KENSHO IWATATE | Fukushima University (original) (raw)
Papers by KENSHO IWATATE
Journal of Neurological Surgery Part B: Skull Base, 2016
Journal of Neurological Surgery Part B: Skull Base
Pseudomeningocele is a rare complication of head trauma. An 7-year-old male child who fell from p... more Pseudomeningocele is a rare complication of head trauma. An 7-year-old male child who fell from playground equipment was admitted to hospital with lambdoid sutural diastatic fracture. As epidural and subgaleal fluid collections gradually developed from the subsequent day of admission, a subgaleal drain was placed for cerebrospinal fluid (CSF) diversion. In addition, the scalp just over the fractured segment was compressed by band after drainage whereby the CSF leak was stopped. On the basis of our experience with this case, we suggest that appropriate management enables repair of posttraumatic pseudomeningocele in early stages of injury.
Cureus, 2021
Treatment of ruptured high-grade Spetzler-Martin (S&M) arteriovenous malformation (AVM) is challe... more Treatment of ruptured high-grade Spetzler-Martin (S&M) arteriovenous malformation (AVM) is challenging and requires a multidisciplinary treatment approach. Here, we report a case of ruptured giant callosal Grade V AVM in a child initially treated with stereotactic radiotherapy followed by endovascular embolization with Onyx; a management approach recently described in a few reports on the “postradiosurgical embolization” method. Complete obliteration was achieved 20 months after stereotactic radiotherapy and embolization. In this article, we discuss the usefulness and significance of postradiosurgical embolization, particularly for high-grade AVMs. To our knowledge, this is the first case with a giant Spetzler-Martin Grade V AVM treated with a postradiosurgical embolization method.
Reports of Practical Oncology & Radiotherapy
Neurologia medico-chirurgica
We conducted a feasibility study to investigate the therapeutic effect of bevacizumab on vestibul... more We conducted a feasibility study to investigate the therapeutic effect of bevacizumab on vestibular schwannomas (VS) associated with neurofibromatosis type 2 (NF2) in a sample of Japanese patients. Ten NF2 patients were selected between 2013 and 2018: nine women and one man, with ages ranging from 12 to 45 years (mean: 29.4). Bevacizumab was administered intravenously in 5 mg/kg doses four times, with an inter-dose interval of 2 weeks. Seventeen tumors were followed for 3-72 months (mean: 39). A reduction from baseline tumor volume of at least 20% was considered a therapeutic radiologic response. Maximum reduction in tumor volume was identified in the 3rd month in 11 tumors, and in the 6th month in three tumors. Three tumors did not show any response to bevacizumab. A radiologic response was detected in seven tumors (41%). There was a significantly lower tumor volume mean in the 3rd month in comparison to the baseline for the entire sample. Tumors in patients aged 25 and above showed a significant reduction in volume in the 3rd month and significantly lower tumor-volume-to-baseline ratio than younger patients in both the 3rd and 6th months. The interaction between 'time' and 'age group' factors significantly affected the therapeutic outcome of bevacizumab on tumor volume. This study investigated the therapeutic effects of bevacizumab on NF2-associated vestibular schwannomas in Japanese patients. Bevacizumab appears to be a useful therapeutic choice in NF2 cases to control the growth of VS. Therefore, a randomised control trial to prove this assumption is necessary.
World neurosurgery, 2017
To characterize the clinical features of patients with neurofibromatosis type 2 (NF2) and determi... more To characterize the clinical features of patients with neurofibromatosis type 2 (NF2) and determine prognostic risk factors for progressive disabilities. In this retrospective cohort study of the Japanese national NF2 registry between 2009 and 2013, clinical data (demographic, history, oncologic, and neurologic) of 807 patients with a diagnosis of NF2 were analyzed. The overall severity of neurologic disability was assessed using a comprehensive 25-point scoring system encompassing a wide variety of neurologic deficits. In 587 patients in whom longitudinal disability data were available, multivariate logistic regression was performed to identify risk factors for significant progression of disability. The clinical characteristics of the Japanese NF2 population were heterogeneous. The median age of onset was 24 years (range, 1-80 years), the male:female ratio was 1:1.29, and the initial severity score was 4 (range, 0-22) out of 25 points. A family history of NF2 was present in 33% of ...
Japanese Journal of Neurosurgery
： Carotid artery stenting (CAS)for severe internal carotid artery stenosis has recently been intr... more ： Carotid artery stenting (CAS)for severe internal carotid artery stenosis has recently been intro − duced as an a】 ternative to carotid endarterectomy ． Here ， we present an unusual clinical course of a patient after CAS using the Angioguard filter device ． Case ： We present the case of a 75 − year − 01d 皿 an who suffered f め m cerebral infarctiQn in the left thalalnus ． Three − dinlensional computed tomography confirmed asymptomatic stenosis (83％)in the lef し internal carotid arter ￥ Carotid artery stenting (CAS)was performed lls｛ ng a distal protection 丘1ter device (Angioguard ， Cordis ， Miarni Lakes ， FL ， USA) ． Following poststenting dilatat ｛ n ， the patient became drowsy and he developed left hemiplegia ． Cerebral angiography showed no slowing or stopping of blood flow ， and no delayed filling to the venous phase ． Diffusion − weighted magnetic resonance imaging (DW − MRI)demonstrated rnultiple tiny cortical infarctions in the left frontal − parietal lobes ipsilateral to the operated side ． The symptoms of the patient appeared more seri − ous than the DW − MRI findings suggested ． After CAS ， the patient showed good recovery after receiving medical treatments for about 2 weeks ． Conclusion ：We suspected that liquified microplaques (く 100μm)passed through the pores of the filter device and embolized cerebral arterioles or capillaries ， which might have caused the symptomatic cerebral infarction ． Although most cerebral infarctions following CAS are asymptomatic ， the filter device used here could not ensure complete absence of the development of symptomatic cerebral infarction ． Therefore ， f皿 ther improve − ment of the filter device is necessary in order to reduce the incidence of microembo1 ｛ sms causing symptomatic cerebral infarction ． Moreover， the characteristics of carotid plaques and the hemodynamics of the carotid artery must be evaluated before performing CAS ， and then the most appropriate treatment 丘om the various therapeutic options should be selected ．
Journal of Neurological Surgery Part B: Skull Base
Brain and nerve = Shinkei kenkyū no shinpo, 2009
Pseudomeningocele is a rare complication of head trauma. An 7-year-old male child who fell from p... more Pseudomeningocele is a rare complication of head trauma. An 7-year-old male child who fell from playground equipment was admitted to hospital with lambdoid sutural diastatic fracture. As epidural and subgaleal fluid collections gradually developed from the subsequent day of admission, a subgaleal drain was placed for cerebrospinal fluid (CSF) diversion. In addition, the scalp just over the fractured segment was compressed by band after drainage whereby the CSF leak was stopped. On the basis of our experience with this case, we suggest that appropriate management enables repair of posttraumatic pseudomeningocele in early stages of injury.
Brain and nerve = Shinkei kenkyū no shinpo, 2009
Pseudomeningocele is a rare complication of head trauma. An 7-year-old male child who fell from p... more Pseudomeningocele is a rare complication of head trauma. An 7-year-old male child who fell from playground equipment was admitted to hospital with lambdoid sutural diastatic fracture. As epidural and subgaleal fluid collections gradually developed from the subsequent day of admission, a subgaleal drain was placed for cerebrospinal fluid (CSF) diversion. In addition, the scalp just over the fractured segment was compressed by band after drainage whereby the CSF leak was stopped. On the basis of our experience with this case, we suggest that appropriate management enables repair of posttraumatic pseudomeningocele in early stages of injury.
Journal of Neuroendovascular Therapy, 2012
Neuropathology, 2010
We report a case of an unusual glioma termed "pr... more We report a case of an unusual glioma termed "primitive polar spongioblastoma" that displayed characteristic palisading tumor cells at the light microscopic level. The patient was a 52-year-old woman who underwent subtotal removal for a left frontotemporal tumor. The palisading pattern was present throughout the tumor. Several glial markers were revealed by immunohistochemical examination, but no neuronal markers were observed. Genetic studies showed O-6-methylguanine-DNA methyltransferase (MGMT) methylation, wild type IDH1, and the absence of 1p/19q loss of heterozygosity (LOH) in the tumor genes. Based on histological and genetic features, this tumor might not be suited to any of neuroepithelial tumor in the recent WHO classification. We consider that cases such as this should be temporarily set under a separate heading and be entrusted to future investigation after more cases have been accumulated.
IntroductionMeningioma is the most common adult primary brain tumor originating from meningeal co... more IntroductionMeningioma is the most common adult primary brain tumor originating from meningeal coverings of the brain and spinal cord. Commonly, World Health Organization (WHO) grade-I meningiomas are slowly growing and surgically curative, some present with clinically aggressive behavior, invading the skull base bone and soft tissues by extending into the extracranial spaces.MethodsTo detect the genetic background of the Skull Base Invasive Low-grade Meningioma (SBILM), we conducted a comprehensive analysis of gene expression was conducted on 32 meningioma samples.ResultsThe cluster analysis of the gene expression profile demonstrated a distinctive clustering pattern of the SBILM. Based on the clinical behavior and the microarray findings, they might be a distinct subgroup of meningiomas.ConclusionFurther studies on characterization of genes specifically expressed by the SBILM could lead to the development of diagnostic tools, differentiating it from other WHO grade-I meningiomas a...
Population Characteristics and Progressive Disability in Neuofibromatosis Type 2, 2017
- OBJECTIVE: To characterize the clinical features of patients with neurofibromatosis type 2 (NF2... more - OBJECTIVE: To characterize the clinical features of patients with neurofibromatosis type 2 (NF2) and determine prognostic risk factors for progressive disabilities.
- METHODS: In this retrospective cohort study of the Jap- anese national NF2 registry between 2009 and 2013, clinical data (demographic, history, oncologic, and neurologic) of 807 patients with a diagnosis of NF2 were analyzed. The overall severity of neurologic disability was assessed using a comprehensive 25-point scoring system encompassing a wide variety of neurologic deficits. In 587 patients in whom longitudinal disability data were available, multivariate logistic regression was performed to identify risk factors for significant progression of disability.
- RESULTS: The clinical characteristics of the Japanese NF2 population were heterogeneous. The median age of onset was 24 years (range, 1e80 years), the male:female ratio was 1:1.29, and the initial severity score was 4 (range, 0e22) out of 25 points. A family history of NF2 was present in 33% of the patients. Most frequent clinical features were bilateral cranial nerve VIII nerve sheath tumor (NST) in 87%, spinal NST in 80%, hearing loss in 65%, spinal dysfunction in 50%, intracranial meningioma in 49%, and facial paresis in
During surgery for gliomas in and around the corticospinal tract (CST) it is fundamental to maxim... more During surgery for gliomas in and around the corticospinal tract (CST) it is fundamental to maximize tumor resection and minimize motor functional complications. However, its achievement is challenging because of the obscurity of the tumor bulk and the invisibility of the CST itself within uniformly appearing white matter. During the past decade innovation has dramatically improved preoperative diagnostic tools that can now provide valuable information on the tumor border and the course of white matter tracts. Especially diffusion-tensor imaging (DTI), depicting differences in tissue anisotropy, allows us to resolve the dominant fiber orientation (eigenvector) in each imaged voxel. DTI-based fiber tracking, or tractography, is accomplished by connecting the eigenvectors of neighboring voxels so as to visualize the course of subcortical fibers (9, 26). Although preopera-tive surgical planning can be done more effectively with these techniques, brain shift occurs during tumor resection and complicates positional relationships. Consequently, navigation with only preoperative images lacks precision. Intraoperative magnetic resonance imaging (iMRI) is an innovative method to solve this problem, and it has recently become widespread (2, 6-8, 16, 23, 27, 32, 33, 35). Since 2006 when we installed the integrated theatre (Brain-SUITE, BrainLAB AG; Heimsteten, Germany) that incorporates high-field (1.5 Tesla) iMRI and neuronavigation, we have used it for these patients (15). Intraoperative MRI enables us to estimate the degree of tumor resection during surgery. In addition, a high magnetic-field MRI enables the visualization of the course of the CST even after brain shift has occurred, through DTI obtained intraoperatively . With this technique, preservation of motor function during surgery can be further maximized. Furthermore, we also perform motor-evoked potential (MEP) monitoring. With direct subcortical stimulation, the location of the CST was electrophysiologically identified. Our hypothesis is that intra-Ⅲ BACKGROUND: Our goal is to indicate the importance of combining intraoperative tractography with motor-evoked potential (MEP) monitoring for glioma surgery in motor eloquent areas. Ⅲ METHODS: Tumor removal was performed in 28 patients with gliomas in and around the corticospinal tract (CST), in an operation theater equipped with an integrated high-field intraoperative magnetic resonance imaging and a neuronavigation system. Diffusion-tensor imaging-based tractography of the CST was implemented preoperatively and intraoperatively. When the surgically manipulated area came close to the corticospinal pathway, MEP responses were elicited by subcortical stimulation. Responsive areas were compared with the locations of fibers traced by preoperative and intraoperative tractography. Imaging and functional outcomes were reviewed. Ⅲ RESULTS: Intraoperative tractography demonstrated significant inward or outward shift during surgery. MEP responses were observed around the tract at various intensities, and the distance between MEP responsive sites and intraoperative tractography was significantly correlated with the stimulation intensity (P < 0.01). The distance from preoperative tractography was not correlated. A more than subtotal resection was achieved in 24 patients (85.7%). Transient motor deterioration was seen in 12 patients (42.8%), and a permanent deficit was seen in 1 patient (3.5%). Ⅲ CONCLUSIONS: We found that intraoperative tractography demonstrated the location of the CST more accurately than preoperative tractography. The results of the linear regression between distance and stimulation intensity were informative for guiding approaches to tumor remnants without impinging on the CST. The combination of intraoperative tractography and MEP monitoring can enhance the quality of surgery for gliomas in motor eloquent areas.
T he glossopharyngeal and vagus nerves and the cranial component of the accessory nerve are toget... more T he glossopharyngeal and vagus nerves and the cranial component of the accessory nerve are together designated the lower CN complex. The nuclei of these nerves are located in the medulla oblongata. The dorsal vagal nuclei form the bulging vagal trigone on the floor of the fourth ventricle. Cranial nerves IX, X, and XI arise from the medulla oblongata as a line of rootlets distributed along the posterior edge of the inferior olive in the postolivary sulcus. These rootlets coalesce to form nerve root bundles, which then traverse the lateral cerebellomedullary cistern. The bundles enter the jugular foramen close to each other through dural openings designated the glossopharyngeal meatus (for CN IX) and the vagal meatus (for CNs X and XI). 27 A permanent dural septum separates the glossopharyngeal from the vagal meatus. Cranial nerve XI is traditionally considered to have both a cranial component (crCN XI) and a spinal root (spCN XI); however, the existence of a crCN XI is disputed, with different authors assigning the "traditional" crCXI rootlets to either CN X or XI. Magnetic resonance imaging has been used successfully to visualize CNs and associated lesions within the basal cisterns. To our knowledge, however, only 1 imaging study has revealed the anatomy of the lower CN complex in detail. Pathological entities such as schwannomas 1,4 and meningiomas 13 can affect the cisternal portions of the lower CN complex. Compression of the REZ Cisternal segments of the glossopharyngeal, vagus, and accessory nerves: detailed magnetic resonance imagingdemonstrated anatomy and neurovascular relationships
Journal of Neurological Surgery Part B: Skull Base, 2016
Journal of Neurological Surgery Part B: Skull Base
Pseudomeningocele is a rare complication of head trauma. An 7-year-old male child who fell from p... more Pseudomeningocele is a rare complication of head trauma. An 7-year-old male child who fell from playground equipment was admitted to hospital with lambdoid sutural diastatic fracture. As epidural and subgaleal fluid collections gradually developed from the subsequent day of admission, a subgaleal drain was placed for cerebrospinal fluid (CSF) diversion. In addition, the scalp just over the fractured segment was compressed by band after drainage whereby the CSF leak was stopped. On the basis of our experience with this case, we suggest that appropriate management enables repair of posttraumatic pseudomeningocele in early stages of injury.
Cureus, 2021
Treatment of ruptured high-grade Spetzler-Martin (S&M) arteriovenous malformation (AVM) is challe... more Treatment of ruptured high-grade Spetzler-Martin (S&M) arteriovenous malformation (AVM) is challenging and requires a multidisciplinary treatment approach. Here, we report a case of ruptured giant callosal Grade V AVM in a child initially treated with stereotactic radiotherapy followed by endovascular embolization with Onyx; a management approach recently described in a few reports on the “postradiosurgical embolization” method. Complete obliteration was achieved 20 months after stereotactic radiotherapy and embolization. In this article, we discuss the usefulness and significance of postradiosurgical embolization, particularly for high-grade AVMs. To our knowledge, this is the first case with a giant Spetzler-Martin Grade V AVM treated with a postradiosurgical embolization method.
Reports of Practical Oncology & Radiotherapy
Neurologia medico-chirurgica
We conducted a feasibility study to investigate the therapeutic effect of bevacizumab on vestibul... more We conducted a feasibility study to investigate the therapeutic effect of bevacizumab on vestibular schwannomas (VS) associated with neurofibromatosis type 2 (NF2) in a sample of Japanese patients. Ten NF2 patients were selected between 2013 and 2018: nine women and one man, with ages ranging from 12 to 45 years (mean: 29.4). Bevacizumab was administered intravenously in 5 mg/kg doses four times, with an inter-dose interval of 2 weeks. Seventeen tumors were followed for 3-72 months (mean: 39). A reduction from baseline tumor volume of at least 20% was considered a therapeutic radiologic response. Maximum reduction in tumor volume was identified in the 3rd month in 11 tumors, and in the 6th month in three tumors. Three tumors did not show any response to bevacizumab. A radiologic response was detected in seven tumors (41%). There was a significantly lower tumor volume mean in the 3rd month in comparison to the baseline for the entire sample. Tumors in patients aged 25 and above showed a significant reduction in volume in the 3rd month and significantly lower tumor-volume-to-baseline ratio than younger patients in both the 3rd and 6th months. The interaction between 'time' and 'age group' factors significantly affected the therapeutic outcome of bevacizumab on tumor volume. This study investigated the therapeutic effects of bevacizumab on NF2-associated vestibular schwannomas in Japanese patients. Bevacizumab appears to be a useful therapeutic choice in NF2 cases to control the growth of VS. Therefore, a randomised control trial to prove this assumption is necessary.
World neurosurgery, 2017
To characterize the clinical features of patients with neurofibromatosis type 2 (NF2) and determi... more To characterize the clinical features of patients with neurofibromatosis type 2 (NF2) and determine prognostic risk factors for progressive disabilities. In this retrospective cohort study of the Japanese national NF2 registry between 2009 and 2013, clinical data (demographic, history, oncologic, and neurologic) of 807 patients with a diagnosis of NF2 were analyzed. The overall severity of neurologic disability was assessed using a comprehensive 25-point scoring system encompassing a wide variety of neurologic deficits. In 587 patients in whom longitudinal disability data were available, multivariate logistic regression was performed to identify risk factors for significant progression of disability. The clinical characteristics of the Japanese NF2 population were heterogeneous. The median age of onset was 24 years (range, 1-80 years), the male:female ratio was 1:1.29, and the initial severity score was 4 (range, 0-22) out of 25 points. A family history of NF2 was present in 33% of ...
Japanese Journal of Neurosurgery
： Carotid artery stenting (CAS)for severe internal carotid artery stenosis has recently been intr... more ： Carotid artery stenting (CAS)for severe internal carotid artery stenosis has recently been intro − duced as an a】 ternative to carotid endarterectomy ． Here ， we present an unusual clinical course of a patient after CAS using the Angioguard filter device ． Case ： We present the case of a 75 − year − 01d 皿 an who suffered f め m cerebral infarctiQn in the left thalalnus ． Three − dinlensional computed tomography confirmed asymptomatic stenosis (83％)in the lef し internal carotid arter ￥ Carotid artery stenting (CAS)was performed lls｛ ng a distal protection 丘1ter device (Angioguard ， Cordis ， Miarni Lakes ， FL ， USA) ． Following poststenting dilatat ｛ n ， the patient became drowsy and he developed left hemiplegia ． Cerebral angiography showed no slowing or stopping of blood flow ， and no delayed filling to the venous phase ． Diffusion − weighted magnetic resonance imaging (DW − MRI)demonstrated rnultiple tiny cortical infarctions in the left frontal − parietal lobes ipsilateral to the operated side ． The symptoms of the patient appeared more seri − ous than the DW − MRI findings suggested ． After CAS ， the patient showed good recovery after receiving medical treatments for about 2 weeks ． Conclusion ：We suspected that liquified microplaques (く 100μm)passed through the pores of the filter device and embolized cerebral arterioles or capillaries ， which might have caused the symptomatic cerebral infarction ． Although most cerebral infarctions following CAS are asymptomatic ， the filter device used here could not ensure complete absence of the development of symptomatic cerebral infarction ． Therefore ， f皿 ther improve − ment of the filter device is necessary in order to reduce the incidence of microembo1 ｛ sms causing symptomatic cerebral infarction ． Moreover， the characteristics of carotid plaques and the hemodynamics of the carotid artery must be evaluated before performing CAS ， and then the most appropriate treatment 丘om the various therapeutic options should be selected ．
Journal of Neurological Surgery Part B: Skull Base
Brain and nerve = Shinkei kenkyū no shinpo, 2009
Pseudomeningocele is a rare complication of head trauma. An 7-year-old male child who fell from p... more Pseudomeningocele is a rare complication of head trauma. An 7-year-old male child who fell from playground equipment was admitted to hospital with lambdoid sutural diastatic fracture. As epidural and subgaleal fluid collections gradually developed from the subsequent day of admission, a subgaleal drain was placed for cerebrospinal fluid (CSF) diversion. In addition, the scalp just over the fractured segment was compressed by band after drainage whereby the CSF leak was stopped. On the basis of our experience with this case, we suggest that appropriate management enables repair of posttraumatic pseudomeningocele in early stages of injury.
Brain and nerve = Shinkei kenkyū no shinpo, 2009
Pseudomeningocele is a rare complication of head trauma. An 7-year-old male child who fell from p... more Pseudomeningocele is a rare complication of head trauma. An 7-year-old male child who fell from playground equipment was admitted to hospital with lambdoid sutural diastatic fracture. As epidural and subgaleal fluid collections gradually developed from the subsequent day of admission, a subgaleal drain was placed for cerebrospinal fluid (CSF) diversion. In addition, the scalp just over the fractured segment was compressed by band after drainage whereby the CSF leak was stopped. On the basis of our experience with this case, we suggest that appropriate management enables repair of posttraumatic pseudomeningocele in early stages of injury.
Journal of Neuroendovascular Therapy, 2012
Neuropathology, 2010
We report a case of an unusual glioma termed &amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;pr... more We report a case of an unusual glioma termed &amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;primitive polar spongioblastoma&amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; that displayed characteristic palisading tumor cells at the light microscopic level. The patient was a 52-year-old woman who underwent subtotal removal for a left frontotemporal tumor. The palisading pattern was present throughout the tumor. Several glial markers were revealed by immunohistochemical examination, but no neuronal markers were observed. Genetic studies showed O-6-methylguanine-DNA methyltransferase (MGMT) methylation, wild type IDH1, and the absence of 1p/19q loss of heterozygosity (LOH) in the tumor genes. Based on histological and genetic features, this tumor might not be suited to any of neuroepithelial tumor in the recent WHO classification. We consider that cases such as this should be temporarily set under a separate heading and be entrusted to future investigation after more cases have been accumulated.
IntroductionMeningioma is the most common adult primary brain tumor originating from meningeal co... more IntroductionMeningioma is the most common adult primary brain tumor originating from meningeal coverings of the brain and spinal cord. Commonly, World Health Organization (WHO) grade-I meningiomas are slowly growing and surgically curative, some present with clinically aggressive behavior, invading the skull base bone and soft tissues by extending into the extracranial spaces.MethodsTo detect the genetic background of the Skull Base Invasive Low-grade Meningioma (SBILM), we conducted a comprehensive analysis of gene expression was conducted on 32 meningioma samples.ResultsThe cluster analysis of the gene expression profile demonstrated a distinctive clustering pattern of the SBILM. Based on the clinical behavior and the microarray findings, they might be a distinct subgroup of meningiomas.ConclusionFurther studies on characterization of genes specifically expressed by the SBILM could lead to the development of diagnostic tools, differentiating it from other WHO grade-I meningiomas a...
Population Characteristics and Progressive Disability in Neuofibromatosis Type 2, 2017
- OBJECTIVE: To characterize the clinical features of patients with neurofibromatosis type 2 (NF2... more - OBJECTIVE: To characterize the clinical features of patients with neurofibromatosis type 2 (NF2) and determine prognostic risk factors for progressive disabilities.
- METHODS: In this retrospective cohort study of the Jap- anese national NF2 registry between 2009 and 2013, clinical data (demographic, history, oncologic, and neurologic) of 807 patients with a diagnosis of NF2 were analyzed. The overall severity of neurologic disability was assessed using a comprehensive 25-point scoring system encompassing a wide variety of neurologic deficits. In 587 patients in whom longitudinal disability data were available, multivariate logistic regression was performed to identify risk factors for significant progression of disability.
- RESULTS: The clinical characteristics of the Japanese NF2 population were heterogeneous. The median age of onset was 24 years (range, 1e80 years), the male:female ratio was 1:1.29, and the initial severity score was 4 (range, 0e22) out of 25 points. A family history of NF2 was present in 33% of the patients. Most frequent clinical features were bilateral cranial nerve VIII nerve sheath tumor (NST) in 87%, spinal NST in 80%, hearing loss in 65%, spinal dysfunction in 50%, intracranial meningioma in 49%, and facial paresis in
During surgery for gliomas in and around the corticospinal tract (CST) it is fundamental to maxim... more During surgery for gliomas in and around the corticospinal tract (CST) it is fundamental to maximize tumor resection and minimize motor functional complications. However, its achievement is challenging because of the obscurity of the tumor bulk and the invisibility of the CST itself within uniformly appearing white matter. During the past decade innovation has dramatically improved preoperative diagnostic tools that can now provide valuable information on the tumor border and the course of white matter tracts. Especially diffusion-tensor imaging (DTI), depicting differences in tissue anisotropy, allows us to resolve the dominant fiber orientation (eigenvector) in each imaged voxel. DTI-based fiber tracking, or tractography, is accomplished by connecting the eigenvectors of neighboring voxels so as to visualize the course of subcortical fibers (9, 26). Although preopera-tive surgical planning can be done more effectively with these techniques, brain shift occurs during tumor resection and complicates positional relationships. Consequently, navigation with only preoperative images lacks precision. Intraoperative magnetic resonance imaging (iMRI) is an innovative method to solve this problem, and it has recently become widespread (2, 6-8, 16, 23, 27, 32, 33, 35). Since 2006 when we installed the integrated theatre (Brain-SUITE, BrainLAB AG; Heimsteten, Germany) that incorporates high-field (1.5 Tesla) iMRI and neuronavigation, we have used it for these patients (15). Intraoperative MRI enables us to estimate the degree of tumor resection during surgery. In addition, a high magnetic-field MRI enables the visualization of the course of the CST even after brain shift has occurred, through DTI obtained intraoperatively . With this technique, preservation of motor function during surgery can be further maximized. Furthermore, we also perform motor-evoked potential (MEP) monitoring. With direct subcortical stimulation, the location of the CST was electrophysiologically identified. Our hypothesis is that intra-Ⅲ BACKGROUND: Our goal is to indicate the importance of combining intraoperative tractography with motor-evoked potential (MEP) monitoring for glioma surgery in motor eloquent areas. Ⅲ METHODS: Tumor removal was performed in 28 patients with gliomas in and around the corticospinal tract (CST), in an operation theater equipped with an integrated high-field intraoperative magnetic resonance imaging and a neuronavigation system. Diffusion-tensor imaging-based tractography of the CST was implemented preoperatively and intraoperatively. When the surgically manipulated area came close to the corticospinal pathway, MEP responses were elicited by subcortical stimulation. Responsive areas were compared with the locations of fibers traced by preoperative and intraoperative tractography. Imaging and functional outcomes were reviewed. Ⅲ RESULTS: Intraoperative tractography demonstrated significant inward or outward shift during surgery. MEP responses were observed around the tract at various intensities, and the distance between MEP responsive sites and intraoperative tractography was significantly correlated with the stimulation intensity (P < 0.01). The distance from preoperative tractography was not correlated. A more than subtotal resection was achieved in 24 patients (85.7%). Transient motor deterioration was seen in 12 patients (42.8%), and a permanent deficit was seen in 1 patient (3.5%). Ⅲ CONCLUSIONS: We found that intraoperative tractography demonstrated the location of the CST more accurately than preoperative tractography. The results of the linear regression between distance and stimulation intensity were informative for guiding approaches to tumor remnants without impinging on the CST. The combination of intraoperative tractography and MEP monitoring can enhance the quality of surgery for gliomas in motor eloquent areas.
T he glossopharyngeal and vagus nerves and the cranial component of the accessory nerve are toget... more T he glossopharyngeal and vagus nerves and the cranial component of the accessory nerve are together designated the lower CN complex. The nuclei of these nerves are located in the medulla oblongata. The dorsal vagal nuclei form the bulging vagal trigone on the floor of the fourth ventricle. Cranial nerves IX, X, and XI arise from the medulla oblongata as a line of rootlets distributed along the posterior edge of the inferior olive in the postolivary sulcus. These rootlets coalesce to form nerve root bundles, which then traverse the lateral cerebellomedullary cistern. The bundles enter the jugular foramen close to each other through dural openings designated the glossopharyngeal meatus (for CN IX) and the vagal meatus (for CNs X and XI). 27 A permanent dural septum separates the glossopharyngeal from the vagal meatus. Cranial nerve XI is traditionally considered to have both a cranial component (crCN XI) and a spinal root (spCN XI); however, the existence of a crCN XI is disputed, with different authors assigning the "traditional" crCXI rootlets to either CN X or XI. Magnetic resonance imaging has been used successfully to visualize CNs and associated lesions within the basal cisterns. To our knowledge, however, only 1 imaging study has revealed the anatomy of the lower CN complex in detail. Pathological entities such as schwannomas 1,4 and meningiomas 13 can affect the cisternal portions of the lower CN complex. Compression of the REZ Cisternal segments of the glossopharyngeal, vagus, and accessory nerves: detailed magnetic resonance imagingdemonstrated anatomy and neurovascular relationships