Patient JA: Surgery for temporal lobe epilepsy

1. Patient JA: Surgery for temporal lobe epilepsy Andrew Venteicher Visiting sub-intern Stanford University July 2010

2. Patient JA • HPI: • 2001: right temporal craniotomy for partial resection of epidermoid cyst of CP angle • 2001 – 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. ID/CC: 24yo right-handed F with medically refractory epilepsy

3. PMH/PSH: C-section 2004 Allergies: phenytoin Outpatient meds: topiramate 200mg BID, levetiracetam 1000mg BID FH: 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 minutes Unable to perform simple arithmetic (may be secondary to effort) Otherwise neurologically intact (CN, motor, sensory, cerebellar, reflexes) Patient JA (cont)

4. 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 epidermoid • of right cerebellopontine angle, relative to MRIs at outside • hospital

5. Pre-op MRI: Coronal FLAIR T1 post-gad • Hyperintensity on FLAIR of right inferior temporal lobe • Non-enhancing right pontine lesion

6. Operative plan Resection for epileptic focus: Right anterior temporal lobectomy 2. Microscopic dissection of epidermoid

7. Neocortical 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 1. Resection of epileptic focus Netter Dr. Nahed/Dr. Eskandar

8. 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 2a. Initial resection of epidermoid A P Dr. Nahed/Dr. Eskandar

9. 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 2b. Dissection to anterior pons A P Dr. Nahed/Dr. Eskandar

10. 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 2c. Resection of tumor off basilar artery A P A P Dr. Nahed/Dr. Eskandar

11. Maintained on home doses of topiramate and levetiracetam • Interval development of superior quadrantanopsia Post-operative course Pre-op Post-op

12. Temporal lobe epilepsy • Background • Choosing a surgical approach

13. 20-40% of epilepsy patients have medically refractory epilepsy • (400,000 patients in the U.S.) • Etiologies: • Mesial temporal sclerosis • Infections: Systemic, CNS • Vascular: AVMs, cavernomas • Neoplasia • Congenital: cortical dysplasias • Traumatic: TBI, post-operative • 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 life Background: Temporal lobe epilepsy Up To Date 2010.

14. Background: Surgery for temporal lobe epilepsy - 80 patients randomized - median of 5 seizures/month - complications: 55% surgical group developed VF defect (rare memory deficit, infarct, infection) Wiebe et al. NEJM 2001.

15. Outcomes: Seizure frequency Neuropsychological outcomes Choosing the surgical approach Approaches: Anterior temporal lobectomy ATL with sparing of superior temporal gyrus Selective amygdalo-hippocampectomy Controversial: Variety of approaches Lack of randomized trials Schramm. Epilepsia 2008.

16. Three RCTs of surgical approaches: 1. ATL with partial or full hippocampectomy 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 Wyler et al. Neurosurgery 1995.

17. Three RCTs of surgical approaches: 2. Left ATL +/- sparing of superior temporal gyrus 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 Hermann et al. Epilepsia 1999.

18. Three RCTs of surgical approaches: • Transsylvianvstranscortical approach for SAH Transsylvian - UC Irvine website 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) Lutz et al. Epilepsia 2004.

19. First author Journal / Year Pts Operation Outcomes Wyler Neurosurgery 70 ATL + full or 69% vs 38% seizure-free at 1 yr 1995 partial hippocampect. No difference in memory Three RCTs of surgical approaches 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 months 2004 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

20. Thank you

21. Mesial temporal lobe epilepsy (MTLE) • Most common indication for epilepsy surgery • “Mesial auras” – rising epigastrium, olfactory/gustatory, and fear • MRI: volume loss and T2/FLAIR hyperintensity in hippocampus Pre-operative planning 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 Up To Date 2010. Berg. Curr Op Neurol 2008. Bender. J Neurosurg 2009.

22. “Quest for optimal resection” • Controversial • Few randomized trials • Variety of methods Schramm. Epilepsia 2008.

23. Pre-op EEG/MEG • Left-dominant language center • Right >> left temporal interictal • epileptiform discharges • Discharges correlate to T2 signal abnormalities in right temporal lobe Papaniculaou et al. J Neurosurg 1999.