Cavernous malformation located medially and deeply in the brain may be prone to false lateralization in cavernous malformation-associated epilepsy.

Background: Cavernous malformation (CM) is a well-known cause of epilepsy. Although the location of the CM is usually consistent with the side of seizure onset, some reports have described discrepancies between results from scalp electroencephalography (EEG) and CM location. This study investigated the prevalence and features of patients showing false lateralization (FL). Particularly, we tested the hypothesis that patients showing FL were more likely to have CM in medial and deep areas of the brain than in other areas. Methods: Patients diagnosed with CM-associated epilepsy in our institution between March 2009 and March 2023 were included in this retrospective analysis. We investigated the presence or absence of FL of interictal epileptiform discharges (IEDs) or ictal discharges against MRI findings or against the true focus as determined from surgical outcomes. We compared the FL group with the non-false-lateralization group (NFL group) to clarify features of CM-associated epilepsy patients showing FL. Results: Thirty-two epilepsy patients with CM were analyzed. The frequency of FL to MRI was 10.3% for IEDs and 7.7% for ictal discharges, while the frequency of FL to true focus after removal surgery was 10.5% for IEDs and 7.7% for ictal discharges. Regarding the FL of IEDs against MRI findings, the percentage of medial and deep lesions was significantly higher in the FL group (3/3, 100%) than in the NFL group (6/26, 23.1%; p = 0.023). No significant differences in age, sex, seizure type, or size of the CM were seen between groups. Conclusions: CM-associated epilepsy can also present with FL, particularly if the location of the CM is medial and deep. Caution may be needed in determining the area for resection based solely on scalp EEG findings.

Endovascular electroencephalography (eEEG) can detect the laterality of epileptogenic foci as accurately as subdural electrodes.

Background: Traditional brain activity monitoring via scalp electroencephalography (EEG) offers limited resolution and is susceptible to artifacts. Endovascular electroencephalography (eEEG) emerged in the 1990s. Despite early successes and potential for detecting epileptiform activity, eEEG has remained clinically unutilized. This study aimed to further test the capabilities of eEEG in detecting lateralized epileptic discharges in animal models. We hypothesized that eEEG would be able to detect lateralization. The purpose of this study was to measure epileptiform discharges with eEEG in animal models with lateralization in epileptogenicity. Materials and methods: We inserted eEEG electrodes into the transverse sinuses of three pigs, and subdural electrodes (SDs) on the surfaces of the left and right hemispheres. We induced epileptogenicity with penicillin in the left brain of pigs F00001 and F00003, and in the right brain of pig F00002. The resulting epileptiform discharges were measured by eEEG electrodes placed in the left and right transverse sinuses, and conducted comparisons with epileptiform discharges from SDs. We also had 12 neurological physicians interpret measurement results from eEEG alone and determine the side (left or right) of epileptogenicity. Results: Three pigs were evaluated for epileptiform discharge detection using eEEG: F00001 (7 months old, 14.0 kg), F00002 (8 months old, 15.6 kg), and F00003 (8 months old, 14.4 kg). The eEEG readings were compared with results from SDs, showing significant alignment across all subjects (p < 0.001). The sensitivity and positive predictive values (PPV) were as follows: F00001 had 0.93 and 0.96, F00002 had 0.99 and 1.00, and F00003 had 0.98 and 0.99. Even though one of the neurological physicians got all sides incorrect, all other assessments were correct. Upon post-experimental dissection, no abnormalities were observed in the brain tissue or in the vascular damage at the site where the eEEG was placed, based on pathological evaluation. Conclusion: With eEEG, lateralization can be determined with high sensitivity (>0.93) and PPV (>0.95) that appear equivalent to those of subdural EEG in the three pigs. This lateralization was also discernible by neurological physicians on visual inspection.

Non-1st seizure was less severe than 1st seizure with non-urgent level among suspected seizures transferred by ambulance.

BACKGROUND: To prioritize emergency medical calls for ambulance transport for patients with suspected seizures, information about whether the event is their 1st or non-1st seizure is important. However, little is known about the difference between 1st and non-1st seizures in terms of severity. We hypothesized that patients transferred multiple times (≥2 times) would represent a milder scenario than patients on their first transfer. The purpose of this study was to compare patients with suspected seizures on 1st transfer by ambulance and patients who had been transferred ≥2 times. METHODS: We statistically compared severity of suspected seizures between two groups of patients with suspected seizures transferred between December 2014 and November 2019 (before the coronavirus disease 2019 pandemic) to our facility by ambulance for either the first time (1st Group) or at least the second time (Non-1st Group). Severity categories were defined as: Level 1 = life-threatening; Level 2 = emergent, needing admission to the intensive care unit; Level 3 = urgent, needing admission to a hospital general ward; Level 4 = less urgent, needing intervention but not hospitalization; and Level 5 = non-urgent, not needing intervention. RESULTS: Among 5996 patients with suspected seizures conveyed to the emergency department by ambulance a total of 14,263 times during the study period, 1222 times (8.6%) and 636 patients (11%) met the criteria. Severity grade of suspected seizures ranged from 1 to 5 (median, 4; interquartile range, 3-4) for the 1st Group and from 1 to 5 (median, 5; interquartile range, 4-5) for the Non-1st Group. Most severe grade ranged from 1 to 5 (median, 4; interquartile range, 4-5) for the Non-1st Group. Severity grade differed significantly between groups (p < 0.001, Mann-Whitney U-test). Uni- and multivariate logistic regression tests also suggested a significant difference (p < 0.001) in severity grades. CONCLUSION: In direct comparisons, grade of suspected seizure severity was lower in the Non-1st Group than in the 1st Group.

False lateralization of scalp EEG and semiology in cavernous malformation-associated temporal lobe epilepsy: A case report.

Background: Several cases of temporal lobe epilepsy (TLE) showing false lateralization of ictal scalp electroencephalography (EEG) have been reported. However, TLE with cavernous malformation indicating false lateralization of both ictal scalp EEG and semiology as in the present case is rare. The aim of this report is to call attention to avoiding overestimation of ictal scalp EEG findings in epilepsy patients with cavernous malformation. Case report: A 25-year-old man without any medical history suffered from seizures for a year despite appropriate anti-epileptic medication. Magnetic resonance imaging (MRI) revealed cavernous malformation in the left amygdala. The seizure type was brief impaired consciousness with left dystonic posturing, preceded by a sensation of blood rushing to the head. Long-term video EEG with scalp electrodes showed periodic sharp waves beginning from the right temporal area during seizures. Although both semiology and ictal scalp EEG indicated right TLE, intracranial EEG revealed the onset of low-voltage fast activity from the left hippocampus near the cavernous malformation. This patient therefore underwent removal of cavernous malformation and left amygdala, and achieved freedom from seizures postoperatively. Conclusion: We reinforce the importance of performing intracranial EEG for cavernous malformation-associated epilepsy when discrepancies between scalp EEG and MRI are evident.

Finger movement functions remain in the ipsilesional hemisphere and compensation by the contralesional hemisphere might not be expected after hemispherotomy -pre- and post-hemispherotomy evaluations in 8 cases.

BACKGROUND: We hypothesized that fine finger motor functions are controlled by the ipsilesional hemisphere, and that gross motor functions are compensated for by the contralesional hemisphere after brain injury in humans. The purpose of this study was to compare finger movements before and after hemispherotomy that defunctionated the ipsilesional hemisphere for patients with hemispherical lesions. METHODS: We statistically compared Brunnstrom stage of the fingers, arm (upper extremity), and leg (lower extremity) before and after hemispherotomy. Inclusion criteria for this study were: 1) hemispherotomy for hemispherical epilepsy; 2) a ≥ 6-month history of hemiparesis; 3) post-operative follow-up ≥ 6 months; 4) complete freedom from seizures without aura; and 5) application of our protocol for hemispherotomy. RESULTS: Among 36 patients who underwent multi-lobe disconnection surgeries, 8 patients (2 girls, 6 boys) met the study criteria. Mean age at surgery was 6.38 years (range, 2-12 years; median, 6 years; standard deviation, 3.5 years). Paresis of the fingers was significantly exacerbated (p = 0.011) compared to pre-operatively, whereas that of the upper limbs (p = 0.07) and lower limbs (p = 0.103) was not. CONCLUSION: Finger movement functions tend to remain in the ipsilesional hemisphere after brain injury, whereas gross motor movement functions such as those of the arms and legs are compensated for by the contralesional hemisphere in humans.

Intraoperative Cone-Beam Computed Tomography Assessment of Spinal Pedicle Screws Placement Precision Is in Full Agreement with Postoperative Computed Tomography Assessment.

OBJECTIVE: To assess agreement between pedicle screw placement evaluated on postoperative computed tomography (CT) and on intraoperative cone-beam CT (CBCT) and compare procedure characteristics when using first-generation and second-generation robotic C-arm systems in the hybrid operating room. METHODS: All patients who received pedicle screws for spinal fusion at our institution between June 2009 and September 2019 and underwent intraoperative CBCT and postoperative CT were included. The CBCT and CT images were reviewed by 2 surgeons to assess the screw placement using the Gertzbein-Robbins and the Heary classifications. Intermethod agreement of screw placement classifications as well as interrater agreement were assessed using Brennan-Prediger and Gwet agreement coefficients. Procedure characteristics using first-generation and second-generation generation robotic C-arm systems were compared. RESULTS: Fifty-seven patients were treated with 315 pedicle screws at thoracic, lumbar, and sacral levels. No screw had to be repositioned. On CBCT, accurate placement was found for 309 screws (98.1%) using the Gertzbein-Robbins classification and 289 (91.7%) using the Heary classification and on CT, these were 307 (97.4%) and 293 (93.0%), respectively. Intermethod between CBCT and CT and interrater agreements between the 2 raters were almost perfect (>0.90) for all assessment. There were no significant differences in mean radiation dose (P = 0.83) and fluoroscopy time (P = 0.82), but length of surgery using the second-generation system was estimated at 107.7 minutes (95% confidence interval, 31.9-183.5 minutes; P = 0.006) shorter. CONCLUSIONS: Intraoperative CBCT provides accurate assessment of pedicle screw placement and enables intraoperative repositioning of misplaced screws.

Development and validation of a recurrent prediction model for patients with unilateral chronic subdural hematoma without hematoma volumetric analysis.

OBJECTIVE: Approximately 10 % of patients with chronic subdural hematoma (CSDH) undergo reoperation after initial surgery. This study aimed to develop a predictive model for the recurrence of unilateral CSDH at initial surgery without hematoma volumetric analysis. METHODS: This single-center retrospective cohort study evaluated pre- and postoperative computed tomography (CT) images of patients with unilateral CSDH. The pre- and postoperative midline shift (MLS), residual hematoma thickness, and subdural cavity thickness (SCT) were measured. CT images were classified based on the internal architecture of the hematoma (homogenous, laminar, trabecular, separated, and gradation subtypes). RESULTS: Total 231 patients with unilateral CSDH underwent burr hole craniostomy. After receiver operating characteristic analysis, preoperative MLS and postoperative SCT showed better areas under the curve (AUCs) (0.684 and 0.756, respectively). According to the CT classification of preoperative hematomas, the recurrence rate was significantly higher in the separated/gradation group (18/97, 18.6 %) than in the homogenous/laminar/trabecular group (10/134, 7.5 %). Four-point score was derived from the multivariate model using the preoperative MLS, postoperative SCT, and CT classification. The AUC of this model was 0.796, and the recurrence rates at 0-4 points were 1.7 %, 3.2 %, 13.3 %, 25.0 %, and 35.7 %, respectively. CONCLUSION: Pre- and postoperative CT findings without hematoma volumetric analysis may predict CSDH recurrence.

Unexplained Progressive Neurological Deficits after Corpus Callosotomy May Be Caused by Autoimmune Encephalitis: A Case of Suspected Postoperative Anti-NMDAR Encephalitis.

The main causes of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis are ovarian teratoma and herpes simplex virus (HSV) encephalitis. We present a rare case of suspected anti-NMDAR encephalitis caused by corpus callosotomy (CC). An 18-year-old woman with Lennox-Gastaut syndrome underwent CC. Although left hemiplegic due to cerebral hemorrhage and impaired consciousness due to cerebral venous sinus thrombosis (CVST) appeared postoperatively, anticoagulant therapy quickly improved CVST and impaired consciousness. However, various unexplained symptoms such as insomnia, hallucination, impulsivity, impaired consciousness, and a new type of drug-resistant cluster seizures gradually developed over a 2-month period. Magnetic resonance imaging revealed the gradual extension of a hyperintense area from the right frontal lobe on fluid-attenuated inversion recovery images. Intravenous methylprednisolone pulse was initiated from postoperative day (POD) 74, followed by intravenous immunoglobulin (IVIg) therapy, although white blood cell counts were normal in all three cerebrospinal fluid (CSF) examinations. After IVIg therapy, the above unexplained symptoms promptly improved. On POD 103, antibodies against NMDAR were revealed in both the serum and CSF collected before these immunotherapies. The patient was transferred to a rehabilitation hospital due to residual left hemiplegia. Psychiatric symptoms and a new onset of drug-resistant seizures may be suggestive of postoperative anti-NMDAR encephalitis, even if CSF findings are mild.

Preoperative assessment of dominant occipital sinus in patients with Chiari malformation type I: anatomical variations and implications for preventing potentially life-threatening surgical complications.

OBJECTIVE: The surgical treatment of Chiari malformation type I (CM-I) frequently involves dural incision at the posterior cranial fossa. In cases of persistent patent occipital sinus (OS), the sinus is usually obliterated and divided. However, there are some patients whose OS is prominent and requires crucial modification of the operative planning to avoid potentially life-threatening massive hemorrhage and disturbance of cerebral venous circulation. In the present study, the anatomical variations of the dominant OS in patients with CM-I were analyzed and the authors attempted to develop treatment recommendations for patients with CM-I with dominant OS. METHODS: The study included 213 patients with CM-I who underwent MR venography (MRV) prior to surgical treatment. OS dominance was assessed using 2D time-of-flight MRV or 3D phase-contrast MRV. Particular attention was paid to the pattern of venous outflow channels. The characteristics of the patients with dominant OS and the surgical outcomes were retrospectively reviewed. RESULTS: Dominant OS was identified in 7 patients (3.3%). The age in those with dominant OS was significantly younger than in those without (p = 0.0202). The incidence of concurrent scoliosis in the patients with dominant OS was significantly higher than in those without (p = 0.0366). All the dominant OSs were found to be of the oblique type. Unilateral oblique OS (OOS) with normal ipsilateral transverse sinus (TS) and hypoplastic contralateral TS was found in 2 patients (0.9%). The authors found 1 patient each (0.5%) who had unilateral OOS with hypoplastic ipsilateral TS and normal contralateral TS, unilateral OOS with bilateral hypoplastic TSs, and bilateral OOSs with bilateral normal TSs. Bilateral OOSs with bilateral hypoplastic TSs were found in 2 patients (0.9%). All these patients had syringomyelia. Instead of performing Y-shaped dural incision and duraplasty, surgical procedures were modified depending on the types of the OOSs to preserve their venous drainage routes. Although massive bleeding from the dominant OS during dural incision occurred in 1 patient, none suffered neurological deterioration. The syrinx volume decreased in all but 1 of the patients postoperatively. CONCLUSIONS: Assessment of the venous drainage pattern using MRV is indispensable for safe surgical treatment in patients with CM-I. The surgical procedure should be modified based on the type of dominant OS to minimize the surgical risks.

Replacement of Valproic Acid with New Anti-Seizure Medications in Idiopathic Generalized Epilepsy.

Background: Little is known regarding the non-inferiority of new anti-seizure medications (ASMs) in terms of replacing valproic acid (VPA) in patients with idiopathic generalized epilepsy (IGE). We hypothesized that replacement of VPA with new ASMs would offer non-inferior or better control of seizure frequency. The purpose of this study was to compare epileptic seizure frequency between the subset of patients with IGE who were on VPA and the subset of patients with IGE who replaced VPA with new ASMs. Methods: Patients with IGE who were on or had been on VPA between January 2016 and March 2022 were divided into a group that replaced VPA with new ASMs (VPA-replace group) and a group that remained on VPA (VPA-continue group). We then compared the groups in terms of seizure frequency and myoclonus. Results: Of the 606 patients on VPA between January 2016 and March 2022, 156 patients with IGE were enrolled to this study (VPA-replace group, n = 68; VPA-continue group, n = 88). The VPA-replace group included significantly more females than the VPA-continue group (p < 0.001). The VPA-replace group also showed significantly higher seizure frequency before replacement (p < 0.001), but not after replacement (p = 0.074). Patients on monotherapy displayed improved seizure frequency with new ASMs (p < 0.001). Among the new ASMs, perampanel (PER) significantly improved seizure frequency (p = 0.002). Forty-two patients in the VPA-replace group who had myoclonus achieved significant improvements (p < 0.001). Among these, patients on PER monotherapy (p < 0.001) or PER + lamotrigine (0.016) showed significantly improved myoclonus scale scores. Conclusions: This study shows the non-inferiority of new ASMs compared to VPA, with better seizure control using new ASMs in subsets of patients with IGE on monotherapy.

Omitting Hyperventilation in Electroencephalogram during the COVID-19 Pandemic May Reduce Interictal Epileptiform Discharges in Patients with Juvenile Myoclonic Epilepsy.

BACKGROUND: To prevent the spread of coronavirus disease 2019 (COVID-19), hyperventilation (HV) activation has been avoided in electroencephalograms (EEGs) since April 2020. The influence of omitting HV in EEG on epilepsy diagnosis remains uncertain for patients with epilepsies other than child absence epilepsy. We hypothesized that EEGs with HV would show more interictal epileptiform discharges (IEDs) than EEGs without HV in patients with juvenile myoclonic epilepsy (JME). METHODS: We reviewed the EEGs of seizure-free patients with JME who underwent EEG, both with and without HV, from January 2019 to October 2021, in our institution, and compared IEDs between EEG with and without HV. RESULTS: This study analyzed 23 JME patients. The IED-positive rate was significantly higher in EEG with HV (65.2%) than in EEG without HV (34.8%, p = 0.016). The mean ± standard deviation number of IEDs per minute was significantly larger during HV (1.61 ± 2.25 × 10-1) than during non-activation of both first EEG (0.57 ± 0.93 × 10-1, p = 0.039) and second EEG (0.39 ± 0.76 × 10-1, p = 0.009). CONCLUSIONS: In JME patients, performing HV during EEG may increase IEDs and appears to facilitate the accurate diagnosis of epilepsy.

Earlier Age at Surgery for Brain Cavernous Angioma-Related Epilepsy May Achieve Complete Seizure Freedom without Aid of Anti-Seizure Medication.

BACKGROUND: The present study hypothesized that some factors may distinguish between patients with a brain cavernous angioma (BCA), who were free from anti-seizure medication (ASM), and patients who still required ASMs postoperatively. The purpose of the study was thus to identify factors associated with ceasing ASMs for patients with drug-resistant epilepsy secondary to BCA, who underwent BCA removal surgery. METHODS: We divided patients into those with drug-resistant epilepsy secondary to BCA who achieved complete seizure freedom without ASMs a year after surgery (No-ASM group) (International League Against Epilepsy (ILAE) classification class I with no epileptiform discharges), and others (ASM group) (ILAE classification ≤ II and/or epileptiform discharges). We statistically compared groups in terms of: (1) age at operation; (2) history of epilepsy; (3) size of BCA; and (4) location of BCA. RESULTS: Overall, a year after the surgery, the No-ASM group comprised 12 patients (48%), and the ASM group comprised 13 patients (52%). In both multi- and univariate logistic regression analyses, age at BCA removal surgery correlated significantly with the No-ASM group (p = 0.043, p = 0.019), but history of epilepsy did not (p = 0.581, p = 0.585). CONCLUSIONS: Earlier age at surgery for patients with drug-resistant epilepsy is encouraged to achieve complete seizure freedom without the need for ASMs when the cause of epilepsy is BCA.

Effects of Vagus Nerve Stimulation following Corpus Callosotomy for Patients with Drug-Resistant Epilepsy.

OBJECTIVE: The effectiveness of vagus nerve stimulation (VNS) for residual seizures after corpus callosotomy (CC) has not yet been fully investigated. We hypothesized that seizure control would be improved by VNS after CC. The purpose of this study was to compare seizure frequency between patients with implantation of a VNS generator (post-VNS group) or without VNS (non-post-VNS group) following CC. METHODS: We retrospectively reviewed patients who underwent CC between January 2009 and May 2019 in our institution. We evaluated proportions of ≥50% reduction in seizure frequency (responders) and seizure reduction rate 1 and 2 years after VNS. To investigate factors related to responders, uni- and multivariate logistic regression analyses were performed regarding age, number of anti-seizure medications (ASMs), addition of novel ASMs (levetiracetam, lacosamide or perampanel), and post-VNS or non-post-VNS status. RESULTS: Thirteen post-VNS patients and 24 non-post-VNS patients were analyzed in this study. Responder rate at 1 year after VNS differed significantly between the post-VNS group (53.9%) and non-post-VNS group (12.5%, p = 0.017). Number of ASMs at the time of CC and post-VNS were significantly associated with responders in univariate analyses (odds ratio [OR] 0.34, 95% confidence interval [CI] 0.13-0.88, p = 0.025 and OR 8.2, 95%CI 1.6-41.6, p = 0.011, respectively), whereas age, sex, seizure frequency, and addition of novel ASMs were not. In multivariate analysis, the presence of VNS procedures after CC was the only factor favorably associated with responder status (OR 82.2, 95%CI 1.55-4355.7, p = 0.03). CONCLUSIONS: VNS therapy after CC may increase the proportion of responders independent of the addition of novel ASMs.

Non-Ruptured Temporal Lobe Dermoid Cyst Concomitant with Focal Cortical Dysplasia Causing Temporal Lobe Epilepsy-A Case Report and Literature Review.

BACKGROUND: Intracranial dermoid cyst is a rare, benign, nonneoplastic tumor-like lesion that could cause seizures, headache, and hydrocephalus. We hypothesized that the temporal lobe dermoid cyst in combination with other factors were causing the epileptic seizure. METHODS: We encountered a 17-year-old girl with anti-seizure medication-resistant epilepsy secondary to dermoid cyst located in the temporal region depicted on magnetic resonance imaging (MRI). She showed neither symptoms of meningitis nor rupture of the cyst according to serial MRI. We hypothesized that temporal lobe dermoid cyst in combination with other factors, such as focal cortical dysplasia (FCD), etc., was causing epileptic seizures in this case. She underwent dermoid cyst removal surgery with resection of the tip of the antero-inferior temporal lobe. RESULTS: Histopathological study showed multiple small intramedullary dermoid cysts in the left antero-inferior temporal lobe in addition to MRI lesions and FCD. CONCLUSION: A patient with medically intractable epilepsy secondary to left temporal lobe dermoid cyst showed multiple intramedullary dermoid cysts and focal cortical dysplasia that might have interacted to create epileptogenicity. To our knowledge, this is the first case report of dermoid cyst concomitant with FCD.

Postoperative Pneumocephalus on Computed Tomography Might Predict Post-Corpus Callosotomy Chemical Meningitis.

BACKGROUND: A corpus callosotomy (CC) is a procedure in which the corpus callosum, the largest collection of commissural fibers in the brain, is disconnected to treat epileptic seizures. The occurrence of chemical meningitis has been reported in association with this procedure. We hypothesized that intraventricular pneumocephalus after CC surgery represents a risk factor for postoperative chemical meningitis. The purpose of this study was to analyze the potential risk factors for postoperative chemical meningitis in patients with medically intractable epilepsy who underwent a CC. METHODS: Among the patients who underwent an anterior/total CC for medically intractable epilepsy between January 2009 and March 2021, participants were comprised of those who underwent a computed tomography scan on postoperative day 0. We statistically compared the groups with (c-Group) or without chemical meningitis (nc-Group) to determine the risk factors. RESULTS: Of the 80 patients who underwent a CC, 65 patients (25 females and 40 males) met the inclusion criteria. Their age at the time of their CC procedure was 0-57 years. The c-Group (17%) was comprised of seven females and four males (age at the time of their CC procedure, 1-43 years), and the nc-Group (83%) was comprised of 18 females and 36 males (age at the time of their CC procedure, 0-57 years). Mann-Whitney U-tests (p = 0.002) and univariate logistic regression analysis (p = 0.001) showed a significant difference in pneumocephalus between the groups. CONCLUSION: Postoperative pneumocephalus identified on a computed tomography scan is a risk factor for post-CC chemical meningitis.

MRI characteristics of syringomyelia associated with foramen magnum arachnoiditis: differentiation from Chiari malformation.

BACKGROUND: It is important to distinguish foramen magnum arachnoiditis (FMA) from Chiari malformation (CM) before surgery because the operative strategies for these diseases differ. In the current study, we compared pretreatment magnetic resonance imaging (MRI) of FMA with CM and investigated the MRI findings useful to differentiate between these diseases. METHODS: We retrospectively reviewed patients with FMA or CM aged ≥ 18 years who underwent surgeries at our institution between 2007 and 2019. The morphologies of the syrinx, neural elements, and posterior cranial fossa were preoperatively evaluated with MRI. We used the receiver operating characteristic (ROC) curve for the fourth ventricle-to-syrinx distance (FVSD). RESULTS: Ten patients with FMAs and 179 with CMs were included. FVSD in the FMA group was significantly shorter than that in the CM group (7.5 mm [IQR, 2.8-10 mm] in FMA vs. 29.9 mm [IQR, 16.3-52.9 mm] in CM, p < 0.0001). The other MRI findings that showed the height, size, and length of the syrinx; size of the foramen magnum; degree of cerebellar tonsillar descent; shape of the cerebellar tonsil; and dorsal subarachnoid space at the foramen magnum differed significantly between the two groups. The ROC curve analysis showed that patients whose FVSD was less than 11 mm could be diagnosed with FMA with a specificity of 90% and sensitivity of 96%. CONCLUSIONS: A more cranial syrinx development (FVSD < 11 mm) appears to be the characteristic MRI finding in FMA.

Modified Computed Tomography Classification for Chronic Subdural Hematoma Features Good Interrater Agreement: A Single-Center Retrospective Cohort Study.

OBJECTIVE: The present study aimed to establish whether our modified Nakaguchi computed tomography (CT) classification improves the interrater agreement of chronic subdural hematoma (CSDH) classification and prediction of CSDH recurrence relative to 2 other CT classifications. METHODS: This retrospective study considered 277 consecutive patients with CSDH and 307 hematomas treated with burr-hole surgery between January 2009 and December 2018. Two neurosurgeons blinded to patients' clinical data classified the CT scans of patients with CSDH into 4 or 5 types according to the Nomura classification (high, iso, low, mixed, and layering), Nakaguchi classification (homogenous, laminar, separated, and trabecular), and our modified Nakaguchi classification (homogenous, gradation, laminar, separated, and trabecular). The κ statistic was used to evaluate the interrater agreement of the 3 CT classifications. Univariable and multivariable logistic regression analyses were used to calculate odds ratios for CSDH recurrence. RESULTS: κ values of the modified, Nakaguchi, and Nomura classification were 0.78, 0.63, and 0.70, respectively. During the 3 months follow-up, the recurrence rate for CSDH was 11.4% (35/307 hematomas). Of the types defined by the modified classification, the gradation type was associated with the highest recurrence (mean recurrence rate, 15.9% ± 0.3%). Multivariable logistic regression analyses showed that a gradation-type hematoma, as defined with the modified classification, was an independent risk factor associated with recurrence (odds ratio, 2.36; 95% confidence interval, 1.11-4.98; P = 0.025). CONCLUSIONS: The modified classification was useful for preoperative CT classification of CSDH and the prediction of recurrence, with high agreement between raters.

Significantly high concentrations of vascular endothelial growth factor in chronic subdural hematoma with trabecular formation.

The underlying mechanism of chronic subdural hematoma (CSDH) after minor head injury is complex, probably due to mechanical injury of the arachnoid membrane, hematological coagulopathy, and pathological angiogenesis in the dura caused by inflammatory cytokines including vascular endothelial growth factor (VEGF). To confirm whether VEGF might be a reliable predictive biomarker for the natural history of CSDH, including progression and recurrence, we analyzed the correlation of VEGF concentration in the subdural fluid with CT findings and clinical features, including interval from minor head injury. Based on CT classification by hematoma density, the mean concentration of VEGF in hematoma fluid was found to be highest in the trabecular group, whereas the recurrence of CSDH was most frequent in the separated group in which VEGF concentration was low. There was a significant correlation between VEGF concentration and the CT classification. Furthermore, only in the trabecular group, a significant negative correlation between the VEGF concentration and interval from minor head injury to surgery was observed. These results suggest that VEGF concentration in the hematoma alone could not be a reliable predictive biomarker for the natural history of CSDH including its recurrence. Amongst the classified groups of CSDH, the trabecular group is likely to follow a different time course of VEGF concentration in the hematoma fluid compared to the other three groups.

Total Spinal Epidural "Blood Patch" Application Through a Racz Catheter in Spontaneous Intracranial Hypotension.

BACKGROUND: Epidural "blood patch" (EBP) is a standard treatment of spontaneous intracranial hypotension (SIH). In recent years, there are some reports of Racz catheter use for EBP performance at upper cervical spine levels. However, the practical use of Racz catheter for single-entry multisite EBP has never been reported until now. CASE DESCRIPTION: We treated a 60-year-old man diagnosed with SIH presenting with cerebrospinal fluid leaks from the cervical to the sacral segments. We discuss the advantages of the single-entry multisite EBP and the convenience of Racz catheter use in such cases. CONCLUSIONS: The Racz catheter can be a convenient means to deliver large-volume EBPs from a single entry point in the treatment of SIH.