despite being the second largest group of potentially operable epilepsies , fle is more challenging both in its diagnosis and localization than other localization - related epilepsies . scalp eeg and diverse seizure semiology often reflect rapid and varied , either simultaneous or successive , propagation patterns . a lateralized lesion on mri can help guide the location of the hypothetical epileptogenic zone . however , bilateral lesions may lead to further ambiguity , and with the increased potential for frontal lobe disinhibition , surgical therapy may not be considered a viable option . an 18-year - old female was first diagnosed with craniopharyngioma at 7  years of age when she presented with headaches . subsequent serial imaging showed tumor recurrence at age 11 , and the intrasellar mass was circumferentially dissected via a bilateral subfrontal craniotomy . seizures were diagnosed 5  years later at age 17 and persisted despite optimized doses of multiple antiseizure medications . for the last six months , she also saw a  little green man  in the bathroom and felt a pressure to laugh . more recently , she began having frequent astatic seizures , resulting in a compound fracture of the left humerus . however , after the second tumor resection surgery , she had a flat affect and increased latency in speech . neuropsychological testing revealed diffuse cognitive deficits , predominantly involving attention , executive function , and psychomotor speed ( see preoperative scores in fig .  3 ) . she graduated from high school but stayed at home , with little motivation or interest in interacting with her environment . interictal eeg showed frontal 1- to 8-hz spike - and - wave complexes , in isolation or long trains , maximal left , occasionally followed by generalized paroxysmal fast activity for 24  s. recorded seizure semiology included a blank facial expression during which she occasionally answered questions and subsequently smiled . on a few occasions , there were brief myoclonic head jerks and pursing of lips . on at least 2 occasions , these progressed to clonic movements of the right face ( figs . 1a a blank facial expression and marked latency of response concomitant with continuous generalized spike - and - wave discharges were also consistent with episodic nonconvulsive status . d ) , while patchy areas of bilateral frontoparietal uptake were seen on siscom ( figs . 1e f ) . since the seizure semiology only infrequently indicated left frontal involvement ( right - face clonic seizure ) and no imaging modality was definitively discordant , invasive evaluation with bilateral subdural electrode implantation was recommended at our institution 's epilepsy management conference . bilateral frontal subdural electrodes were implanted over the encephalomalacic region , along with the interhemispheric fissure ( yellow ) and orbitofrontal ( red ) and lateral frontal regions ( green ) ( fig . four 6-contact depth electrodes ( 3 left , 1 right ) were implanted in the frontal lobes ( purple ) ( fig . one electrode was placed with the long axis parallel to the middle frontal gyrus , with distal contacts corresponding to the anterior cingulate cortex ( figs . c ) , and the other two were aimed mesially and laterally from the lateral convexity . with a lead time of 200 ms , all seizures ( >  15 ) arose from the left frontal electrodes before contralateral recruitment . the patient was taken back to the or , and left - sided grid and strips were placed over the lateral convexity and the interhemispheric fissure ( fig . the second invasive recording showed seizure onset from the anterior grid and the interhemispheric strip . the patient underwent resection of the left mesial frontal region and an anterior corpus callosotomy . neuropsychological testing one year later showed significant improvement in nearly all cognitive domains , with most test scores improving to the normal range . postoperative mri and neuropsychological test scores one year after surgery are shown in fig . she now shows interest in her environment , has rekindled old friendships , and aspires to go to college . an 18-year - old female was first diagnosed with craniopharyngioma at 7  years of age when she presented with headaches . subsequent serial imaging showed tumor recurrence at age 11 , and the intrasellar mass was circumferentially dissected via a bilateral subfrontal craniotomy . seizures were diagnosed 5  years later at age 17 and persisted despite optimized doses of multiple antiseizure medications . for the last six months , she also saw a  little green man  in the bathroom and felt a pressure to laugh . more recently , she began having frequent astatic seizures , resulting in a compound fracture of the left humerus . however , after the second tumor resection surgery , she had a flat affect and increased latency in speech . neuropsychological testing revealed diffuse cognitive deficits , predominantly involving attention , executive function , and psychomotor speed ( see preoperative scores in fig .  3 ) . she graduated from high school but stayed at home , with little motivation or interest in interacting with her environment . interictal eeg showed frontal 1- to 8-hz spike - and - wave complexes , in isolation or long trains , maximal left , occasionally followed by generalized paroxysmal fast activity for 24  s. recorded seizure semiology included a blank facial expression during which she occasionally answered questions and subsequently smiled . on a few occasions , there were brief myoclonic head jerks and pursing of lips . on at least 2 occasions , these progressed to clonic movements of the right face ( figs . a blank facial expression and marked latency of response concomitant with continuous generalized spike - and - wave discharges were also consistent with episodic nonconvulsive status . d ) , while patchy areas of bilateral frontoparietal uptake were seen on siscom ( figs . 1e f ) . since the seizure semiology only infrequently indicated left frontal involvement ( right - face clonic seizure ) and no imaging modality was definitively discordant , invasive evaluation with bilateral subdural electrode implantation was recommended at our institution 's epilepsy management conference . bilateral frontal subdural electrodes were implanted over the encephalomalacic region , along with the interhemispheric fissure ( yellow ) and orbitofrontal ( red ) and lateral frontal regions ( green ) ( fig . four 6-contact depth electrodes ( 3 left , 1 right ) were implanted in the frontal lobes ( purple ) ( fig . on the left , one electrode was placed with the long axis parallel to the middle frontal gyrus , with distal contacts corresponding to the anterior cingulate cortex ( figs . c ) , and the other two were aimed mesially and laterally from the lateral convexity . with a lead time of 200  ms , all seizures ( >  15 ) arose from the left frontal electrodes before contralateral recruitment . the patient was taken back to the or , and left - sided grid and strips were placed over the lateral convexity and the interhemispheric fissure ( fig . the second invasive recording showed seizure onset from the anterior grid and the interhemispheric strip . the patient underwent resection of the left mesial frontal region and an anterior corpus callosotomy . neuropsychological testing one year later showed significant improvement in nearly all cognitive domains , with most test scores improving to the normal range . postoperative mri and neuropsychological test scores one year after surgery are shown in fig . she now shows interest in her environment , has rekindled old friendships , and aspires to go to college . as slow growing extra - axial tumors , craniopharyngiomas account for 515% of all intracranial tumors in childhood . typical presenting symptoms include headache and growth failure from pressure effects on the hypothalamic  pituitary axis . seizures and psychiatric symptoms are uncommon presenting symptoms , but subsequent seizure prevalence rates of 28% and neurocognitive deficits ( full - scale iq  <  80 ) in up to 20% of children are described , . surgery with or without adjuvant external beam radiation is the most common first - line treatment . despite gross total removal the optimum surgical strategy for management of pediatric craniopharyngioma remains an area of active debate . some groups advocate gross total resection , while others favor a more limited subtotal resection ( if the tumor is adherent to adjacent structures ) and supplementary local external beam radiotherapy . in the last decade , our own hospital experience includes 31 children with craniopharyngiomas , none of whom presented with seizures . although seven patients have had eegs for paroxysmal events or altered mental status , only the patient presented here has developed seizures to date ( 3% ) . our patient 's course highlights the need for consideration of surgical strategies to minimize iatrogenic encephalomalacic injury with tumor resection such as craniopharyngiomas . identifying the epileptogenic zone in the frontal lobes is a challenge . both rapid ipsilateral and contralateral propagation and large clinically silent regions may indicate clinical onset only after the seizure propagates to an eloquent region . , gelastic seizures and frontal absence semiologies implicated the mesial frontal region including the anterior cingulate cortex , while the facial motor seizures illustrated motor cortex involvement . although mri was more skewed to the right frontal region , the eeg showed either generalized discharges or left lateralization with occasional right facial clonic activity ; there was no indication of independent right frontal involvement either by eeg or by seizure semiology . we felt that this was enough to warrant a surgical approach , especially given the increasing severity of her epilepsy and its devastating impact on her quality of life . the first bilateral monitoring established lateralization , while the second provided coverage of the implicated region and enabled grid - based resection . not widely adopted in the united states , bilateral electrode implantation utilizing stereoelectroencephalography may be another methodology to lateralize and localize the epileptogenic zone in patients with poorly lateralized seizures . while the literature of intractable epilepsy seldom mentions encephalomalacia as an etiology , gliosis has significant potential for epileptogenesis , whether from posttraumatic or iatrogenic injury such as may be with tumor resection . this may in part be because completeness of resection of encephalomalacia as determined by mri is felt to be necessary to achieve seizure freedom . preoperative widespread interictal discharges also did not have an adverse effect on our patient 's outcome , and all postoperative eegs have not shown any epileptiform discharges . the frontal lobe syndrome exhibited by our patient included dysfunction in all three behaviorally relevant circuits including executive dysfunction mediated by the dorsolateral prefrontal circuit , apathy mediated by the anterior cingulate circuit , and sensory disinhibition ( visual hallucinations ) involving the orbital frontal region , . with an anterior corpus callosotomy and resection confined to the left mesial region , well within the visible lesion , seizures resolved with no epileptogenicity as seen on subsequent eegs . additionally , there was marked improvement in all domains of the frontal lobe syndrome suggesting that large parts of the frontal lobe were involved as the irritative , symptomatogenic , and functional deficit zones , rather than as the epileptogenic zone   and that at least in some patients , these zones can be  reversed  with successful epilepsy surgery . while the epileptogenic zone typically extends beyond the visible margins on mri , it may also be confined to a smaller substrate well within the visible mri lesion as in our patient . in spite of widespread eeg abnormalities , multiple seizure semiologies , and bilateral mri involvement , successful frontal epilepsy surgery outcomes provide a unique opportunity to further our understanding of the frontal lobe syndrome and its risk factors . this , in turn , may translate to more patients being considered as candidates for resective rather than palliative epilepsy surgery .
epilepsy surgery in frontal lobe epilepsy ( fle ) has less favorable seizure - free outcomes than temporal lobe epilepsies . 
 possible contributing factors include fast propagation patterns and large clinically silent areas which are characteristics of the frontal lobes . 
 bilateral frontal lobe abnormalities on mri are another relative contraindication to epilepsy surgery . for example , bilateral encephalomalacia may be a presupposition to bilateral or multifocal epilepsy 
 . the possibility of potential disinhibition with already poor reserves may be another deterrent to consideration for resective epilepsy surgery . 
 as such , conventional surgical approaches to intractable epilepsy with bilateral frontal injury may be limited to palliative procedures like vagus nerve stimulation and corpus callosotomy . 
 we present a case in which the epileptogenic zone was a subset of the acquired , bilateral , cystic encephalomalacia . 
 this iatrogenic injury resulted from two prior craniotomies for excision of craniopharyngioma and its recurrence.following the initial bilateral and subsequent unilateral , subdural grid- and depth electrode - based localization and resection , our patient has remained seizure - free 2  years after epilepsy surgery with marked improvement in her quality of life , as corroborated by her neuropsychological test scores . 
 our patient 's clinical course is testament to the potential role for resective strategies in selected cases of intractable epilepsy associated with bifrontal injury . 
 reversal of behavioral deficits with frontal lobe epilepsy surgery such as in this patient provides a unique opportunity to further our understanding of the complex nature of frontal lobe function .