Transcript Mesial temporal lobe epilepsy

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 angle
2001 – 2010:
• first seizure was on POD 0
• on medication, she has weekly episodes of strange noise and taste in
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.
her
Patient JA (cont)
PMH/PSH:
Allergies:
Outpatient meds:
FH:
SH:
ROS:
C-section 2004
phenytoin
topiramate 200mg BID, levetiracetam 1000mg BID
No history of CNS tumors, seizure disorder.
Seven-month old daughter. Daily marijuana, no other drug use.
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)
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
Pre-op MRI: Coronal
FLAIR
T1 post-gad
•
Hyperintensity on FLAIR of right inferior temporal lobe
•
Non-enhancing right pontine lesion
Operative plan
1. Resection for epileptic focus:
Right anterior temporal lobectomy
2. Microscopic dissection of epidermoid
1. Resection of epileptic focus
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
Netter
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
Dr. Nahed/Dr. Eskandar
2a. Initial resection of epidermoid
• Approach through
medial aspect of
temporal lobe
A
P
• Gross: encountered
pearly white mass
• Path: stratified
squamous epithelium,
keratin, cholesterol
• Rad: T1 dark, T2 bright,
typically no enhancement
Dr. Nahed/Dr. Eskandar
2b. Dissection to anterior pons
• Approach through
medial aspect of
temporal lobe
A
P
• Gross: encountered
pearly white mass
• Path: stratified
squamous epithelium,
keratin, cholesterol
• Rad: T1 dark, T2 bright,
typically no enhancement
Dr. Nahed/Dr. Eskandar
2c. Resection of tumor off basilar artery
• Approach through
medial aspect of
temporal lobe
A
P
• Gross: encountered
pearly white mass
• Path: stratified
squamous epithelium,
keratin, cholesterol
• Rad: T1 dark, T2 bright,
typically no enhancement
Dr. Nahed/Dr. Eskandar
Post-operative course
• Maintained on home doses of topiramate and levetiracetam
• Interval development of superior quadrantanopsia
Pre-op
Post-op
Temporal lobe epilepsy
1. Background
2. Choosing a surgical approach
Background: Temporal lobe epilepsy
•
•
•
20-40% of epilepsy patients have medically refractory epilepsy
(400,000 patients in the U.S.)
Etiologies:
1. Mesial temporal sclerosis
2. Infections: Systemic, CNS
3. Vascular: AVMs, cavernomas
4. Neoplasia
5. Congenital: cortical dysplasias
6. Traumatic: TBI, post-operative
7. 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
Up To Date 2010.
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.
Choosing the surgical approach
Outcomes:
Seizure frequency
Neuropsychological outcomes
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.
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.
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.
3.
Three RCTs of surgical approaches:
Transsylvian vs transcortical 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.
Three RCTs of surgical approaches
First author Journal / Year
Pts
Wyler
Neurosurgery
1995
70
Hermann
Epilepsia
1999
30
Lutz
Epilepsia
2004
•
•
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Operation
ATL + full or
partial hippocampect.
80
Outcomes
69% vs 38% seizure-free at 1 yr
No difference in memory
Left ATL
+ / - STG resection
60% vs 55% seizure-free (N.S.)
No change in naming
transcortical vs
transsylvian AH
75% seizure-free at 7 months
(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 planning
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
Neocortical temporal lobe epilepsy (NTLE)
• Rarer
• “Lateral auras” – auditory, visual, somatosensory
• Usually structural : post-trauma, tumor, vascular malformation
Pre-op assessment
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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.
“Quest for optimal resection”
• Controversial
• Few randomized trials
• Variety of methods
Schramm. Epilepsia 2008.
Pre-op EEG/MEG
Papaniculaou et al.
J Neurosurg 1999.
•
Left-dominant language center
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Right >> left temporal interictal
epileptiform discharges
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Discharges correlate to T2 signal
abnormalities in right temporal lobe