Pediatric Epilepsy Surgery

Pediatric Epilepsy Surgery
Epilepsy surgery in children: Time is critical
Section I. PRESURGICAL EVALUATION IN CHILDREN
CHAPTER 1. The role and limits of seizure semiology
What can be determined from semiologyin children?
Age dependence of semiology
CHAPTER 2. The role and limits of surface EEG and source imaging
Surface EEG
General principles
Developmental substrates – Maturational issues
The epileptic generator
Technical issues
Practical “dos and don’ts” – Tips to avoid pitfalls
Source imaging
Background
Basic principles of source imaging
Localization of the epileptogenic zone in conjunction with other non-invasive neurophysiological and imaging modalities
Contribution to the decision making relevant to the indication for invasive monitoring
ESI/MSI: pros and cons
EEG-triggered fMRI
CHAPTER 3. The role and limits of structural and functional neuroimaging
Structural imaging in presurgical evaluation
Functional imaging to identify the epileptogenic zone
Mapping eloquent cortex
CHAPTER 4. The role and limitations of cognitive evaluation
Purposes of the presurgical neuropsychological evaluation
Domains included in the neuropsychological evaluation and guidelines for determining assessment tools within those domains
School-age children
Considerations for young (preschool) and children with intellectual disability
Intracarotid anaesthetic procedures in children
Language testing
Memory
Challenges for and limitations of the presurgical neuropsychological evaluation in children
Future directions
CHAPTER 5. The role and limits of behavioral and psychiatric evaluation
Overlap of epilepsy and psychiatric conditions
Neurologic pathways to psychiatric illness
Common psychiatric comorbidities
Attention deficit hyperactivity disorder (ADHD)
Anxiety and depression
Comorbidity in drug-resistant epilepsy
Surgery in neurology and psychiatry
Role of neurobehavioral evaluation
Elements of neurobehavioral evaluation
Risk and benefit analysis
Limits of neurobehavioral evaluation
Research directions for the future
CHAPTER 6. Intracranial EEG recordings and electrical stimulation
General indications
iEEG methods: subdural/depth, SEEG, ECoG
Subdural electrodes and combination of subdural/depth electrodes
Stereo-electro-encephalography (SEEG)
Intra-operative electro-corticography (ECoG)
Defining the epileptogenic zone (EZ): spontaneous and provoked
Ictal onset zone
Irritative, continuous epileptiform discharges, and functional deficit zones
Defining critical cortex: intra-operative and extra-operative
Extra-operative electrical stimulation
Intra-operative electrical stimulation
CHAPTER 7. Why is the epilepsy case conference important?
CHAPTER 8. Socio-economic aspects and epilepsy surgery in children
What is required?
Developing (“resource poor”) countries
Africa
South Asia
China
Middle East
Latin America
Developed (“resource equipped”) countries
Specific paediatric issues
Types of surgeries?
Solutions
Section II. SEMIOLOGY IN CHILDREN
CHAPTER 9. The temporal lobe: Semiology
Ictal signs of temporal lobe seizures
Behavioral change
Ictal emotional signs
Ictal motor signs
Autonomic symptoms
Age dependency of different peri-ictal signs
Etiology and seizure semiology
Lateralizing signs in childhood temporal lobe seizures
Interobserver agreement on childhood seizure semiology
Further pitfalls of TLE seizure semiology
“Temporal-like” seizure semiology in extratemporal epilepsies
TLE caused by extratemporal lesions
CHAPTER 10. The frontal lobe: Semiology
Frontal lobe functional anatomyrelevant to seizure semiology
Clinical patterns of frontal lobe ictal semiology
Tonic seizures
Versive seizures
Hypermotor seizures
Motor stereotypies
Autonomic seizures
Differential diagnosis and frontal lobe epilepsy syndromes
Do pediatric frontal lobe seizures and epilepsy differ from adults?
CHAPTER 11. The posterior cortex: Semiology
Semiology of seizures originating from the parietal lobe
Semiology of seizures originating from the occipital lobe
Particular findings in young children
Auras
Oculo-motor manifestations
Simple and complex motor behaviours
EEG features
CHAPTER 12. The insula: Semiology
Overview
Insular lobe semiology in children: is there any specificity?
Auras
Vegetative signs
Motor manifestations
Section III. ETIOLOGY AND EPILEPSY SURGERY
CHAPTER 13. Focal (isolated) cortical dysplasia Type I
Histological classification of FCD Type I – work in progress
Imaging in isolated FCD Type I
MRI in isolated FCD Type I
PET and SPECT in isolated FCD Type I
Seizures in FCD Type I
EEG in FCD Type I
Presurgical work-up and epilepsy surgery in FCD Type I
CHAPTER 14. Focal cortical dysplasia Type II
Histopathological and MR aspects of FCD type II
Histopathological aspects
Neuroradiological methodology and diagnosis
Clinical and neurophysiological aspects
Clinical data
EEG and video-EEG features
Invasive techniques and surgical outcome
Invasive monitoring: when and why
Surgery and outcome
CHAPTER 15. Other malformations of cortical development
Heterotopias
Subependymal (periventricular) nodular heterotopias
Subcortical nodular heterotopias
Subcortical band heterotopias
Polymicrogyria
CHAPTER 16. Tuberous sclerosis
Clinical presentation
Surgical referral and pre-operative assessment
Intracranial EEG recordings
Surgical approaches
Outcome
CHAPTER 17. Hemimegalencepahly and diffuse hemispheric malformations of cortical development
Specific epilepsy surgery indications
Recommended presurgical evaluation
Clinical considerations
Interictal and ictal video EEG
Available results
Seizures
Contra-lateral hemiplegia and homonymous lateral hemianopia
Suggested follow-up
CHAPTER 18. Benign tumors (WHO grades I and II)
Neuro-pathological classification of brain tumors WHO grade I and II frequently associated with epilepsy (so-called LEATs)
MRI in patients with epilepsy in association with brain tumors
Incidences, prevalences, frequencies in pediatric brain tumors
Brain tumors and epileptogenicity
Medical therapy/AEDs in children with epilepsy in association with brain tumors
Surgery in children with seizures associated with benign tumors
Tumor-surgery vs. epilepsy surgery and lesionectomy vs. tailored resection
Radiotherapy and chemotherapy in patients with epilepsy and benign supratentorial brain tumors (WHO grade I and II)
Surgery in patients with epilepsy in association with brain tumors WHO grade II and higher
CHAPTER 19. Vascular causes and perinatal hypoxic-ischemic events
Prenatal and perinatal lesions
Arterial ischemic strokes and porencephalic cysts in children
Venous stroke and cerebral sinovenous thrombosis
Intracranial hemorrhage and hemorrhagic stroke in term infants
Watershed lesions and ulegyria due to hypoxic ischemic events
Vascular lesions in preterm children
Seizure types and epilepsy syndromes in pre/perinatal vascular lesions
Presurgical evaluation in pre/perinatal vascular lesions
Surgery in pre- and perinatal vascular lesions and lesions caused by hypoxic ischemic events
Postoperative outcome
Epilepsy surgery in vascular lesions occurring in childhood
Cavernomas
Epidemiology
Seizures and epilepsy
Pathophysiology and neuroimaging
Surgical treatment and outcome
Hematological testing for neurosurgery
CHAPTER 20. Sturge-Weber syndrome
Clinical presentation
Diagnostic workup
Medical and surgical treatment
CHAPTER 21. Hypothalamic hamartoma
History
Epidemiology
Genetics
Anatomical aspects
Pathology and pathophysiology
Clinical-EEG features and natural history
Gelastic and dacrystic seizures
Other seizure types
Cognition and behaviour
Psychiatric symptoms
HH and epilepsy: which part of the brain is seizing?
Intrinsic epileptogenesis
Secondary epileptogenesis
The running-down phenomenon
Presurgical evaluation
Magnetic resonance (MR) imaging
Electroencephalography and video-EEG seizure monitoring
Neuropsychological or neurodevelopmental testing
Electrocorticography and invasive EEG monitoring
Treatment
Surgical treatment
Antiepileptic drugs
Vagus nerve stimulation
Ketogenic diet
Corpus callosotomy
Deep brain stimulation
CHAPTER 22. Cerebello-pontine hamartoma
Clinical presentation
Pathological and functional considerations
Surgical treatment and outcomes
Concluding remarks
CHAPTER 23. Epilepsies following cerebral infections
Epilepsy post-viral encephalitis
Epilepsy post-herpes simplex virus encephalitis
Epilepsy surgery in post-encephalitis epilepsy (PEE)
Epilepsies post-bacterial meningitis (EPBM)
Epilepsy surgery in epilepsies post-bacterial meningitis
Epilepsy in neurocysticercosis (NCC)
Epilepsy surgery for epilepsy due to NCC
Epilepsy surgery in rare post-infection epilepsy
CHAPTER 24. Rasmussen encephalitis
Historical perspective
Diagnosis
General comments
European Consensus criteria
Differential diagnosis
Ancillary studies
Pathology
Treatment
Medical treatment
Surgery
Outcomes
Seizure control
Sensori-motor function
Vision
Cognitive/developmental outcomes
Language function
Adaptive function
Educational outcomes
Mood/behavior/psychological
Quality of life
Outcomes in adulthood
Summary of outcomes
Timing of surgery
Post-surgical management
Directions for future research
CHAPTER 25. Post-traumatic epilepsy
Epidemiology
Prevalence and incidence
Risk factors
Pathophysiology
Treatment
Medical
Surgical
CHAPTER 26. Mesial temporal lobe epilepsy in children
Pathological substrates of pediatric temporal lobe epilepsy
Risk factors for pediatric temporal lobe epilepsy
Role of dual pathology in pediatric temporal lobe epilepsy
Clinical manifestations of temporal lobe epilepsy in children
EEG features of pediatric temporal lobe epilepsy
Surgical outcome in children with hipocampal sclerosis and dual pathology
Timing of surgeries in relation to neuropsychological outcome
Surgical technique
Outcome regarding seizures
CHAPTER 27. Epilepsy surgery in MRI-negative patients
MRI-negative focal epilepsy
Difference between MRI-negative and non-lesional epilepsy
Factors influencing MRI diagnosis
Influence of the MRI technique and timing of evaluation
Unspecific and subtle MRI abnormalities
Definition of MRI-negativity
Selection of surgical candidates
Presurgical diagnostic work-up
3D-MEG/EEG source analysis
PET and SPECT
Multimodal non-invasive diagnostic work-up
Invasive EEG
Functional considerations
Outcome after MRI-negative epilepsy surgery
CHAPTER 28. Landau-Kleffner syndrome
Background, clinical presentation and differential diagnosis
Multiple subpial transections of the dorsal surface of the temporal gyrus into the sylvian fissure
Recommended presurgical evaluation
Methohexitol suppression test (MHXT)
Electrical intracarotid amobarbital test
Magnetoencephalography (MEG)
Available results
Specific follow-up
New ideas about aetiology
Section IV. SURGICAL TECHNIQUES FOR THE NEUROLOGIST
CHAPTER 29. Lesionectomy
Patient selection
General principles
Anesthesia protocol
Image guidance
Skin/bone/dura
Delineation of the lesion
Hemostasis/closure
Safety
Deep seated lesion
Eloquent areas
Complete resection boundaries
Lesion-specific considerations
Anatomic or electrophysiological limits?
Mesial temporal lobe lesions
Respect of the non-epileptic brain
Future of lesionectomy?
CHAPTER 30. Surgery for temporal lobe epilepsy
Historical background of surgical treatment
Planning resection
General surgical remarks
Considerations in tumors associated with drug-resistant epilepsy
Resection strategies
Surgical steps for standard anterior temporal lobectomy
Surgical steps for combined temporal pole and mesial resection
Surgical steps for transsylvian selective amygdalo-hippocampectomy
Surgical steps for transcortical selective amygdalo-hippocampectomy
Surgical steps for subtemporal selective amygdalo-hippocampectomy
Surgical steps for extended lesionectomy
Results
Histopathological findings
Seizure outcome
Developmental and cognitive outcome
Operative complications
CHAPTER 31. Extratemporal localization and eloquent areas
Presurgical evaluation
Neurophysiology
MEG
Neuroimaging
Surgery
Surgical decision-making
Anesthetic considerations
Neuronavigation and intra-operative MRI
Surgical technique: resection/disconnection
Cortical resections
Disconnections
Multiple subpial transections
Intra-operative monitoring
Thermal ablation
Outcomes
Functional and developmental outcome
Complications
Pathology
CHAPTER 32. Corpus callosotomy: Surgical techniques
Surgical history
Specific technical aspects, open surgery
Pitfalls
Results and outcome
Complication considerations
Considerations and caveats before performing the callosotomy
CHAPTER 33. Hemispherotomy and multilobar surgery
Historical background: from hemispherectomy to hemispherotomy
Description of the surgical procedures of hemispherotomy
Advantages and disadvantages of horizontal and vertical hemispherotomies
Multilobar disconnection and resection
Posterior disconnection
Other multilobar surgeries
Surgical planning
Perioperative management
Outcome
Seizure outcome
Developmental outcome
Repeated surgery
Complications
CHAPTER 34. Surgical procedures for hypothalamic hamartomas
The “classical” neurosurgical approaches
Recent alternative surgical techniques
The transcallosal anterior interforniceal approach
The endoscopic approach
Stereotactic thermoablation
Gamma Knife Radiosurgery
Interstitial radiosurgery
Other surgical approaches
CHAPTER 35. Minimally invasive epilepsy surgery
Principles and technological foundations of minimally invasive epilepsy surgery
Modifications of standard epilepsy procedures using smaller and “keyhole” craniotomies
Minimally invasive approaches to temporal lobe epilepsy surgery
Minimally invasive approaches to hemispherectomy and other functional hemispherectomy variants of anatomical hemispherectomy
Endoscopic epilepsy surgery
Endovascular epilepsy surgery
The future of minimally invasive epilepsy surgery
CHAPTER 36. Pediatric epilepsy surgery techniques: a worldwide survey
General issues
Medical intraoperative management
Skin preparation, opening and hemostasis
Closure
Postoperative imaging
Anesthetic agents
Temporal lobe resections
Callosal section
Hemispheric surgery
Temporal lobe tumors
Cavernoma
Complications
Neurosurgical pediatric epilepsy surgery training
CHAPTER 37. Technical aspects of invasive monitoring
Localizing the epileptogenic zone
Localization of the functional/eloquent zone
The subdural method
Indications, advantages and disadvantages of subdurals
Implantation technique of subdural grids alone or in combination with depth electrodes
The stereo-electroencephalography (SEEG) method
Indications, advantages and disadvantages of SEEG
Technique of SEEG implantation
Invasive monitoring morbidity
Section V. PALLIATIVE EPILEPSY SURGERY
CHAPTER 38. Corpus callosotomy: Indications and results
Corpus callosotomy and seizure generalization
Pre-operative evaluation and indications
Lennox-Gastaut syndrome and callosotomy
Other senarios for callosotomy
Cognitive, behavioral, psychosocial, and quality of life outcomes
Consequences of callosotomy
CHAPTER 39. Vagus nerve stimulation
VNS efficacy
Quality of life
Safety
CHAPTER 40. Deep brain stimulation
History of deep brain stimulation in epilepsy
Overview of the different stimulation targets
Epileptogenic network targets
Ictal onset zone DBS
Closed-loop DBS
Deep brain stimulation in children
Section VI. FOLLOWING SURGERY
CHAPTER 41. Long-term follow-up and transition to adult life
Acute post-surgical care
Common issues
Action plan
Intermediate care
Common issues
Action plan
Long term follow-up and transition to adult life
Common issues
Action items
CHAPTER 42. Surgical failure, early recurrence and re-operation
Surgical failure
Reasons for failure: incomplete resection of the epileptogenic zone
Incomplete pre-operative data
Co-localization of eloquent and epileptogenic cortex
Non-contiguous epileptogenic zones
Insufficient intracranial electrode coverage
Surgical inaccessability
Emergence of a new epileptogenic focus
Re-operation
CHAPTER 43. Postoperative imaging
Structural imaging modalities in the immediate and late postoperative period
Expected and unexpected brain imaging findings in the immediate postoperative period
Imaging and localization of implanted depth and subdural electrodes for invasive monitoring
Brain imaging as a research tool in the postoperative epilepsy patient
MRI safety of implanted neuromodulatory devices for epilepsy
CHAPTER 44. Time to stop antiepileptic drugs
Why should we consider reducing AEDs?
What are the risks of reducing AEDs?
Do we know if postoperative AED reduction increases relapse risk?
What are the consequences of a seizure relapse following AED reduction?
In whom should we consider AED withdrawal?
When can we start to reduce AEDs?
Current practice and opinions
Is early postoperative withdrawal unsafe?
CHAPTER 45. Cognition, language, and memory outcomes
Temporal lobe resection
Frontal lobe resection
Parietal or occipital lobe resection
Multilobar resection (excluding hemidisconnections)
Hemispheric resection
Age at surgery
Long-term follow-up
CHAPTER 46. Psychosocial outcomes following seizure surgery
Adult reports of psychosocial outcome
Behavior and emotion
Social competence
Quality of life, family, and satisfaction with outcome
CHAPTER 47. Comprehensive evaluation of outcomes
What is needed to report outcome?
Seizure outcome
Complications/unexpected events
Neurocognitive and psychiatric outcome
Psychosocial/quality of life
Section VII. FUTURE PERSPECTIVES
CHAPTER 48. A comprehensive epilepsy surgery program for children: State-of-the-art and future perspectives
Specificities of childhood epilepsies
The surgical treatment gap
Candidates for a presurgical evaluation or a patient eligible for surgery: On what do they differ
Professional expertise
Which presurgical evaluation strategy and for whom
Minimal requirements
Video-EEG recording of seizures
Other investigation tools
Invasive VEEG monitoring
Postoperative long-term follow-up facilities
Future challenges and perspectives