Eagle jugular syndrome accompanied by de novo brainstem cavernous malformation: a case-based systematic review.

BACKGROUND: Eagle jugular syndrome (EJS), recently identified as a cause of cerebrovascular disease (CVD) due to venous obstruction by an elongated styloid process (SP), is reported here alongside a case of concurrent de novo cerebral cavernous malformation (CCM). This study aims to explore the potential causal relationship between EJS and de novo CCM through a comprehensive literature review. METHOD: Systematic literature reviews, spanning from 1995 to 2023, focused on EJS cases with definitive signs and symptoms and de novo CCM cases with detailed clinical characteristics. Data on the pathophysiology and clinical manifestations of EJS, as well as potential risk factors preceding de novo CCM, were collected to assess the relationship between the two conditions. RESULT: Among 14 patients from 11 articles on EJS, the most common presentation was increased intracranial hypertension (IIH), observed in 10 patients (71.4%), followed by dural sinus thrombosis in four patients (28.6%). In contrast, 30 patients from 28 articles were identified with de novo CCM, involving 37 lesions. In these cases, 13 patients developed CCM subsequent to developmental venous anomalies (43%), seven following dural arteriovenous fistula (dAVF) (23%), and two after sinus thrombosis (6%). In a specific case of de novo brainstem CCM, the development of an enlarged condylar emissary vein, indicative of venous congestion due to IJV compression by the elongated SP, was noted before the emergence of CCM. CONCLUSION: This study underscores that venous congestion, a primary result of symptomatic EJS, might lead to the development of de novo CCM. Thus, EJS could potentially be an indicator of CCM development. Further epidemiological and pathophysiological investigations focusing on venous circulation are necessary to clarify the causal relationship between EJS and CCM.

[Simulation and Navigation in the Neurosurgical Field Using Three-Dimensional Hholograms by Mixed Reality Devices].

Recently, three-dimensional(3D)holograms from mixed-reality(MR)devices have become available in the medical field. 3D holographic images can provide immersive and intuitive information that has been reported to be very useful for preoperative simulations. Compared with conventional 3D images on a two-dimensional(2D)monitor, 3D holograms offer a higher level of realism, allowing observation of the images anytime and anywhere if the MR device is operational. Even during surgery, surgeons can check realistic 3D holograms in front of them, above the surgical field, without having to turn their heads toward a 2D monitor on the wall. 3D holograms can also be used for neuronavigation if the hologram is tracked to the patient's real head. This method can be defined as 3D augmented reality(AR)navigation, which shows a hologram of a target, such as a tumor or aneurysm, inside the head and brain. In the future, interventions using these techniques with 3D holograms from MR devices are expected to evolve and develop new types of treatments for endoscopic surgery or fluoroscopy-guided endovascular surgery.

Embolic stroke induced by rotational persistent 1st intersegmental artery compression.

A 45-year-old man suffered multiple cerebral infarctions in the vertebrobasilar artery territory, followed by second stroke against conservative treatment. Radiological examinations revealed intra-arterial defect in left persistent 1st intersegmental artery (PFIA) at C1 level, suggesting mural thrombus, and mechanical compression of left PFIA at the level with head rotation to the right clearly revealed by reconstructed 3-dimensional radiological images, but no findings of atlantoaxial instability. One month after the second stroke, posterior fixation was performed. Postoperative course was uneventful without subsequent stroke for 24 months. This unique case demonstrated that PFIA might associate with cerebral stroke as a clinical condition of bow hunter's stroke even in middle age. Reconstructed 3-dimensional radiological images might be useful for clear demonstration of the pathophysiology in this complex clinical entity.

[Auditory Brainstem Response: ABR].

Intraoperative auditory brainstem response(ABR)monitoring has been established as a reliable method to evaluate cochlear function. Intraoperative ABR is mandatory in microvascular decompression for hemifacial spasm, trigeminal neuralgia, and glossopharyngeal neuralgia. Cerebellopontine tumor with remaining effective hearing function also requires ABR monitoring during surgery to preserve hearing function. Prolonged latency and subsequent amplitude decrease in the ABR wave V predicts postoperative hearing impairment. Therefore, when alerted to an intraoperative ABR during surgery, the surgeon should release the cerebellar retraction stressing the cochlear nerve and wait for the abnormal ABR to recover.

Efficacy and safety of intraventricular fibrinolytic therapy for post-intraventricular hemorrhagic hydrocephalus in extreme low birth weight infants: a preliminary clinical study.

PURPOSE: To evaluate the efficacy and safety of our unique therapy for treating post-intraventricular hemorrhagic hydrocephalus (PIVHH) in low birth weight infants (LBWls) through an early stage fibrinolytic therapeutic strategy involving urokinase (UK) injection into the lateral ventricle, called the "Ventricular Lavage (VL) therapy." METHODS: Overall, 43 consecutive infants with PIVHH were included. Most were extremely LBWIs (n = 39). Other cases included very LBWIs (n = 2) and full-term infants (n = 2). VL therapy involved continuous external ventricular drainage (EVD) management using a very fine catheter and intermittent slow injection of 6000 IU of UK every 3-6 h to actively dissolve hematomas. RESULTS: Early EVD management (within 3 weeks of IVH onset) was performed in 25 infants, with combination VL therapy in 21 infants. Five initiated late EVD management (≥ 3 weeks after IVH onset); the remaining 13 were treated conservatively for several weeks, delaying surgical intervention. Eighteen of 21 (86%) infants who received VL therapy did not require permanent shunt surgery. There were no serious complications, including the absence of secondary hemorrhage and infection. Two-thirds of the infants treated in the late stages required permanent shunt, and various shunt-related complications frequently occurred. A good outcome occurred in 13/17 infants in the early treatment group, despite most subjects having an IVH grade IV, and in 6/15 in the late treatment group. CONCLUSIONS: Permanent shunt surgery needs were dramatically reduced following early VL therapy, and functional outcomes were favorable. VL therapy might be a promising strategy that could lead to the development of new treatments for PIVHH.

Hinge and floating decompressive craniotomy for infantile acute subdural hematoma: technical note.

Cranioplasty complications after decompressive craniectomy (DC) in infants are not fully recognized. We aimed to devise and assess the efficacy of a hinge and floating DC (HFDC) technique for treating infantile acute subdural hematoma. Five infants, aged 2-20 months, were included. Intracranial pressure was controlled below 20 mmHg, no additional surgery was required, and there was no incidence of surgical site infection or bone graft resorption.

Diagnostic impact of monitoring transcranial motor-evoked potentials to prevent ischemic complications during endovascular treatment for intracranial aneurysms.

The present study aimed to determine the incidence of intraprocedural motor-evoked potential (MEP) changes and to correlate them with intraprocedural ischemic complications and postprocedural neurological deficits in patients after endovascular intracranial aneurysm treatment. This study analyzed data from 164 consecutive patients who underwent endovascular coil embolization to treat intracranial aneurysms under transcranial MEP monitoring. We analyzed associations between significant changes in MEP defined as > 50% decrease in amplitude, and intraprocedural complications as well as postoperative neurological deficits. Factors associated with postprocedural neurological deficits were also assessed. The treated aneurysms were predominantly located in the anterior circulation (71%). Fourteen (9%) were located at perforators or branches that supplied the pyramidal tract. Intraprocedural complications developed in eight (5%) patients, and four of eight (50%) patients occurred postprocedural neurological deficits. Significant intraprocedural MEP changes occurred during seven of eight endovascular procedures associated with intraprocedural complications and salvage procedures were performed immediately. Among these changes, four transient MEP changes, recovered within 10 min, were not associated with postprocedural neurological deficits, whereas three permanent MEP changes were associated with postprocedural neurological deficits and mRS ≥ 1 at discharge. Aneurysms located at perforators/branches supplying the pyramidal tract, and permanent intraprocedural MEP changes were associated with postprocedural neurological deficits. We conclude that intraprocedural transcranial MEP monitoring can reliably identify ischemic changes and can initiate prompt salvage procedures during endovascular aneurysm treatment.

Ocular blood flow by laser speckle flowgraphy to detect cerebral ischemia during carotid endarterectomy.

Laser speckle flowgraphy (LSFG) is a noninvasive technique that can measure relative blood flow velocity in the optic fundus contributed by the ophthalmic artery, the main first branch originating from the internal carotid artery (ICA). The aim of this study was to assess the feasibility of ocular blood flow measurement by LSFG to detect ischemic stress due to carotid clamping during carotid endarterectomy (CEA). Nineteen patients undergoing CEA with ocular blood flow measurement by LSFG and intraoperative monitoring (IOM) were prospectively enrolled between August 2016 and March 2019. The mean blur rate (MBR) of ocular blood flow by LSFG, representing relative blood flow of the branch of the retinal artery originating from the optic nerve head, was compared between before and after carotid clamping during CEA. The correlation between the reduction ratio of MBR and the regional saturation oxygen (rSO2) index by near infrared spectroscopy was investigated. Ocular blood flow measurement by LSFG could not be performed in one patient with a severe cataract. In the other 18 patients, LSFG could be performed in all 106 sessions during surgery. The MBR reduction ratio between before and after carotid clamping ranged from - 12 to 100%. The MBR reduction ratio was positively correlated with the rSO2 index (r = 0.694, 95% confidence interval: 0.336-0.877, p = 0.001). The MBR reduction ratio of ocular blood flow by LSFG after carotid clamping was significantly correlated with the rSO2 index. The ocular blood flow by LSFG could be considered an adjunct modality for evaluating cerebral ischemic tolerance during CEA.

Motor evoked potential monitoring can evaluate ischemic tolerance to carotid artery occlusion during surgery.

Balloon test occlusion (BTO) is a useful examination for evaluating ischemic tolerance to internal carotid artery (ICA) occlusion. The aim of this study was to investigate the relationships between intraoperative motor evoked potential (MEP) monitoring and the results of preoperative BTO. Between 2013 and 2017, 32 patients undergoing surgery under general anesthesia with intraoperative MEP monitoring, in whom preoperative BTO was performed, were identified. A receiver operator characteristic (ROC) analysis was performed to determine the appropriate cutoff value of MEP amplitude for BTO-positive. Furthermore, the accuracy of MEP monitoring for BTO-positive was compared with electroencephalogram (EEG) and somatosensory evoked potential (SEP) monitoring. Four of 32 (12.5%) patients were BTO-positive. The cutoff value of MEP amplitude for BTO-positive was a > 80% reduction from the baseline level, which showed sensitivity of 100% and specificity of 100%. Thus, the sensitivity and specificity for BTO-positive were significantly higher for MEP than for EEG (100% and 72.0%, p = 0.02) in 28 patients, but they were not significantly different compared with SEP (33.3% and 100%, p = 0.48) in 21 patients. MEP monitoring might be one of the alternatives for evaluating ischemic tolerance to ICA occlusion during surgery. The cutoff value of MEP amplitude was a > 80% reduction.

C2 extradural schwannoma compressing the dominant internal jugular vein: a case report.

We describe a rare case of extradural schwannoma in the upper cervical spine compressing the dominant internal jugular vein (IJV) presenting with atypical headaches. A 50-year-old woman complained of a subcutaneous neck mass associated with atypical headaches. Radiological examinations revealed the right IJV was compressed anteriorly by C2 extradural mass and occluded with markedly dilated collateral cerebral venous drainage through deep cervical veins. Subtotal removal was performed via the posterolateral approach and the atypical headaches resolved immediately. This case demonstrates that extradural schwannoma in the upper cervical spine could compress the IJV and manifest as cerebral venous circulation disturbances.

Bite injuries caused by transcranial electrical stimulation motor-evoked potentials' monitoring: incidence, associated factors, and clinical course.

PURPOSE: The incidence of bite injuries associated with transcranial electrical stimulation motor-evoked potentials monitoring reportedly ranges from 0.13 to 0.19%. However, in clinical practice, bite injuries appear to occur more frequently than previously reported. Our aim was to identify the incidence of and perioperative risk factors associated with bite injuries caused by transcranial electrical stimulation motor-evoked potential monitoring. METHODS: Patients who underwent elective surgery with transcranial electrical stimulation motor-evoked potential monitoring at a single tertiary hospital in Japan between June 2017 and December 2017 were included in this study. All patients were assessed by oral surgeons preoperatively and postoperatively. The associated factors with bite injuries were explored by the univariate analysis. RESULTS: 12 of 186 patients experienced 13 bite injuries, including three lip, six oral mucosa, and four tongue injuries. No patient required suture repair. 11 of 12 patients had uneventful postoperative courses and were cured within 12 postoperative days. One patient with a tongue ulcer and a hematoma had difficulty in oral intake and persistent dysgeusia. Patient severe movement during transcranial electrical stimulation motor-evoked potential monitoring was associated with bite injuries (p = 0.03). CONCLUSIONS: The incidence of bite injuries assessed by oral surgeons was 6.5% in patients with transcranial electrical stimulation motor-evoked potential monitoring, and the patients with severe movement during the monitoring tended to incur bite injuries. In rare cases, transcranial electrical stimulation motor-evoked potential monitoring may cause difficulty in oral intake and dysgeusia.

Efficacy of the visual evoked potential monitoring in endoscopic transnasal transsphenoidal surgery as a real-time visual function.

BACKGROUND: Visual evoked potential (VEP) is used as a means of intraoperative visual function monitoring. It remains unclear, however, whether intraoperative VEP monitoring is a means of real-time visual function monitoring that has satisfactory effectiveness and sensitivity. To evaluate this, the relationships between VEP waveform changes in endoscopic transsphenoidal surgery and postoperative visual function were analyzed retrospectively. MATERIALS AND METHODS: Intraoperative VEP monitoring was carried out during 82 endoscopic transnasal transsphenoidal surgeries for 164 eyes at Nara Medical University Hospital, Nara, Japan under total intravenous anesthesia. Red light flash stimulation was provided to each eye independently. The VEP recording and postoperative visual function were then analyzed. RESULTS: In 160 of 164 eyes (98%), steady VEP monitoring was performed. Stable VEP was acquired from eyes with a corrected visual acuity >0.1. VEP was not recorded in four eyes that had a corrected visual acuity under 0.05. A transient VEP decrease was observed in 26 eyes, 8 of which had improved visual acuity and 18 of which had no change in visual acuity. A permanent gradual VEP decrease occurred in eight eyes; this finding did not correspond to a change in visual function. The visual acuity of the patients who underwent the transsphenoidal operation in our study did not worsen. CONCLUSION: Intraoperative monitoring of VEP predicts postoperative visual function, and a reversible change in VEP indicates that visual function will be preserved. Intraoperative VEP monitoring will be mandatory for surgeries harboring a risk of visual impairment.

Pretreatment with and ongoing use of omega-3 fatty acid ethyl esters reduce the slow-flow phenomenon and prevent in-stent restenosis in patients undergoing carotid artery stenting.

OBJECTIVE: Carotid artery stenting (CAS) is a less invasive alternative to carotid endarterectomy, but it is essential to prevent thromboembolic complications during CAS and to suppress in-stent restenosis (ISR) after CAS because of the relatively high risk of periprocedural and follow-up stroke events. Clinical trials have demonstrated the strong relationship of carotid plaque vulnerability with the subsequent risk of ipsilateral ischemic stroke and thromboembolic complications during CAS. Recent studies demonstrated that both low eicosapentaenoic acid (EPA) and low docosahexaenoic acid (DHA) levels were significantly associated with lipid-rich coronary and carotid plaques, but little is known about the effect of administration of omega-3 fatty acids (O-3FAs) containing EPA and DHA before and after CAS for stabilizing carotid plaque, preventing thromboembolic complications, and suppressing ISR. In this study, the efficacy of pretreatment with and ongoing daily use of O-3FA in addition to statin treatment was evaluated in patients undergoing CAS. METHODS: This study was a nonrandomized prospective trial with retrospective analysis of historical control data. From 2012 to 2015, there were 100 consecutive patients with hyperlipidemia undergoing CAS for carotid artery stenosis who were divided into two groups. Between 2012 and 2013 (control period), 47 patients were treated with standard statin therapy. Between 2014 and 2015 (O-3FA period), patients were treated with statin therapy and add-on oral O-3FA ethyl esters containing 750 mg/d DHA and 1860 mg/d EPA from 4 weeks before CAS, followed by ongoing daily use for at least 12 months. In all patients, the plaque morphology by virtual histology intravascular ultrasound, the incidence of new ipsilateral ischemic lesions on the day after CAS, the slow-flow phenomenon during CAS, and ISR within 12 months after CAS were compared between the periods. RESULTS: The slow-flow phenomenon during CAS with filter-type embolic protection devices decreased in the O-3FA period (1 of 53 patients [2%]) compared with the control period (7 of 47 patients [15%]; P = .02). Furthermore, ISR for 12 months after CAS was significantly decreased in the O-3FA period (1 of 53 patients [2%]) compared with the control period (10 of 47 patients [21%]; P = .01). On virtual histology intravascular ultrasound analysis, the fibrofatty area was significantly smaller and the fibrous area was significantly greater in the O-3FA period. On multivariate logistic regression analysis, a low EPA/arachidonic acid ratio and a symptomatic lesion were the factors related to vulnerable plaque (P = .01 [odds ratio, 5.24; 95% confidence interval, 1.65-16.63] and P = .01 [odds ratio, 11.72; 95% confidence interval, 2.93-46.86], respectively). CONCLUSIONS: Pretreatment with O-3FA reduces the slow-flow phenomenon generated by plaque vulnerability during CAS, and on-going daily use of O-3FA suppresses ISR after CAS.

Partial wrap-clipping of the entrance of the pseudolumen of a fusiform aneurysm in the posterior inferior cerebellar artery: a technical note.

BACKGROUND: Fusiform aneurysms in the posterior inferior cerebellar artery (PICA) are rare and challenging to treat. Surgical treatment options for a fusiform aneurysm in the PICA include trapping with/without bypass and wrap-clipping, when elimination of the pathological wall from the systemic circulation and prevention of perforator injury are important. In addition, lower cranial nerve impairment due to surgical manipulation should also be avoided. METHOD: A fusiform-shaped aneurysm was found in a proximal part of the PICA by magnetic resonance angiography undertaken for evaluation of repeated vertigo in a 36-year-old man. The patient underwent direct surgery via a lateral suboccipital transcondylar fossa approach. The entrance of the pseudolumen was the only part to be wrapped and obstructed by clip application, through the corridor between the acoustic and glossopharyngeal nerves to avoid lower cranial nerve injury. RESULTS: Indocyanine green (ICG) videoangiography demonstrated obliteration of pseudolumen and patency of peripheral PICA and perforator contributing to the medulla oblongata. The postoperative course was uneventful without periprocedural complications, including dysphagia and hoarseness. CONCLUSIONS: Partial wrap-clipping technique for obstruction of the entrance into a pseudolumen is one of alternatives for dissecting fusiform-shaped aneurysm in the PICA. ICG videoangiography was helpful to confirm the obliteration of the pseudolumen and patency of parent vessel and perforators.

Quantitative analysis of the trajectory of simulated basilar apex aneurysms through the internal carotid artery to assess the need for an orbitozygomatic approach.

BACKGROUND: The aim of this study was to identify the correlation between the location of the internal carotid artery (ICA) and the need for an orbitozygomatic approach (OZA) when approaching a basilar apex (BX) aneurysm. MATERIALS AND METHODS: By imaging the virtual trajectory to access the basilar artery (BA) through the ICA, the correlations among the height of the BX, the height and lateral breadth of the bifurcation of the ICA, and the need for removal of the orbital rim or zygomatic arch were investigated using three-dimensional computed tomography angiography (3DCTA) data of approximately 80 random samples not limited to BX aneurysms. Furthermore, the utility of 3D simulation to determine the need for the OZA was verified using data from five patients with BX aneurysms. RESULTS: The height of the bifurcation of the ICA was inversely correlated and the height of the BX was positively correlated with the need for the OZA (both p < 0.017). Among patients undergoing surgery, clipping was successfully performed without the OZA in two patients in whom the distance from the simulated skull point on the extended line from the BX through the bifurcation of the ICA was more than 4 cm from the zygoma and orbital rim. CONCLUSIONS: It is necessary to determine the spatial relationship between the basilar artery and the ICA to decide whether the OZA is needed for surgery. Correlations of the height of the ICA and BX with the need for the OZA were not very strong individually, though they were significant. Therefore, simulation using 3DCTA appears to be important for planning the surgical approach for the treatment of BX aneurysms.

Antitumor effects of minodronate, a third-generation nitrogen-containing bisphosphonate, in synergy with γδT cells in human glioblastoma in vitro and in vivo.

Nitrogen-containing bisphosphonates (N-BPs), which prevent bone resorption, exert direct and γδT cell (GDT)-mediated antitumor effects against several tumor cell types, including glioblastoma (GBM). However, limited information is available regarding the antitumor effects of N-BPs in GBM. Specifically, the antitumor effects of minodronate (MDA), a third-generation N-BP, in GBM are yet unclear. This study aimed to investigate the antitumor effects of MDA in GBM in vitro and in vivo. We performed growth inhibition and apoptosis detection assays using the GBM cell lines U87MG and U138MG. Apoptosis inhibition assays were also conducted. In vivo xenograft assays were performed in highly immunodeficient NOD.Cg-Prkdc(scid) Il2rg(tm1Sug)/Jic mice subcutaneously implanted with U87MG and U138MG cells. Growth inhibition and apoptosis detection assays demonstrated that MDA inhibited GBM cell growth via apoptosis, which was markedly enhanced by ex vivo expanded GDT. A pan-caspase inhibitor, z-VAD-fmk, inhibited MDA-induced U138MG apoptosis and MDA/GDT-induced U87MG and U138MG apoptosis. But z-VAD-fmk increased MDA-induced U87MG apoptosis. MDA/GDT-mediated apoptosis was blocked by the anti-T cell receptor (TCR) Vγ9, mevalonate pathway inhibitor, granzyme B inhibitor, and antitumor necrosis factor (TNF)-α. In vivo xenograft assays showed that combined intraperitoneal administration of MDA/GDT induced antitumor effects on unestablished U87MG-derived subcutaneous tumors. MDA exerted direct and GDT-mediated anti-GBM apoptotic effects in a caspase-dependent manner. GDT recognized MDA-exposed GBM cells via TCRVγ9 and induced apoptosis via granzyme B and TNF-α release. Because MDA elicited anti-GBM effects in synergy with GDT in vivo, a combination of MDA and ex vivo-generated GDT could be an effective treatment in patients with GBM.

Influence of Diabetes Mellitus and Cigarette Smoking on Variability of the Clopidogrel-Induced Antiplatelet Effect and Efficacy of Active Management of the Target P2Y12 Reaction Unit Range in Patients Undergoing Neurointerventional Procedures.

BACKGROUND: Optimal antiplatelet inhibition is essential in patients undergoing neurointerventional procedures; however, variability in response to clopidogrel can contribute to thromboembolic and hemorrhagic complications. The present study evaluated the influence of diabetes mellitus and cigarette smoking on clopidogrel reactivity. METHODS: Between 2011 and 2013, 71 consecutive patients underwent aneurysmal coil embolization (CE) or carotid artery stenting (CAS) and received clopidogrel (75 mg daily) and aspirin (100 mg daily) before the treatment. The patients were divided into 2 groups: CE (n = 31) and CAS (n = 40). The patients underwent prospective assessment of preoperative platelet function using VerifyNow assay and received adjunctive cilostazol (200 mg daily, triple antiplatelet therapy) in case of clopidogrel hyporesponse. Patients with clopidogrel hyper-response underwent clopidogrel dose reduction (clopidogrel, 12.5-50 mg daily). RESULTS: Clopidogrel resistance was noted in 15 patients (37.5%) in the CAS group and in 4 patients (12.9%) in the CE group (P = .031). Clopidogrel hyper-response was noted in 2 patients (5%) in the CAS group and in 11 patients (54.8%) in the CE group (P < .001). There was a significant difference in the baseline clinical characteristics between the 2 groups. In the multivariate logistic regression analysis, diabetes and age were independent predictors of clopidogrel hyporesponse, whereas current smoker was an independent predictor of clopidogrel hyper-response. CONCLUSIONS: Significant differences in baseline clinical characteristics were present when comparing patients undergoing endovascular treatment of unruptured cerebral aneurysms and carotid artery stenosis. Diabetes mellitus and current smoker status were independent factors related to reactivity to clopidogrel.

[Cerebral hemorrhage].

Intracerebral hemorrhage (ICH) remains a serious condition for which early aggressive care is warranted. Japanese evidence-based stroke guidelines were published in 2015 to present the current and comprehensive recommendations for the diagnosis and treatment of stroke. In the spontaneous ICH, topics focused on prevention, management in the acute and chronic stage, complications, management of coagulopathy and blood pressure, prevention and control of secondary brain injury and intracranial pressure, the role of surgery, and other pathologies of ICH. The management of ICH in pregnancy and the puerperium was newly added. These guidelines provide a framework for goal-directed treatment of the patient with ICH.

Visualization of Regional Cerebral Blood Flow Dynamics during Cortical Venous Occlusion using Laser Speckle Contrast Imaging in a Rat Model.

BACKGROUND: Cerebral venous ischemia (CVI) is a rare but potentially significant complication of neurosurgical procedures. However, it is still unclear how cerebral venous occlusion (VO) affects regional cerebral blood flow (rCBF) dynamics. To elucidate its pathophysiology in detail, we examined the real-time perfusion dynamics during adjacent vein occlusions using laser speckle contrast imaging (LSCI) in a rat 2-vein occlusion model. METHODS: Two cortical veins were occluded photochemically using rose Bengal dye in 6 male Wistar rats; rCBF was measured in real time with an LSCI before and after VO. Regions of interest were defined between the 2 veins (A) and on the opposite side of the first occluded vein (B) on semi-quantitative pseudocolor images for off-line analysis. Histopathologic evaluation was performed 3 days after the procedure to assess the extent of infarction. RESULTS: LSCI revealed a stepwise reduction in CBF, with a sudden decrease just after the first vein occlusion (~20%) and a further decrease after the second (~30%). Significant differences were observed between rCBF dynamics within regions of interest A and B (P = .0004). All rats exhibited infarcts in the superficial cerebral cortex histopathologically. CONCLUSIONS: This is the first report of LSCI specifically applied to the study of CVI. The extensive real-time measurement with high temporal and spatial resolution revealed the stepwise reduction in rCBF during sequential VO and the ensuing infarcts.