Revealing the contribution of basilar membrane's biological activity to the mechanism of the cochlear phonosensitive amplification

Explaining the mechanism of the cochlear active phonosensitive amplification has been a major problem in medicine.The basilar membrane(BM)is the key infrastructure.In 1960,Nobel Laureate von B′ek′esy first discovered BM's traveling wave motion.Since that time,BM's models only have considered the traveling wave but not the biological activity.Therefore,a new model considering changes of BM's stiffness in space and time is established based on the immersed boundary method to describe its biological activity.It not only reproduces the results of traveling wave motion but also explains the mechanization on the generation of traveling wave.An important discovery is that changes of BM's stiffness in space and time will cause the unstable global resonance,which will induce amplification of sounds in cochlea.An important inference is that biological activity shall be included in the application of mechanical principles to the analysis of life,which is the essential difference between biomechanics and general mechanics.

More to it than meets the eye: a case report of incomitant esotropia in a child caused by a giant basilar aneurysm

Background:Esotropia is a common concern in pediatric ophthalmology consultations.While most cases stem from strabismus,it is crucial for physicians to differentiate atypical features that might indicate underlying organic causes,such as VI nerve palsy,hinting at the presence of intracranial spaceoccupying lesions.Although the occurrence of cerebral aneurysms in children is rare,they can have severe consequences.Case Description:Here,we described an extremely rare case of giant basilar fusiform aneurysm measuring 4.0 cm×3.9 cm×3.9 cm in an otherwise healthy 8-year-old child,and analyzed its atypical features that suggested an intracranial etiology.We further described an endovascular approach,performed by interventional radiologists,and discussed its advantages over the conventional neurosurgery.The patient continued to be followed by our multidisciplinary team.He had a stable post-operative course and made an excellent recovery neurologically.At the 1-year follow-up,he was orthophoria with excellent vision and stereopsis.Conclusions:To our knowledge,this is the first pediatric case in Canada where a giant intracranial aneurysm was treated endovascularly.The salient red flags—progressive incomitant esotropia and diplopia,the presence of myopia(rather than hyperopia),nystagmus and abnormal saccadic movements—should be astutely recognized by clinicians as intracranial giant aneurysms carry a poor prognosis.A multidisciplinary approach is essential for the management of such cases.

Analysis of the Risk of Basilar Aneurysm Rupture Based on CTA Morphological Parameters

Objective:To investigate morphological risk factors of basilar aneurysm rupture based on computer tomography angiography(CTA)parameters.Materials and methods:The clinical and CTA data of 43 patients with basilar aneurysm admitted to Shaanxi Provincial People's Hospital from January 2015 to July 2023 were analyzed.The patients were divided into“ruptured group”and“unruptured group,”and the morphological parameters of aneurysms were measured.The general data and morphological parameters between the two groups were statistically analyzed.Logistic regression was used to analyzed statistically significant parameters,and the receiver operating characteristic curve was drawn to evaluate its diagnostic effectiveness.Results:Irregular aneurysms were more likely to rupture than regular aneurysms(χ^(2)=13.971,P<0.05).The maximum diameter(4.92[3.37-6.94]mm),length-width ratio(1.31[1.14-1.55]),height(4.08[2.71-5.34]mm),aspect ratio(0.99[0.84-1.45]),and inflow angle(133.63±11.21°)of aneurysms in the ruptured group were larger than the unruptured group,and the differences were statistically significant(P<0.05).Binary logistic regression showed that aneurysm shape(OR=39.347,P=0.021),length-width ratio(OR=313.062,P=0.033),and inflow angle(OR=1.156,P=0.004)were independent risk factors for rupture.The area under the curve were 0.809,0.842.and 0.894,respectively.Conclusion:Aneurysm shape,aspect ratio,and blood flow incidence angle are independent risk factors for basilar aneurysm rupture,which means that they can be used to predict the risk of rupture to a certain extent.

Incidental Finding of a Fenestrated Vertebrobasilar Junction Aneurysm

Basilar artery fenestration is a rare anatomical variation resulting from the failed fusion of the two vertebral arteries during embryonic life. In order of frequency, it is the second most common location of vascular fenestrations after the anterior communicating artery. Vertebrobasilar junction aneurysms are uncommon but often associated with basilar artery fenestration. We report the case of a fenestrated vertebrobasilar junction saccular aneurysm in a 57-year-old woman. The diagnosis was incidentally made on CT angiography which found the anatomical variant and the aneurysm. The radiological features illustrating this association are detailed here and a brief discussion of its pathogenesis and management was made. Vertebrobasilar junction aneurysms are rare and their presence should suggest an associated basilar fenestration.

Differential Effect of Calcium-Activated Potassium and Chloride Channels on Rat Basilar Artery Vasomotion

Spontaneous, rhythmical contractions, or vasomotion, can be recorded from cerebral vessels under both normal physiological and pathophysiological conditions. We investigated the cellular mechanisms underlying vasomotion in the cerebral basilar artery （BA） of Wistar rats. Pressure myograph video microscopy was used to study the changes in cerebral artery vessel diameter. The main results of this study were as follows： （1） The diameters of BA and middle cerebral artery （MCA） were 314.5±15.7 μm （n=15） and 233.3±10.1 μm （n=12） at 10 mmHg working pressure （P〈0.05）, respectively. Pressure-induced vasomotion occurred in BA （22/28, 78.6%）, but not in MCA （4/31, 12.9%） from 0 to 70 mmHg working pressure. As is typical for vasomotion, the contractile phase of the response was more rapid than the relaxation phase; （2） The frequency of vasomotion response and the diameter were gradually increased in BA from 0 to 70 mmHg working pressure. The amplitude of the rhythmic con- tractions was relatively constant once stable conditions were achieved. The frequency of contractions was variable and the highest value was 16.7±4.7 （n=13） per 10 min at 60 mmHg working pressure; （3） The pressure-induced vasomotion of the isolated BA was attenuated by nifedipine, NFA, 181]-GA, TEA or in Ca2＋-free medium. Nifedipine, NFA, 18^-GA or Ca2＋-free medium not only dampened vasomotion, but also kept BA in relaxation state. In contrasts, TEA kept BA in contraction state. These results sug- gest that the pressure-induced vasomotion of the isolated BA results from an interaction between Ca2＋-activated C1- channels （CaCCs） currents and Kca currents. We hypothesize that vasomotion of BA depends on the depolarizing of the vascular smooth muscle cells （VSMCs） to activate CaCCs. Depolarization in turn activates voltage-dependent Ca2＋ channels, synchronizing contractions of adjacent cells through influx of extracellular calcium and the flow of calcium through gap junctions. Subsequent calcium-induced calcium release from ryanodine-sensitive stores activates Kca channels and hyperpo- larizes VSMCs, which provides a negative feedback loop for regenerating the contractile cycle.

A Clinical Study on the Effect of Yinxing Damo (银杏达莫) Combined with Betahistine Hydrochloride Injection on Vertebral Basilar Artery Ischemic Vertigo

To evaluate the therapeutic efficacy of Yinxing Damo （银杏达莫, YXDM） combined with Betahistine Hydrochloride Injection （BHI） on vertebra basilar artery ischemic vertigo （VBIV）. Methods： Ninety patients with VBIV were randomly divided into two groups; 45 patients （the treated group） were treated with YXDM and BHI intravenous dripping, once a day for 14 days. Another 45 patients （control group） were treated with Xueshuantong （血栓通） and BHI intravenous dripping, once daily for 14 days. The clinical syndromes and the index of the transcranial Doppler （TCD） and hemorheology were observed. Results： The total effective rate was 100% in the treated group, which was better than that in the control group 90.5%, （P〈0. 05）. The indexes of TCD and hemorheology in the treated group were obviously improved after treatment, （P〈0.01）. Conclusion： YXDM combined with BHT injection had better effect in treating patients with VBIV is an ideal drug for VBIV.

Convulsive-like movements as the first symptom of basilar artery occlusive brainstem infarction:A case report

BACKGROUND Convulsive-like movements are rare in basilar artery occlusive cerebral infarction(BAOCI).These manifestations may easily be mistaken for epileptic seizures caused by compromised anterior circulation or by cortical lesions.Delayed diagnosis of this condition affects its subsequent treatment and prognosis.Therefore,it is critical to recognize this type of phenomenon in the early stage.CASE SUMMARY A 55-year-old male patient presented with unconsciousness,rigidity,and a paroxysmal twitch in both lower limbs.These conditions lasted for nearly 2 h and resembled status epilepticus.After the initial conditions subsided,hemiplegia occurred and then subsided rapidly.The family refused thrombolytic therapy because the symptoms were similar to Todd paralysis after epilepsy.However,magnetic resonance imaging showed left pontine infarction.No abnormality was observed in a video electroencephalogram during the interictal period.Digital subtraction angiography revealed that the basilar artery was occluded and that the posterior communicating arteries were patent.Fortunately,the patient received a good prognosis after antiplatelet therapy,lipid regulation,balloon dilatation of the basilar artery,and rehabilitation.CONCLUSION Convulsive-like movements may be an early sign of basilar artery occlusive brainstem infarction.It is important to identify this phenomenon in a timely manner.

EFFECT OF LIPOSOMAL TRANSFECTION OF HTERT ON APOPTOSIS OF NEWBORN RAT COCHLEAR BASILAR MEMBRANE CELLS

Objective The aim of this study is to investigate the effect of transfected hTERT gene on cell apoptosis of newborn rat cochlear basilar membrane cells (CBMCs). Methods CBMCs isolated from newborn rat cochlear were transfected using a plasmid containing human telomerase reverase transcriptase gene (pCI-neo-hTERT) , and were screened using G418 to obtain stable transfected cell lines. Cell apoptosis rate was analyzed by flow cytometry. hTERT and apoptosis related genes expression were detected by reverse transcriptase polymerase chain reaction (RT-PCR). Results hTERT gene expression was detected 72 hours after gene transfection in transfected cells. The apoptotic rate of transfected CBMCs significantly reduced. Expression of apoptosis related genes correspondingly changed. Conclusion Transfection of hTERT gene leads to reduced apoptosis rate in newborn rat CBMCs.and lower expression of apaf1, Caspase3 and BCL2 in transfected cells as compared to that of normal CBMCs.

Enterprise stent-within-stent embolization of a basilar artery perforator aneurysm

Objective and Importance—Vertebrobasilar artery aneurysms can be very challenging to treat and are preferentially dealt with using endovascular tech-niques, since they are associated with lower risk than surgical clipping. Small aneurysms located on perfo-rating arteries can pose problems though, as their dimensions may not be favorable for coiling and leave the endovascular surgeon without many options. We present a basilar perforating artery aneurysm that was successfully embolized using a stent-within-stent technique. Clinical Presentation—A 47 year old fe-male presented with a Hunt-Hess 3, Fisher Grade-3 subarachnoid hemorrhage with blood in the pre-pontine cistern. Initial imaging (CT angiogram and digital subtraction angiography) did not reveal an aneurysm. Follow-up angiography on post-bleed day eight demonstrated a three-millimeter basilar perforating artery aneurysm. After an unsuccessful coiling attempt a closed-cell stent-within-stent tech-nique was used to divert flow away from the aneu-rysm neck to induce aneurysm thrombosis. Interven-tion (or Technique)—Multiple attempts were made to access and stabilize a microcatheter in the small basilar perforator artery aneurysm in order to de-liver coils for endovascular embolization;this could not be done safely. Therefore a closed-cell 4.5 × 22 mm Enterprise stent (Cordis Neurovascular, Inc., Miami Lakes, Florida) was deployed in the basilar artery across the origin of the perforator aneurysm in order for the stent tines to divert flow away from the aneurysm neck and induce thrombosis. Persistant brisk flow within the aneurysm continued however, and a second closedcell 4.5 × 22 mm Enterprise stent was placed within the first one to increase the stent metal surface area across the aneurysm neck to further reduce flow into the aneurysm. Subsequently, angiography demonstrated stagnant blood flow in the aneurysm dome and the aneurysm spontaneously thrombosed, sparing all associated vessels. Conclu-sion—Stent-within-stent technique should be consid-ered as a possible endovascular treatment option for small side-wall and perforator artery aneurysms that can’t be safely treated with coils or embolic agents.

Nitrogen monoxide vector of ultrasonic atomizing inhalation improves vertebro-basilar artery insufficiency Hemodynamic changes are detected by transcranial Doppler test

BACKGROUND： Latest researches at home and abroad indicate that glycerol trinitrate plays its function because it can metabolize into nitrogen monoxide （NO） in vivo. OBJECTIVE： To study the therapeutic effects of NO vector of ultrasonic atomizing inhalation on vertebro-basilar artery insufficiency （VBI） through transcranial Doppler （TCD） detection and serum NO content and indirect effect of TCD on cerebral blood flow changes. DESIGN： Randomized grouping and controlled clinical study. SETTING： Department of Neurology, the Fourth People＇s Hospital of Jinan. PARTICIPANTS： A total of 130 patients who were diagnosed as VBI were selected from Department of Neurology, the Fourth People＇s Hospital of Jinan from December 2001 to December 2005. The involved inpatients were checked by CT and MRI, and met the VBI diagnostic standard enacted by the Fourth National Academic Meeting of Cerebrovascular Disease in 1995. All patients and their relatives provided the confumed consent. They were randomly divided into low-dose treatment group （n =60）, high-lose treatment group （n =30） and control group （n =40）. METHODS： Patients in the low-dose and high-dose treatment groups were given ultrasonic atomizing inhalation of 3 mg and 5 mg glycerol trinitrate, respectively, for 20 minutes, once a day. In addition, ligustrazine and energy mixture were used once a day for three days in a course. Cases in the control group were only given ligustrazine and energy mixture. All selected cases accepted TCD, blood NO content was checked at the time of beginning, after the first time and after a period of treatment. According to the TCD test, VBI patients were divided into two groups （high-low flow velocity）. The vertebral artery （VA） and basal artery （BA） of left or right sides were detected by 2 Hz detector via occipital window. MAIN OUTCOME MEASURES： ①Blood flow velocity of systolic phase, blood flow velocity of diastole phase and vascular resistance in left and right VA and BA detected by using TCD before treatment, after treatment for one course; ②content of serum NO indirectly measured by using nitric acid disoxidation technique. RESULTS： All 130 VBI patients were involved in the final analysis. ①Changes of hemodynamic indexes： Systolic phase of VA and diastole phase of BA were higher in low-dose treatment group than that in the control group after first treatment, and there was significant difference （P 〈 0.05）; meanwhile, systolic phase and diastole phase of VA and systolic phase of BA were also higher in treatment group than that in the control group after one course （P 〈 0.05）. However, both systolic phase and diastole phase of VA and BA were lower in high-dose treatment group than that in the control group after first treatment and one course, and there was significant difference （P 〈 0.05）. ②Content of serum NO： After first treatment, there was no significant difference between low-dose treatment group and high-dose treatment group （P 〉 0.05）; but both groups were higher than control group, and there was significant difference （P 〈 0.05, 0.01）. CONCLUSION： NO vector of ultrasonic atomizing inhalation can improve VBI so as to improve cerebral blood-supply state.

Enhancing hippocampal blood flow after cerebral ischemia and vasodilating basilar arteries:in vivo and in vitro neuroprotective effect of antihypertensive DDPH

1-（2,6-Dimethylphenoxy）-2-（3,4-dimethoxyphenylethylamino）-propane hydrochloride （DDPH） is a novel antihypertensive agent based on structural characteristics of mexiletine and verapamine. We investigated the effect of DDPH on vasodilatation and neuroprotection in a rat model of cerebral ischemiain vivo, and a rabbit model of isolated basilar arteriesin vitro. Our results show that DDPH （10 mg/kg） significantly increased hippocampal blood flowin vivo in cerebral ischemic rats, and exerted dose-dependent relaxation of isolated basilar arteries contracted by histamine or KCl in thein vitro rabbit model. DDPH （3 × 10–5 M） also inhibited histamine-stimulated extracellular calcium inlfux and intracellular calcium release. Our ifndings suggest that DDPH has a vasodilative effect bothin vivo andin vitro, which mediates a neuropro-tective effect on ischemic nerve tissue.

The vasorelaxant effect of pinocembrin on the rat basilar artery and its potential mechanisms

Aim To evaluate the vasorelaxant effects of the flavonone pinocembrin in isolated rat basilar artery rings and to investigate its possible mechanisms. Methods The isotonic contractions of the basilar artery rings from SD rats were recorded. Results Pinocembrin exerted vasorelaxation in a close-dependent manner in KCL （60 mmol · L^-1 ） or 5-HT （ 1 μmol · L^- 1）-induced sustained contraction and partial loss of the vasorelaxation in endothelium- denuded rings. Pretreatment with pinocembrin （30 or 50 μmol · L^-1 ） attenuated contractile responses to KC1 （ 10 - 60 mmol · L^-1 ） and 5-HT （0. 001 - 10 μmol · L^-1 ）. The pinocembrin -induced vasorelaxation was significant- ly reduced by the nitric oxide synthase inhibitor Nco-nitro-L-arginine methyl ester （L-NAME, 100 μmol · L^-1） , the guanylate cyclase inhibitor ODQ （5 μmol · L^-1） and the cyclooxygenase inhibitor indomethacin （5 μmol · L^-l）. The voltage-dependent K＋ channel blocker 4-aminopyridine （100 μmol · L^-1）, the ATP-sensitive K ＋ channel blocker glibenclamide （10μmol · L^-1） and Ca2＋-activated K ＋ channel blocker tetraethylammonium （1 retool· L^-1） remarkably attenuated pinocembrin-induced relaxations. Pinocembrin also inhibited contraction in- duced by increasing external calcium in Ca2＋-free medium plus 60 mmol · L^-1 KC1. Conclusion These results demonstrate that pinocembrin has a vasorelaxant effect on isolated rat basilar artery rings and may exert its action through an endothelium-dependent pathway, involving NO-cGMP, and also through an endothelium-independent 2＋ pathway, opening K ＋ channels and blockade of Ca channels.

By regulating IP3/PKC/TRPV4 pathway hyperoside induces endothelium-dependent vasodilatation in rat basilar artery following four vessel occlusion ischemia reperfusion

OBJECTIVE To investigate regulatory effects of hyperoside(Hyp)on IP3/PKC/TRPV4 pathway in rat cerebral basilar artery(CBA)subjected to global cerebral ischemia-reperfusion(I/R).METHODS The model of global cerebral I/R in rats was established by four-vessel occlusions methods.The treated rats were administrated with Hyp(50 mg·kg^-1)group,Hyp(50 mg·kg^-1)+HC-067047(10 mg·kg^-1),Hyp(50 mg·kg^-1)+2APB(2 mg·kg^-1),Hyp(50 mg·kg^-1)+BisI(2.5 mg·kg^-1),Hyp(50 mg·kg^-1)+2APB(2 mg·kg^-1)+BisI(2.5 mg·kg^-1).Hematoxylin-eosin(HE)and Nissl staining were performed and the contents of methane dicarboxylic aldehyde(MDA),neuron-specific enolase(NSE),S100β and the activity of lactic dehydrogenase(LDH)in serum were measured by enzyme-linked immunosorbnent assay(ELISA).The specific blocker N-nitro-L-arginine-methyl-ester(L-NAME)and indomethacin(Indo)were used to delete the prostacyclin(PGI2)and nitric oxide(NO)dependent relaxation.The protein expression level of TRPV4 was detected by Western blotting.Ca2+intensity in vascular smooth muscle cells was measured by confocal laser scanning microscope and flow cytometry was performed to observe the apoptosis of CBA endothelial cells after in vivo administration.RESULTS Hyp induced a dose-dependent relaxation of CBA in IR rats via a PGI2 and NO independent manner,as evidenced by alleviated patho⁃logical changes and up-regulated expression of TRPV4 protein in the endothelial cells from cerebral vessels.Hyp signifi⁃cantly reduced the contents of MDA,NSE,S100βand the activity of LDH in serum and decreased the fluorescence intensity of Ca2+in cerebral vascular smooth muscle cells by in vivo administration.The apoptotic rate of endothelial cells in Hyp treated group was significantly less than that in IR group.CONCLUSION Hyp does in fact ameliorate I/R injury by regulatingIP3/PKC/TRPV4 pathway.

Enhancement of vibration velocity of basilar membrane elicited with electric stimuli by nitric oxide synthase blockade

Objectics: To demonstrate the effects of NO synthase (NOS ) blockade on the OHCs. Methods: The Nnitro L-arginine (L-NNA) was used and the vibration velocity of basilar membrane (BMV ) was observed. Pigmented guinea pigs were anesthetized and surgically prepared to permit infusion of L- NNA into the scala tympani of basal turn of cochlea . The basilar membrane (BM ) vibration and compound action potential (cAP ), endocochlear potential (EP ) and cochlear mierophonic (CM ) were monitored. Eight μ1 of 1. 6 mmol/L- L- NNA was infused into the perilymph of scala tympani . The BM velocity responses elicited with direct current (DC ) pulses were recorded. Results: The BMV was increased by approximately 3 folds following infusion of L-NNA. The CM de creased by a small amount and there was no significant change in CP. This phenomenon occurs only in the cochlearsensitivity has been lost less than 40 dB . No improvement in BM velocity if the cochlear sensitivity was ’normal’ or was damaged too severely. Conclusion: The results imply that NO bas the excitotoxicity on OHCs, it can promote the injury of cochlea when noise is exposed. L-NNA may act as a guardian when facts of trauma act on cochlea.

Direct current pulse elicits basilar membrane vibration in guinea pigs

Objective:To study the electromotility of the basilar membrane (BM) of guinea pigs in vivo. Methods :A pair of platinum-iridium wire electrodes were deposited into the holes drilled into the scala vestibuli and scala tympani on the basal turn of cochlea. The organ of Corti was stimulated with rectangular, constant current pulses . The displacement and velocity of BM were measured with laser doppler velocimeter. Results: The electrically elicited displacement of BM moved toward the scala where the electrode was positively charged. The waveform of BM displacement generally corresponded to the shape of the rectangular pulse of electric current. Ringing responses could be seen at the onset and offset of current pulse reflecting transient responses of the organ of Corti. In the cochlea of hearing-impaired or dead animal, direct current (DC) could still elicit a BM displacement but the ringing response was attenuated or disappeared. This phenomenon was probably due to metabolic disturbance in the damaged outer hair cells. In the sensitive cochlea, the BM vibration induced with direct current was similar to that induced by acoustic stimulation, and the BM moves in a traveling wave pattern. Conclusion: The findings of this experiment implicated that the DC stimulation of the cochlea conduces the contraction or elongation of OHCs. The electromotility of OHCs provides sufficient force to displace the BM. In the electrically stimulated normal cochlea,transient response of OHCs can induce resonant vibration at the same frequency as that Of the characteristic frequency (CF) of a partition in the BM. The vibration should be an active process of energy depletion associated with the cochlear amplifier.The vibration of BM can propagate to other partition of BM according to the traveling wave theory. This characteristic has laid the foundation for the electromotile hearing and electrically evoked otoacoustic emission.

Effects of 3，4－Dihydroxyacetophenone on Hypoxic Vasoconstriction in Isolated Pulmonary and Basilar Arterial Rings

The effects of 3, 4-DHAP on hypoxic vasoconstriction response in pulmonary (PA) and basilar arterial(BA) rings of rabbits and their mechanism were compared in vitro.3,4-DHAP in different concentration (2.64×10-4,7.92×10-4,2.376×10-3mol/L) decreased the basal tone of PA rings by 32. 39±9.4 mg, 68. 96±26. 54 mg and 145. 60±58.07 mg respectively,while the tension of the BA rings was decreased by 13. 80±5. 08 mg,17.18±3.36 mg and 25. 00±4.02 mg respectively.In PA rings it also decreased the percentage increase in tension induced by hypoxia(TIH%)from the control value 48. 82±5.75% to 10.02±3. 62%,2.14±0.96%, and 0.00% respectively, while in BA rings from 27.27±5.78% to 11. 23±2.71%,7.49±1. 62%, and 1.45±1.13% respectively. The effects of 3,4-DHAP on TIH% were partially blocked by indomethacin 10 M and L-NWE 10 M.The results showed that 3, 4-DHAP can decrease the hypoxic pulmonary and basilar vasoconstriction in vitro. which can be partially inhibited by cyclooxygenase inhibitor and NO/EDRF inhibitor.

Predictors of unfavorable outcome at 90 days in basilar artery occlusion patients

BACKGROUND In a previous study,basilar artery occlusion(BAO)was shown to lead to death or disability in 80%of the patients.The treatment for BAO patients in the acute stage includes thrombolysis and intra-arterial thrombectomy,but not all patients benefit from these treatments.Thus,understanding the predictors of outcome before initiating these treatments is of special interest.AIM To determine the predictors related to the 90-d clinical outcome in patients with BAO in an Asian population.METHODS We performed a retrospective case review of patients admitted to a tertiary stroke center between 2015 and 2019.We used the international classification of diseases-10 criteria to identify cases of posterior circulation stroke.A neurologist reviewed every case,and patients fulfilling the criteria defined in the Basilar Artery International Cooperation Study were included.We then analyzed the patients’characteristics and factors related to the 90-d outcome.RESULTS We identified a total of 99 patients as real BAO cases.Of these patients,33(33.3%)had a favorable outcome at 90 d(modified Rankin Scale:0–3).Moreover,72 patients received intra-arterial thrombectomy,while 13 patients received intravenous tissue-type plasminogen activator treatment.We observed a favorable outcome in 33.3%of the cases and an unfavorable outcome in 66.7%of the cases.We found that the initial National Institutes of Health Stroke Scale(NIHSS)score and several BAO symptoms,including impaired consciousness,tetraparesis,and pupillary abnormalities,were significantly associated with an unfavorable outcome(P<0.05),while cerebellar symptoms were associated with a favorable outcome(P<0.05).In the receiver operating characteristic(ROC)analysis,the areas under the ROC curve of initial NIHSS score,impaired consciousness,tetraparesis,cerebellar symptoms,and pupillary abnormalities were 0.836,0.644,0.727,0.614,and 0.614,respectively.Initial NIHSS score showed a higher AUROC(0.836)compared to BAO symptoms.CONCLUSION The most important predictor of an unfavorable outcome was the initial NIHSS score.BAO symptoms,including tetraparesis,impaired consciousness,and pupillary abnormality were also related to an unfavorable outcome.

Surgical Clipping of a Basilar Tip Aneurysm: Case Report and Literature Review

Basilar tip aneurysms account for 5% - 8% of all intracranial aneurysms. They are known to rupture more frequently than aneurysms in other locations. Surgical clipping of basilar apex aneurysms however challenging;remains the treatment of choice in Ivory Coast due in part, to multiple technical barriers. A 60-year-old right-handed patient presented to our Neurosurgical Unit in February 2nd 2013 after a sudden onset of altered consciousness. Neurological examination revealed both an upper motor neuron and meningeal syndromes with a Glasgow Coma Scale of 12. Brain NECT scan and a subsequent brain CT angiography showed a subarachnoid haemorrhage and a 3.8 mm (height) × 5.2 mm (width) basilar tip aneurysm respectively. Surgical clipping of the aneurysm was indicated but due to multiple technical barriers, surgery was delayed and the patient underwent surgery after the critical vasospasm period. The patient developed a hospital acquired pneumonia after surgery and was successfully treated with antibiotics. Since her discharge, she has been asymptomatic. We sought to report this case of a basilar apex aneurysm successfully occluded with non-ferromagnetic SUGITA clips and to share our experience of clipping these lesions through the frontotemporal approach. The patient was informed that non identifying information from the case would be submitted for publication, and she provided consent.

Numerical Simulation of Flow Behavior in Basilar Bifurcation Aneurysms Based on 4-Dimensional Computed Tomography Angiography

Initiation, growth, and rupture of cerebral aneurysms are caused by hemodynamic factors. It is extensively accepted that the cerebral aneurysm wall is assumed to be rigid using computational fluid dynamics (CFD). Furthermore, fluid-structure interactions have been recently applied for simulation of an elastic cerebral aneurysm model. Herein, we examined cerebral aneurysm hemodynamics in a realistic moving boundary deformation model based on 4-dimensional computed tomographic angiography (4D-CTA) obtained by high time-resolution using numerical simulation. The aneurysm of the realistic moving deformation model based on 4D-CTA at each phase was constructed. The effect of small wall deformation on hemodynamic characteristics might be interested. So, four hemodynamic factors (wall shear stress, wall shear stress divergence, oscillatory shear index and residual residence time) were determined from the numerical simulation, and their behaviors were assessed in the basilar bifurcation aneurysm.