Surgical Management Of Medically Intractable Temporal Lobe
Epilepsy By Amr Farid Lecturer Of Neurosurgery Mansoura
University
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Why we should help? Quality of life Physical injury
Neuropsychological functions impairment Psychiatric problems Sudden
unexpected death in epilepsy Complications of AEDs (Inexperienced
prescriptions)
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Seizure classification: 1. Partial seizures A) Simple partial
seizure Motor Sensory Autonomic Psychic B) Complex partial With
simple partial onset Without simple partial onset, altered
awareness / memory from the onset C) Partial seizures (simple or
complex) evolving to secondary generalization Introduction
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2. Primary generalized (convulsive or nonconvulsive) A)Absence
seizures. B)Myoclonic seizure C)Clonic, tonic and tonic-clonic
seizures D)Atonic seizures 3. Unclassified seizures 4. Prolonged or
repetitive seizures (status epilepticus) Introduction
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Mesial and Neocortical Temporal Epilepsy Clinical Features MTLE
1.Warning symptoms localized to the epigastrium,throught, or chest
with or without fear. 2.Initial motionless staring 3.oro-alimentary
masticatory or swallowing automatisms with or without repetitive
manual automatism 4.Seizures are significantly longer in duration
(> 1 minute). 5.Ipsilateral automatisms followed by
contralateral dystonic posturing. NTLE 1.A phenomenon of dreamy
state with memory of past scenes (dj vu ) 2. Auditory
hallucinations 3. Early contralateral dystonic posturing. 4. Rapid
spread to suprasylvian area produce versive and colonic motor
movement of head,eye and face. Introduction
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Localization of Partial Seizure Focus 70% 10% 20% Introduction
This is the most common type of adult-onset epilepsy. Causes such
as hippocampal sclerosis, low- grade tumors and cortical
dysplasias, vascular malformation
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Pre-operative Assessment Electro physiologically
Electroencephalography (EEG) Continuous Video EEG Value OF EEG
Diagnostic tool Spikes, poly spike Sharp wave Sharp and slow waves
complexes. Introduction
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Limitations of EEG: Normal EEG findings do not exclude
epilepsy. The initial EEG may show normal results in 50% of cases.
Increasing the duration of recording. Deep focus. Artifact
Introduction
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Electrode Placement (A) Non invasive electrodes 1- Scalp
Electrodes: Standard 10-20 system. 2- Zygomatic and Periorbital
Electrodes: (Anterior temporal foci) Introduction
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The international 10-20 electrode system
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(B) Semi-invasive Electrodes Nasopharyngeal Electrodes: mesial
temporal and orbitofrontal foci. Sphenoidal Electrodes: for long
term,with less artifacts. Foramen Ovale Electrodes: mesiobasal
temporal lobe epilepsy. Tympanic Electrodes: middle or posterior
basal temporal regions Introduction
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(C) Invasive Electrodes Epidural Electrodes Subdural Strip and
Grid Electrodes Implanted Intracerebral Electrodes (Depth
Electrodes) Introduction Seizures are lateralized but not localized
(eg, a left-sided). Seizures are localized but not lateralized (eg,
both temporal lobes). Seizures are neither localized nor
lateralized (eg. diffuse ictal). Seizure localization is discordant
with other data Intraoperative, ECoG
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Partial Onset Seizure Left TLE Generalized Onset Seizure
Introduction
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Origin Of EEG abnormality
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Introduction Neuroradiology Functional Magnetic Resonance
Imaging (fMRI): PET and SPECT imaging especially has shown both
increased glucose metabolism and blood flow respectively in the
epileptic cortex, which is depressed in the post-ictal and
interictal states. MRS is a newer tool that demonstrates regional
metabolic alteration in epileptogenic tissue.
Magnetoencephalography: Measurement of extracranial magnetic
fields
MRI features of HS Introduction Primary signs Atrophic
unilateral hippocampus. Hyperintensity on both T2 W and FLAIR
images Loss of the hippocampal internal architecture and that of
normal digitations of the head. Secondary signs Unilateral atrophy
of the mamillary body, fornix,amygdala. Increased T2 W signal in
ant. temporal white matter with loss of grey-white demarcation in
the ipsilateral anterior temporal lobe. Unilateral dilatation of
the temp. horn.
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Functional and Morphologic Data Fusion for Epileptogenic Foci
Localisation MRI +SPECT (Lt TLE)MRI-PET fusion image (Lt TLE)
Introduction
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Scheme for preoperative evaluation in TLE Introduction
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Surgical Treatment of TLE General Surgical procedures:
Resection techniques is simple excision of the structural lesion
Disconnection techniques (hippocampal transection ) Augmentation
techniques ( vagal stimulation). Gamma knife radiosurgery
Stereotactic radiofrequency ablation techniques.
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Epileptic Zones Introduction
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Temporal Lobectomy: Temporal lobe resection produces a seizure-
free state in 60% to 80 % of patients: Anterior temporal lobectomy
(ATL) is the most common surgical procedure performed in
adolescents and adults. Selective Amygdalohippocampectomy for
patients with MTLE
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Temporal Lobectomy: A) Anterior temporal lobectomy with
amygdalo- hippocampectomy Introduction
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B) Selective Approaches to The Mesial Temporal Area
Introduction
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Trans-sylvian approach Introduction
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Meyers loop Introduction Risk for superior quadrant hemianopsia
50 100% after standard temporal lobectomy up to 50% after
trans-sylvian selective amygdalohippocampectomy
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Introduction
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This study is to compare: seizure and neuropsychological
outcomes after: seizure and neuropsychological outcomes after:
Anterior temporal lobe resection plus amygdalo-hippocampectomy (AH)
versus selective amygdalo- hippocampectomy (AH) through trans
sylvian approach In the treatment of medically intractable temporal
lobe epilepsy
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This study was conducted on 24 patients with medically
intractable Temporal Lobe Epilepsy at Tohoku University Hospital.
Patients & Methods
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Inclusion criteria Medically intractable epilepsy due to
identified temporal lobe focus. Lesions may be intra or extra axial
within the anatomical confines of the temporal lobe. Both of
neocortical and mesial temporal lobe. Exclusion criteria Patients
unfit for surgery. Presence of multiple brain lesions. Pure
extratemporal epileptogenic zone. Patients & Methods
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(a)Presurgical evaluation Drug resistant epilepsy : failure of
two tolerated, appropriately chosen (whether as monotherapies or in
combination) to achieve sustained seizure freedom over period of
two years. Detailed history :patients and close contact. Clinical
assessment Electrophysiological assessment via ( VEEG).
Neuroimaging via routine MRI brain,(FDG-PET), Interictal SPECT and
magneto-encephalography (MEG) were done to conrm diagnosis.
Patients & Methods
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Neuropsychological Test Battery Neuropsychological Test Battery
Wechsler Adult Intelligence scale (WAIS-R: VIQ, PIQ, FIQ) and
Wechsler Memory Scale (WMS-R: verbal, non verbal,full memory)
pre-operative and one year post operatively. Changes or discrepancy
of the score greater than 10 was defined as significant
improvement,changes within 10 defined as no significant changes and
if lower than 10 will be considered impairment. Also difference
between Verbal and non verbal memory scores pre-operatively greater
than ten was defined as verbal dominant memory impairment and vice
verse or less than ten difference shows non significant laterality.
Patients & Methods
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Case example Pre-op Post-op Pattern of memory impairment Verbal
dominant VDMI No dominancy Post-op gains or declines Significant
gain No change Patients & Methods WMS-R Verbal memory 63 75
Non-verbal memory 82 83
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(b) Procedures Operative Techniques: Two groups of patients
enrolled into the study: Group (A):Anterior temporal Iobectomy and
amygdalo- hippocampectomy (14 patients). Group (B):Selective
amygdalohippocampectomy (AH) through trans-sylvian approach (10
patients). Post operative Histopathological Studies Patients &
Methods
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(c) Patients' follow up All patients will be followed up for
1-2 Years after the procedure via: Seizure frequency every 1 month
(Engel class.) Neurological examination Neuropsychological
(WMS,WAIS)R. Radiologically by MRI Electro-physiologically by
inter-ictal EEG. All the patients will be kept on anti epileptic
drug regimen throughout the follow up period. Statistical methods
Data were analyzed using JMP software, version 11 Patients &
Methods
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Preoperative status: 19 to 53yrs with mean of 34.8yrs and
standard deviation of 10.9yrs Age: ranged from 19 to 53yrs with
mean of 34.8yrs and standard deviation of 10.9yrs Results
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Demographic data and febrile seizure history in both groups
Type of surgery ATL/AHSAH 1410No. 32.837.7Age (Y)Mean 9.712.3Std.
Dev Sex 98F 52M 10.317.8Epilepsy onset (Y)Mean 7.19.7Std. Dev
Handedness 10L 1310R Associated conditions 75Febrile Seizure
22Meningitis, Febrile seizure 53No associated conditions
Results
Preoperative pattern of memory impairment and side of the Temp.
focus Results
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The pre operative WMS-R scores The left TLE group performed
worse than right TLE group on verbal memory. But for demonstration
of the pre operative non verbal memory scores were not so
confirmatory
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Results Seizure Outcome Engel classification
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Results Seizure outcome in Engel classification according to
the type of surgery Majority of patients shows better seizure
outcome after Temporal lobe epilepsy surgery. Engel class IA (79%
ATL/AH, 70% SAH), Engel II A (14% ATL/AH &10% SAH) Engle IIB
(7% ATL/AH and 10% SAH) and (10%Engle IID with SAH group).
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Results Seizure outcome and the duration of epilepsy Seizure
outcome and the duration of epilepsy Better Engel class with
patients who have shorter duration while worse control in patients
with longer period (25% Engel class I, 30-36yrs),(75% Engel Class
I, 8- 13yrs).
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Results Age of patients and seizure outcome Young age group
(19-23Y) shows 83% Engel class lA while older group (46-53Y)shows
lower outcome (67% Engel class. lA)
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Neuropsychological outcome Intelligence Quotient (IQ)
Significant improvement in full IQ after surgery (43% ATL/AH and
30% SAH) groups with minimal impairment percent (7% ATL/AH) but the
majority of patients shows no significant difference in pre-post
operative Full IQ scores (50% ATL/AH and 70% SAH). Results
Case No 3 Post operative MRI Hippocampus Head Fimbria
Parahippocampal gyrus
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Temporal lobe epilepsy (TLE) is the most common focal. Hippocampal
sclerosis (HS) its major pathological substrate. Risk factors for
post operative cognitive decline after surgery TLE surgery
effective for intractable epilepsy with 70-80% favorable seizure
outcome Goals of surgery is to abolish the seizures and avoid any
neurologic deficits. A secondary goal, in cases of tumors and
vascular malformations is to entirely remove conclusion
