BACKGROUND AND IMPORTANCE: Primary intracranial malignant melanomas (PIMMs) are quite rare, compr... more BACKGROUND AND IMPORTANCE: Primary intracranial malignant melanomas (PIMMs) are quite rare, comprising 1% of melanomas and 0.07% of intracranial tumors. PIMMs have been reported in a variety of intracranial locations, but there has only been 1 reported instance of PIMM occurring in the brainstem. In this study, we describe the second reported case of primary pontine malignant melanoma and its treatment. CLINICAL PRESENTATION: A 40-year-old man presented with right hemiparesis, diplopia, and dysarthria. MRI demonstrated a hemorrhagic, expansile, and heterogeneously enhancing lesion in the left pons with edema extending to the left thalamus and posterior limb of the internal capsule. Surgical resection was performed through a transpetrosal approach. Pathology resulted as malignant melanoma immunopositive for BRAF V600E mutation. Complete oncological workup revealed no other lesions; thus, he was diagnosed with PIMM of the brainstem. CONCLUSION: We report a rare case of primary pontine...
INTRODUCTION: The pathogenesis of intracranial aneurysms (IAs) is complex, with both genetic and ... more INTRODUCTION: The pathogenesis of intracranial aneurysms (IAs) is complex, with both genetic and environmental risk factors. Much effort has been devoted to identifying the molecular mechanisms of IAs to develop new therapies halting the progression of IAs. METHODS: Deep whole exome sequencing was performed for 11 anterior circulation, sporadic saccular IAs from 10 unrelated patients. Paired aneurysm-peripheral blood DNA samples were compared to evaluate the somatic saccular aneurysm exome alterations. Variants were validated with deep next generation sequencing methods. The genetic landscape of a validation cohort of 60 aneurysms was analyzed by targeted deep sequencing of a vascular panel of genes. RESULTS: Whole exome sequencing revealed somatic variants in 7 of 11 saccular aneurysms. Most coding somatic variants found were missense (68%). Somatic variants in multiple genes were common, all falling into similar allele frequencies (3-18%). Two aneurysms from one patient underwent ...
INTRODUCTION: Activating variants in platelet-derived growth factor receptor beta (PDGFRB) are as... more INTRODUCTION: Activating variants in platelet-derived growth factor receptor beta (PDGFRB) are associated with aneurysms. Our group previously described a patient with multiple fusiform intracranial aneurysms who was found to have a somatic mosaic variant in PDGFRB. The relationship between the mosaic effects of PDGFRB variants and the vascular phenotypes is not well understood. METHODS: Following death due to subarachnoid hemorrhage, samples from the index patient’s intracranial, coronary, aortic, and radial arteries were biopsied and preserved. DNA was extracted and alternate allele fractions (AAF) of PDGFRB variants were determined using digital droplet PCR. Histopathological analysis was performed by a board-certified neuropathologist. RESULTS: A total of 80 biopsies were obtained. The AAFs of variant PDGFRB in the vertebral artery, basilar artery, and P1 segment aneurysms were 28.7%, 16.4%, and 17.8%, respectively. The AAF of the coronary and radial artery aneurysms were 22.3% ...
BackgroundActivating variants in platelet‐derived growth factor receptor beta (PDGFRB), including... more BackgroundActivating variants in platelet‐derived growth factor receptor beta (PDGFRB), including a variant we have previously described (p.Tyr562Cys [g.149505130T>C [GRCh37/hg19]; c.1685A>G]), are associated with development of multiorgan pathology, including aneurysm formation. To investigate the association between the allele fraction genotype and histopathologic phenotype, we performed an expanded evaluation of post‐mortem normal and aneurysmal tissue specimens from the previously published index patient.Methods and ResultsFollowing death due to diffuse subarachnoid hemorrhage in a patient with mosaic expression of the above PDGFRB variant, specimens from the intracranial, coronary, radial and aortic arteries were harvested. DNA was extracted and alternate allele fractions (AAF) ofPDGFRBwere determined using digital droplet PCR. Radiographic and histopathologic findings, together with genotype expression ofPDGFRBwere then correlated in aneurysmal tissue and compared to non...
Emerging evidence suggest WHO grade III meningiomas that arise de novo as opposed to dedifferenti... more Emerging evidence suggest WHO grade III meningiomas that arise de novo as opposed to dedifferentiating from a lower grade may harbor differing prognoses. To investigate this, a single institution retrospective analysis of prospectively acquired patients between 1999 and 2018 was performed. Clinical data and radiographic parameters were reviewed to calculate progression free survival and overall survival in patients undergoing microsurgical resection. Next generation targeted sequencing of meningioma associated genes was performed on 11 tumors. Eighteen patients were identified as undergoing surgical resection of WHO grade III meningioma. Nine patients (50%) had de novo arising tumors and nine patients had secondary progressive tumors. To compare outcomes, only those patients undergoing gross total resection (Simpson grade I) were included for survival analysis. There was an improvement in median progression free survival for de novo resected tumors as compared to secondary progressive tumors (p = 0.02). Median overall survival for patients with de novo tumors was not statistically improved compared to that of secondary progressive tumors (p = 0.22). Next generation sequencing of targeted genes (NF2, BAP1, TRAF7, KLF4, SMO and AKT) revealed 5/11 tumors containing mutations in the NF2 gene, 2/11 containing BAP1 mutations, and a single tumor containing mutations in both NF2 and TRAF7. More mutations in NF2 and BAP1 were seen in the secondary progressive tumors. In conclusion, patients undergoing gross total resection for de novo arising grade III meningiomas showed improved progression free survival, though similar overall survival, as compared to those patients with secondary progressive tumors. Further studies focused on tumor associated genes and other associated risk factors are needed to improve risk-stratification.
OBJECTIVEDespite their technical simplicity, cranioplasty procedures carry high reported morbidit... more OBJECTIVEDespite their technical simplicity, cranioplasty procedures carry high reported morbidity rates. The authors here present the largest study to date on complications after cranioplasty, focusing specifically on the relationship between complications and timing of the operation.METHODSThe authors retrospectively reviewed all cranioplasty cases performed at Harborview Medical Center over the past 10.75 years. In addition to relevant clinical and demographic characteristics, patient morbidity and mortality data were abstracted from the electronic medical record. Cox proportional-hazards models were used to analyze variables potentially associated with the risk of infection, hydrocephalus, seizure, hematoma, and bone flap resorption.RESULTSOver the course of 10.75 years, 754 cranioplasties were performed at a single institution. Sixty percent of the patients who underwent these cranioplasties were male, and the median follow-up overall was 233 days. The 30-day mortality rate was...
OBJECTIVE The authors' aim was to report the largest study on predictors of infection after c... more OBJECTIVE The authors' aim was to report the largest study on predictors of infection after cranioplasty and to assess the predictive value of intraoperative bone flap cultures before cryopreservation. METHODS They retrospectively examined all cranioplasties performed between March 2004 and November 2014. Throughout this study period, the standard protocol during initial craniectomy was to obtain a culture swab of the extracted autologous bone flap (ABF)-prior to its placement in cytostorage-to screen for microbial contamination. Two consecutive protocols were employed for the use and interpretation of the intraoperative swab culture results: A) From March 2004 through June 2013, any culture-positive ABF (+ABF) was discarded and a custom synthetic prosthesis was implanted at the time of cranioplasty. B) From July 2013 through November 2014, any ABF with a skin flora organism was not discarded. Instead, cryopreservation was maintained and the +ABF was re-implanted after a 10-minu...
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences, Jan 26, 2015
Preoperative embolization of meningioma is commonly performed; however, there is no consensus on ... more Preoperative embolization of meningioma is commonly performed; however, there is no consensus on the best embolic material to reduce intraoperative blood loss and surgery time. We retrospectively assessed the safety and efficacy of 56 cases of preoperative embolization of the middle meningeal artery with N-butyl cyanoacrylate (NBCA) in 105 cases of surgery for meningioma. We also defined a blood loss to tumor volume ratio to compensate for bias caused by tumor volume, and analyzed limited cases (the embolized group n = 52, the non-embolized group n = 21) of the convexity, the parasagittal region, the falx, and the sphenoidal ridge. The blood loss to tumor volume ratio was significantly less in the embolized group (p < 0.007). Preoperative embolization could be useful for cases with the external carotid artery as the dominant feeder vessel (p < 0.02); however, the efficacy decreased for cases with an internal carotid artery feeder. Transient complications occurred in four cases...
Glioblastoma (GBM) is a heterogeneous tumor made up of cell states that evolve over time. Here, w... more Glioblastoma (GBM) is a heterogeneous tumor made up of cell states that evolve over time. Here, we modeled tumor evolutionary trajectories during standard-of-care treatment using multimodal single-cell analysis of a primary tumor sample, corresponding mouse xenografts subjected to standard of care therapy, and recurrent tumor at autopsy. We mined the multimodal data with single cell SYstems Genetics Network AnaLysis (scSYGNAL) to identify a network of 52 regulators that mediate treatment-induced shifts in xenograft tumor-cell states that were also reflected in recurrence. By integrating scSYGNAL-derived regulatory network information with transcription factor accessibility deviations derived from single-cell ATAC-seq data, we developed consensus networks that regulate subpopulations of primary and recurrent tumor cells. Finally, by matching targeted therapies to active regulatory networks underlying tumor evolutionary trajectories, we provide a framework for applying single-cell-bas...
Glioblastoma is a heterogeneous tumor made up of cell states that evolve over time. We modeled tu... more Glioblastoma is a heterogeneous tumor made up of cell states that evolve over time. We modeled tumor evolutionary trajectories during standard-of-care treatment using multimodal single-cell analysis of a primary tumor sample, corresponding mouse xenografts subjected to standard of care therapy, and recurrent tumor at autopsy. We mined the multimodal data with single cell SYstems Genetics Network AnaLysis (scSYGNAL) to identify a network of 52 regulators that mediate treatment-induced shifts in xenograft tumor-cell states that were also reflected in recurrence. By integrating scSYGNAL-derived regulatory network information with transcription factor accessibility deviations derived from single-cell ATAC-seq data, we developed consensus networks that regulate subpopulations of primary and recurrent tumor cells. Finally, by matching targeted therapies to active regulatory networks underlying tumor evolutionary trajectories, we provide a framework for applying single-cell-based precision...
Single-cell analysis has become a powerful approach for the molecular characterization of complex... more Single-cell analysis has become a powerful approach for the molecular characterization of complex tissues. Methods for quantifying gene expression1 and chromatin accessibility2 of single cells are now well-established, but analysis of chromatin regions with specific histone modifications has been technically challenging. Here, we adapt the recently published CUT&Tag method3 to scalable single-cell platforms to profile chromatin landscapes in single cells (scCUT&Tag) from complex tissues. We focus on profiling Polycomb Group (PcG) silenced regions marked by H3K27 trimethylation (H3K27me3) in single cells as an orthogonal approach to chromatin accessibility for identifying cell states. We show that scCUT&Tag profiling of H3K27me3 distinguishes cell types in human blood and allows the generation of cell-type-specific PcG landscapes from heterogeneous tissues. Furthermore, we use scCUT&Tag to profile H3K27me3 in a brain tumor patient before and after treatment, identifying cell types in...
Experimental and molecular pathology, Apr 16, 2017
Metastasis to the pineal region is a rare event, and esophageal adenocarcinoma metastatic to the ... more Metastasis to the pineal region is a rare event, and esophageal adenocarcinoma metastatic to the pineal region is exceptionally rare, with only two cases reported in the current literature. Here, we characterize a third case of metastatic esophageal adenocarcinoma to the pineal region, and compare clinicopathological characteristics among all three cases. The three patients were men, with ages at neurological presentation ranging from 48 to 65years. Time from initial esophageal adenocarcinoma diagnosis to development of neurologic symptoms ranged from 12 to 23months. Neuroimaging in all cases showed an isolated enhancing pineal region mass with sizes ranging from 1.8 to 2.2cm. All cases were believed to have local control of esophageal disease prior to metastatic sequela, with initial treatment including esophageal resection with or without chemoradiation therapy. No cases had evidence of primary site disease progression at time of metastatic presentation, nor were there signs of ot...
Robot-assisted stereoelectroencephalography (sEEG) is frequently employed to localize epileptogen... more Robot-assisted stereoelectroencephalography (sEEG) is frequently employed to localize epileptogenic zones in patients with medically refractory epilepsy (MRE). Its methodology is well described in adults, but less so in children. Given the limited information available on pediatric applications, the objective is to describe the unique technical challenges and considerations of sEEG in the pediatric population. In this report, we describe our institutional experience with the technical aspects of robot-assisted sEEG in an exclusively pediatric epilepsy surgery unit, focusing on pre-, intra-, and post-operative nuances that are particular to the pediatric population. The pediatric population presents several unique challenges in sEEG, including reduced skull thickness relative to adults, incomplete neurologic development, and often special behavioral considerations. Pre-operative selection of putative epileptogenic zones requires careful multidisciplinary decision-making. Intraoperative attention to nuances in positioning, clamp selection, registration, and electrode placement are necessary. Activity considerations and electrode migration and removal are key post-operative considerations. Robot-assisted sEEG is a valuable tool in the armamentarium of techniques to characterize MRE. However, special considerations must be given to the pediatric population to optimize safety and efficacy.
BACKGROUND AND IMPORTANCE: Primary intracranial malignant melanomas (PIMMs) are quite rare, compr... more BACKGROUND AND IMPORTANCE: Primary intracranial malignant melanomas (PIMMs) are quite rare, comprising 1% of melanomas and 0.07% of intracranial tumors. PIMMs have been reported in a variety of intracranial locations, but there has only been 1 reported instance of PIMM occurring in the brainstem. In this study, we describe the second reported case of primary pontine malignant melanoma and its treatment. CLINICAL PRESENTATION: A 40-year-old man presented with right hemiparesis, diplopia, and dysarthria. MRI demonstrated a hemorrhagic, expansile, and heterogeneously enhancing lesion in the left pons with edema extending to the left thalamus and posterior limb of the internal capsule. Surgical resection was performed through a transpetrosal approach. Pathology resulted as malignant melanoma immunopositive for BRAF V600E mutation. Complete oncological workup revealed no other lesions; thus, he was diagnosed with PIMM of the brainstem. CONCLUSION: We report a rare case of primary pontine...
INTRODUCTION: The pathogenesis of intracranial aneurysms (IAs) is complex, with both genetic and ... more INTRODUCTION: The pathogenesis of intracranial aneurysms (IAs) is complex, with both genetic and environmental risk factors. Much effort has been devoted to identifying the molecular mechanisms of IAs to develop new therapies halting the progression of IAs. METHODS: Deep whole exome sequencing was performed for 11 anterior circulation, sporadic saccular IAs from 10 unrelated patients. Paired aneurysm-peripheral blood DNA samples were compared to evaluate the somatic saccular aneurysm exome alterations. Variants were validated with deep next generation sequencing methods. The genetic landscape of a validation cohort of 60 aneurysms was analyzed by targeted deep sequencing of a vascular panel of genes. RESULTS: Whole exome sequencing revealed somatic variants in 7 of 11 saccular aneurysms. Most coding somatic variants found were missense (68%). Somatic variants in multiple genes were common, all falling into similar allele frequencies (3-18%). Two aneurysms from one patient underwent ...
INTRODUCTION: Activating variants in platelet-derived growth factor receptor beta (PDGFRB) are as... more INTRODUCTION: Activating variants in platelet-derived growth factor receptor beta (PDGFRB) are associated with aneurysms. Our group previously described a patient with multiple fusiform intracranial aneurysms who was found to have a somatic mosaic variant in PDGFRB. The relationship between the mosaic effects of PDGFRB variants and the vascular phenotypes is not well understood. METHODS: Following death due to subarachnoid hemorrhage, samples from the index patient’s intracranial, coronary, aortic, and radial arteries were biopsied and preserved. DNA was extracted and alternate allele fractions (AAF) of PDGFRB variants were determined using digital droplet PCR. Histopathological analysis was performed by a board-certified neuropathologist. RESULTS: A total of 80 biopsies were obtained. The AAFs of variant PDGFRB in the vertebral artery, basilar artery, and P1 segment aneurysms were 28.7%, 16.4%, and 17.8%, respectively. The AAF of the coronary and radial artery aneurysms were 22.3% ...
BackgroundActivating variants in platelet‐derived growth factor receptor beta (PDGFRB), including... more BackgroundActivating variants in platelet‐derived growth factor receptor beta (PDGFRB), including a variant we have previously described (p.Tyr562Cys [g.149505130T>C [GRCh37/hg19]; c.1685A>G]), are associated with development of multiorgan pathology, including aneurysm formation. To investigate the association between the allele fraction genotype and histopathologic phenotype, we performed an expanded evaluation of post‐mortem normal and aneurysmal tissue specimens from the previously published index patient.Methods and ResultsFollowing death due to diffuse subarachnoid hemorrhage in a patient with mosaic expression of the above PDGFRB variant, specimens from the intracranial, coronary, radial and aortic arteries were harvested. DNA was extracted and alternate allele fractions (AAF) ofPDGFRBwere determined using digital droplet PCR. Radiographic and histopathologic findings, together with genotype expression ofPDGFRBwere then correlated in aneurysmal tissue and compared to non...
Emerging evidence suggest WHO grade III meningiomas that arise de novo as opposed to dedifferenti... more Emerging evidence suggest WHO grade III meningiomas that arise de novo as opposed to dedifferentiating from a lower grade may harbor differing prognoses. To investigate this, a single institution retrospective analysis of prospectively acquired patients between 1999 and 2018 was performed. Clinical data and radiographic parameters were reviewed to calculate progression free survival and overall survival in patients undergoing microsurgical resection. Next generation targeted sequencing of meningioma associated genes was performed on 11 tumors. Eighteen patients were identified as undergoing surgical resection of WHO grade III meningioma. Nine patients (50%) had de novo arising tumors and nine patients had secondary progressive tumors. To compare outcomes, only those patients undergoing gross total resection (Simpson grade I) were included for survival analysis. There was an improvement in median progression free survival for de novo resected tumors as compared to secondary progressive tumors (p = 0.02). Median overall survival for patients with de novo tumors was not statistically improved compared to that of secondary progressive tumors (p = 0.22). Next generation sequencing of targeted genes (NF2, BAP1, TRAF7, KLF4, SMO and AKT) revealed 5/11 tumors containing mutations in the NF2 gene, 2/11 containing BAP1 mutations, and a single tumor containing mutations in both NF2 and TRAF7. More mutations in NF2 and BAP1 were seen in the secondary progressive tumors. In conclusion, patients undergoing gross total resection for de novo arising grade III meningiomas showed improved progression free survival, though similar overall survival, as compared to those patients with secondary progressive tumors. Further studies focused on tumor associated genes and other associated risk factors are needed to improve risk-stratification.
OBJECTIVEDespite their technical simplicity, cranioplasty procedures carry high reported morbidit... more OBJECTIVEDespite their technical simplicity, cranioplasty procedures carry high reported morbidity rates. The authors here present the largest study to date on complications after cranioplasty, focusing specifically on the relationship between complications and timing of the operation.METHODSThe authors retrospectively reviewed all cranioplasty cases performed at Harborview Medical Center over the past 10.75 years. In addition to relevant clinical and demographic characteristics, patient morbidity and mortality data were abstracted from the electronic medical record. Cox proportional-hazards models were used to analyze variables potentially associated with the risk of infection, hydrocephalus, seizure, hematoma, and bone flap resorption.RESULTSOver the course of 10.75 years, 754 cranioplasties were performed at a single institution. Sixty percent of the patients who underwent these cranioplasties were male, and the median follow-up overall was 233 days. The 30-day mortality rate was...
OBJECTIVE The authors' aim was to report the largest study on predictors of infection after c... more OBJECTIVE The authors' aim was to report the largest study on predictors of infection after cranioplasty and to assess the predictive value of intraoperative bone flap cultures before cryopreservation. METHODS They retrospectively examined all cranioplasties performed between March 2004 and November 2014. Throughout this study period, the standard protocol during initial craniectomy was to obtain a culture swab of the extracted autologous bone flap (ABF)-prior to its placement in cytostorage-to screen for microbial contamination. Two consecutive protocols were employed for the use and interpretation of the intraoperative swab culture results: A) From March 2004 through June 2013, any culture-positive ABF (+ABF) was discarded and a custom synthetic prosthesis was implanted at the time of cranioplasty. B) From July 2013 through November 2014, any ABF with a skin flora organism was not discarded. Instead, cryopreservation was maintained and the +ABF was re-implanted after a 10-minu...
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences, Jan 26, 2015
Preoperative embolization of meningioma is commonly performed; however, there is no consensus on ... more Preoperative embolization of meningioma is commonly performed; however, there is no consensus on the best embolic material to reduce intraoperative blood loss and surgery time. We retrospectively assessed the safety and efficacy of 56 cases of preoperative embolization of the middle meningeal artery with N-butyl cyanoacrylate (NBCA) in 105 cases of surgery for meningioma. We also defined a blood loss to tumor volume ratio to compensate for bias caused by tumor volume, and analyzed limited cases (the embolized group n = 52, the non-embolized group n = 21) of the convexity, the parasagittal region, the falx, and the sphenoidal ridge. The blood loss to tumor volume ratio was significantly less in the embolized group (p < 0.007). Preoperative embolization could be useful for cases with the external carotid artery as the dominant feeder vessel (p < 0.02); however, the efficacy decreased for cases with an internal carotid artery feeder. Transient complications occurred in four cases...
Glioblastoma (GBM) is a heterogeneous tumor made up of cell states that evolve over time. Here, w... more Glioblastoma (GBM) is a heterogeneous tumor made up of cell states that evolve over time. Here, we modeled tumor evolutionary trajectories during standard-of-care treatment using multimodal single-cell analysis of a primary tumor sample, corresponding mouse xenografts subjected to standard of care therapy, and recurrent tumor at autopsy. We mined the multimodal data with single cell SYstems Genetics Network AnaLysis (scSYGNAL) to identify a network of 52 regulators that mediate treatment-induced shifts in xenograft tumor-cell states that were also reflected in recurrence. By integrating scSYGNAL-derived regulatory network information with transcription factor accessibility deviations derived from single-cell ATAC-seq data, we developed consensus networks that regulate subpopulations of primary and recurrent tumor cells. Finally, by matching targeted therapies to active regulatory networks underlying tumor evolutionary trajectories, we provide a framework for applying single-cell-bas...
Glioblastoma is a heterogeneous tumor made up of cell states that evolve over time. We modeled tu... more Glioblastoma is a heterogeneous tumor made up of cell states that evolve over time. We modeled tumor evolutionary trajectories during standard-of-care treatment using multimodal single-cell analysis of a primary tumor sample, corresponding mouse xenografts subjected to standard of care therapy, and recurrent tumor at autopsy. We mined the multimodal data with single cell SYstems Genetics Network AnaLysis (scSYGNAL) to identify a network of 52 regulators that mediate treatment-induced shifts in xenograft tumor-cell states that were also reflected in recurrence. By integrating scSYGNAL-derived regulatory network information with transcription factor accessibility deviations derived from single-cell ATAC-seq data, we developed consensus networks that regulate subpopulations of primary and recurrent tumor cells. Finally, by matching targeted therapies to active regulatory networks underlying tumor evolutionary trajectories, we provide a framework for applying single-cell-based precision...
Single-cell analysis has become a powerful approach for the molecular characterization of complex... more Single-cell analysis has become a powerful approach for the molecular characterization of complex tissues. Methods for quantifying gene expression1 and chromatin accessibility2 of single cells are now well-established, but analysis of chromatin regions with specific histone modifications has been technically challenging. Here, we adapt the recently published CUT&Tag method3 to scalable single-cell platforms to profile chromatin landscapes in single cells (scCUT&Tag) from complex tissues. We focus on profiling Polycomb Group (PcG) silenced regions marked by H3K27 trimethylation (H3K27me3) in single cells as an orthogonal approach to chromatin accessibility for identifying cell states. We show that scCUT&Tag profiling of H3K27me3 distinguishes cell types in human blood and allows the generation of cell-type-specific PcG landscapes from heterogeneous tissues. Furthermore, we use scCUT&Tag to profile H3K27me3 in a brain tumor patient before and after treatment, identifying cell types in...
Experimental and molecular pathology, Apr 16, 2017
Metastasis to the pineal region is a rare event, and esophageal adenocarcinoma metastatic to the ... more Metastasis to the pineal region is a rare event, and esophageal adenocarcinoma metastatic to the pineal region is exceptionally rare, with only two cases reported in the current literature. Here, we characterize a third case of metastatic esophageal adenocarcinoma to the pineal region, and compare clinicopathological characteristics among all three cases. The three patients were men, with ages at neurological presentation ranging from 48 to 65years. Time from initial esophageal adenocarcinoma diagnosis to development of neurologic symptoms ranged from 12 to 23months. Neuroimaging in all cases showed an isolated enhancing pineal region mass with sizes ranging from 1.8 to 2.2cm. All cases were believed to have local control of esophageal disease prior to metastatic sequela, with initial treatment including esophageal resection with or without chemoradiation therapy. No cases had evidence of primary site disease progression at time of metastatic presentation, nor were there signs of ot...
Robot-assisted stereoelectroencephalography (sEEG) is frequently employed to localize epileptogen... more Robot-assisted stereoelectroencephalography (sEEG) is frequently employed to localize epileptogenic zones in patients with medically refractory epilepsy (MRE). Its methodology is well described in adults, but less so in children. Given the limited information available on pediatric applications, the objective is to describe the unique technical challenges and considerations of sEEG in the pediatric population. In this report, we describe our institutional experience with the technical aspects of robot-assisted sEEG in an exclusively pediatric epilepsy surgery unit, focusing on pre-, intra-, and post-operative nuances that are particular to the pediatric population. The pediatric population presents several unique challenges in sEEG, including reduced skull thickness relative to adults, incomplete neurologic development, and often special behavioral considerations. Pre-operative selection of putative epileptogenic zones requires careful multidisciplinary decision-making. Intraoperative attention to nuances in positioning, clamp selection, registration, and electrode placement are necessary. Activity considerations and electrode migration and removal are key post-operative considerations. Robot-assisted sEEG is a valuable tool in the armamentarium of techniques to characterize MRE. However, special considerations must be given to the pediatric population to optimize safety and efficacy.
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Papers by Samuel Emerson