scholarly journals Surgical pathology of epilepsy‐associated non‐neoplastic cerebral lesions: A brief introduction with special reference to hippocampal sclerosis and focal cortical dysplasia

2013 ◽  
Vol 33 (4) ◽  
pp. 442-458 ◽  
Author(s):  
Hajime Miyata ◽  
Tomokatsu Hori ◽  
Harry V. Vinters
Keyword(s):  
Special Reference ◽  
Focal Cortical Dysplasia ◽  
Hippocampal Sclerosis ◽  
Cortical Dysplasia ◽  
Surgical Pathology ◽  
Cerebral Lesions

scholarly journals Somatic mutation involving diverse genes leads to a spectrum of focal cortical malformations

2021 ◽  
Author(s):  
Dulcie Lai ◽  
Meethila Gade ◽  
Edward Yang ◽  
Hyun Yong Koh ◽  
Nicole M. Walley ◽  
...  
Keyword(s):  
Focal Cortical Dysplasia ◽  
Hippocampal Sclerosis ◽  
Cortical Development ◽  
Copy Number Variants ◽  
Cortical Dysplasia ◽  
Disease Genes ◽  
Type I ◽  
Type Ii ◽  
Loss Of Function ◽  
Brain Malformations

Post-zygotically acquired genetic variants, or somatic variants, that arise during cortical development have emerged as important causes of focal epilepsies, particularly those due to malformations of cortical development. Pathogenic somatic variants have been identified in many genes within the PI3K-AKT3-mTOR-signaling pathway in individuals with hemimegalencephaly and focal cortical dysplasia (type II), and more recently in SLC35A2 in individuals with focal cortical dysplasia (type I) or non-dysplastic epileptic cortex. Given the expanding role of somatic variants across different brain malformations, we sought to delineate the landscape of somatic variants in a large cohort of patients who underwent epilepsy surgery with hemimegalencephaly or focal cortical dysplasia. We evaluated samples from 123 children with hemimegalencephaly (n=16), focal cortical dysplasia type I and related phenotypes (n=48), focal cortical dysplasia type II (n=44), or focal cortical dysplasia type III (n=15) classified using imaging and pathological findings. We performed high-depth exome sequencing in brain tissue-derived DNA from each case and identified somatic single nucleotide, indel, and large copy number variants. In 75% of individuals with hemimegalencephaly and 29% with focal cortical dysplasia type II, we identified pathogenic variants in PI3K-AKT-mTOR pathway genes. Four of 48 cases with focal cortical dysplasia type I (8%) had a likely pathogenic variant in SLC35A2. While no other gene had multiple disease-causing somatic variants across the focal cortical dysplasia type I cohort, four individuals in this group had a single pathogenic or likely pathogenic somatic variant in CASK, KRAS, NF1, and NIPBL, genes associated with neurodevelopmental disorders. No rare pathogenic or likely pathogenic somatic variants in any neurological disease genes like those identified in the focal cortical dysplasia type I cohort were found in 63 neurologically normal controls (P = 0.017), suggesting a role for these novel variants. We also identified a somatic loss-of-function variant in the known epilepsy gene, PCDH19, present in a very small number of alleles in the dysplastic tissue from a female patient with focal cortical dysplasia IIIa with hippocampal sclerosis. In contrast to focal cortical dysplasia type II, neither focal cortical dysplasia type I nor III had somatic variants in genes that converge on a unifying biological pathway, suggesting greater genetic heterogeneity compared to type II. Importantly, we demonstrate that FCD types I, II, and III, are associated with somatic gene variants across a broad range of genes, many associated with epilepsy in clinical syndromes caused by germline variants, as well as including some not previously associated with radiographically evident cortical brain malformations.

scholarly journals Temporal lobe epilepsy associated with 'triple pathology' of hippocampal sclerosis, focal cortical dysplasia and cavernoma in the ipsilateral frontal lobe

2009 ◽  
Vol 2 (1) ◽  
pp. 34-41 ◽  
Author(s):  
Kazuhiro Samura ◽  
Takato Morioka ◽  
Kimiaki Hashiguchi ◽  
Yasushi Miyagi ◽  
Hiroshi Shigeto ◽  
...  
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Frontal Lobe ◽  
Temporal Lobe ◽  
Focal Cortical Dysplasia ◽  
Hippocampal Sclerosis ◽  
Cortical Dysplasia

Focal Cortical Dysplasia IIIa in Hippocampal Sclerosis-Associated Epilepsy: Anatomo-Electro-Clinical Profile and Surgical Results From a Multicentric Retrospective Study

Neurosurgery ◽  
2021 ◽  
Vol 89 (Supplement_2) ◽  
pp. S93-S93
Author(s):  
Massimo Cossu ◽  
Piergiorgio d’Orio ◽  
Carmen Barba ◽  
Sofia Asioli ◽  
Francesco Cardinale ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Focal Cortical Dysplasia ◽  
Hippocampal Sclerosis ◽  
Cortical Dysplasia ◽  
Clinical Profile ◽  
Surgical Results

scholarly journals Resective surgery for medically refractory epilepsy using intraoperative MRI and functional neuronavigation: the Erlangen experience of 415 patients

2016 ◽  
Vol 40 (3) ◽  
pp. E15 ◽  
Author(s):  
Karl Roessler ◽  
Andrea Hofmann ◽  
Bjoern Sommer ◽  
Peter Grummich ◽  
Roland Coras ◽  
...  
Keyword(s):  
Surgical Procedures ◽  
Focal Cortical Dysplasia ◽  
Hippocampal Sclerosis ◽  
Cortical Dysplasia ◽  
Intraoperative Mri ◽  
Class I ◽  
Seizure Outcome ◽  
Incomplete Resection ◽  
Diffuse Glioma ◽  
Resection Volume

OBJECTIVE Intraoperative overestimation of resection volume in epilepsy surgery is a well-known problem that can lead to an unfavorable seizure outcome. Intraoperative MRI (iMRI) combined with neuronavigation may help surgeons avoid this pitfall and facilitate visualization and targeting of sometimes ill-defined heterogeneous lesions or epileptogenic zones and may increase the number of complete resections and improve seizure outcome. METHODS To investigate this hypothesis, the authors conducted a retrospective clinical study of consecutive surgical procedures performed during a 10-year period for epilepsy in which they used neuronavigation combined with iMRI and functional imaging (functional MRI for speech and motor areas; diffusion tensor imaging for pyramidal, speech, and visual tracts; and magnetoencephalography and electrocorticography for spike detection). Altogether, there were 415 patients (192 female and 223 male, mean age 37.2 years; 41% left-sided lesions and 84.9% temporal epileptogenic zones). The mean preoperative duration of epilepsy was 17.5 years. The most common epilepsy-associated pathologies included hippocampal sclerosis (n = 146 [35.2%]), long-term epilepsy-associated tumor (LEAT) (n = 67 [16.1%]), cavernoma (n = 45 [10.8%]), focal cortical dysplasia (n = 31 [7.5%]), and epilepsy caused by scar tissue (n = 23 [5.5%]). RESULTS In 11.8% (n = 49) of the surgeries, an intraoperative second-look surgery (SLS) after incomplete resection verified by iMRI had to be performed. Of those incomplete resections, LEATs were involved most often (40.8% of intraoperative SLSs, 29.9% of patients with LEAT). In addition, 37.5% (6 of 16) of patients in the diffuse glioma group and 12.9% of the patients with focal cortical dysplasia underwent an SLS. Moreover, iMRI provided additional advantages during implantation of grid, strip, and depth electrodes and enabled intraoperative correction of electrode position in 13.0% (3 of 23) of the cases. Altogether, an excellent seizure outcome (Engel Class I) was found in 72.7% of the patients during a mean follow-up of 36 months (range 3 months to 10.8 years). The greatest likelihood of an Engel Class I outcome was found in patients with cavernoma (83.7%), hippocampal sclerosis (78.8%), and LEAT (75.8%). Operative revisions that resulted from infection occurred in 0.3% of the patients, from hematomas in 1.6%, and from hydrocephalus in 0.8%. Severe visual field defects were found in 5.2% of the patients, aphasia in 5.7%, and hemiparesis in 2.7%, and the total mortality rate was 0%. CONCLUSIONS Neuronavigation combined with iMRI was beneficial during surgical procedures for epilepsy and led to favorable seizure outcome with few specific complications. A significantly higher resection volume associated with a higher chance of favorable seizure outcome was found, especially in lesional epilepsy involving LEAT or diffuse glioma.

Focal Cortical Dysplasia IIIa in Hippocampal Sclerosis-Associated Epilepsy: Anatomo-Electro-Clinical Profile and Surgical Results From a Multicentric Retrospective Study

Neurosurgery ◽  
2020 ◽  
Author(s):  
Massimo Cossu ◽  
Piergiorgio d'Orio ◽  
Carmen Barba ◽  
Sofia Asioli ◽  
Francesco Cardinale ◽  
...  
Keyword(s):  
Focal Cortical Dysplasia ◽  
Hippocampal Sclerosis ◽  
Cortical Dysplasia ◽  
Clinical Profile ◽  
Class I ◽  
Seizure Outcome ◽  
Surgical Results ◽  
Postoperative Control ◽  
Postoperative Seizure

Abstract BACKGROUND Hippocampal sclerosis (HS) may be associated with focal cortical dysplasia IIIa (FCD IIIa) in patients undergoing surgery for temporal lobe epilepsy (TLE). OBJECTIVE To investigate whether the anatomo-electro-clinical profile and surgical outcome in patients with HS-related TLE are affected by coexisting FCD IIIa. METHODS A total of 220 patients, operated in 5 centers, with at least 24 mo follow-up (FU), were retrospectively studied. Preliminary univariate and subsequent multivariate analyses were performed to investigate possible associations between several potential presurgical, surgical, and postsurgical predictors and different variables (Engel's class I and Engel's class Ia, co-occurrence of FCD IIIa). RESULTS At last available postoperative control (FU: range 24-95 mo, median 47 mo), 182 (82.7%) patients were classified as Engel's class I and 142 (64.5%) as Engel's class Ia. At multivariate analysis, extension of neocortical resection and postoperative electroencephalogram were significantly associated with Engel's class I, whereas length of FU had a significant impact on class Ia in the whole cohort and in isolated HS (iHS) patients, but not in the FCD IIIa group. No differences emerged in the anatomo-electro-clinical profile and surgical results between patients with FCD IIIa and with iHS. CONCLUSION Coexistence of FCD IIIa did not confer a distinct anatomo-electro-clinical profile to patients with HS-related epilepsy. Postoperative seizure outcome was similar in FCD IIIa and iHS cases. These findings indicate limited clinical relevance of FCD IIIa in HS-related epilepsy and might be useful for refining future FCD classifications. Further studies are needed to clarify the correlation of class Ia outcome with the duration of FU.

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