[Significance of Colorectal Cancer Resection for the Elderly].

INTRODUCTION: Elderly patients requiring surgical treatment is increasing in Japan, and while surgical treatment is expected to be effective even in the very elderly, there is a lack of evidence for the safety and efficacy of surgical resection due to problems with perioperative management and operative tolerance. We therefore retrospectively examined the short-term and long-term outcomes of colorectal cancer surgery for the very elderly at our hospital. SUBJECTS: The study included 14 cases of colorectal cancer in the very elderly who underwent radical resection at our hospital between January 2010 and March 2020. RESULTS: The mean age was 92 years, PS; 1/2=8/6, ASA-PS; 2/3/4=8/4/2, primary site was C/A/T/S/R= 2/5/2/2/3, pStage; 1/2/3=1/9/4, and only 1 case of decompression with ileus tube due to obstructive symptoms was treated before surgery. All patients underwent radical surgery. Median blood loss was 61 mL, median operation time was 190.5 min, and median postoperative hospital stay was 16 days. 5 patients had CD≥2 complications. All patients did not receive adjuvant chemotherapy, and recurrence in was observed 3 patients. CONCLUSION: Surgical treatment of very elderly patients seems to be acceptable under appropriate patient selection.

Long-term outcomes of robot-assisted versus minimally invasive esophagectomy in patients with thoracic esophageal cancer: a propensity score-matched study.

BACKGROUND: Recently, robot-assisted minimally invasive esophagectomy (RAMIE) has gained popularity worldwide. Some studies have compared the long-term results of RAMIE and minimally invasive esophagectomy (MIE). However, there are no reports on the long-term outcomes of RAMIE in Japan. This study compared the long-term outcomes of RAMIE and MIE. METHODS: This retrospective study included 86 patients with thoracic esophageal cancer who underwent RAMIE or MIE at our hospital from June 2010 to December 2016. Propensity score matching (PSM) was employed, incorporating co-variables such as confounders or risk factors derived from the literature and clinical practice. These variables included age, sex, body mass index, alcohol consumption, smoking history, American Society of Anesthesiologists stage, comorbidities, tumor location, histology, clinical TNM stage, and preoperative therapy. The primary endpoint was 5-year overall survival (OS), and the secondary endpoints were 5-year disease-free survival (DFS) and recurrence rates. RESULTS: Before PSM, the RAMIE group had a longer operation time (min) than the MIE group (P = 0.019). RAMIE also exhibited significantly lower blood loss volume (mL) (P < 0.001) and fewer three-field lymph node dissections (P = 0.028). Postoperative complications (Clavien-Dindo: CD ≥ 2) were significantly lower in the RAMIE group (P = 0.04), and postoperative hospital stay was significantly shorter than the MIE group (P < 0.001). After PSM, the RAMIE and MIE groups consisted of 26 patients each. Blood loss volume was significantly smaller (P = 0.012), postoperative complications (Clavien-Dindo ≥ 2) were significantly lower (P = 0.021), and postoperative hospital stay was significantly shorter (P < 0.001) in the RAMIE group than those in the MIE group. The median observation period was 63 months. The 5-year OS rates were 73.1% and 80.8% in the RAMIE and MIE groups, respectively (P = 0.360); the 5-year DFS rates were 76.9% and 76.9% in the RAMIE and MIE groups, respectively (P = 0.749). Six of 26 patients (23.1%) in each group experienced recurrence, with a median recurrence period of 41.5 months in the RAMIE group and 22.5 months in the MIE group. CONCLUSIONS: Compared with MIE, RAMIE led to no differences in long-term results, suggesting that RAMIE is a comparable technique.

Prospective evaluation of common hepatic duct histopathology at the time of choledochal cyst excision ranging from children to adults.

PURPOSE: To evaluate common hepatic duct just distal to the HE anastomosis (d-CHD) prospectively for mucosal damage, inflammation, fibrosis, dysplasia, carcinoma in situ, malignant transformation, effects of serum amylase, and symptoms at presentation in CC cases ranging from children to adults. METHODS: Cross-sections of d-CHD obtained at cyst excision 2018-2023 from 65 CC patients; 40 children (< 15 years old), 25 adults (≥ 15) were examined with hematoxylin and eosin, Ki-67, S100P, IMP3, p53, and Masson's trichrome to determine an inflammation score (IS), fibrosis score (FS), and damaged mucosa rate (DMR; damaged mucosa expressed as a percentage of the internal circumference). RESULTS: Mean age at cyst excision ("age") was 18.2 years (range: 3 months-74 years). Significant inverse correlations were found for age and DMR (p = 0.002), age and IS (p = 0.011), and age and Ki-67 (p = 0.01). FS did not correlate with age (p = 0.32) despite significantly increased IS in children. Dysplasia was identified in a 4-month-old girl with cystic CC. Serum amylase was elevated in high DMR subjects. CONCLUSIONS: High DMR, high IS, and evidence of dysplasia in pediatric CC suggest children are at risk for serious sequelae best managed by precise histopathology, protocolized follow-up, and awareness that premalignant histopathology can arise in infancy.

Percutaneous transjugular approach without arterial monitoring for the treatment of a direct carotid-cavernous fistula with vascular Ehlers-Danlos syndrome: illustrative case.

BACKGROUND: Vascular Ehlers-Danlos syndrome (vEDS) because of COL3A1 mutations is a rare inherited collagen vascular disease associated with spontaneous arterial dissections, aneurysms, vessel rupture, and organ rupture. A direct carotid-cavernous fistula (CCF) is the most common central nervous system vascular anomaly in vEDS; however, its treatment is challenging due to extremely fragile arteries and veins. OBSERVATIONS: A 22-year-old woman presented with pulsatile tinnitus and mild diplopia. CCF formation without trauma, cervical dissecting aneurysms, thin skin, and multiple ligament tears, as well as a genetic analysis, led to a diagnosis of vEDS. To minimize the risk of vascular injury in the thoracoperitoneal cavity, the internal jugular vein was directly punctured and the CCF was embolized transvenously using the triple-overlay road-mapping technique without arterial monitoring. The CCF was completely occluded, and the patient showed an excellent clinical course without neurological or vascular complications. LESSONS: Physicians and neurosurgeons should consider vEDS when treating younger patients with spontaneous CCF without trauma and investigate the possibility of genetic abnormalities and systemic vascular pathology. Transvenous embolization of a CCF through the transjugular route using the triple-overlay road-mapping technique can minimize the risk of vascular injury in a patient with vEDS.

Incidence of anastomotic stricture after hepaticojejunostomy with continuous sutures in patients who underwent laparoscopic pancreaticoduodenectomy.

PURPOSE: Laparoscopic hepatojejunostomy (HJ) with continuous sutures is commonly performed in laparoscopic pancreaticoduodenectomy (LPD). This study aimed to investigate the long-term surgical outcomes of HJ in LPD. METHODS: We retrospectively evaluated 103 consecutive patients who underwent pancreaticoduodenectomy via laparoscopic HJ with continuous suturing using multifilament (n = 48) or monofilament-absorbable sutures (n = 47). RESULTS: During follow-up, anastomotic stricture of HJ was identified in 8 (7.8%) patients via balloon enteroscopy-assisted cholangiography. The median time from surgery to confirmation of stricture formation was 7.6 months (range 3.6-19.4). The incidence of HJ stricture was significantly higher in patients with a thin bile duct (diameter < 6.0 mm) than in those with a thick bile duct (diameter ≥ 6.0 mm) [7/27 (25.9%) vs. 1/76 (1.3%), respectively, p < 0.01]. Similarly, it was significantly higher in the monofilament group than in the multifilament group [7/54 (13.0%) vs. 1/49 (2.0%), respectively, p = 0.04]. In the monofilament suture group, 37.5% of patients with thin bile ducts developed stricture after HJ. A multivariate analysis revealed that a thin bile duct was an independent risk factor for HJ stricture (hazard ratio: 25.3, p < 0.01). CONCLUSIONS: Stricture after laparoscopic HJ using continuous sutures frequently occurs in patients with thin bile ducts, particularly when monofilament-absorbable suture is used.

Morphological characteristics of infected subdural hematoma: Comparison with images of chronic subdural hematoma.

OBJECTIVES: Infected subdural hematoma (ISH) is a rare type of subdural empyema, with fewer than 50 cases reported to date. Its radiological features have not been adequately described, making diagnosis challenging. At our institution, two adults presented with ISH, which exhibited a characteristic shape on preoperative imaging. PATIENTS AND METHODS: This study examined ISH cases and chronic subdural hematoma (CSH) cases that underwent surgery at the Ishikawa Prefectural Central Hospital between January 2016 and March 2018. To distinguish ISH from CSH, we focused on three specific radiological features: the biconvex shape of the hematoma, presence of a high-density region at the lower end of the hematoma on plain computed tomography (CT), and presence of a hyper-intense signal within the hematoma on diffusion weighted imaging (DWI). RESULTS: We analyzed 30 ISH (current and previously reported) and 102 CSH cases in our study. We found no statistically significant associations between the hematoma type (ISH or CSH) and the presence of a high-density region at the lower end of the hematoma on plain CT (p = 0.13) or the presence of hyperintensity in the hematoma on DWI (p = 1.00). Conversely, a statistically significant association was found between the hematoma type and the biconvex shape of the hematoma (p < 0.01). CONCLUSION: These results suggest that the shape of the hematoma on imaging provides valuable information that can be used to differentiate ISH from CSH and optimize therapeutic approaches.

A Rare Case of Chronic Subdural Hematoma Coexisting With Metastatic Tumor.

BACKGROUND: Incidence of chronic subdural hematoma (CSH) associated with metastases of extraneural malignancies is rare. We report a rare case of CSH wherein most of the CSH cavity was occupied with metastatic cancer cells; in addition, we review the literature. CASE DESCRIPTION: A 68-year-old man with a history of gastric cancer presented to our hospital with dysarthria and shoulder paralysis; CSH was diagnosed from preoperative imaging findings. When the hematoma was removed via a small craniotomy, besides the hematoma, we observed an abnormal mass of tissue in the capsule. Pathologically, the mass was consistent with the findings of metastatic gastric cancer. Although the symptoms immediately disappeared postoperatively, a symptomatic acute subdural hematoma with midline shift was observed on postoperative day 27. Emergency craniotomy and hematoma and tumor removal were performed. Pathologic examination showed hemorrhagic necrosis in the tumor, which had not been initially observed. The postoperative course progressed without hematoma recurrence. CONCLUSIONS: To the best of our knowledge, this is the first report of a CSH accompanied by tumor metastasis in most of the CSH cavity. Although rare, if a patient with cancer has CSH, the CSH should be treated considering the possibility of metastasis.

Receptor Tyrosine Kinases: Principles and Functions in Glioma Invasion.

Protein tyrosine kinases are enzymes that are capable of adding a phosphate group to specific tyrosines on target proteins. A receptor tyrosine kinase (RTK) is a tyrosine kinase located at the cellular membrane and is activated by binding of a ligand via its extracellular domain. Protein phosphorylation by kinases is an important mechanism for communicating signals within a cell and regulating cellular activity; furthermore, this mechanism functions as an "on" or "off" switch in many cellular functions. Ninety unique tyrosine kinase genes, including 58 RTKs, were identified in the human genome; the products of these genes regulate cellular proliferation, survival, differentiation, function, and motility. Tyrosine kinases play a critical role in the development and progression of many types of cancer, in addition to their roles as key regulators of normal cellular processes. Recent studies have revealed that RTKs such as epidermal growth factor receptor (EGFR), platelet-derived growth factor receptor (PDGFR), c-Met, Tie, Axl, discoidin domain receptor 1 (DDR1), and erythropoietin-producing human hepatocellular carcinoma (Eph) play a major role in glioma invasion. Herein, we summarize recent advances in understanding the role of RTKs in glioma pathobiology, especially the invasive phenotype, and present the perspective that RTKs are a potential target of glioma therapy.

Two cases of primary supratentorial intracranial rhabdomyosarcoma with DICER1 mutation which may belong to a "spindle cell sarcoma with rhabdomyosarcoma-like feature, DICER1 mutant".

Rhabdomyosarcoma is the most common soft-tissue sarcoma affecting children and adolescents. It is defined as a malignant neoplasm characterized by morphologic, immunohistochemical, ultrastructural, or molecular genetic evidence of primary skeletal muscle differentiation, usually in the absence of any other pattern of differentiation. Primary intracranial rhabdomyosarcoma (PIRMS) is an extremely rare neoplasm, with only 60 cases reported in the literature, and generally has poor prognosis with an overall survival of only 9.1 months. The DICER1 gene encodes an RNA endoribonuclease that plays a key role in gene expression regulation through the production of small RNAs. Herein, we report two cases of PIRMS with somatic DICER1 mutation showing morphological and immunohistochemical evidence of primary skeletal muscle differentiation; the two cases share common clinical features, including young age, supratentorial tumor, and onset of intratumoral bleeding. Although methylation profiling was not performed, both cases shared clinical and pathological characteristics in common with recently proposed methylation entity "spindle cell sarcoma with rhabdomyosarcoma-like features, DICER1 mutant (SCS-RMSlike-DICER1)''. Our cases provide further evidence of the link between primary intracranial sarcoma and DICER1 mutation which may form a distinct entity.

Enlargement of Langerhans cell histiocytosis of the hypothalamus with progression into the basal ganglia and white matter.

BACKGROUND: Langerhans cell histiocytosis (LCH) is a rare disease that may affect the central nervous system; it is caused by dendritic cell proliferation, and typically occurs in children. LCH frequently appears in the pituitary stalk and rarely results in multiple enhanced lesions in the brain parenchyma. CASE DESCRIPTION: We present a case of a 40-year-old woman who deveolped panhypopituitarism and central diabetes insipidus in the postpartum period requiring hormone replacement therapy. At first, magnetic resonance imaging only revealed thickening of the pituitary stalk; while 6 months later, a single enhanced mass lesion was detected in the hypothalamus. Another 5 months later, the lesion had enlarged with appearance of multiple, enhanced satellite lesions in the basal ganglia and white matter. The patient underwent successful craniotomy to obtain a biopsy sample; LCH of the hypothalamus was definitively diagnosis by histopathological examination. Steroids were administrated and resulted in significant reduction of all lesions. CONCLUSIONS: Definitive histopathological diagnosis and subsequent appropriate therapy, such as steroid administration, are required when LCH lesions in the hypothalamus become progressively enlarged and new lesions appear in the brain parenchyma.

Damage of the right dorsal superior longitudinal fascicle by awake surgery for glioma causes persistent visuospatial dysfunction.

Patients with glioma frequently present with neuropsychological deficits preoperatively and/or postoperatively, and these deficits may remain after the chronic phase. However, little is known about postoperative recovery course of right hemispheric function. We therefore studied the characteristics and causes of persistent cognitive dysfunction in right cerebral hemispheric glioma. Eighteen patients who underwent awake surgery participated in this study. All patients who received preoperative neuropsychological examinations were assigned to two groups according to their test results: preoperative deficit and normal. They were reassessed 1 week and 3 months after surgery. The rates of remaining deficits in the deficit group at chronic phase were higher than those of the normal group for all functions. Despite preoperative normal function, the remaining rate for visuospatial cognitive deficits was the highest among all functions. The voxel-based lesion-symptom mapping analysis for visuospatial cognition revealed that a part of the medial superior and middle frontal gyri were resected with high probability in patients with low visuospatial cognitive accuracy. Our study indicates that in patients with preoperative neuropsychological deficits, these deficits tend to remain until the chronic phase. Visuospatial dysfunction frequently persists until the chronic phase, which might reflect damage to the superior longitudinal fasciclus I and II.

Sigmoidocolocystoplasty for neurogenic bladder reviewed after 20 years.

BACKGROUND/PURPOSE: We report the current status of patients who underwent augmentation cystoplasty (AC) at least 20years previously. METHODS: Surgical history, incidence of urinary tract infection (UTI) and bladder stones, vesicoureteral reflux (VUR), urine cytology, renal function, a colon cancer tumor marker (carcinoembryonic antigen: CEA), and patient outcomes were assessed. RESULTS: Forty patients who underwent AC (mean age: 34.4years; mean follow-up time: 24.3years) were analyzed. Mean age at AC was 11years. Incidence of bladder stones was 30%. There were no incidences of carcinoma after AC, and CEA levels were not increased. Ureteral reimplantation (URI) was performed in 21 patients. URI performed at the same time as AC was successful in 14 cases (93%) and unsuccessful in 1 (7%) because of persistent VUR. UTI developed after AC in only 1 patient (2.5%) with persistent VUR. This patient required unilateral nephrectomy 18years after the AC because of repeated UTIs. Thirty-four patients (85%) were employed, and 4 (10%) were married. Two of the 19 female patients (11%) had experienced pregnancy and delivery. Five patients (13%) had mental disorders. CONCLUSION: Ultra long-term follow-up suggests that AC is a safe procedure with manageable sequelae, although some mental health issues remain. TYPE OF STUDY: Case series with no comparison group. LEVEL OF EVIDENCE: Level IV.

Biological basis and clinical study of glycogen synthase kinase- 3ß-targeted therapy by drug repositioning for glioblastoma.

BACKGROUND: Glycogen synthase kinase (GSK)-3ß has emerged as an appealing therapeutic target for glioblastoma (GBM). Here, we investigated the therapeutic effect of the current approved drugs against GBM via inhibition of GSK3ß activity both, in experimental setting and in a clinical study for recurrent GBM patients by repositioning existent drugs in combination with temozolomide (TMZ). MATERIALS AND METHODS: Progression-free and overall survival rates were compared between patients with low or high expression of active GSK3ß in the primary tumor. GBM cells and a mouse model were examined for the effects of GSK3ß-inhibitory drugs, cimetidine, lithium, olanzapine, and valproate. The safety and efficacy of the cocktail of these drugs (CLOVA cocktail) in combination with TMZ were tested in the mouse model and in a clinical study for recurrent GBM patients. RESULTS: Activation of GSK3ß in the tumor inversely correlated with patient survival as an independent prognostic factor. CLOVA cocktail significantly inhibited cell invasion and proliferation. The patients treated with CLOVA cocktail in combination with TMZ showed increased survival compared to the control group treated with TMZ alone. CONCLUSIONS: Repositioning of the GSK3ß-inhibitory drugs improved the prognosis of refractory GBM patients with active GSK3ß in tumors. Combination of CLOVA cocktail and TMZ is a promising approach for recurrent GBM.

[Multiple Tentorial Dural Arteriovenous Fistulas with Acquired Pial Arteriovenous Fistula Presented with Unilateral Eye Symptoms Successfully Treated by Transarterial Embolization and Direct Surgery:A Case Report].

A 58-year-old man presented with slowly progressive chemosis, exophthalmos, and blepharedema of the left eye. Digital subtraction angiography revealed multiple dural arteriovenous fistulas(dAVFs)involving the bilateral tentorium, superior sagittal sinus, and right frontal convexity. In addition, occlusion of the left cavernous sinus and left sigmoid sinus were observed, which could lead to venous hypertension and might be associated with the occurrence of multiple dAVFs. Along with the congestion of the left ophthalmic vein, increased intracranial pressure due to the left tentorial dAVF with cortical venous reflux could have caused the left eye symptoms; therefore, the tentorial lesion was treated first. Although the proximal occlusion of the vein of Labbe, drainer of the left tentorial dAVF, was achieved after embolization using n-butyl cyanoacrylate via the external carotid artery, an arteriovenous shunt between the middle cerebral artery and the distal site of the vein of Labbe was newly visualized after embolization. The newly visualized lesion was treated with further surgical intervention. A pial AVF arising from several peripheral branches of the left middle cerebral artery with drainage into the distal site of the vein of Labbe was confirmed during the surgery, and interruption of the vein of Labbe was performed. The left eye symptoms of the patient significantly improved after the surgery, and postoperative angiogram revealed no residual shunt. Thus, the patient was treated using a combined approach of endovascular and direct surgeries, after which he recovered uneventfully.

MR Spectroscopy to Distinguish between Supratentorial Intraventricular Subependymoma and Central Neurocytoma.

PURPOSE: The purpose of this study was to discriminate supratentorial intraventricular subependymoma (SIS) from central neurocytoma (CNC) using magnetic resonance spectroscopy (MRS). METHODS: Single-voxel proton MRS using a 1.5T or 3T MR scanner from five SISs, five CNCs, and normal controls were evaluated. They were examined using a point-resolved spectroscopy. Automatically calculated ratios comparing choline (Cho), N-acetylaspartate (NAA), myoinositol (MI), and/or glycine (Gly) to creatine (Cr) were determined. Evaluation of Cr to unsuppressed water (USW) was also performed. Mann-Whitney U test was carried out to test the significance of differences in the metabolite ratios. Detectability of lactate (Lac) and alanine (Ala) was evaluated. RESULTS: Although a statistically significant difference (P < 0.0001) was observed in Cho/Cr among SIS, control spectra, and CNC, no statistical difference was noted between SIS and control spectra (P = 0.11). Statistically significant differences were observed in NAA/Cr between SIS and CNC (P = 0.04) or control spectra (P < 0.0001). A statistically significant difference was observed in MI and/or Gly to Cr between SIS and control spectra (P = 0.03), and CNC and control spectra (P < 0.0006). There were no statistical differences between SIS and CNC for MI and/or Gly to Cr (P = 0.32). Significant statistical differences were found between SIS and control spectra (P < 0.0053), control spectra and CNC (P < 0.0016), and SIS and CNC (P < 0.0083) for Cr to USW. Lac inverted doublets were confirmed in two SISs. Triplets of Lac and Ala were detected in four spectra of CNC. CONCLUSION: The present study showed that MRS can be useful in discriminating SIS from CNC.

Fluorescence intensity and bright spot analyses using a confocal microscope for photodynamic diagnosis of brain tumors.

BACKGROUND: In photodynamic diagnosis using 5-aminolevulinic acid (5-ALA), discrimination between the tumor and normal tissue is very important for a precise resection. However, it is difficult to distinguish between infiltrating tumor and normal regions in the boundary area. In this study, fluorescent intensity and bright spot analyses using a confocal microscope is proposed for the precise discrimination between infiltrating tumor and normal regions. METHODS: From the 5-ALA-resected brain tumor tissue, the red fluorescent and marginal regions were sliced for observation under a confocal microscope. Hematoxylin and eosin (H&E) staining were performed on serial slices of the same tissue. According to the pathological inspection of the H&E slides, the tumor and infiltrating and normal regions on confocal microscopy images were investigated. From the fluorescent intensity of the image pixels, a histogram of pixel number with the same fluorescent intensity was obtained. The fluorescent bright spot sizes and total number were compared between the marginal and normal regions. RESULTS: The fluorescence intensity distribution and average intensity in the tumor were different from those in the normal region. The probability of a difference from the dark enhanced the difference between the tumor and the normal region. The bright spot size and number in the infiltrating tumor were different from those in the normal region. CONCLUSIONS: Fluorescence intensity analysis is useful to distinguish a tumor region, and a bright spot analysis is useful to distinguish between infiltrating tumor and normal regions. These methods will be important for the precise resection or photodynamic therapy of brain tumors.

[Intraluminal Thrombus in Internal Carotid Artery Successfully Treated with Adjuvant Anticoagulant Therapy Followed by Carotid Endarterectomy:A Case Report].

BACKGROUND: An intraluminal thrombus in the carotid artery is relatively rare. A high frequency of perioperative symptomatic stroke has been reported in patients undergoing carotid endarterectomy, and no standard therapy has yet been developed. CASE PRESENTATION: A 69-year-old woman, with no history of trauma, presented with ischemic stroke and mild right hemiparesis. Computed tomography and MRI showed an infarction in the left parietal region. A carotid Doppler study showed carotid stenosis on the left side. Further investigation with digital subtraction angiography confirmed significant carotid artery stenosis with an intraluminal thrombus in the left internal carotid artery. She was treated with initial intravenous anticoagulant therapy followed by carotid endarterectomy with thrombus removal 14 days after admission(subacute phase). There was no postoperative complication and she had uneventful course over 3 years of follow-up. CONCLUSION: Initial adjuvant anticoagulant therapy for symptomatic intraluminal thrombus followed by carotid revascularization is an effective surgical strategy. A meticulous surgical procedure is required to perform a carotid endarterectomy in patients with an intraluminal thrombus.

Li(+) Local Structure in Li-Tetraglyme Solvate Ionic Liquid Revealed by Neutron Total Scattering Experiments with the (6/7)Li Isotopic Substitution Technique.

Equimolar mixtures of lithium bis(trifluoromethanesulfonyl)amide (LiTFSA) and tetraglyme (G4: CH3O-(CH2CH2O)4-CH3) yield the solvate (or chelate) ionic liquid [Li(G4)][TFSA], which is a homogeneous transparent solution at room temperature. Solvate ionic liquids (SILs) are currently attracting increasing research interest, especially as new electrolytes for Li-sulfur batteries. Here, we performed neutron total scattering experiments with (6/7)Li isotopic substitution to reveal the Li(+) solvation/local structure in [Li(G4)][TFSA] SILs. The experimental interference function and radial distribution function around Li(+) agree well with predictions from ab initio calculations and MD simulations. The model solvation/local structure was optimized with nonlinear least-squares analysis to yield structural parameters. The refined Li(+) solvation/local structure in the [Li(G4)][TFSA] SIL shows that lithium cations are not coordinated to all five oxygen atoms of the G4 molecule (deficient five-coordination) but only to four of them (actual four-coordination). The solvate cation is thus considerably distorted, which can be ascribed to the limited phase space of the ethylene oxide chain and competition for coordination sites from the TFSA anion.

Chronic spatial working memory deficit associated with the superior longitudinal fasciculus: a study using voxel-based lesion-symptom mapping and intraoperative direct stimulation in right prefrontal glioma surgery.

OBJECTIVE Although the right prefrontal region is regarded as a silent area, chronic deficits of the executive function, including working memory (WM), could occur after resection of a right prefrontal glioma. This may be overlooked by postoperative standard examinations, and the disabilities could affect the patient's professional life. The right prefrontal region is a part of the frontoparietal network and is subserved by the superior longitudinal fasciculus (SLF); however, the role of the SLF in spatial WM is unclear. This study investigated a persistent spatial WM deficit in patients who underwent right prefrontal glioma resection, and evaluated the relationship between the spatial WM deficit and the SLF. METHODS Spatial WM was examined in 24 patients who underwent prefrontal glioma resection (right, n = 14; left, n = 10) and in 14 healthy volunteers using a spatial 2-back task during the long-term postoperative period. The neural correlates of spatial WM were evaluated using lesion mapping and voxel-based lesion-symptom mapping. In addition, the spatial 2-back task was performed during surgery under direct subcortical electrical stimulation in 2 patients with right prefrontal gliomas. RESULTS Patients with a right prefrontal lesion had a significant chronic spatial WM deficit. Voxel-based lesion-symptom mapping analysis revealed a significant correlation between spatial WM deficit and the region that overlapped the first and second segments of the SLF (SLF I and SLF II). Two patients underwent awake surgery and had difficulties providing the correct responses in the spatial 2-back task with direct subcortical electrical stimulation on the SLF I, which was preserved and confirmed by postoperative diffusion tensor imaging tractography. These patients exhibited no spatial WM deficits during the postoperative immediate and long-term periods. CONCLUSIONS Spatial WM deficits may persist in patients who undergo resection of the tumor located in the right prefrontal brain parenchyma. Injury to the dorsal frontoparietal subcortical white matter pathway, i.e., the SLF I or SLF I and II, could play a causal role in this chronic deficit. A persistent spatial WM deficit, without motor and language deficits, could affect the professional life of the patient. In such cases, awake surgery would be useful to detect the spatial WM network with appropriate task during tumor exploration.