Patient JA: Surgery for temporal lobe epilepsy
Andrew Venteicher
Visiting sub-intern
Stanford University
July 2010
Patient JA
ID/CC: 24yo right-handed F with medically refractory epilepsy
HPI: 2001: right temporal craniotomy for partial resection of epidermoid cyst of CP
angle2001 – 2010:• first seizure was on POD 0• on medication, she has weekly episodes of strange noise and taste in
her mouth followed by LOC, vocalizations, repetitive oral movements, and convulsive activity.
• incomplete seizure control on trials of oxcarbazepine, lamotrigene.• embarrassing post-ictal behavior, afraid to leave her house.• on disability for epilepsy.
Patient JA (cont)
PMH/PSH: C-section 2004Allergies: phenytoinOutpatient meds: topiramate 200mg BID, levetiracetam 1000mg BIDFH: No history of CNS tumors, seizure disorder.SH: Seven-month old daughter. Daily marijuana, no other drug use.ROS: Poor memory, depressed mood.
Exam: Memory: 2/3 at five minutesUnable to perform simple arithmetic (may be secondary to effort)
Otherwise neurologically intact (CN, motor, sensory, cerebellar, reflexes)
Pre-op MRI: Axial
T2
• T2 hyperintensity of right inferior and middle temporal gyri, correlated well with epileptiform discharges on EEG/MEG
• Progression of incompletely resected epidermoidof right cerebellopontine angle, relative to MRIs at outside hospital
Pre-op MRI: Coronal
FLAIR
• Hyperintensity on FLAIR of right inferior temporal lobe
• Non-enhancing right pontine lesion
T1 post-gad
Operative plan
1. Resection for epileptic focus:
Right anterior temporal lobectomy
2. Microscopic dissection of epidermoid
1. Resection of epileptic focusNeocortical structures• Corticoectomy of middle temporal gyrus
• Extended inferiorly to middle fossa floor
• Extended anteriorly to temporal tip
• Removed anterior 2cm of superior temporal lobe
Mesiotemporal structures• Entered temporal horn of lateral ventricle to access hippocampus
• Interoperative corticography: eight-lead electrode recorded frequent spikes from anterior hippocampus
• Anterior hippocampus and amygdala resected
• Entered medial pia to access ambient cistern
Netter
Dr. Nahed/Dr. Eskandar
2a. Initial resection of epidermoid
• Approach through medial aspect of temporal lobe
• Gross: encountered pearly white mass
• Path: stratified squamous epithelium, keratin, cholesterol
• Rad: T1 dark, T2 bright, typically no enhancement
A P
Dr. Nahed/Dr. Eskandar
2b. Dissection to anterior pons
• Approach through medial aspect of temporal lobe
• Gross: encountered pearly white mass
• Path: stratified squamous epithelium, keratin, cholesterol
• Rad: T1 dark, T2 bright, typically no enhancement
A P
Dr. Nahed/Dr. Eskandar
2c. Resection of tumor off basilar artery
• Approach through medial aspect of temporal lobe
• Gross: encountered pearly white mass
• Path: stratified squamous epithelium, keratin, cholesterol
• Rad: T1 dark, T2 bright, typically no enhancement
A PA P
Dr. Nahed/Dr. Eskandar
Post-operative course
• Maintained on home doses of topiramate and levetiracetam• Interval development of superior quadrantanopsia
Pre-op Post-op
Background: Temporal lobe epilepsy
• 20-40% of epilepsy patients have medically refractory epilepsy(400,000 patients in the U.S.)
• Etiologies:1. Mesial temporal sclerosis2. Infections: Systemic, CNS3. Vascular: AVMs, cavernomas4. Neoplasia5. Congenital: cortical dysplasias6. Traumatic: TBI, post-operative7. Genetics
• Familial lateral temporal lobe epilepsy with auditory features (AD)
• Familial mesial temporal lobe epilepsy (usually AD)• Indications for surgery: medically refractory, negatively
impacts patient’s quality of lifeUp To Date 2010.
Background: Surgery for temporal lobe epilepsy
Wiebe et al. NEJM 2001.
- 80 patients randomized- median of 5 seizures/month- complications: 55% surgical
group developed VF defect (rare memory deficit, infarct, infection)
Choosing the surgical approach
Outcomes:Seizure frequencyNeuropsychological outcomes
Approaches:Anterior temporal lobectomyATL with sparing of superior temporal gyrusSelective amygdalo-hippocampectomy
Controversial:Variety of approachesLack of randomized trials
Schramm. Epilepsia 2008.
Three RCTs of surgical approaches:1. ATL with partial or full hippocampectomy
Wyler et al. Neurosurgery 1995.
Patients: 70.
Subjects: age 18-40 , complex partial seizures, originate from medial temporal lobe (EEG), IQ > 69, no foreign lesions
Operation: ATL of 4.5cm (superior, middle, and inferior), with either partial or full hippocampectomy
Results: - At one year, 69% (total) versus 38% (partial) were seizure-free after surgery- At 6 months, no difference in several memory tests
Three RCTs of surgical approaches:2. Left ATL +/- sparing of superior temporal gyrus
Hermann et al. Epilepsia 1999.
Patients: 28.
Subjects: complex partial seizures, originate from left temporal lobe (EEG), left dominant (WADA), IQ > 69,no foreign lesions
Operation: ATL of 4-4.5cm of middle/inferior temporal lobe +/- STG, with full hippocampectomy
Results: - At 6-8 months, no difference in proportion seizure-free (60% vs 55%)- At 6-8 months, no difference in change in visual naming ability
Three RCTs of surgical approaches:3. Transsylvian vs transcortical approach for SAH
Lutz et al. Epilepsia 2004.
Patients: 80.
Subjects: diagnosis of hippocampal sclerosis, age > 16, IQ > 69, not left-handed
Operation: transsylvian – pterional crani then through lateral ventricle
transcortical – crani centered on MTG
Results: - Variety of tests: memory, attention, and executive function- 73% vs 77% were seizure -free at 7 months (NS)- word fluency improved only in pts with transcortical approach (no other differences in many other tests)
Transsylvian - UC Irvine website
Three RCTs of surgical approaches
Wyler Neurosurgery 70 ATL + full or 69% vs 38% seizure-free at 1 yr1995 partial hippocampect. No difference in memory
First author Journal / Year Pts Operation Outcomes
Hermann Epilepsia 30 Left ATL 60% vs 55% seizure-free (N.S.)1999 + / - STG resection No change in naming
Lutz Epilepsia 80 transcortical vs 75% seizure-free at 7 months2004 transsylvian AH (no difference)
Slight difference in neuropsych
• Tailor to experience of surgeon/institution• Tailor to patient’s pre-op localization studies• More RCTs may be helpful, incorporating
QOL/neuropsychologic outcomes
Thank you
Pre-operative planningMesial temporal lobe epilepsy (MTLE)
Up To Date 2010.Berg. Curr Op Neurol 2008.Bender. J Neurosurg 2009.
• Most common indication for epilepsy surgery• “Mesial auras” – rising epigastrium, olfactory/gustatory, and fear • MRI: volume loss and T2/FLAIR hyperintensity in hippocampus
Neocortical temporal lobe epilepsy (NTLE)
• Rarer • “Lateral auras” – auditory, visual, somatosensory• Usually structural : post-trauma, tumor, vascular malformation
Pre-op assessment
• Interdisiplinary team• MRI w/ and w/o contrast• EEG, MEG, video-EEG• Neuropsychological testing
“Quest for optimal resection”
Schramm. Epilepsia 2008.
• Controversial
• Few randomized trials
• Variety of methods