Clinical features and prognostic factors of patients with cancer-associated stroke.

BACKGROUND: Cerebrovascular diseases in cancer patients significantly aggravate their condition and prognosis; therefore, prompt and accurate diagnosis and treatment are important. The purpose of this study was to investigate patient demographics, laboratory data, brain magnetic resonance imaging (MRI) findings, and prognosis among patients with stroke and cancer, especially cancer-associated ischemic stroke (CAIS). METHODS: We performed a retrospective, single-center study. We enrolled consecutive patients who had acute stroke and were admitted to our hospital between January 2011 and December 2021. We collected general demographic characteristics, cancer histopathological type, laboratory data, brain MRI findings, and prognosis data. RESULTS: Among 2040 patients with acute stroke, a total of 160 patients (7.8%) had active cancer. The types of strokes were cerebral infarction, cerebral hemorrhage, subarachnoid hemorrhage, and transient ischemic attack in 124, 25, 5, and 6 patients, respectively. Among the patients with ischemic stroke, there were 69 cases of CAIS. Pancreas and adenocarcinoma were the most frequent types of primary tumor and histopathology. Patients with adenocarcinoma and those with cerebral infarctions in both bilateral anterior and posterior cerebral circulation areas showed higher D-dimer levels. Pancreatic cancer and high plasma D-dimer levels were associated with poor survival rate. CONCLUSION: CAIS was seen more frequently in patients with pancreatic cancer and adenocarcinoma. Pancreatic cancer and high plasma D-dimer levels were potential factors of poor prognosis in patients with CAIS.

Primary neurolymphomatosis of the trigeminal nerve.

We report a case of a primary malignant lymphoma of the trigeminal nerve that was associated with facial pain. A 65-year-old man was examined at another hospital for unilateral facial pain. Carbamazepine was prescribed, but his symptoms did not improve. Magnetic resonance imaging (MRI) revealed swelling of the trigeminal nerve and a mass lesion in Meckel's cave. The patient was referred to our hospital at this point. Gadolinium-enhanced MRI and F18-Fluorodeoxyglucose-position emission tomography suggested a likely malignant tumour and a biopsy was performed. Histopathological examination showed diffuse a large B cell lymphoma. The patient was treated with high-dose methotrexate (HD-MTX) and radiotherapy. Despite responding well to initial treatment, the patient relapsed, with lymphoma observed throughout the body. He died of pneumonia 18 months after the initial diagnosis. Facial pain is a symptom that is commonly managed in general practice. If symptoms do not improve, repeated imaging studies, including contrast MRI, is warranted. This is the first reported case of primary neurolymphomatosis (NL) of the trigeminal nerve associated with facial pain alone. Furthermore, HD-MTX and radiotherapy may be considered for the management of primary NL of a cranial nerve.

Facephenes and rainbows: Causal evidence for functional and anatomical specificity of face and color processing in the human brain.

Neuroscientists have long debated whether some regions of the human brain are exclusively engaged in a single specific mental process. Consistent with this view, fMRI has revealed cortical regions that respond selectively to certain stimulus classes such as faces. However, results from multivoxel pattern analyses (MVPA) challenge this view by demonstrating that category-selective regions often contain information about "nonpreferred" stimulus dimensions. But is this nonpreferred information causally relevant to behavior? Here we report a rare opportunity to test this question in a neurosurgical patient implanted for clinical reasons with strips of electrodes along his fusiform gyri. Broadband gamma electrocorticographic responses in multiple adjacent electrodes showed strong selectivity for faces in a region corresponding to the fusiform face area (FFA), and preferential responses to color in a nearby site, replicating earlier reports. To test the causal role of these regions in the perception of nonpreferred dimensions, we then electrically stimulated individual sites while the patient viewed various objects. When stimulated in the FFA, the patient reported seeing an illusory face (or "facephene"), independent of the object viewed. Similarly, stimulation of color-preferring sites produced illusory "rainbows." Crucially, the patient reported no change in the object viewed, apart from the facephenes and rainbows apparently superimposed on them. The functional and anatomical specificity of these effects indicate that some cortical regions are exclusively causally engaged in a single specific mental process, and prompt caution about the widespread assumption that any information scientists can decode from the brain is causally relevant to behavior.

Epidural Blood Patch Using a Racz Catheter for Spontaneous Intracranial Hypotension With Unclear Leak Points.

Using a Racz catheter (Brevi-XL™, Epimed Inc., NY, USA) to insert an epidural blood patch (EBP) may be an effective method of reaching the target epidural space in the cervical region. We would like to present a case, wherein a targeted EBP via Racz catheter was used in the management of spontaneous intracranial hypotension. When the leak point is clear via imaging, EBP should be performed exactly at that point. However, if the leak point is unclear, with only a contrast agent pool detected via imaging, EBP should be performed to mask the entire region of the pool. In both cases, EBP via Racz catheter is a convenient and effective method for the management of spontaneous intracranial hypotension. Further cases may be needed to verify our results.

Left Atrial Volume Index as a Predictor for Large-Vessel Occlusion in Cardiogenic Cerebral Infarction: A Single-Center Cohort Study.

OBJECTIVE: The left atrial volume index (LAVI) is considered to be the most accurate index to estimate the size of the left atrium (LA). In this study, we investigated the relationship between LA size measured by LAVI and the occurrence of large-vessel occlusion (LVO) in patients with cardiogenic cerebral infarction (CCI). METHODS: This retrospective single-center cohort study involved 118 patients with CCI within the internal carotid artery (ICA) or middle cerebral artery regions seen between January 2015 and July 2020. In all patients, the type of CCI was determined according to the Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Scores (TOAST) subtype diagnosis criteria. LVO was defined as positive when magnetic resonance imaging and computed tomography angiography showed ICA, M1, or M2 occlusion, with all others defined as non-LVO. Clinical characteristics, including LAVI, were evaluated in the records of several patients to investigate if they were risk factors for developing LVO. RESULTS: Seventy patients (59%) were diagnosed as having LVO infarction (ICA occlusion, n = 19 [16%]; M1 occlusion, n = 26 [22%]; and M2 occlusion, n = 25 [21%]). Echocardiography showed no difference between LVO and non-LVO in terms of the ejection fraction (P = 0.64), LA dimension (P = 0.93), and LA volume (P = 0.06). However, LAVI significantly differed between the LVO and non-LVO groups (P = 0.02). Multivariate logistic regression analysis showed larger LAVI as a significant risk factor for LVO (P = 0.01). CONCLUSIONS: Our findings suggest that a larger LAVI is a predictor of developing LVO in patients with CCI.

Correlation of T1- to T2-weighted signal intensity ratio with T1- and T2-relaxation time and IDH mutation status in glioma.

The current study aimed to test whether the ratio of T1-weighted to T2-weighted signal intensity (T1W/T2W ratio: rT1/T2) derived from conventional MRI could act as a surrogate relaxation time predictive of IDH mutation status in histologically lower-grade gliomas. Strong exponential correlations were found between rT1/T2 and each of T1- and T2-relaxation times in eight subjects (rT1/T2 = 1.63exp-0.0005T1-relax + 0.30 and rT1/T2 = 1.27exp-0.0081T2-relax + 0.48; R2 = 0.64 and 0.59, respectively). In a test cohort of 25 patients, mean rT1/T2 (mrT1/T2) was significantly higher in IDHwt tumors than in IDHmt tumors (p < 0.05) and the optimal cut-off of mrT1/T2 for discriminating IDHmt was 0.666-0.677, (AUC = 0.75, p < 0.05), which was validated in an external domestic cohort of 29 patients (AUC = 0.75, p = 0.02). However, this result was not validated in an external international cohort derived from TCIA/TCGA (AUC = 0.63, p = 0.08). The t-Distributed Stochastic Neighbor Embedding analysis revealed a greater diversity in image characteristics within the TCIA/TCGA cohort than in the two domestic cohorts. The failure of external validation in the TCIA/TCGA cohort could be attributed to its wider variety of original imaging characteristics.

Treatment of Fourth Ventricle Arachnoid Cyst via Anterior Hone of Lateral Ventricle Using Flexible Endoscope.

BACKGROUND: Arachnoid cysts are common anomalies in the intracranial region. However, an intraventricular arachnoid cyst is rare, and occurrence within the fourth ventricle is especially uncommon; only 16 cases have been described in the literature. Arachnoid cysts in the fourth ventricle may cause obstructive hydrocephalus or cerebellar ataxia or cranial nerve palsy. Treatment of a fourth ventricular arachnoid cyst is complete or partial resection via a midline suboccipital approach. Recently, endoscopic fenestration has become the procedure of choice in the treatment of arachnoid cysts in supratentorial locations, but as yet there has been no report of treating a fourth ventricle arachnoid cyst using a flexible endoscope. CASE DESCRIPTION: We present the case of a 43-year-old man who suffered a recurrence of an arachnoid cyst in the fourth ventricle that had been partially excised 8 years previously using midline suboccipital craniectomy. Because of concerns of adhesions following the previous craniectomy, we decided to perform endoscopic treatment via the anterior horn of the lateral ventricle. CONCLUSIONS: As per our knowledge, this is the first case reporting the treatment of an arachnoid cyst of the fourth ventricle using a flexible endoscope via the anterior horn of the lateral ventricle. This method can be used to treat arachnoid cysts of the fourth ventricle.

Real-time spectrum quantification of tumor-related fluorescence during neurosurgery: A preliminary report.

OBJECTIVES: The fluorescent dye, 5-aminolevulinic acid (5-ALA), is currently applied for fluorescence-guided resections of high-grade gliomas. Present limitations of this technique are qualitative and subjective analyses, which show little of the background structures. This paper describes the intraoperative quantitative analysis of fluorescence intensity, hot-spot enhancement by frame averaging, and observation of surrounding structures by using 1000-nm lighting in real time. PATIENTS AND METHODS: A sample of diluted protoporphyrin IX (PpIX) in a bottle and 37 samples from nine patients with brain lesions were involved in this study. In this preliminary study, we determined appropriate conditions for image averaging and filters and selected the most sensitive spectrometer. In addition, we utilized a 1000-nm lighting system to visualize surrounding structures with no interference from PpIX fluorescence. RESULTS: The novel system permitted the real-time quantitative analysis of PpIX fluorescence in operative fields by illuminating structures with 1000-nm-lighting. The real-time quantification provided subjective evaluations for surgical decision-making. We found good correlations between the fluorescence and PpIX contents in brain tissue. Furthermore, 1000-nm lighting visualized the anatomical structures and PpIX fluorescence simultaneously. CONCLUSION: The combination of spectroscopy and a 1000-nm lighting system could enable surgeons to create a spectrogram of targets of interest while observing background structures. The spectrometer that we selected is highly sensitive to PpIX fluorescence and enables us to perform intraoperative real-time tissue mapping. By using a real-time system, we can perform quantitative and objective evaluations to achieve maximal tumor resection.

Disconnection of the pathological connectome for multifocal epilepsy surgery.

OBJECTIVERecent neuroimaging studies suggest that intractable epilepsy involves pathological functional networks as well as strong epileptogenic foci. Combining cortico-cortical evoked potential (CCEP) recording and tractography is a useful strategy for mapping functional connectivity in normal and pathological networks. In this study, the authors sought to demonstrate the efficacy of preoperative combined CCEP recording, high gamma activity (HGA) mapping, and tractography for surgical planning, and of intraoperative CCEP measures for confirmation of selective pathological network disconnection.METHODSThe authors treated 4 cases of intractable epilepsy. Diffusion tensor imaging-based tractography data were acquired before the first surgery for subdural grid implantation. HGA and CCEP investigations were done after the first surgery, before the second surgery was performed to resect epileptogenic foci, with continuous CCEP monitoring during resection.RESULTSAll 4 patients in this report had measurable pathological CCEPs. The mean negative peak-1 latency of normal CCEPs related to language functions was 22.2 ± 3.5 msec, whereas pathological CCEP latencies varied between 18.1 and 22.4 msec. Pathological CCEPs diminished after complete disconnection in all cases. At last follow-up, all of the patients were in long-term postoperative seizure-free status, although 1 patient still suffered from visual aura every other month.CONCLUSIONSCombined CCEP measurement, HGA mapping, and tractography greatly facilitated targeted disconnection of pathological networks in this study. Although CCEP recording requires technical expertise, it allows for assessment of pathological network involvement in intractable epilepsy and may improve seizure outcome.

Clinical Impact and Implication of Real-Time Oscillation Analysis for Language Mapping.

BACKGROUND: We developed a functional brain analysis system that enabled us to perform real-time task-related electrocorticography (ECoG) and evaluated its potential in clinical practice. We hypothesized that high gamma activity (HGA) mapping would provide better spatial and temporal resolution with high signal-to-noise ratios. METHODS: Seven awake craniotomy patients were evaluated. ECoG was recorded during language tasks using subdural grids, and HGA (60-170 Hz) maps were obtained in real time. The patients also underwent electrocortical stimulation (ECS) mapping to validate the suspected functional locations on HGA mapping. The results were compared and calculated to assess the sensitivity and specificity of HGA mapping. For reference, bedside HGA-ECS mapping was performed in 5 epilepsy patients. RESULTS: HGA mapping demonstrated functional brain areas in real time and was comparable with ECS mapping. Sensitivity and specificity for the language area were 90.1% ± 11.2% and 90.0% ± 4.2%, respectively. Most HGA-positive areas were consistent with ECS-positive regions in both groups, and there were no statistical between-group differences. CONCLUSIONS: Although this study included a small number of subjects, it showed real-time HGA mapping with the same setting and tasks under different conditions. This study demonstrates the clinical feasibility of real-time HGA mapping. Real-time HGA mapping enabled simple and rapid detection of language functional areas in awake craniotomy. The mapping results were highly accurate, although the mapping environment was noisy. Further studies of HGA mapping may provide the potential to elaborate complex brain functions and networks.

A Case of Facial Spasm Associated with Ipsilateral Cerebellopontine Angle Arachnoid Cyst.

The authors report a rare case of right cerebellopontine angle cyst related to hemifacial spasm. The patient was a 66-year-old woman with a 3-year history of right hemifacial spasm. The cyst was diagnosed preoperatively by T2-weighted magnetic resonance imaging, which demonstrated a hyperintense area in the right cerebellopontine angle. A small artery was displaced by the cyst and compressed the root exit zone of the facial nerve. Decompression of the cyst and the vasculature using a microsurgical technique resulted in total recovery from hemifacial spasm.

Functional localization of the supplementary motor area.

The supplementary motor area (SMA) is a key structure involved in behavioral planning and execution. Although many reports have indicated that SMA is organized somatotopically, its exact organization remains still unclear. This study aimed to functionally map SMA using functional magnetic resonance imaging (fMRI) and validate the fMRI-SMA by electrocortical stimulation (ECS) and postsurgical symptoms. Total 32 healthy volunteers and 24 patients participated in this study. Motor tasks were right and left finger tapping and language tasks included simple reading, lexical decision for presented words, and verb generating tasks. SPM8 was used to conduct individual and group analyses. In all subjects, the lexical decision task induced the greatest number of active fMRI pixels in SMA. fMRI during the language tasks showed anterior part of SMA compared to finger tapping tasks. We found an overlap spot with all different tasks in posterior part of SMA, which we termed SMA core. Six patients underwent awake craniotomy for ECS mapping for primary regions and SMA. During awake craniotomy, ECS to posterior part of SMA, which might involve the possible SMA core consistently, evoked both speech arrest and flaccid hemiparesis. The SMA mapping suggested posterior part of SMA might play more important roles in any executions, which might involve the SMA core.

Rapid and minimum invasive functional brain mapping by real-time visualization of high gamma activity during awake craniotomy.

BACKGROUND: Electrocortical stimulation (ECS) is the gold standard for functional brain mapping during an awake craniotomy. The critical issue is to set aside enough time to identify eloquent cortices by ECS. High gamma activity (HGA) ranging between 80 and 120 Hz on electrocorticogram is assumed to reflect localized cortical processing. In this report, we used real-time HGA mapping and functional neuronavigation integrated with functional magnetic resonance imaging (fMRI) for rapid and reliable identification of motor and language functions. METHODS: Four patients with intra-axial tumors in their dominant hemisphere underwent preoperative fMRI and lesion resection with an awake craniotomy. All patients showed significant fMRI activation evoked by motor and language tasks. During the craniotomy, we recorded electrocorticogram activity by placing subdural grids directly on the exposed brain surface. RESULTS: Each patient performed motor and language tasks and demonstrated real-time HGA dynamics in hand motor areas and parts of the inferior frontal gyrus. Sensitivity and specificity of HGA mapping were 100% compared with ECS mapping in the frontal lobe, which suggested HGA mapping precisely indicated eloquent cortices. We found different HGA dynamics of language tasks in frontal and temporal regions. Specificities of the motor and language-fMRI did not reach 85%. The results of HGA mapping was mostly consistent with those of ECS mapping, although fMRI tended to overestimate functional areas. CONCLUSIONS: This novel technique enables rapid and accurate identification of motor and frontal language areas. Furthermore, real-time HGA mapping sheds light on underlying physiological mechanisms related to human brain functions.

[Dynamics of the language/memory functional regions determing using ECoG and fMRI].

We compared electrocorticography (ECoG) with invasive intracranial noninvasive functional MRI using language-related tasks. Twenty patients underwent bilateral implantation of subdural electrodes (more than 80 channels) for diagnosing intractable epilepsy. Before implantation of the electrodes, language-related fMRI was performed, and the fMR images were superimposed on individual brain images. Brain mapping with electrocortical stimulation was performed on the basis of the fused fMR and brain MR images, and the specificity and sensitivity of language-related fMRI was calculated. For careful interpretation of spatial and temporal ECoG changes with semantic tasks, we developed a software to visualize semantic-ECoG dynamics in the brain. Semantic-ECoG was recorded during word, figure, and face recognition as well as memory tasks. The raw ECoG data were processed by averaging and time-frequency analysis, and the functional profiles were projected onto the individual brain surface. Acquired ECoG was classified using Support Vector Machine and Sparse Logistic Regression to decode brain signals. Because of variations in electrode locations, we normalized the ECoG electrodes by using SPM8. Although fMRI has 90% sensitivity, its specificity is only up to 50%. The basal temporal-occipital cortex was activated within 250 ms after visual object presentation. Compared to other stimuli, face stimulation evoked significantly higher ECoG amplitudes. Among different brain regions, the hippocampus was predominantly activated during the memory task. The prediction rate of ECoG classification was 90%, which was sufficient for clinical use. Semantic-ECoG is a powerful technique to detect and decode human brain functions.

Hydrocephalus due to diffuse villous hyperplasia of the choroid plexus.

An 8-month-old female presented with hydrocephalus caused by cerebrospinal fluid (CSF) overproduction due to bilateral choroid plexus enlargement, which was clinically diagnosed as diffuse villous hyperplasia of the choroid plexus, but differentiation from bilateral choroid plexus papilloma was difficult. She initially underwent ventriculoperitoneal shunt surgery, but developed marked retention of ascites. Therefore, the peritoneal end of the shunt was removed for external drainage, but excessive CSF (1,500 ml/day) was collected. Computed tomography and magnetic resonance imaging revealed marked symmetric enhancement of the choroid plexuses in the bilateral lateral ventricles. Thallium-201 chloride single-photon emission computed tomography showed pronounced uptake on both early and delayed images, and good washout. CSF examination revealed no abnormalities such as atypical cells, and a ventriculoatrial shunt was inserted, achieving good control of the hydrocephalus.