The intracranial vasculature of canines represents a model for neurovascular ischemia and training residents and fellows in endovascular neurosurgery

BACKGROUND

We describe use of a canine model to evaluate physiological effects and neuroprotective strategies in the setting of cerebral ischemia and endovascular neurosurgery training.

METHODS

We performed transfemoral digital subtraction cerebral and cervical angiography on eight anesthetized dogs. Angiographic images of cerebral arteries were obtained following cannulation of the femoral artery. Cerebral ischemia models were made after angiography.

RESULTS

The canine cerebral vasculature exhibited extensive tortuosity of the carotid and vertebral arteries. Conversely, the bilateral anterior spinal arteries were easily catheterized using microcatheters and microguidewires. The basilar artery and its branches were facilely cannulable. Circle of Willis continuity sans hypoplasia or aplasia of its constitutive segments was appreciated in all animals. The middle cerebral arteries could be easily accessed via the posterior communicating arteries. We generated an empirically evaluable therapeutically interventional experimental animal model of cerebral ischemia by occluding the middle cerebral artery using small coils for a duration between 15 and 60 min.

CONCLUSION

Unique amenability of the canine intracranial vasculature to selective and microcatheter cannulation renders experimentally induced cerebral, cerebellar, and brainstem via occlusion of the supratentorial and infratentorial arteries a simple matter. The neural vasculature irrigating the canine cerebrum, brainstem, and cerebellum may consequently prove useful in helping young and nascent endovascular neurosurgeons in developing and refining their skills of microcatheter navigation and manipulation and deployment of therapeutic devices to achieve effective occlusion of aneurysms, arteriovenous malformations, arteriovenous fistulas, and neoplasms of the intracranial cavity.

Intravenous r-tPA Dose Influence on Outcome after Middle Cerebral Artery Ischemic Stroke Treatment by Mechanical Thrombectomy

Background and Objectives: Pretreatment with intravenous thrombolysis (IVT) is still recommended in all eligible acute ischemic stroke patients with large-vessel occlusion before mechanical thrombectomy (MTE). However, the added value and safety of bridging therapy versus direct MTE remains controversial. We aimed at evaluating the influence of r-tPA dose level in patients with middle cerebral artery (MCA) occlusion treated with MTE. Materials and Methods: We prospectively compared clinical and radiological outcomes in 38 bridging patients, with 65 receiving direct MTE for MCA stroke admitted to Vilnius University Hospital Santaros Clinics. Following our protocol, r-tPA infusion was stopped just before MTE in the operating room. Therefore, we divided all bridging patients into three groups according to the amount of r-tPA they received: bolus, partial dose or full dose. Functional independence at 90 days was assessed by a modified Rankin Scale score, i.e., from 0–2. The safety outcomes included 90-day mortality and any intracerebral hemorrhage (ICH). Results: Baseline characteristics and functional outcome at 90 days did not differ between the bridging and direct MTE groups. Shorter MTE procedure and hospitalization time (p = 0.025 and p = 0.036, respectively) were observed in the direct MTE group. An IVT treatment subgroup analysis showed higher rates of symptomatic ICH (p < 0.001) and longer intervals between imaging to MTE (p = 0.005) in the full r-tPA dose group. Conclusions: In patients with an MCA stroke, direct MTE seems to be a safe and equally effective as bridging therapy. The optimal r-tPA dose remains unclear. Randomized trials are needed to accurately evaluate the added value of r-tPA in patients treated with MTE.

Intracranial Atherosclerosis: A Disease of Functional, not Anatomic Stenosis? How Trans-Stenotic Pressure Gradients Can Help Guide Treatment

BACKGROUND

Most trials have assessed intracranial atherosclerotic disease (ICAD) severity based on angiographic stenosis. However, anatomic stenosis might not accurately identify the actual state of functional post-stenotic flow limitation.

OBJECTIVE

To investigate whether angiographic stenosis correlates with physiologic distal flow limitation, measured as trans-stenotic pressure gradients, in ICAD patients.

METHODS

In patients referred for endovascular treatment of anterior circulation symptomatic ICAD who failed maximal medical therapy (MMT) per SAMMPRIS (Stenting versus Aggressive Medical Therapy for Intracranial Arterial Stenosis) criteria, angiographic luminal diameters and percentages of stenosis were correlated with trans-stenotic pressure gradients, calculated as distal/proximal pressure ratios (DPPR) and proximal minus distal pressure gradients (PDPG), by way of Spearman correlation coefficients.

RESULTS

Nine patients (3 men, 6 women) were evaluated. Atherosclerotic lesions' locations included internal carotid artery in 5 subjects (2 cavernous, 3 supraclinoid) and proximal middle cerebral artery (M1) in 4 patients. Mean percentage of stenosis was 80 ± 8% (range 75%-94%). Minimal lumen diameter at the most stenotic ICAD site ranged from 0.2 to 0.9 mm (0.59 ± 0.41 mm). DPPR ranged from 0.38 to 0.63 (0.56 ± 0.14). PDPG ranged from 35 to 57 mm Hg (50 ± 8 mm Hg). Spearman coefficients showed no correlation between DPPR or PDPG and angiographic minimal luminal diameters or percentages of stenosis. There were no procedural complications related to trans-stenotic pressure measurements.

CONCLUSION

Angiographic stenosis does not reflect the physiologic severity of distal flow limitation in patients with ICAD. Hemodynamic assessment using trans-stenotic pressure ratios and gradients may serve as a more reliable predictive biomarker for MMT failure and response to revascularization.

[A Case of Unruptured Cerebral Aneurysm Arising from Duplicate Origin of the Middle Cerebral Artery]

We experienced a case of an unruptured cerebral aneurysm arising from a duplicate origin of the middle cerebral artery(MCA). Initially, we diagnosed the condition as an unruptured aneurysm arising from the internal carotid artery on three-dimensional computed tomography;neck clipping was attempted. However, an unidentified vessel was found around the aneurysmal neck, which could not be easily separated from the aneurysm, making neck clipping difficult. Thus, we only completed coating of the aneurysm without neck clipping. Postoperatively, cerebral angiography showed that the unidentified vessel originated from the internal carotid artery and fused with the MCA horizontal segment. We recognized that the identified vessel was a duplicate origin of the MCA. Few reports on the treatment of an aneurysm arising from a duplicate origin of the MCA are available;there has been no discussion on whether this vessel can be occluded. We assumed that occlusion of the proximal end of the duplicate origin of the MCA together with the aneurysm was unlikely to cause ischemia as the duplicate origin of the MCA fuse with MCA. Coil embolization was performed for the aneurysm, and the duplicate origin was unexpectedly preserved immediately after coil embolization. However, it was not enhanced on cerebral angiography performed after several months, and no cerebral infarction was noted on magnetic resonance imaging. If preservation of the duplicate origin of the MCA is difficult, occlusion of the aneurysm together with the proximal end of the duplicate origin of the MCA can be considered as a surgical strategy.

Unilateral Abducens Nerve Palsy Following Perinatal Stroke of the Middle Cerebral Artery

The authors describe a case of unilateral abducens nerve palsy following perinatal stroke of the middle cerebral artery. A 1-year-old boy presented with left eye esotropia but no other ocular abnormalities. The patient's history, examination, and diagnostic tests were consistent with abducens nerve palsy. He underwent left medial rectus recession of 5.5 mm and left lateral rectus resection of 7 mm followed by patching. At 15 months after surgery, primary gaze by prism alternate cover testing revealed a 4 prism diopter (PD) esophoria (small angle in left gaze with essentially no action of lateral rectus) and 2 PD right hyperphoria. Ophthalmologic management of abducens nerve palsy entails addressing neurological sequelae in a timely manner, treating the esotropia and strabismic amblyopia to optimize visual system development. [J Pediatr Ophthalmol Strabismus. 2020;57:e30-e33.].

Toward automated classification of pathological transcranial Doppler waveform morphology via spectral clustering

Cerebral Blood Flow Velocity waveforms acquired via Transcranial Doppler (TCD) can provide evidence for cerebrovascular occlusion and stenosis. Thrombolysis in Brain Ischemia (TIBI) flow grades are widely used for this purpose, but require subjective assessment by expert evaluators to be reliable. In this work we seek to determine whether TCD morphology can be objectively assessed using an unsupervised machine learning approach to waveform categorization. TCD beat waveforms were recorded at multiple depths from the Middle Cerebral Arteries of 106 subjects; 33 with Large Vessel Occlusion (LVO). From each waveform, three morphological features were extracted, quantifying onset of maximal velocity, systolic canopy length, and the number/prominence of peaks/troughs. Spectral clustering identified groups implicit in the resultant three-dimensional feature space, with gap statistic criteria establishing the optimal cluster number. We found that gap statistic disparity was maximized at four clusters, referred to as flow types I, II, III, and IV. Types I and II were primarily composed of control subject waveforms, whereas types III and IV derived mainly from LVO patients. Cluster morphologies for types I and IV aligned clearly with Normal and Blunted TIBI flows, respectively. Types II and III represented commonly observed flow-types not delineated by TIBI, which nonetheless deviate from normal and blunted flows. We conclude that important morphological variability exists beyond that currently quantified by TIBI in populations experiencing or at-risk for acute ischemic stroke, and posit that the observed flow-types provide the foundation for objective methods of real-time automated flow type classification.

Mycotic Aneurysm of the Middle Cerebral Artery Leading to Subarachnoid Hemorrhage, as the Initial Presentation of Bartonella henselae Endocarditis

Bartonella species was first reported as a cause of endocarditis in 1993, currently it is thought to account for 3-4 percent of all diagnosed cases. Initial symptoms of Bartonella endocarditis are non-specific like weight loss, fever and fatigue. There are very few reported cases of Bartonella endocarditis causing mycotic aneurysm. We present a case of a 60-year-old male who presented with subarachnoid hemorrhage secondary to mycotic aneurysm. Due to high suspicion of endocarditis leading to mycotic aneurysm he underwent transesophageal echocardiography which showed mitral valve vegetations. His blood cultures were negative, he was eventually diagnosed with Bartonella henselae by elevated IgG titers greater than 1:800. Due to repeated mycotic aneurysms on antibiotics, he underwent surgical mitral valve replacement along with the full course of antibiotics and has been asymptomatic since.

Head Biometry in Fetuses with Isolated Congenital Heart Disease

PURPOSE

 Altered cerebral hemodynamics are involved in changes in head biometry in fetuses with congenital heart disease (CHD). We compared head growth in different CHD groups with published normative values and investigated whether CHD groups differ from each other in terms of head circumference (HC) development over gestational age (GA).

MATERIALS AND METHODS

 Retrospective cohort study consisting of 248 CHD fetuses. Subgroups were generated according to the expected ascending aorta oxygen saturation: Low placental blood content (BC) and therefore low oxygen delivery to the brain (group 1: n = 108), intermediate placental and systemic BC due to intracardiac mixing of blood (group 2: n = 103), high placental BC (group 3: n = 13) and low placental BC and low oxygen delivery to the brain without mixing of blood (group 4: n = 24). Furthermore, group 1 was divided into antegrade (n = 34) and retrograde (n = 74) flow through the aortic arch. Comparisons were made at a GA of 22, 30 and 38 weeks.

RESULTS

 Estimated values of zHC (z-score transformed) were not significantly different between the four CHD groups at the three time points in gestation (all p > 0.05). Within group 1 fetuses with retrograde aortic arch flow showed a significant negative association between HC and GA compared to reference values (b = -0.054, p < 0.001) and had significantly lower zHC values at 38 weeks (-0.836) compared to fetuses with antegrade flow (0.366, p = 0.009).

CONCLUSION

 Our data do not confirm that CHD fetuses in general have a significantly smaller HC. HC becomes smaller throughout gestation depending on the direction of aortic arch flow.

[Intracranial Pseudoaneurysm Arising after Radiotherapy for Oligodendroglioma:A Case Report]

Intracranial pseudoaneurysms arising after radiotherapy for brain tumors are a relatively rare occurrence and associated with high-volume radiotherapy such as stereotactic radiosurgery. Herein, the authors report a rare case of intracranial pseudoaneurysm after conventional radiotherapy for oligodendroglioma. Case:A 46-year-old female incidentally presented with an intracranial hemorrhage from a middle temporal artery aneurysm. Four years earlier, she underwent surgical resection and conventional radiation therapy for oligodendroglioma. The aneurysm was successfully treated with middle cerebral artery(MCA)aneurysm trapping, in conjunction with a parietal branch superficial temporal artery-MCA bypass, to prevent re-rupture. Formation of intracranial pseudoaneurysm after conventional radiotherapy is extremely rare. However, the occurrence of cerebral aneurysm(s), as well as vascular stenosis during follow-up for brain tumors treated with radiotherapy, should be considered.

[The Analysis of the Thickness of a Cerebral Aneurysm:Can Predict the Translucent-type of Unruptured Middle Cerebral Artery Aneurysm Preoperatively?]

OBJECT

The rupture risk of cerebral aneurysms is determined by various factors. However, it is not clear whether the thickness of the aneurysm wall also influences the rupture risk. In this study, under the assumption that thin-walled aneurysms have a higher rupture risk compared with thick-wall aneurysms, we evaluate the usefulness of computed fluid dynamics(CFD)to identify thin-walled cerebral aneurysms.

METHODS

Fifty-four unruptured middle cerebral aneurysms from 53 patients were analyzed using CFD before the operation. We divided these aneurysms into two groups: translucent-type aneurysms and others. To analyze the difference of these groups, individual elements(age, gender, volume, and aspect ratio)and hemodynamic factors(wall shear stress[WSS], flow coefficient, and flow coefficient per volume)were examined using CFD.

RESULTS

Univariate analysis detected significant relationships between the translucent-type aneurysms and gender, aspect ratio, WSS and flow coefficient per volume. Multiple logistics regression also identified a significant relationship with gender and flow coefficient per volume. The receiver operating characteristic curve demonstrated that the flow coefficient per volume could predict translucent-type aneurysms(area under the curve 0.84, cut-off value 1.32, sensitivity 76.2%, and specificity 87.9%).

CONCLUSION

Gender and the flow coefficient per volume could predict translucent-type aneurysms of the middle cerebral artery. CFD analysis might be a useful tool to predict translucent-type aneurysms.

[False Aneurysm Formation at the Origin of the M2 Segment of the Middle Cerebral Artery Following a Blunt Head Trauma:A Case Report]

A 43-year-old man fell from a 1m-high truck loading platform and sustained an injury in the occiput. On admission, he was alert and neurologically intact. Computed tomography(CT)showed hemorrhage in the right sylvian fissure and parenchyma adjacent to the sphenoid wing. Magnetic resonance angiography detected no abnormalities. The course was uneventful for 11 days. However, on the 12th day, he spontaneously manifested with stupor. CT and CT angiography revealed expansion of the hemorrhage and an aneurysm arising from the origin of the M2 segment of the right middle cerebral artery. After superficial temporal artery to middle cerebral artery bypass, the aneurysm, a reddish pulsatile mass, was removed from the origin of the torn M2 segment, and the laceration was sutured. The histological diagnosis was false aneurysm. He recovered and was discharged 4 months after the trauma. Traumatic cerebral aneurysms are rare in the proximal segment of the middle cerebral artery. However, they should be distinguished from nontraumatic true aneurysms in the same region and treated as false aneurysms, which are major and critical traumatic aneurysms, for favorable outcomes.

Tulip Giant Aneurysm Amputation and "Shingle Clip Cut Clip" Technique for Microsurgical Reconstruction of a Giant Thrombosed Middle Cerebral Artery Aneurysm

In this video, we present the case of a 61-year-old female who was brought to the emergency department after she had partial complex seizures. Computed tomography and magnetic resonance imaging of the brain revealed a right temporal lobe mass, which was initially thought to be a tumor. The patient was therefore referred to us for further management. The round nature of the lesion raised suspicion for an aneurysm. Computed tomography angiography was performed, followed by a diagnostic conventional cerebral angiogram, and confirmed the presence of a giant thrombosed aneurysm. Giant aneurysms represent 3%-5% of all cerebral aneurysms.¹ They are more common in females with a ratio of 2:1 to 3:1.¹ They have a high risk of rupture up to 50% in the posterior circulation and 40% in the anterior circulation over 5 years according to the International Study of Unruptured Intracranial Aneurysms Investigators.^2,3 Their treatment can be complex and treacherous. Treatment options vary widely from parent artery sacrifice in select cases to clip reconstruction to an array of endovascular approaches such as flow diversion. In some cases a combination of both open and endovascular approaches might be necessary.^4-8 In our case, we opted for an open surgical clip reconstruction. A superior temporal artery-middle cerebral artery bypass was attempted to allow for trapping of the aneurysm without risking ischemic complication distal to it. Unfortunately, the patient's vessels were too atherosclerotic to maintain patency. A strategy was then devised, which consisted of cutting the dome of the aneurysm and clearing the distal two thirds of the clot ("tulip technique") and then completing thrombus resection under temporary occlusion. Once clot removal was completed, the aneurysm was clipped using the "shingle clip cut clip" technique (Video 1). The patient's postoperative course was uneventful, and the patient remained seizure free.

Outcome in Survivors of Middle Cerebral Artery Territory Ischemic Stroke: Can it be predicted?

BACKGROUND

Stroke is the fourth leading cause of disability worldwide. The present study was designed to assess functional disability in middle cerebral artery (MCA) territory ischemic stroke patients by applying standard scales for stroke severity, cognitive impairment, disability, dependency and depression. We also wanted to study whether baseline assessment predicts outcome at 1 month.

METHODOLOGY

After institutional ethics committee approval, patients were enrolled from the inpatients of the Department of Medicine at Topiwala National Medical College and BYL Nair Charitable Hospital, Mumbai from July 2014 to December 2015. Various clinical parameters were recorded on admission. On day 5(±1) the National Institutes of health Stroke Scale (NIHSS), Mini Mental state examination (MMSE) were administered. On 1 month follow up, these were repeated along with Modified Rankin scale, Barthel's index (BI) and Hospital Anxiety and Depression Scale (HADS). Presence of certain risk factors for stroke were reviewed at 1 month.

RESULTS

75 patients were enrolled. There was a delay in reaching the hospital and therefore imaging, in a greater majority. Only 4% could be imaged within the first 3 hours. Mean NIHSS score at day-5 was 9 and at day-30 was 6. Thus it had significantly reduced over 1 month. The MMSE remain unchanged at day 5 and at day 30. Lower baseline MMSE scores correlated with poorer outcomes on NIHSS, BI and mRS at 1 month. Both BI and mRS at 1 month indicated that about 60% of the cases had poor outcome. Amongst 48 of the non-aphasic MCA strokes, 11(22.92%) had depression. An NIHSS score of 6 or above on day 5, predicted poor outcome at 1 month. Presence of aphasia, dominant lobe affection and female sex were associated with a higher disability at 1 month. Around 30% cases had at least 1 risk factor uncontrolled at 1 month follow-up.

CONCLUSIONS

Our findings show that disability assessment late in the first week after onset of stroke using NIHSS accurately forecast outcome at one month after onset of stroke. The MMSE too is not expected to change at 1 month. Those with aphasia are expected to have greater disability. Based on or study we recommend that stroke patients should be assessed with NIHSS and MMSE before discharge, to explain the prognosis of the patient. Also more intense counselling on controlling blood pressure and diabetes as well as abstinence from smoking should be undertaken routinely.

Systematic error and cognitive bias in obstetric ultrasound

Linked Comment: Ultrasound Obstet Gynecol 2019; 53: 454-464.

Multivariate Analysis For Predicting Internal Carotid (IC) And Middle Cerebral (MC) Aneurysmal Rupture By Hemodynamic Parameters

Currently, aneurysmal rupture can hardly be predicted and the search for an objective and precise indicator is ongoing. The objective of this study was to find a rupture prediction indicator (RPI) based on hemodynamic parameters of unruptured aneurysms focusing on the internal carotid (IC) and middle cerebral (MC) arteries. Computational fluid dynamics simulations were performed and hemodynamic parameters were calculated using three-dimensional C-arm computed tomography (3D C-arm CT) images of a total of 137 unruptured aneurysms (69 IC and 68 MC artery aneurysms) with known outcomes of rupture or unrupture. Multivariate analysis was applied to build an RPI model. The final RPI models contained the pressure-loss coefficient at the time maximum (TMAXPLc). Ruptured aneurysms were found to have lower TMAXPLc than unruptured aneurysms. The mean values were 1.002 (95%CI 0.827 to 1.177) and 1.466 (95%CI 1.352 to 1.579), respectively (P=0.002). TMAXPLc may thus be a useful parameter for rupture prediction of IC and MC artery aneurysms.

[Perioperative stroke effectively treated by an acute stroke team including anesthesia department: a case report]

Perioperative stroke is cerebral infarction occurring in the perioperative period. The incidence of perioperative stroke in non-cardiac, and non-neurologic surgery is about 0.7%, but the mortality can be as high as 26% to 40%. The outcome of the patients with perioperative stroke can be disastrous. Here we report a case of perioperative ischemic stroke that occurred after surgery of lumbar decompression and pedical screw fixation. A 76-year-old female admitted to our hospital because of lumbar spinal stenosis. Her medical history included hypertension and diabetes for ten years. Her personal history included a smoking history of 60 years by 2 cigarettes per day, not quitting. Her carotid artery ultrasound showed multiple low echo plaques on the right side and multiple high echo plaques on the left side of the carotid artery, but without distinct stenosis. Other examinations and tests showed no distinct abnormality. She went on a lumbar decompression and pedical screw fixation uneventfully. The blood loss was 400 mL and autologous blood transfusion 150 mL. The arterial blood pressure (ABP) maintained during 100-130 mmHg/60-80 mmHg (1 mmHg=0.133 kPa). Sixty minutes after she recovered from general anesthesia, the patient developed symptoms of slurred speech and right limbs weakness. The anesthesio-logist evaluated the patient immediately with National Institute of Health Stroke Scale (NIHSS). The NIHSS score was 11 and a stroke was highly suspected. The acute stroke team was therefore initiated and fast responded. Within 4 h, digital subtraction angiography (DSA) was proceeded, which showed the M1 segment of the left middle cerebral artery was occluded and the local stenosis of her right middle cerebral artery was up to 80%. After the successful embolectomy by Solitaire stent, the left middle cerebral artery reflowed and the forward blood flow was thrombolysis in myocardial infarction (TIMI) grade 3. The patient was discharged after 33 days after the surgery with a NIHSS of 9. Our case provides an example that an acute stroke team that included the department of anesthesiology can be beneficial to the patients' perioperative strokes. During the perioperative period, anesthesiologists should be included into the acute stroke team, because anesthesiologists and anesthesia nurses might be first observers of those early onset strokes. Our case also put forward this thought that a standard peri-operative stroke evaluation tool, like NIHSS, should be discussed and applied to facilitate and accelerate the initiation of perioperative acute stroke team.

Stent-assisted coiling embolization of middle cerebral artery trifurcation wide-necked aneurysms

OBJECTIVE

The aim of this study was to examine the effects of stent-assisted coiling embolization of middle cerebral artery (MCA) trifurcation wide-necked aneurysms in clinical practice.

PATIENTS AND METHODS

57 patients with MCA trifurcation wide-necked aneurysms underwent stent-assisted coiling embolization using a solitaire AB stent. All 57 patients completed the surgery successfully. Embolization efficacy was graded according to the modified Raymond scale.

RESULTS

There were 52 cases of complete embolization, 4 cases of residual aneurysm neck, and 1 case of residual aneurysm body. 50 patients participated in a 6-36-month follow-up. There has not been observed any aneurysm rupture and hemorrhage. 50 patients received digital subtraction angiography (DSA) re-examination; 46 patients presenting complete embolization had no aneurysm relapses; 3 patients had residual aneurysm neck demonstrated; 1 patient had no aneurysm neck and others 2 were in stable condition. Finally, the patient with residual aneurysm body showed no sign during follow-up reexamination.

CONCLUSIONS

Stent-assisted coiling embolization of intracranial wide-necked aneurysms using the solitaire AB stent was safe and effective.

[A prenatal ultrasound study of cerebral sulci and gyrus development in fetuses with tetralogy of Fallot]

OBJECTIVE

To evaluate the development of the cerebral sulci and gyrus and cerebral blood flow in fetuses with tetralogy of Fallot (ToF) in the second and third trimesters using ultrasound imaging.

METHODS

Forty fetuses (23-33⁺⁶ weeks) with ToF diagnosed using ultrasound imaging between December, 2015 and September, 2016 were analyzed in this study. The development of the cerebral sulci and gyrus was evaluated by measuring the parietal-occipital fissure (POF) depth, POF angle, sylvian fissure (SF) depth, SF width, uncovered insular width, calcarine fissure (CF) depth, hemisphere depth on the views of POF, SF and CF, uncovered insular ratio, biparietal diameter (BPD), and head circumference (HC). Cerebral hemodynamics were assessed by measuring the umbilical artery resistance index, umbilical artery pulsation index, middle cerebral artery pulsation index (MCA-PI), middle cerebral artery resistance index, the cerebral-to-placental resistance ratio, and the cerebroplacental ratio.

RESULTS

In ToF fetuses, the POF depth, SF depth, CF depth, BPD, HC and hemisphere depth on the views of parietal-occipital sulcus and calcarine sulcus were significantly smaller than those in the control group (P<0.05). The middle cerebral artery resistance index, middle cerebral artery pulsation index, the cerebral-to-placental resistance ratio and the cerebroplacental ratio were also significantly lower in ToF fetuses than in the control group (P<0.05).

CONCLUSION

The cerebral sulci and gyrus in ToF fetuses in second and third trimesters show underdevelopment compared with those in normal fetuses, and the changes in hemodynamics caused by abnormal cardiac structure might be one of the reasons for cerebral sulci and gyrus underdevelopment in fetuses with ToF.

Effect of dexmedetomidine on cerebral ischemia-reperfusion rats by activating mitochondrial ATP-sensitive potassium channel

The aim of the study reported here was to evaluate whether the mitochondrial ATP-sensitive potassium (mitoK_ATP) channel could participate in the effect of dexmedetomidine on cerebral ischemia-reperfusion (I/R) rats. Forty rats were randomly assigned into 5 groups: sham operation (S) group; cerebral I/R group; dexmedetomidine (D) group; 5-hydroxydecanoate (5-HD) group; 5-HD + D group. The cerebral I/R were produced by 2 h right middle cerebral artery occlusion followed by 24 h reperfusion. Dexmedetomidine (50μg/kg) was injected intraperitoneally before ischemia and after the onset of reperfusion. 5-HD (30 mg/kg) was injected intraperitoneally at 1 h before ischemia. The neurological deficit score (NDS) and the levels of super oxide dismutase (SOD), malondialdehyde (MDA), myeloperoxidase (MPO), Interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) were evaluated. Compared to group S, NDS and the levels of MDA, MPO, IL-6 and TNF-α were significantly higher, and SOD levels were significantly lower in the other groups (P < 0.05). Compared to group I/R,NDS and the levels of MDA, MPO, IL-6 and TNF-α were significantly lower, and SOD level was significantly higher in group D (P < 0.05). Compared to group D, NDS and the levels of MDA, MPO, IL-6 and TNF-α were significantly higher, and SOD level was significantly lower in group5-HD + D (P < 0.05). The activation of the mitoK_ATP channel could contribute to the protective effect of dexmedetomidine on rats induced by focal cerebral ischemia-reperfusion injury.

[Analysis of CT perfusion imaging in chronic cerebral circulatory insufficiency and its relationship with crossed cerebellar diaschisis]

Objective: To investigate the change of cerebral microcirculation of chronic cerebral circulation insufficiency(CCCI) patients and the relationship between CCCI and crossed cerebellar diaschisis(CCD)by using 320-detector row of low-dose volume CT perfusion imaging. Methods: A total of 158 patients (103 males, 55 females, from 45 to 82 years old, the mean age was 62.9) with symptoms of CCCI were admitted to the First Affiliated Hospital of Wenzhou Medical University from June 2013 to January 2016. Low-dose CTP imaging of whole brain was performed to them using 320-detector row volume CT scanner. The perfusion parameters such as cerebral blood flow(CBF), cerebral blood volume(CBV), mean transit time(MTT), time to peak(TTP) and DLY in both cerebral blood supply areas and cerebellum were got, so were the 4-dimensional CTA images, and rCBF, rCBV, rMTT and rTTP were calculated by ipsilateral/contralateral value. Comparative t-test and independent t-test were applied to analyzing these parameters quantitatively.Chi-square test and Logistic regression model were applied to analyzing the related clinical risk factors. Results: (1) All 108 patients in CCCI group showed asymmetric perfusion within two cerebral hemispheres in CTP images. The CBF, CBV of diseased side were lower than the contralateral mirror area (t(CBF)=-12.89, t(CBV)=-7.031, P(CBF, CBV)<0.001); the MTT of the diseased side was shorter than the contralateral mirror area (t(MTT) =13.310, P(MTT)<0.001); the TTP of the diseased side was longer than the contralateral mirror area (t(TTP)=-4.012, P(TTP)<0.001). The rCBF and rCBV of CCCI group were lower than that in non-CCCI group (t(rCBF)=3.079, t(rCBV)=2.760, P(rCBF, rCBV)<0.01), while the rTTP of CCCI group was longer than that in non-CCCI group (t(rTTP)=4.846, P(rTTP)<0.001). (2)The results of Chi-square test showed that the differences of gender (χ(2)=4.036, P=0.045), hyperlipidemia (χ(2)=7.687, P=0.006), as well as smoking (χ(2)=11.868, P=0.001) had statistical significance between CCCI group and non-CCCI group.Multi-factor Logistic regression analysis showed that hyperlipidemia (OR value=3.736, P=0.016) and smoking (OR value=4.641, P=0.01) were the risk factors of CCCI, while gender had no relationship with it.(3)The incidence of CCD was 18.5% in the CCCI group, and at the same time, the supratentorial corresponding blood supply areas were classified.A total of 10(34.5%) cases were in blood supply area of posterior cerebral artery, 6(20.7%) cases were in blood supply area of middle cerebral artery, 12(41.4%) cases were of anterior cerebral artery, while only 1(3.5%) case was of basal ganglia, in which 4 cases were in blood supply area of posterior cerebral artery, another 4 cases were middle cerebral artery, 7 cases were of anterior cerebral artery and no case of basal ganglia respectively leading CCD alone. Conclusions: CTP could display the microcirculation situation of abnormal brain tissue perfusion area intuitively and quantitatively. Additionally, it could reflect the degree of relationship between cerebral several blood supply areas and cerebellum.

[Efficacy of intravenous thrombolysis in acute ischemic stroke with hyperdense middle cerebral artery sign]

Objective: To observe the efficacy and safety of recombinant tissue-type plasminogen activator (rtPA) intravenous thrombolysis (IVT) in the treatment of acute cerebral infarction with hyperdense middle cerebral artery sign (HMCAS). Methods: Acute cerebral infarction patients with HMCAS from July 2010 to November 2015 at the First Affiliated Hospital of Dalian Medical University were collected.These patients were divided into two groups depending on whether they received IVT or not.The Nation Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) were used to evaluate early and long-time therapeutic effects.Efficacy and safety were compared between the two groups. Results: A total of 93 patients were eligible for the analysis, with 45 cases in IVT group and 48 cases in non-IVT group.As time went by, NIHSS score in IVT group showed significant downward trend than the non-IVT group.The rate of patients with good outcome in IVT group was higher than that in non-IVT group (P<0.05). The rate of hemorrhage transformation (HT) in IVT group and non-IVT group was 35.6% (16/45) and 10.4% (11/48), respectively, and the difference was statistically significant (P<0.05). While no statistically significant difference was found about the rate of symptomatic intracranial hemorrhage (sICH) (8.9% vs 2.1%, P>0.05) and mortality (33.3% vs 27.1%, P>0.05) between these two groups.Logistic regression analysis identified relativity between IVT treatment and good outcome (P<0.05), hemorrhage transformation (P<0.05), rather than mortality (P>0.05). Conclusions: Intravenous thrombolysis with rt-PA is an effective and safe treatment for most acute ischemic stroke patients with HMCAS and can promote early neurologic improvement and significantly improve long-term functional prognosis.Although Ⅳ thrombolysis can increase the risk of overall HT, it does not add risk in sICH and mortality.