![• Advanced MRI techniques — Quantitative MRI techniques have limited
diagnostic value over and above visual inspection but may provide useful
prognostic information.
• FDG-PET — Measurement of interictal cerebral glucose metabolism using
[18F]-2-deoxyglucose PET (FDG-PET) is a sensitive functional neuroimaging
technique in patients with temporal lobe epilepsy. Unilateral temporal lobe
hypo-metabolism on FDG-PET
• Ictal SPECT — Ictal SPECT studies are used to map increased cerebral blood
flow during seizures to assist in localizing the epileptogenic zone
• Subtraction ictal SPECT coregistered to MRI (SISCOM)
• Speech and language localization](https://image.slidesharecdn.com/epilepsysurgery-241223123040-d3c68b2b/85/Epilepsy-surgery-surgery-surgery-surgery-pptx-19-320.jpg)
Epilepsy surgery. surgery. surgery. surgery.pptx
- 1. Joint session on Epilepsy Surgery case presentation Presented : Beruk K. (NR3) Moderator : Prof Getahun M.(Internist, Consultant Neurologist, Headache subspecialist August 9, 2023 G.c
- 2. Outlines • Brief Introduction • History • Physical Examination • EEG • Brain MRI • Additional Investigations • Discussion
- 3. Introduction • Epilepsy is one of the most common chronic neurologic disorders • Around 50 million people worldwide have epilepsy, making it one of the most common neurological diseases globally. • Drug-resistant epilepsy affects about one-third of people living with epilepsy.
- 5. • Drug-resistant epilepsy is defined as the “Failure of adequate trials of two tolerated, appropriately chosen and used antiepileptic drug (AED) schedules (whether as monotherapies or in combination) to achieve sustained seizure freedom,” • which could be either 3 times the prior interseizure interval or 1 year which ever is longer • Patients with epilepsy have worse quality of life, family function, and social support compared to other patients who are chronically ill. • Furthermore, patients with drug-resistant epilepsy face an increased risk of sudden unexpected death in epilepsy (SUDEP)
- 6. • The surgical treatment of most patients is divided into the diagnostic phase and the therapeutic phase. • Currently modern non-resective techniques, i. such as laser interstitial thermal therapy, ii. gamma knife radiosurgery, and iii. devices such as vagal nerve stimulation (VNS) and responsive neurostimulation, • However, epilepsy surgery currently remains grossly underused
- 7. Indications of surgery • The most common criteria used to define surgical candidacy are 1. Seizure frequency (>1 per month) and 2. Failure of 2 antiepileptic drugs. ≥ • In cases of lesional epilepsy, surgery can be considered even earlier.
- 8. Surgical candidates • Early referral for epilepsy surgery, as soon as drug resistance is ascertained i. The localization of seizure onset, ii. Underlying surgical pathology, and iii. Seizure type(s) are important determinants of surgical candidacy and outcomes • The most favorable candidates are those with magnetic resonance imaging (MRI)-identified lesions that represent both the pathologic process underlying the epileptogenic brain tissue and the location of seizure onset. • Such MRI findings, together with concordant electroencephalography (EEG) data, are pivotal in selecting operative candidates and determining the strategy for the surgical procedure.
- 9. Seizure outcomes after surgery • Approximately 60–65% of patients are seizure free after temporal lobe resection, compared with 40% of patients after extra temporal resection • Epilepsy surgery is associated with specific cognitive decline (most often involving verbal memory and naming after dominant lobe resections), but cognition may also improve in some patients
- 10. Epilepsy surgery complications • Surgical complications are usually minor or transient. • Major and minor neurologic complications were reported in 4.7% and 10.9% of patients, respectively, • with resective surgery with the most common being minor visual field defect(Affecting one quadrant or less) • Mortality appears to be lower if patients are rendered seizure free after epilepsy surgery
- 12. • Patients who have epilepsy due to a structural abnormality seen on brain MRI have better surgical outcomes than those without an MRI abnormality. • However, not all radiographically “normal” MRIs are indeed normal. • The most common culprit is focal cortical dysplasia. • In one study, 60% of patients with histologically confirmed focal cortical dysplasia had “normal” MRIs when performed and reported outside a major epilepsy center, but only 37% of these were still “normal” when reviewed at the epilepsy center.
- 13. Surgical Evaluation • The goals of the surgical evaluation are 1. To identify the epileptogenic zone, 2. Determine the extent to which it can be resected, and 3. Avoid operative morbidity, especially injury to eloquent cortex. • In general, decisions rely most heavily on the concordance of clinical seizure semiology, ictal and interictal scalp electroencephalography (EEG) findings, and structural magnetic resonance imaging (MRI). • Positron emission tomography (PET), single-photon emission computed tomography (SPECT), and magnetoencephalography (MEG) typically play a confirmative role in cases of questionable structural lesions or in patients with multiple lesions or a normal MRI.
- 14. Clinical Evaluation • Multidisciplinary resources and personnel. • The history and neurologic examination are critical to confirm the diagnosis and characterize seizure semiology and clinical localization. • Emphasis should be placed on the presence of multiple or differing seizure semiology's, which may raise concern for multiple epileptogenic zones. • Careful mapping of brain function is performed before resective surgery, especially when the epileptogenic zone is in or near eloquent cortex.
- 16. Neuropsychological testing • Neuropsychological studies are performed to evaluate the presence of verbal or nonverbal learning and memory deficits. • To determine preoperative cognitive performance as a baseline that can be compared with a postoperative examination • To identify and quantify ictal and postictal deficits as an aid to seizure characterization, lateralization, and localization • To provide evidence-based predictions of cognitive risk associated with the proposed surgery • To provide comprehensive preoperative counseling, including Neuropsychologic education of the patient and family
- 17. • The diagnostic tools include grids, strips, depth electrodes, or stereo-EEGs, and these tools can be used as dictated by the needs of the specific patient.
- 18. High-resolution brain MRI • All patients undergoing surgical evaluation should have a high-resolution brain MRI with sequences optimized for visualization of the hippocampus and gray-white matter junction. • The MRI should include coronal or oblique-coronal T1- and T2-weighted and fluid-attenuated inversion recovery (FLAIR) sequences.
- 19. • Advanced MRI techniques — Quantitative MRI techniques have limited diagnostic value over and above visual inspection but may provide useful prognostic information. • FDG-PET — Measurement of interictal cerebral glucose metabolism using [18F]-2-deoxyglucose PET (FDG-PET) is a sensitive functional neuroimaging technique in patients with temporal lobe epilepsy. Unilateral temporal lobe hypo-metabolism on FDG-PET • Ictal SPECT — Ictal SPECT studies are used to map increased cerebral blood flow during seizures to assist in localizing the epileptogenic zone • Subtraction ictal SPECT coregistered to MRI (SISCOM) • Speech and language localization
- 20. • Preoperatively, functional MRI and the intracarotid amobarbital procedure (also called the Wada test) are two methods used to assess language localization and predict postoperative language and memory outcomes. • Functional MRI is generally preferred over intracarotid amobarbital given its superior safety profile
- 23. IDENTIFICATION • Name - A.M • Age -28 • Sex – Male • Handedness – Right Handed • Educational Status – High school • Address – Addis Ababa • Religion – Muslim • Occupation- None
- 24. History of present illness • This is a 28 years old Right handed male patient presented with abnormal body movement of 7 years duration • The abnormal body movement is characterized by initially flexion and extension of the left upper extremity • Accompanied with head deviation to the Left side after which it spreads to the Right side of the body with subsequent loss of consciousness, • The abnormal body movement lasts 1-2minutes • Prior to the Abnormal body movement he usually has tingling sensation of the left hand 5-10 minute
- 25. • Post ictally he fully regains consciousness • No post ictal aphasia, weakness of extremities and facial deviation
- 26. • Initially went to Menilik hospital for ophthalmologic evaluation after he had diplopia and proptosis of the Left eye and was on follow-up for Lt eye Lacrimal gland tumor and was on started on Carbamazepine 200mg po BID and Phenobarbitone 100mg po BID for the seizure.
- 27. • The episodes have no diurnal variation and he tends to have the abnormal body movement through out the day • Otherwise no history of Trauma, substance use, family history of similar illness, fever, cough, vomiting or diarrhea, bowel or bladder incontinence, weakness, lip smacking, tongue bite, personality changes,
- 28. Course over the 8months of stay in our OPD • Was referred Carbamazepine 200mg po BID and Phenobarbitone 100mg po BID • Progressively Carbamazepine was escalated to 600mg po BID • Despite that he had poor seizure control and Sodium Valproate was added and Progressively escalated to 1000mg/500mg • Still he has 1-2 episodes of the Abnormal body movement daily
- 29. Epileptogenic zone • ??Right Frontal lobe
- 30. Physical Examination • General Appearance – comfortable • Vital sign i. BP – 120/70mmhg ii. PR – 78 Bpm iii. RR – 20 Bpm iv. Temp – 36.8 c v. Spo2 – 98 % on Atm air • HEENT – Pink Conjunctiva, there is left eye Proptosis
- 31. • LGS – No palpable lymphadenopathy in accessible areas • Chest – Clear and Bilaterally good air entry • CVS – S1 and S2 were well heard, no murmur or gallop • Abdominal Exam – Soft moves with respiration no palpable mass or organomegally • GUS – No CVA tenderness • Int/ Msk – No rash, deformity or edema
- 32. • Nervous system examination • GCS – 15/15 I. Cranial nerves – Pupils are midsized and reactive bilaterally He has difficulty moving his Lt eye upwards and to the left There is left eye Ptosis Decreased touch sensation on V1 branch of trigeminal nerve on the Lt side Other cranial nerves are intact
- 33. II. Motor - symmetric Bulk, no spontaneous or induced fasciculation, Normotonic Power is 5/5 in all muscle groups bilaterally Reflex is 2/4 over the biceps, brachioradialis, triceps, knee, and ankle Plantar is downgoing bilaterally Sensory is intact to pain, touch, vibration and position Coordination is intact
- 34. Baseline Investigations • CBC WBC = 5.8K(Neut-3.8k, Lymp-1.6K ) Hgb = 16 MCV = 39.2 PLT = 276K • Serum Electrolytes NA+ = 135, K+ = 4.3, Cl- =98, Mg+ = 2, Ca++ = 9.47 • Renal function Cr = 0.6, Urea = 8.7 • Liver function test AST =23, ALT =20 ALP =30 • ESR = 4 • ALB = 5.0
- 35. EEG • 1st EEG – Generalized epileptiform discharge with background slowing • 2nd EEG – Rt Focal Epileptiform discharge with background slowing
- 38. Brain MRI 1st Brain MRI • Left High anterior frontal lobe cortical Dysplasia • Left upper anterior peripheral temporal lobe convexity small arachnoid cyst( Incidental finding ) • Left Orbital Lacrimal gland lobulated enhancing mass cause left side proptosis likely Pleomorphic adenoma
- 40. • 2nd Brain MRI • Left frontal cortical thickening with blurred gray white differentiation likely focal cortical dysplasia DDX Low grade diffuse glioma • Left Temporal lobe small arachnoid cyst ( Incidental finding )
- 41. Assessments • P1 – Focal to Bilateral tonic clonic seizure • P2 – Low grade Adenocystic carcinoma of the Lacrimal gland
- 42. What Makes him a candidate for Epilepsy surgery? • Refractory seizure • Semiology • Imaging results
- 43. Discussion
- 44. References • Bradley Neurology 8th edition • Mayo Clinic neurology Board Review 2nd Edition • Up-to-date Online material • Latest Epilepsy Neurocontinuum • NEJM • PUBMED • JAMA • Epilepsia
- 45. Thank You
Editor's Notes
- #3: It is estimated that up to 70% of people living with epilepsy could live seizure-free if properly diagnosed and treated. Epilepsy is defined as at least two unprovoked seizures occurring in a time frame of more than 24 h apart. It is also considered present when the recurrence rate of a single unprovoked seizure is more than 60% over the next 10 years, or when a diagnosis of epilepsy syndrome is madeApproximately 20 to 30 percent of patients with epilepsy will have medically and socially disabling seizure disorders.
- #4: In this study, about half of patients with epilepsy became seizure free for 1 year with the first attempted ASM, but of those who did not, only about a quarter responded to the second attempted ASM regimen, and returns only diminished further when attempting treatment with a third regimen (Kwan and Brodie, 2000; Chen et al., 2018). 50%----------11.6%--------------4.4% 47%(first AED)---------13%(second AED)----------1%(3rd monotherapy) Meaning 1/3rd will not be seizure free despite multiple therapy and require surgery
- #5: Seizures cause most epilepsy-related deaths: drowning, car and bicycle accidents, aspiration pneumonia, alcohol withdrawal, status epilepticus, and SUDEP. SUDEP is not well understood. Researchers do not understand the exact cause of SUDEP, but these are possible reasons2–4 it happens: Breathing changes: A seizure may cause a person to have pauses in breathing. If these pauses last too long, they can reduce the oxygen in the blood to a dangerous level.
- #6: Surgical procedures for epilepsy range from focal resection of the epileptogenic cortex (antero-mesial temporal lobe and other focal cortical resections) to interventions that remove or isolate the cortex of a grossly diseased hemisphere (functional hemispherectomy, anterior corpus callosotomy, multiple subpial transections). What are Gamma Knife radiosurgery techniques? The Gamma Knife® utilizes a technique called stereotactic radiosurgery, which uses multiple beams of radiation converging in three dimensions to focus precisely on a small volume, such as a tumor, permitting intense doses of radiation to be delivered to that volume safely.
- #7: From Neurocontinuum Lesional epilepsy surgery doesn’t require to wait for refractory seizure
- #8: Timing of referral to evaluate for epilepsy surgery : Expert consensus recommendations from the Surgical therapies ILAE recommendation Referral to Surgery should be done as soon as Drug resistance is confirmed
- #9: Early referral for epilepsy surgery – as soon as drug resistance is ascertained – is supported by 2022 expert consensus recommendations from the ILAE
- #11: Epilepsy surgery is often considered dangerous and thus is thought of as a last resort for patients with drug-resistant epilepsy. In fact, epilepsy surgery is generally safe; most complications associated with epilepsy surgery are minor (defined as resolving completely within 3 months of surgery, whereas major complications persist beyond that time frame). Major and minor neurologic complications were reported in 4.7% and 10.9% of patients, respectively, with resective surgery, with the most common being minor visual field deficits (affecting one quadrant or less). Perioperative mortality was rare (0.4% in temporal lobe cases and 1.2% in extratemporal cases) Paradoxical improvement
- #12: 3 landmark studies have shown the importance of the study Medical vs surgical therapy for temporal lobe epilepsy At one year the cumulative proportion of patients who were free of seizures impairing awareness was 58% in surgical group ad 8% in the medical group(P<0.001)
- #14: Evaluation by expert is much sensitive than normal physician 6cm vs 4cm The resection size is typically different for dominant and nondominant resection. The lateral resection usually measures around 6 cm from the temporal pole on the right but is less extensive on the left to reduce the chance of language deficits. The typical left dominant temporal lobectomy measures about 4 cm from the temporal pole
- #15: Possible contraiindication Patients who are usually not surgical candidates for focal cortical resection include individuals with bilateral or multifocal seizure onset, those with significant medical comorbidities that preclude the surgery, and patients with generalized-onset epilepsy Scalp EEG may miss a focal origin, especially if the initial discharge is of low voltage and high frequency (3). A mesial hemispheric origin may also be missed because of only distant scalp EEG electrode coverage and a likely tangential dipole orientation
- #16: Scalp EEG may miss a focal origin, especially if the initial discharge is of low voltage and high frequency (3). A mesial hemispheric origin may also be missed because of only distant scalp EEG electrode coverage and a likely tangential dipole orientation
- #18: After referral to Epilepsy surgery center First thing is confirming epilepsy and then ruling out pseudoresistance Multidisiplinary team is required 1) Epileptologist 2) Neuropsychologist 3) Neurosurgery 4) Neuroradiologist
- #20: The sensitivity of a single 20-minute routine EEG recording to detect interictal epileptiform discharges is only around 50%, although sensitivity can be increased by performing the EEG in the sleep-deprived state, performing EEG within 24 hours of a seizure event, or repeating EEG on multiple occasions.
- #21: Stereotactic EEG guidance with aim of delineating seizure foci and propagation intellectual disability has traditionally been a relative contraindication to temporal lobectomy because it implies bilateral and potentially diffuse rather than focal brain pathology. In some studies, low intelligence quotient (IQ) has been associated with lower postoperative seizure remission rates and increased risk of postoperative cognitive sequelae. Routine and video-EEG — Routine EEG recording with standard activating procedure and long-term scalp-recorded video-EEG monitoring are essential to confirm and localize the site of seizure onset in individuals with focal epilepsy.
- #22: 1.5 Tesla, 3 Tesla, 7 Tesla In patients with focal cortical dysplasia, MRI findings may be subtle and include mild cortical thickening, a prominent deep sulcus, a cortical signal intensity change, blurring of the gray-white junction, or aberrant cortical architecture (image 3). intellectual disability has traditionally been a relative contraindication to temporal lobectomy because it implies bilateral and potentially diffuse rather than focal brain pathology. In some studies, low intelligence quotient (IQ) has been associated with lower postoperative seizure remission rates and increased risk of postoperative cognitive sequelae. Routine and video-EEG — Routine EEG recording with standard activating procedure and long-term scalp-recorded video-EEG monitoring are essential to confirm and localize the site of seizure onset in individuals with focal epilepsy. Thin-section 3D volumetric MRI and reformatted 1.5 mm 3D spoiled gradient echo (SPGR) sequences are particularly useful, since it is difficult to resolve volume-averaged normal cortical in folding from true abnormalities if the spatial resolution of the images is coarser than 1.5 mm. Higher field strength (eg, 3-Tesla) also aids in detecting cortical dysplasia.
- #23: F-fluorodeoxyglucose (FDG) PET/CT Subtraction ictal SPECT coregistered to MRI (SISCOM) is a modification of the ictal SPECT technique that superimposes ictal and interictal SPECT images and brain MRI. Speech and language localization — In selected patients, eloquent cortex involved with speech and language function must be well defined before temporal lobe and frontal lobe resections to minimize operative morbidity.
- #24: Functional MRI is a noninvasive neuroimaging technique that is capable of language localization as well as lateralization of language processes. In many epilepsy centers, this has largely replaced Intracarotid amobarbital procedures. Wada test takes around 30-90minute
- #25: Intracarotid amobarbital administration is an invasive procedure that has been used for many years in surgical candidates to determine the language-dominant hemisphere as well as assess the risk of postoperative memory decline after temporal lobectomy Other anesthetic agents such as pentobarbital, etomidate, methohexital, and propofol have been investigated as alternatives to amobarbital, which has not been consistently available.
- #26: Left hippocampal increased intensity and assymetery atrophy of left fornix
- #28: Examples of conditions for which hemispherectomy is often the recommended procedure include Rasmussen syndrome, Sturge-Weber syndrome, and hemimegalencephaly. Multiple subpial transection (MST) for lesionectomy not possible due to elocuent cortex
- #29: UN Refugee camp
- #30: This is a 28 years old Right handed male patient presented with abnormal body movement of 7 years duration, the abnormal body movement is characterized by initially flexion and extension of the left upper extremity accompanied with forced head deviation to the Left side after which it spreads to the Right side of the body with subsequent loss of consciousness, usually he has tingling sensation of the left hand 5-10 minute before the Abnormal body movement starts.
- #35: Late forced head turn to the left signifies a Rt frontal lobe origin of seizure No automatism unlike temporal lobe seizures No post ictal confusion makes it more frontal lobe Atypical automastisms go for frontal Pedaling, bicycling go for frontal lesion Brief and often in cluster of seizures Nocturnal predominant
- #38: Lt eye counts from 2 meter range and the Rt eye counts from 6 meter distance
- #40: Couldn’t afford serum drug level
- #41: EEG done 6months apart EEG the Dominant background rhythms consisits of large amount of bilateral symmetric 30-250 microvolts rhythmic 5-7Hz activities seen over the posterior head region This is an abnormal wake EEG due to the presence of generalized epileptiform and non epileptiform (Delta slowing) discharges.
- #42: A more recent study using concomitant intracranial and scalp electrodes found that intracranial spikes synchronizing over an area of less than 6 cm2 were never associated with a scalp EEG signal. Rather, 90% of spikes with a source area of more than 10 cm2 yielded detectable spikes on a scalp EEG, whereas only 10% of cortical spikes with less than 10 cm2 of source area were seen on a scalp EEG.
- #44: ~~1 year difference between the 2 MRI Brain MRI done on 17/10/2022 There is left anterior Peripheral Temporal lobe convexity extra axialcystic lesion measuring 2.1*2cm which is isotense to csf on all sequences. The lesion sowed no contrast enhancement. There is also left high anterior frontal lobe focal cortical thickening which is isotense to the cortex on all sequences and showed no contrast enhancement and measures 1cm diameter. There is Left superior ad lateral quadrant intenslt enhancing lobulated mass probably arising from the lacrimal gland measuring 3.9 cm * 2.1cm cause pressure effect on the overlying bone and mass effect on the eye globe and displacing it medially and anteriorly , the lesion has T2 shortening and intermediate signal intensity on T2 weightened image and showed mild restricted diffusivity on ADC map
- #46: Left superolateral orbital enhancing extrarconal avidly enhancing mass lesion with proptosis and mass effect on adjacent ocular muscle and focal orbital roof dehiscence DDX Low grade minor salivary tumors of lacrimal origin, orbital hemangioma [Histopathologic correlation recommended]
- #47: Focal aware motor to bilateral tonic clonic
- #48: which suggest a right frontal lobe lesion Its purposes are to localize the epileptogenic zone (whose resection is necessary and sufficient to eliminate seizures), identify incongruent evidence that may indicate the need for additional tests including invasive EEG, and Determine whether planned surgical resection poses risk to cerebral functions
- #49: Its purposes are to (1) localize the epileptogenic zone (whose resection is necessary and sufficient to eliminate seizures), (2) identify incongruent evidence that may indicate the need for additional tests including invasive EEG, and (3) determine whether planned surgical resection poses risk to cerebral functions