adjunctive vagus nerve stimulation for refractory epilepsy. Neurology 59(4):S26–S30CrossRefGoogle Scholar
  59. Rvylin P et al (2014) The long-term effect of vagus nere stimulation on quality of life in patients with pharmacoresistant focal epilepsy: the PuLsE (open prospective randomized long-term effectiveness) trial. Epilepsia 55:893–900CrossRefGoogle Scholar
  60. Saba S, Blum S (2014) Aphasia due to isolated infarction of the corpus callosum. Br Med J Case Rep.
  61. Saneto RP et al (2006) Vagus nerve stimulation for intractable seizures in children. Pediatr Neurol 35:323–326CrossRefPubMedGoogle Scholar
  62. Sass KJ et al (1990) Postcallosotomy language impairments in patients with crossed cerebral dominance. J Neurosurg 72:85–90CrossRefPubMedGoogle Scholar
  63. Shim KW et al (2008) Changing the paradigm of 1-stage total callosotomy for the treatment of pediatric generalized epilepsy. J Neurosurg Pediatr 2:29–36CrossRefPubMedGoogle Scholar
  64. Sorenson JM et al (1997) Corpus callosotomy for medically intractable seizures. Pediatr Neurosurg 27(5):260–267CrossRefPubMedGoogle Scholar
  65. Spencer SS et al (1988) Corpus callosotomy for epilepsy. I. Seizure effects. Neurology 38(1):19–24CrossRefPubMedGoogle Scholar
  66. Spencer SS et al (1993) Anterior, total, and two-stage corpus callosum section: differential and incremental seizure responses. Epilepsia 34(3):561–567CrossRefPubMedGoogle Scholar
  67. Tanriverdi T et al (2009) Long-term seizure outcome after corpus callosotomy: a retrospective analysis of 95 patients. J Neurosurg 110(2):332–342CrossRefPubMedGoogle Scholar
  68. Tatum WO et al (1999) Ventricular asystole during vagus nerve stimulation for epilepsy in humans. Neurology 52:1267–1269CrossRefPubMedGoogle Scholar
  69. The Vagus Nerve Stimulation Study Group (1995) A randomized controlled trial of chronic vagus nerve stimulation for treatment of medically intractabe seizures. Neurology 45:224–230CrossRefGoogle Scholar
  70. Utham BM, Wilder BJ, Penry JK et al (1993) Treatment of epilepsy by stimulation of the vagus nerve. Neurology 43:1338–1345CrossRefGoogle Scholar
  71. Uthman BM et al (2004) Effectiveness of vagus nerve stimulation in epilepsy patients: a 12-year observation. Neurology 63:1124–1126CrossRefPubMedGoogle Scholar
  72. Vale FL et al (2011) Long-term outcome of vagus nerve stimulation therapy after failed epilepsy surgery. Seizure 20:244–248CrossRefPubMedGoogle Scholar
  73. van Wagenen WP, Herren RY (1940) Surgical division of the commisural pathways in the corpus callosum. Relation to spread of an epileptic attack. Arch Neurol Psychiatr 44:740–759CrossRefGoogle Scholar
  74. Waxman SG (2003) Clinical neuroanatomy, 25th edn. McGraw-Hill, New YorkGoogle Scholar
  75. Wheless JW (2011) Chapter 70: vagus nerve stimulation therapy. In: Wyllie E (ed) Wyllie’s tratment of epilepsy: principles and practice, 5th edn. Lippincott Williams & Wilkins, PhiladelphiaGoogle Scholar
  76. Wilfong AA, Schultz RJ (2006) Vagus nerve stimulation for treatment of epilepsy in Rett syndrome. Dev Med Child Neurol 48(8):683–686CrossRefPubMedGoogle Scholar
  77. Wilson DH, Reeves A, Gazzaniga M (1978) Division of the corpus callosum for uncontrollable epilepsy. Neurology 28(7):649–653CrossRefPubMedGoogle Scholar
  78. Wong TT et al (2006) Corpus callosotomy in children. Childs Nerv Syst 22:999–1011CrossRefPubMedGoogle Scholar
  79. Wu JY et al (2006) Magnetic source imaging localizes epileptogenic zone in children with tuberous sclerosis complex. Neurology 66(8):1270–1272CrossRefPubMedGoogle Scholar
  80. Zabara J (1985a) Peripheral control of hypersynchronous discharge in epilepsy. Electroencephalogr Clin Neurophysiol 61:s162CrossRefGoogle Scholar
  81. Zabara J (1985b) Time course of seizure control to brief repetitive stimuli. Epilepsia 26:518Google Scholar
  82. Zabara J (1992) Inhibition of experimental seizures in canines by repetitive vagal stimulation. Epilepsia 33:1005–1012CrossRefPubMedGoogle Scholar
  83. Zanchetti A, Wang SC, Moruzzi G (1952) The effect of vagal afferent stimulation on the EEG pattern of the cat. Electroencephalogr Clin Neurophysiol 4:357–361CrossRefPubMedGoogle Scholar

Authors and Affiliations

  1. 1.Florida Hospital for ChildrenOrlandoUSA

Section editors and affiliations

  • James Thomas Rutka
    • 1
  1. 1.The Arthur and Sonia Labatt Brain Tumour Research CentreThe Hospital for Sick Children, The University of TorontoTorontoUSA

Personalised recommendations