S-Slide 1 Epilepsy Surgery American Epilepsy Society Slide 2
S-Slide 2 Candidates for Epilepsy Surgery Persistent seizures
despite appropriate pharmacological treatment (usually at least two
drugs at limits of tolerability) Impairment of quality of life due
to ongoing seizures Slide 3 S-Slide 3 Presurgical Evaluation
History and exam MRI scan Mesial Temporal Sclerosis (MTS), tumor,
vascular malformation, dysplasia Video/EEG monitoring with scalp
EEG interictal epileptiform discharges ictal Seizure semiology
Ictal EEG discharge Additional electrodes Slide 4 S-Slide 4
Presurgical Evaluation Figure 1a Right hippocampal sclerosis
(arrow) sclerosis (arrow) Slide 5 S-Slide 5 Presurgical Evaluation
Figure 1b Figure 1c Left mesial temporal sclerosis Slide 6 S-Slide
6 Presurgical Evaluation Functional Imaging PET hypometabolism
interictally SPECT hypoperfusion interictally hyperperfusion
ictally subtraction and co-registration with MRI Slide 7 S-Slide 7
Presurgical Evaluation SISCOM Result in a patient with
extratemporal epilepsy with extratemporal epilepsy Slide 8 S-Slide
8 Presurgical Evaluation Neuropsychological testing Pre-operative
baseline Aid in localization Predicting risk of cognitive decline
with surgery Wada (intracarotid amobarbital) test language
lateralization Memory prediction of postoperative decline Slide 9
S-Slide 9 Presurgical Evaluation Intracranial EEG when needed Grids
and strips, most commonly subdural Parenchymal depth electrodes,
especially for recording from hipppocampus Identification of ictal
onset Brain mapping cortical stimulation SSEPs Functional MRI Slide
10 S-Slide 10 Types of Surgical Procedures Resective Surgery:
single seizure focus in non-eloquent region. Palliative Surgery:
For drop attacks: corpus callosotomy For Rasmussens encephalitis or
hemimegalencephaly: hemispherectomy Slide 11 S-Slide 11 Surgical
Treatment of Epilepsy Modified from McKhann G.M. and Howard M.A.:
Epilepsy Surgery: Disease Treatment and Investigative Opportunity,
in Diseases of the Nervous System: Clinical Neurobiology, 2002.
CurativePalliative Pathologies Pathologies MTS TLENon-MTS TLE MTS
TLENon-MTS TLE LesionalFrontal Lobe epilepsy LesionalFrontal Lobe
epilepsy - Low Grade GliomaSMA/cingulate epilepsy - Low Grade
GliomaSMA/cingulate epilepsy - Cav. MalformationMalformations of
cortical development - Cav. MalformationMalformations of cortical
development Procedures Procedures Lesionectomy Hemispherectomy
Disconnection Lesionectomy Hemispherectomy Disconnection Lobectomy
Topectomy (Callosotomy) Lobectomy Topectomy (Callosotomy) MSTs MSTs
Figure 2 Slide 12 S-Slide 12 Surgical Treatment of Epilepsy MRI
frameless stereotactic localization of focal cortical dysplasia at
the base of the central sulcus (center of cross hairs). Slide 13
S-Slide 13 Surgical Treatment of Epilepsy Functional
hemispherectomy: extent of cortical resections in temporal and
central cortex with disconnection of residual frontal and occipital
cortex by transecting white matter fibers (not shown). Slide 14
S-Slide 14 Vagus Nerve Stimulation The vagus nerve stimulator
(courtesy of Cyberonics Inc.) Reprinted with permission. Slide 15
S-Slide 15 Vagus Nerve Stimulation Percentage Change All Seizures
VNS Study Group, 1995 Handforth, et al., 1998 Results of two
randomized, controlled trials in medically refractory partial
seizures. Slide 16 S-Slide 16 Vagus Nerve Stimulation Responder
Rates VNS Study Group, 1995 Handforth, et al., 1998 Responder rates
from the randomized controlled trials Slide 17 S-Slide 17
Metaanalysis of AEDs and VNS Efficacy Marson et al (1997) Slide 18
S-Slide 18 Epilepsy and Head Injury 5% of all epilepsy may be
attributed to head injury. Most patients with early seizures after
head injury do not develop epilepsy. With loss of consciousness: 2%
develop epilepsy With hospitalization: 7-15% develop epilepsy Slide
19 S-Slide 19 Epilepsy and Head Injury Risks to developing
epilepsy: penetrating injury (up to 50%), early seizures,
hemorrhage, low score in G.C.S., cortical lesion, volume lost,
depressed fx, metal fragments, loss of consciousness. 60% of
epilepsy occurs in within 1 yr., 80% in 2 yrs, 88% by 10 yrs.
Yablon, Arch Phys Med Rehab 1993. Willmore, Epilepsy: A
Comprehensive Text 1997. Slide 20 S-Slide 20 Epilepsy and Head
Injury Mayo clinic study: Severe injury (contusion, hematoma, focal
deficit, 24 hr. of amnesia or LOC): 11.5% epilepsy (in 5 yr.)
Moderate injury (fracture, > 30 min LOC, amnesia): 1.6% Milder
injury: no increased risk. Severe injury and early seizure: 36%
Annegers., Neurology, 1980. Slide 21 S-Slide 21 Head Injury and
Prophylactic AEDs 404 pts, severe head injury with cortical damage
randomized in < 24 hr: DPH vs. placebo. Seizures in one week:
placebo 14%, phenytoin 4% Once late seizure occurs, 86% recurrence.
Recommend: Use prophylactic AED for 1-2 weeks after severe head
trauma, then stop. If late seizures occur, treat with AED. Temkin,
NEJM 1990.
