the new proposal for classification of focal cortical dysplasia ( fcd ) recognizes a particular type , iiid fcd , associated with an epileptogenic lesion acquired in early life ( i.e. , traumatic injury , ischemic injury or encephalitis ) .
fcd group associated with certain other epileptogenic lesions ( in particular , hippocampal sclerosis , tumors and vascular malformations ) .
histopathologically , type iiid fcd consists of altered cortical architecture and cytoarchitectural composition , occurring adjacent to the principal early - life lesion .
there is not yet much information regarding the prevalence of these cortical dysplastic changes among patients with these kinds of early - life lesions , and imaging  pathologic correlations are only at the beginning ; nevertheless , it could be inferred that such an association is probably high .
epileptic seizures secondary to early - life brain injuries often follow a protracted and drug - resistant course . given the destructive nature and involvement of multiple brain regions by initial injury , many of these patients are not considered suitable for epilepsy surgery .
others with well - lateralized hemispheric lesions undergo extensive procedures ( hemispherectomy / hemispherotomy ) which , although associated with successful postsurgical seizure control , may induce new or aggravate previously existing neurological deficits .
this work aims to denote that a ) selected cases with converging semiological , electrophysiological and structural / functional imaging evidence of localized ictal onsets may show favorable postsurgical results to focal - tailored resections and b ) accompanying mesio - temporal pathology ipsilateral to the gross lesion may not contribute to seizure generation .
patient 1 was a 10-yr - old boy originally diagnosed with left hemispheric atrophy and an ipsilateral parietotemporooccipital porencephalic cyst .
he developed right - sided upper extremity hemiparesis , mild left superior quadrantanopia , and drug - resistant seizures ( for history , presurgical evaluations and treatment details , see the supplementary data ) .
recent mri verified the presence of left hemispheric atrophy and large left - sided parietotemporooccipital porencephalic cyst and revealed an ipsilaterally malformed hippocampusmedial temporal region with increased flair signal ( fig . 
an ipsilateral multilobar , parieto - occipital resection , sparing the mesial temporal structures , rendered the patient seizure free ( fig . 
patient 2 was a 25-yr - old man with lifelong history of intractable seizures secondary to serious posterior left head trauma sustained at the age of 4  months .
magnetic resonance imaging ( mri ) presented posterior left hemispheric atrophy , a prominent area of tissue loss and gliotic lesion over the lateral temporoparietal region and ipsilateral hippocampal atrophy plus temporal horn enlargement ( fig . 
2a ) . surgical treatment involved extensive resection of the lateral temporo - parieto - occipital area , including the principal gliotic region and the lateral - inferior occipital region , sparing the medial temporal area ( fig . 
patient 1 was a 10-yr - old boy originally diagnosed with left hemispheric atrophy and an ipsilateral parietotemporooccipital porencephalic cyst .
he developed right - sided upper extremity hemiparesis , mild left superior quadrantanopia , and drug - resistant seizures ( for history , presurgical evaluations and treatment details , see the supplementary data ) .
recent mri verified the presence of left hemispheric atrophy and large left - sided parietotemporooccipital porencephalic cyst and revealed an ipsilaterally malformed hippocampusmedial temporal region with increased flair signal ( fig . 
an ipsilateral multilobar , parieto - occipital resection , sparing the mesial temporal structures , rendered the patient seizure free ( fig . 
patient 2 was a 25-yr - old man with lifelong history of intractable seizures secondary to serious posterior left head trauma sustained at the age of 4  months .
magnetic resonance imaging ( mri ) presented posterior left hemispheric atrophy , a prominent area of tissue loss and gliotic lesion over the lateral temporoparietal region and ipsilateral hippocampal atrophy plus temporal horn enlargement ( fig . 
2a ) . surgical treatment involved extensive resection of the lateral temporo - parieto - occipital area , including the principal gliotic region and the lateral - inferior occipital region , sparing the medial temporal area ( fig . 
given the recent introduction of the new classification scheme for fcd , it is not surprising that there is not yet much information regarding the incidence of iiid fcd among patients with epilepsy with early - life - acquired lesions and corresponding surgical outcomes .
it is very likely that this type of pathology eluded detection in previous years , the neuropathologic focus being the  principal  lesion .
.   reported on a series of 25 children having suffered pre- or peri - natal ( mostly ischemic ) injury , all with a broad spectrum of accompanying cortical dysplastic changes , mostly type i fcd ( which apparently conforms to type iiid current classification ) .
slightly more than half of these patients were offered lobar and multilobar resections with class i engel outcomes achieved in   50% of them . there was a high incidence of extensive and not well - localized interictal and ictal eeg abnormalities in this series , suggesting the presence of large and diffuse epileptogenic zones .
a subgroup of eight cases had had an early - life - acquired anoxic  ischemic or inflammatory lesion .
all eight patients underwent multilobar resections with class i engel outcomes achieved in only 25% of them .
in contrast to the abovementioned studies , iida et al .   reported engel class i outcomes in 6/8 patients with congenital porencephalic cysts undergoing focal cortical resections guided by acute intraoperative ecog .
most of these patients had semiological evidence plus well - localized and lesion - concordant surface eeg findings in the presurgical work - up , implicating discrete cortical areas for ictal genesis .
an interesting feature in both our cases was the mri presence of additional medial temporal pathology on the side of operation .
this could be compatible with medial temporal sclerosis in patient 2 , while patient 1 presented more complex features of hippocampal  parahippocampal region white  gray matter blurring , increased t2/flair signal and malformed / abnormally rotated hippocampus .
these findings should raise the possibility of medial temporal ictal onsets , given literature data suggesting such a relationship in patients with congenital extratemporal porencephalic cysts and medial temporal sclerosis [ 79 ] .
however , neither semiology nor surface eeg localization supported such a hypothesis . a subtemporal strip
placed in patient 2 demonstrated only late involvement of the mediobasal temporal region during seizures .
in addition , both patients enjoy excellent seizure control , 30  months and 18  months postoperatively , without having resected medial temporal structures . among 29 patients with pre- or peri - natal hypoxia and low - grade fcd ,
all of these patients underwent extensive resections ( mostly hemispherectomies ) including medial temporal structures , so it is difficult to deduce the epileptogenic potential the lesioned medial temporal region might possess . among 24 patients with congenital extratemporal porencephaly ,
burneo et al .   reported 9 with additional medial temporal sclerosis ; an incidence very close to that of krsek 's study .
five of these patients had ipsilateral temporal lobe ictal onsets and achieved class i engel outcomes following temporal lobectomy .
however , 3 others had extratemporal ictal onsets , based on video - eeg findings .
ho et al .   reported evidence of medial temporal atrophy / sclerosis , based on mri hippocampal and amygdalar volumetry in 21 out of 22 cases with congenital porencephaly .
in contrast , reported ictal onsets localized in the vicinity of congenital extratemporal porencephalic cysts with excellent results ( engel class i ) following tailored resections .
. concerning neuropathologic classification , the recent proposal   does not offer a specific subcategory among type iii fcd for cases with the constellation of fcd , early - life injury and medial temporal sclerosis , or any other medial temporal malformative lesion , if present distant to the principal early - life lesion and neighboring dysplasia .
our findings , along with literature data , suggest that the organization of the epileptogenic substrate in type iiid fcd probably varies along a spectrum including on the one side cases with extensive ictal onset zones and non - satisfactory outcomes following focal resections and on the other side cases with well - localized ictal onsets and engel class i outcomes following tailored resections , even though mri may suggest more extensive and complex pathology . within such complex imaging lesions ,
the epileptogenic potential is not necessarily uniformly distributed , and abnormal areas ( such as the hippocampal - medial temporal region ) may actually not contribute to ictogenesis , while in other cases be an essential component of it .
the real challenge in presurgical evaluation is , therefore , to carefully determine which part , if any , of the whole abnormality is critical for seizure onsets .
our experience suggests that stereotyped focal - onset seizure semiology along with concordant localized interictal / ictal eeg and functional data is essential for identifying such candidates .
 focal cortical dysplasia ( fcd ) type iiid is a newly proposed type associated with early - life brain insults . 
 such patients are often considered unsuitable for resective epilepsy surgery , given the usually wide extent of the lesion and the poor correlation of mri to the epileptogenic pathology . 
 two patients with intractable epilepsy , early - life ischemic / traumatic injury and mri findings of extensive unilateral cystic - gliotic and ipsilateral medial temporal sclerotic - malformative lesions were subjected to presurgical evaluation revealing well - localized neocortical ictal onsets . 
 they underwent tailored neocortical resections sparing medial temporal areas and achieved engel class i postsurgical outcomes . 
 histopathology was consistent with type iiid focal cortical dysplasia . 
 successful outcomes with tailored resections may be achieved in cases with this subtype of focal cortical dysplasia , in the presence of converging and well - localized semiological , eeg and functional imaging data , even on a background of complex and extensive mri abnormalities . 
 medial temporal pathology , although often present in this setting , is not necessarily the site of ictal onsets , and its resection may not be always mandatory for a favorable outcome . 