Declining trend in the estimated annual rupture rate of unruptured cerebral aneurysms in Japan: a nationwide study.

The incidence of subarachnoid hemorrhages (SAHs) in Japan has recently decreased. However, trends in the annual rates of unruptured cerebral aneurysms (UCAs) are unclear because calculations based on follow-up periods are limited to patients with ruptured cerebral aneurysms. We aimed to clarify current trends in the estimated annual rupture rates of UCAs in Japan and to identify the most relevant contributing factors. We analyzed data from the Japanese Ministry of Health, Labour and Welfare and records of the Japan Neurosurgical Society. The estimated annual rupture rates of UCAs between 2003 and 2018 were calculated according to age-adjusted mortality rates of SAH and number of treated ruptured cerebral aneurysms (RCAs). We estimated trends in annual rupture rates using sensitivity analysis and assessed associations between estimated annual rupture rates and the prevalences of hypertension and current smoking. The estimated annual rupture rate of UCAs significantly decreased from 1.44 to 0.87% and from 0.92 to 0.76%, respectively, in terms of age-adjusted mortality rates of SAH and number of treated RCAs (p < 0.001). The range of changes in estimated annual rupture rates of UCAs was - 1.13%‒0.83%, representing a declining UCA trend of 88%. The estimated annual rupture rates of UCAs declined by 0.02-0.10% and 0.01-0.05% with every percent decrease in hypertension and current smoking prevalence, respectively. The estimated annual rupture rate of UCAs has recently decreased in Japan, possibly due to a decrease in the prevalence of hypertension rather than smoking.

Pulsatility index of superficial temporal artery was associated with cerebral infarction after direct bypass surgery for moyamoya disease.

OBJECTIVE: Direct bypass surgery by superficial temporal artery (STA) - middle cerebral artery anastomosis is an established procedure for moyamoya disease (MMD). However, some patients may develop cerebral infarction (CI) due to the watershed shift phenomenon after the surgery. This study sought to investigate the correlation between the postoperative changes of STA flow as well as cerebral blood flow (CBF) and the incidence of CI after direct bypass surgery for MMD. METHODS: We conducted a retrospective study of 62 hemispheres in 50 subjects who underwent direct bypass surgery for MMD. All subjects underwent pre- and post-operative MR imaging, ultrasound evaluation of STA, and single-photon emission computed tomography. The presence of CI was correlated with preoperative CBF, the delta difference of each value of the STA between before and after the surgery, and the postoperative increase ratio of CBF. RESULTS: All bypass procedures were patent, and CI was observed in 4 cases (6.4%). There was no significant association between the incidence of CI and both pre- and post-operative CBF. However, there was a significant difference in delta pulsatility index (PI) of the STA between cases with or without CI (-0.38±0.22 and -0.87±0.63, respectively, p=0.03). Whereas, other factors did not show any significant differences between those with or without CI. CONCLUSIONS: A relatively high postoperative PI of the STA was significantly associated with the incidence of CI after direct bypass surgery for MMD. A larger study is needed to confirm these findings.

Usefulness of stent placement for innominate artery stenosis via the right brachial artery under protection by balloon guide catheter: a technical case report.

A method of cerebral protection during endovascular treatment for innominate artery stenosis (IAS) has not been established. Herein, we report a case of symptomatic IAS in a 76-year-old woman. A balloon guide catheter (BGC) was inserted through the right brachial artery (BA) and guided distally to the stenosis. The BGC balloon was inflated, and stenting was performed with balloon protection of both the anterior and posterior cerebral circulation, without any complications. Stenting of the IAS with the BGC using the BA approach is useful, as it is a simple technique that can prevent distal embolization.

Vessel Wall Imaging of Evolving Unruptured Intracranial Aneurysms.

Background and Purpose- Unruptured intracranial aneurysms (UIAs) have various scenarios of growth and rupture. Magnetic resonance vessel wall imaging can detect aneurysmal wall thickening with inflammation and neovascularization. This study was performed to explore the vessel wall imaging findings of UIAs with consecutive follow-up. Methods- A total of 60 aneurysms with serial angiography over 2 years (mean period, 49 months, range, 24-192 months) were evaluated by vessel wall imaging. UIAs were morphologically categorized into 3 patterns: stable, whole sac expansion, or daughter sac formation. Aneurysm wall enhancement (AWE) was evaluated after administration of gadolinium. Results- Thirty-three of the 60 UIAs (55%) demonstrated no morphological changes, whereas 16 UIAS (27%) showed whole sac expansion and 11 UIAs (18%) demonstrated daughter sac formation. AWE was significantly less frequent in stable UIAs compared with UIAs showing morphological changes ( P<0.01). Aneurysms with daughter sac formation showed a significantly higher frequency of AWE than those demonstrating whole sac expansion. In the majority of UIAs with daughter sac formation, AWE was detected in the main aneurysm and not in the developing component. Conclusions- UIAs demonstrate various modes of growth. The pattern of AWE might be useful for identifying unfavorable morphological changes of UIAs.

Hyperperfusion after Endovascular Reperfusion Therapy for Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Patients with acute ischemic stroke (AIS) may display prolonged neurological deficits and conscious disturbance even after successful endovascular thrombectomy. We hypothesized that hemodynamic change after reperfusion might influence outcomes. This study investigated the factors causing hyperperfusion and outcomes. METHODS: We retrospectively analyzed 27 patients with AIS who underwent successful acute revascularization (TICI: Thrombolysis in Cerebral Infarction 2b + 3). Changes of the neurological status were precisely assessed by using the National Institutes of Health Stroke Scale (NIHSS). Ischemic lesions were scored by MRI with diffusion-weighted imaging (DWI), and blood flow in the middle cerebral artery territory was assessed by MRI with arterial spin labeling. Univariate analysis was performed to investigate correlations between hyperperfusion and demographic factors or the functional prognosis. RESULTS: Thirteen of the 27 (48%) patients developed hyperperfusion after reperfusion. A significant correlation was seen between hyperperfusion and the improvement of NIHSS at 24 hours (P < .0001), the duration of disturbance of consciousness (days) (P < .0001), DWI-ASPECTS (P = .001), hemorrhagic transformation (P = .007), and mRS less than or equal to 2 at 90 days (P = .007). CONCLUSIONS: The present findings suggested that some patients with AIS will develop hyperperfusion after successful acute revascularization. The status of hyperperfusion could prolong conscious disturbance and affect outcomes. Since the mechanism of hyperperfusion after revascularization depends on stroke etiology, diagnosing the type of ischemic stroke in the acute stage is important for managing postoperative treatment.

Clinicopathological Insights From Vessel Wall Imaging of Unruptured Intracranial Aneurysms.

Background and Purpose- The clinical significance of vessel wall imaging (VWI) remains unclear in patients with unruptured intracranial aneurysms. This study was performed to investigate the correlations between aneurysm wall imaging findings and histopathologic aneurysm wall architectures. Methods- A total of 9 aneurysms was evaluated by VWI and subsequently characterized with histopathology. We used VWI to visualize the aneurysm wall and determine if there was aneurysm wall enhancement after gadolinium contrast administration. Results- Aneurysm wall structures were identified in 6 of 9 unruptured intracranial aneurysms by native VWI, and wall enhancement was identified in 5 of these 6 aneurysms. Histopathologic studies revealed that wall thickening accompanied by atherosclerosis, neovascularization, and macrophage infiltration corresponded to visualization of the aneurysm wall by native VWI and to aneurysm wall enhancement. Conclusions- VWI can visualize thickening of the aneurysm wall, and wall enhancement corresponded to histologically confirmed degenerative changes accompanied by neovascularization and prominent macrophage infiltration.

[Hyperperfusion after Revascularization for Quasi-moyamoya Disease Associated with Graves' Disease:A Case Report].

We report a case of cerebral hyperperfusion syndrome accompanied by postoperative intracerebral hemorrhage following blood flow reconstruction for quasi-moyamoya disease associated with Graves' disease that had caused cerebral infarctions. A 44-year-old woman presented with repeated sensory impairment of the fingers on the left hand and weakness of the right lower limb and multiple cerebral infarctions developed in the bilateral frontal lobes. Magnetic resonance angiography and cerebral angiography suggested quasi-moyamoya disease. On hospitalization, untreated Graves' disease was identified and treated first. Revascularization was performed in the region of the right middle cerebral artery, where reduced cerebral blood flow and depressed vascular reactivity persisted half a year after treatment of Graves' disease, but postoperative cerebral hemorrhage appeared after 5 days due to hyperperfusion syndrome around the anastomotic site. Lethal hyperperfusion syndrome following revascularization of quasi-moyamoya disease associated with Graves' disease appears very rare and has not been reported previously.

[Metastasis of Hepatocellular Carcinoma to the Membrane of Chronic Subdural Hematomas:A Case Report].

An 81-year-old man presented with gait disturbance. Two months previously, he suffered from hepatocellular carcinoma and transarterial chemoembolization was performed. A head computed tomography(CT)scan revealed bilateral chronic subdural hematomas. The patient's gait disturbance was improved after achievement of bilateral burr hole drainage. A head CT two months after treatment revealed no recurrence of the hematomas. However, head CT images obtained four months after treatment revealed an abnormal mass in the right parietal region attached to the internal surface of the skull. The mass was located in the same region from where the chronic subdural hematomas were previously removed via burr hole drainage, and was suspected to have originated from the dura mater. We performed craniotomy and total removal of the mass. The dura mater was intact, and macroscopically, the mass originated from the organized membrane of the chronic subdural hematoma. A pathological examination revealed metastasis of hepatocellular carcinoma to the membrane of the chronic subdural hematomas. Head magnetic resonance imaging(MRI)performed 39 days after craniotomy presented a new lesion in the left parietal region attached to the internal surface of the skull. The patient subsequently died 46 days post-operation. When examining chronic subdural hematomas in cancer patients, histological examination of the dura mater, hematoma, and membrane of the hematoma are important. The possibility of metastasis to the capsule of the hematoma should be considered.

[A case of lateral ventricle metastasis from gastric carcinoma].

Metastatic brain tumors of the lateral ventricles are rare. Approximately half of the reported cases have originated from renal carcinoma;to the best of our knowledge, only 1 case originating from gastric carcinoma has been reported. A 57-year-old man presented with dull headache, left hemiparesis, and constructional apraxia of the right upper extremity. He had undergone gastrectomy for gastric carcinoma 8 years previously. Magnetic resonance imaging revealed an enhanced tumor extending from the right caudate nucleus to the right lateral ventricle with peritumoral edema. Complete resection of the tumor was achieved via the right transcallosal approach. The histopathological diagnosis was metastasis from the gastric carcinoma. After the resection, the patient temporarily showed a lack of spontaneity and extrapyramidal signs of the right upper and lower limbs;his condition improved after 3 weeks. He was discharged 2 months after the surgery, without any neurological deficits. Patients with tumors of the lateral ventricles may present with various characteristic neurological symptoms in the perioperative period;therefore, a thorough neurological examination is necessary.

Usefulness of combined bypass surgery for moyamoya disease in infants under 1 year of age: A technical case report.

Background: Among pediatric cases of moyamoya disease (MMD), cerebral ischemic symptoms often progress and worsen rapidly in infants under one year of age; therefore, it is important to treat them as early as possible. However, direct bypass surgery is often technically difficult for infants due to their small blood vessels. Here, we describe our technique to resolve the technical challenges encountered during superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass surgery in infants aged <1 year with MMD, focusing on specific procedures. Case Description: We performed bilateral STA-MCA and indirect bypass in a 1-year-old girl with MMD and cerebral infarction. Before treatment, a peripherally inserted central venous catheter (PICC) was placed to avoid ischemic attacks associated with crying, dehydration, and malnutrition. All examinations and procedures that would be stressful to the patient, such as blood examinations, were performed using PICC or under sedation. The STA-MCA diameters were 0.8 and 1.2 mm, respectively. After suturing the planned anastomosis with one stitch using an 11-0 monofilament nylon thread, the thread was lifted upward, and the arterial wall was incised. Anastomosis was performed using an 11-0 monofilament nylon thread with 2-4 stitches on each side. The operation was completed without patency problems. Postoperative blood flow improved, and the patient had a good treatment course. Conclusion: Direct bypass for MMD patients aged <1 year is technically challenging; however, the vessels can be connected if the procedure is carefully performed with consideration of the characteristics of the infant's vessels.

Compatibility of the semijailing technique with extremely soft i-ED coils for ruptured blood blister-like and dissecting aneurysms: patient series.

BACKGROUND: Optimal treatment options for ruptured blood blister-like aneurysms (BBAs) and dissecting aneurysms (DAs) have not yet been established. Endovascular treatment may achieve vessel reconstruction with the preservation of antegrade blood flow; however, securing curative hemostasis at the fragile rupture point remains a major concern. OBSERVATIONS: Two ruptured BBAs and two ruptured DAs treated by stent-assisted coiling with the semijailing technique in the last 2 years are described herein. The devices used were braided stents and i-ED coils, which are new low-memory shape and extremely soft coils. Neither rebleeding nor ischemic complications were observed. All patients had a favorable outcome and showed no recurrence after treatment. LESSONS: All aneurysms were treated without ischemic complications or rebleeding. The good compatibility of braided stents and the new concept coils in stent-assisted coiling by the semijailing technique provides insight into these intractable hemorrhagic vascular pathologies.

Human cranial bone-derived mesenchymal stem cells cultured under simulated microgravity can improve cerebral infarction in rats.

The efficacy of transplanting human cranial bone-derived mesenchymal stem cells (hcMSCs) cultured under simulated microgravity (sMG) conditions has been previously reported; however, their effect on cerebral infarction remains unknown. Here, we examined the efficacy of transplanting hcMSCs cultured in an sMG environment into rat models of cerebral infarction. For evaluating neurological function, hcMSCs cultured in either a normal gravity (1G) or an sMG environment were transplanted in rats 1 day after inducing cerebral infarction. The expression of endogenous neurotrophic, axonal, neuronal, synaptogenic, angiogenic, and apoptosis-related factors in infarcted rat brain tissue was examined using real-time polymerase chain reaction and western blotting 35 days after stroke induction. The RNAs of hcMSCs cultured under 1G or sMG environments were sequenced. The results showed that neurological function was significantly improved after transplantation of hcMSCs from the sMG group compared with that from the 1G group. mRNA expressions of nerve growth factor, fibroblast growth factor 2, and synaptophysin were significantly higher in the sMG group than in the 1G group, whereas sortilin 1 expression was significantly lower. RNA sequencing analysis revealed that genes related to cell proliferation, angiogenesis, neurotrophy, neural and synaptic organization, and inhibition of cell differentiation were significantly upregulated in the sMG group. In contrast, genes promoting microtubule and extracellular matrix formation and cell adhesion, signaling, and differentiation were downregulated. These results demonstrate that hcMSCs cultured in the sMG environment may be a useful source of stem cells for the recovery of neurological function after cerebral infarction.

Flow Redirection Endoluminal Device Flow Diverter Placement for Recurrent Dolichoectatic Vertebrobasilar Artery Aneurysm Treated with Multiple Low-Profile Visualized Intraluminal Support Stents: A Case Study.

Objective: We report a case of dolichoectatic vertebrobasilar aneurysms treated with multiple low-profile visualized intraluminal support (LVIS) stents followed by flow redirection endoluminal device (FRED) flow diverter to prevent the growth of the thrombosed aneurysm. Case Presentation: A 71-year-old man developed diplopia due to oculomotor nerve palsy after 11 years of follow-up for an enlarging thrombosed dolichoectatic vertebrobasilar artery aneurysm. He initially had a fusiform thrombosed aneurysm from the right vertebral artery to the basilar artery. This lesion was tortuous and strongly compressed the pons. A total of 11 LVISs were deployed from the right posterior cerebral artery to the right vertebral artery. Six months after surgery, there was no enlargement of the thrombosed aneurysm on MRI and the contrast leakage out of the stent was markedly reduced in DSA compared to immediately after surgery. One year and seven months after surgery, contrast leakage out of the stent was increased in DSA. The FRED was placed within the overlapped LVISs, and contrast leakage was somewhat reduced. After 2 years and 7 months from the initial treatment, the contrast leakage was still observed. However, there was no enlargement of the aneurysm and no complications related to treatments were observed. Conclusion: Treatment with multiple LVIS stents followed by FRED flow diverter treatment for dolichoectatic vertebrobasilar aneurysms (DVAs) may be one of the treatment options for controlling the growth of thrombotic aneurysms without complications, but the long-term prognosis of this case is unclear, and careful follow-up is mandatory.

Impact of intravenously administered cranial bone-derived mesenchymal stem cells on functional recovery in experimental spinal cord injury.

Impairments of the central nervous system, such as stroke, brain trauma, and spinal cord injury (SCI), cannot be reversed using current treatment options. Herein, we compared the characteristics of rat cranial bone-derived mesenchymal stem cells (rcMSCs) and rat bone marrow-derived mesenchymal stem cells (rbMSCs). We also investigated the therapeutic effects of intravenously administered rcMSCs and rbMSCs in a rat model of cervical SCI (cSCI) and elucidated its undrelying mechanism. Comprehensive comparative bioinformatics analysis of rcMSCs and rbMSCs RNA sequencing revealed that genes associated with leukocyte transendothelial migration and chemokine signaling were significantly downregulated in rcMSCs. Rats were divided into three groups that received intrtravenous administration of rcMSC, rbMSC, or phosphate-buffered saline (control) 24 h after cSCI. The rcMSC-treated group showed improved functional recovery over the rbMSC-treated and control groups, and reduced lesion volume compared with the control group. The mRNA expression of nitric oxide synthase 2 at the spinal cord lesion site was significantly higher in the rcMSC-treated group than in the control and rbMSCs-treated groups, whereas that of transforming growth factor-ß was significantly higher in the rcMSC-treated group compared to that in the control group. The transcriptome data indicated that rcMSCs and rbMSCs differentially affect inflammation. The intravenous administration of rcMSCs contributed to functional recovery and lesion reduction in cSCI. The rcMSCs have the potential to induce an anti-inflammatory environment in cSCI.

The 5-Factor Modified Frailty Index as a More Useful Associated Factor Than Chronological Age After Unruptured Cerebral Aneurysm Surgery: A Nationwide Registry Study.

BACKGROUND: Although chronological age is associated with mortality and morbidity after surgery for unruptured cerebral aneurysms (UCAs), there is little evidence regarding an association between the simplified 5-factor modified frailty index (mFI-5) and postoperative outcomes based on age group. OBJECTIVE: To investigate the association of the mFI-5 score with worse outcomes, mortality, and complications in patients after surgery for UCA by chronological age groups using a Japanese national database. METHODS: This study included 32 902 patients with UCAs enrolled in a Japanese national database between 2011 and 2015. Age group (younger than 65 years, 65-74 years, and 75 years or older), sex, UCA location, treatment, medications, Barthel Index (BI), medical history, mFI-5 score, and in-hospital mortality and complications were evaluated. We identified risk factors for worsening BI score, in-hospital mortality, and overall postoperative complications in each age group. RESULTS: In total, 14 465 patients were enrolled in this study. Multivariable analysis showed that elderly groups and patients with an mFI-5 score ≥2 items were associated with worsening BI scores (odds ratio 1.95; 95% CI 1.52-2.51) and in-hospital complications (odds ratio 1.79; CI 1.49-2.15), despite having no association with in-hospital mortality. Multivariable analysis by age groups showed that the mFI-5 score ≥2 items was associated with in-hospital complications in all age groups, unlike chronological age in patients younger than 74 years. CONCLUSION: The mFI-5 score was a more useful associated factor of in-hospital complications than chronological age in patients younger than 74 years undergoing surgery for UCA.

A novel rat model for longitudinal electrophysiological evaluation after cold-induced brain injury.

OBJECTIVE: Cerebral contusion models of cold-induced injury are widely used in animal studies. However, owing to the difficulty of longitudinal recording of electrical stimulation transcranial motor evoked potential (tcMEP) in brain injury models of incomplete paralysis, to the authors' knowledge there have been no multimodal evaluations of cold-induced brain injury models that have included motor function and electrophysiological and histological evaluations. Therefore, in this study the authors aimed to perform a multimodal evaluation of a rat model of brain injury. METHODS: A brain injury model in female rats and a tcMEP recording technique based on the authors' previous study were established to enable multifaceted analysis, including longitudinal electrophysiological evaluation. RESULTS: The model showed incomplete paralysis of the right forelimb. Motor function showed recovery over time, and histological evaluation showed tissue changes associated with cerebral contusion. In addition, stable tcMEP waveforms were recorded before and after surgery and up to 4 weeks after injury. The tcMEP amplitude decreased significantly after injury and recovered over time. Furthermore, the amplitudes at 1, 7, and 14 days after injury were significantly lower than those at preinjury (p < 0.0006, p < 0.0007, and p < 0.0067, respectively). CONCLUSIONS: In the present study, the authors established a novel cold-induced brain injury rat model and technique that allowed for the evaluation of longitudinal tcMEP recording and demonstrated that multimodal evaluation for brain injury can be performed. This model can potentially be applied in future investigations of various therapies for brain injury.

Effectiveness of tuning an artificial intelligence algorithm for cerebral aneurysm diagnosis: a study of 10,000 consecutive cases.

Diagnostic image analysis for unruptured cerebral aneurysms using artificial intelligence has a very high sensitivity. However, further improvement is needed because of a relatively high number of false positives. This study aimed to confirm the clinical utility of tuning an artificial intelligence algorithm for cerebral aneurysm diagnosis. We extracted 10,000 magnetic resonance imaging scans of participants who underwent brain screening using the "Brain Dock" system. The sensitivity and false positives/case for aneurysm detection were compared before and after tuning the algorithm. The initial diagnosis included only cases for which feedback to the algorithm was provided. In the primary analysis, the sensitivity of aneurysm diagnosis decreased from 96.5 to 90% and the false positives/case improved from 2.06 to 0.99 after tuning the algorithm (P < 0.001). In the secondary analysis, the sensitivity of aneurysm diagnosis decreased from 98.8 to 94.6% and the false positives/case improved from 1.99 to 1.03 after tuning the algorithm (P < 0.001). The false positives/case reduced without a significant decrease in sensitivity. Using large clinical datasets, we demonstrated that by tuning the algorithm, we could significantly reduce false positives with a minimal decline in sensitivity.

Factors contributing to restenosis after carotid artery stenting and the usefulness of magnetic resonance plaque imaging: A study of 308 consecutive patients.

PURPOSE: Carotid artery stenting (CAS) is an alternative treatment strategy to carotid endarterectomy. However, post-intervention in-stent restenosis (ISR) remains a complication. The timing, frequency, and prognostic factors of ISR are unclear. The incidence and timing of post-CAS ISR were investigated, including plaque imaging to investigate the prognostic factors. METHODS: We retrospectively investigated 308 patients diagnosed with carotid stenosis who underwent CAS between April 2008 and April 2020. The patients also underwent carotid ultrasonography (US) at 1, 3, 6, and 12 months postinterventionally and every 6 months thereafter. Contributory factors in patients with ISR were also investigated. RESULTS: The percentage value of ISR was 4.9% (15/308). The median time from the procedure to ISR was 7 months. The ISR rate was higher for patients with a plaque/muscle ratio of ≤ 2.30 on T2-weighted imaging (T2WI) on black-blood magnetic resonance imaging (BB MRI) (p = 0.022). A plaque/muscle ratio of ≤ 2.30 on BB MRI T2WI was identified as an independent risk factor for ISR. A comparison of the incidence of ISR and the plaque/muscle ratio level on MRI T2WI was also significant (p < 0.001). In T2WI imaging of BB MRI, the cutoff value for detecting ISR from the Plaque/Muscle ratio was 1.310 [area under the curve (AUC) = 0.935, Sensitivity = 100%, specificity = 85.2%]. CONCLUSIONS: The incidence of post-CAS ISR was 4.9%, at a median time of 7 months after stenting. Plaque/muscle ratio on T2WI in pre-intervention MRI plaque imaging may be a useful predictor of post-intervention ISR.

Abdominal Aortic Calcification Volume Is Associated with Wall Enhancement of Unruptured Intracranial Aneurysm.

OBJECTIVE: Inflammatory atherosclerotic remodeling of unruptured intracranial aneurysms (UIAs) wall, which could be detected as aneurysm wall enhancement (AWE) in MR vessel wall imaging (VWI), plays a pivotal role in pathophysiology of progression to rupture. On the other hand, abdominal aortic calcification reflects the extent of systemic atherosclerosis, which in turn predicts the risk of atherosclerotic cardiovascular as well as cerebrovascular diseases. This study sought to investigate whether the abdominal aortic calcification was associated with increased wall enhancement of UIAs in VWI. METHODS: This retrospective study reviewed subjects who underwent evaluation using 3T MR-VWI of UIAs and abdominal CT before endovascular treatments for UIAs between 2018 to 2020. Abdominal aortic calcification volume (ACV) was quantitatively measured from abdominal CT scans between renal arteries and bifurcation. The presence of AWE was correlated with patient profile, aneurysm morphology, and the ACV. RESULTS: A total of 42 patients with 50 UIAs were included. AWE was detected in 19 (38.0%) UIAs. Maximum diameter (9.2 ± 5.0 mm vs 5.3 ± 1.5 mm, P < 0.01) and the ACV (8.2 ± 6.0 mL vs 4.7 ± 4.6 mL, P = 0.038) were significantly higher in UIAs with AWE than those without AWE. CONCLUSIONS: The ACV was significantly associated with increased wall enhancement of UIAs. Systemic atherosclerosis might be a risk factor for the instability of UIAs. Future studies examining the effect of medications for systemic atherosclerosis on the extent of AWE in UIAs is warranted.

Longitudinal electrophysiological changes after mesenchymal stem cell transplantation in a spinal cord injury rat model.

Transcranial electrically stimulated motor-evoked potentials (tcMEPs) are widely used to evaluate motor function in humans and animals. However, the relationship between tcMEPs and the recovery of paralysis remains unclear. We previously reported that transplantation of mesenchymal stem cells to a spinal cord injury (SCI) rat model resulted in various degrees of recovery from paraplegia. As a continuation of this work, in the present study, we aimed to establish the longitudinal electrophysiological changes in this SCI rat model after mesenchymal stem cell transplantation. SCI rats were established using the weight-drop method. The model rats were transvenously transplanted with two types of mesenchymal stem cells (MSCs), one derived from rat cranial bones and the other from the bone marrow of the femur and tibia bone, 24 h after SCI. A phosphate-buffered saline (PBS) group that received only PBS was also created for comparison. The degree of paralysis was evaluated over 28 days using the Basso-Beattie-Bresnahan (BBB) scale and inclined plane task score. Extended tcMEPs were recorded using a previously reported bone-thinning technique, and the longitudinal electrophysiological changes in tcMEPs were investigated. In addition, the relationship between the time course of recovery from paralysis and reappearance of tcMEPs was revealed. The appearance of the tcMEP waveform was earlier in MSC-transplanted rats than in PBS-administered rats (earliest date was 7 days after SCI). The MEP waveforms also appeared at approximately the same level on the BBB scale (average score, 11 points). Ultimately, this study can help enhance our understanding of the relationship between neural regeneration and tcMEP recording. Further application of tcMEP in regenerative medicine research is expected.