• Title/Summary/Keyword: Basilar artery

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Role of $Na^+/Ca^{2+}$ Exchange in the Control of Contractility in Rabbit Basilar Arterial Smooth Muscle

  • Kim, Eui-Yong;Han, Jin
    • The Korean Journal of Physiology
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    • v.28 no.2
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    • pp.159-167
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    • 1994
  • The contraction of rabbit basilar artery was examined as a function of changes in the $Na^+$ electrochemical gradient in order to determine the contribution of $Na^+/Ca^{2+}$ exchange to the modulation of contractility. Ouabain $(10^{-5}\;M)$ or $K^+-free$ Tyrode solution caused an increase in tonic tension even in the presence of a $Ca^{2+}$ channel blocker $(10^{-6}\;M\;verapamil)$ and an ${\alpha}-receptor$ blocker $(10^{-5}\;M\;phentolamine)$. After treatment with ouabain $(10^{-5}\;M)$, contractions were augmented by reduction of external $Na^+$ concentration. The longer the treatment with ouabain $(10^{-5}\;M)$ was, the larger the amplitude of $Na^+-free$ contracture was. $Na^+-free$ contracture wag induced by either substitution of equimolar Tris for $Na^+$ or substitution of equimolar $Li^+\;for\;Na^+$. The competition between $Na^+\;and\;Ca^{2+}$ for the $Na^+/Ca^{2+}$ exchange carrier would exist, because it was observed that contractility was dependent on the $Na^+$ electrochemical gradient or the extracellular $Ca^{2+}$ concentration (2 mM, 4 mM). Ryanodine $(10^{-7}\;M)$, the blocker of intracellular $Ca^{2+}$ release from the sarcoplasmic reticulum, did not suppress the development of $Na^+-free$ contracture. The contractile response to norepinephrine $(10^{-6}\;M)$ was augmented by reducing the extracellular $Na^+$ concentration. The relaxation rate from caffeine-induced contraction was dependent on the extracellular $Na^+$ concentration (0 mM, 140 mM). From the above results, it could be suggested that $Na^+/Ca^{2+}$ exchange can move $Ca^{2+}$ either into or out of rabbit basilar arterial smooth muscle. $Ca^{2+}$ entry or extrusion is dependent upon the $Na^+$ electrochemical gradient. $Na^+/Ca^{2+}$ exchange plays a significant role in the regulation of contractility in rabbit basilar arterial smooth muscle.

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Two Types of Voltage-dependent Outward Potassium Currents in Smooth Muscle Cells of Rabbit Basilar Atery

  • Kang, Tong-Mook;So, In-Suk;Uhm, Dae-Yong;Kim, Ki-Whan
    • The Korean Journal of Physiology and Pharmacology
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    • v.1 no.2
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    • pp.169-183
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    • 1997
  • We have investigated the two types of voltage-dependent outward potassium (K) currents, i.e. delayed rectifier K current ($I_{K(V)}$) and 'A-like' transient outward K current ($I_{to}$) with patch-clamp technique in single smooth muscle cells (SMCs) isolated from rabbit basilar artery, and investigated the characteristics of them. The time-courses of activation were well fitted by exponential function raised to second power ($n^2$) in $I_{K(V)}$ and fourth power ($n^4$) in $I_{to}$. The activation, inactivation and recovery time courses of $I_{to}$ were much faster than that of $I_{K(V)}$. The steady-state activation and inactivation of $I_{K(V)}$ was at the more hyperpolarized range than that of $I_{to}$ contrary to the reports in other vascular SMCs. Tetraethylammonium chloride (TEA; 10 mM) markedly inhibited $I_{K(V)}$ but little affected $I_{to}$. 4-Aminopyridine (4-AP) had similar inhibitory potency on both currents. While a low concentration of $Cd^{2+}$ (0.5 mM) shifted the current- voltage relationship of $I_{to}$ to the positive direction without change of maximum conductance, $Cd^{2+}$ did not cause any appreciable change for $I_{K(V)}$.

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Airway management in a displaced comminuted fracture of the mandible and atlas with a vertebral artery injury: A case report

  • Paramaswamy, Rathna
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.18 no.3
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    • pp.183-187
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    • 2018
  • Complex cervical spine fractures are a serious complications of maxillofacial trauma and associated with high mortality and neurological morbidity. Strict vigilance in preventing further insult to the cervical spine is a crucial step in managing patients who are at risk for neurologic compromise. We report a rare case of a right transverse process of atlas fracture with right-sided vertebral artery injury that was associated with a comminuted fracture of the body and angle of the mandible, which restricted mouth opening. Airway management was performed by an awake fiber-optic nasotracheal intubation, where neck movement was avoided with a cervical collar. Vertebral artery injuries may have disastrous consequences, such as basilar territory infarction and death, and should be suspected in patients with head and neck trauma. After mandibular plating, the patient was on cervical collar immobilization for 12 weeks and anti-coagulant therapy.

Clinical study on the estimation of blood flow velocity using doppler ultrasound of the cerebral artery in stroke patients (도플러 초음파를 이용한 중풍환자(中風患者)의 뇌혈관(腦血管) 혈류측정(血流測定)에 관한 임상적(臨床的) 연구(硏究) (경동맥(頸動脈), 추골동맥(椎骨動脈) 및 기저동맥(基底動脈)을 중심으로))

  • Chang, In-Su;Sun, Jungn-Ki
    • The Journal of Korean Medicine
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    • v.17 no.1 s.31
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    • pp.345-360
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    • 1996
  • Background and Purpose: To evaluate the blood flow velocity using doppler ultrasound of the carotid artery, vertebral artery, and basilar artery in stroke patients Material and Methods: To evaluate the blood flow, I measured the peak systolic velocity and mean velocity of the common carotid artery(CCA), internal carotid artery(ICA), external carotid artery (ECA). vertebral artery(VA), and basilar artery(BA) in 44 stroke patients and 15 healthy adults. To investigate the difference between ischemic stroke patients and normal healthy adults, I selected 44 ischemic stroke patients diagnosed by brain CT and brain MRI, and 15 healthy adults who did not have any symptoms of stroke, hypertension, heart disease, and diabetes melitus. Results: Peak velocity in normal adults was 50.6${\pm}$1.6cm/sec in the CCA, 67.2${\pm}$1.7cm/sec in the ICA, 62.5${\pm}$2.4cm/see in the ECA, 45.5${\pm}$1.9cm/sec VA. and 50.5${\pm}$3.5cm/sec in the BA. Mean velocity in normal adults was 26.9${\pm}$1.1cm/sec in the CCA, 43.7${\pm}$1.4cm/sec in the ICA, 26.7${\pm}$1.3cm/sec in the ECA. 31.6${\pm}$1.9cm/sec in the VA and 33.0${\pm}$2.6cm/sec in the BA. In this study, there was a significant increase in the velocity of ICA, ECA, and VA of ischemic stroke patients in comparison with normal healthy adults. And the blood flow velocity of this study in the CCA and ECA was different from other reported foreign values and the other known values in my country. Conclusion: There was a significant difference in the blood flow velocity between ischemic stroke patients and normal healthy adults. And the blood flow velocity of this study was different from other reported foreign values and the other known values in my country. Therefore, it needs more detailed studies about old aged Korean and ischemic stroke patients than previous studies.

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The Effects of Myofascial Relaxation on Blood Flow Velocity of the Cranial Artery and Pain Level in Cervicogenic Headache Patients (근막이완술이 경추성 두통환자의 뇌혈류와 통증수준에 미치는 영향)

  • Lee, Joon-Hee;Kang, Da-Haeng;Kang, Jeong-Il
    • The Journal of Korean Physical Therapy
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    • v.22 no.5
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    • pp.49-56
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    • 2010
  • Purpose: The aim of this study was to evaluate a possible role for cranial artery velocity in cervicogenic headache. Methods: We studied 13 patients with cervicogenic headaches (M=9, F=4, age=$24.50{\pm}3.50\;y$) these were compared to 20 normal subjects (M=10, F=10, age=$23.30{\pm}2.90\;y$). Cervicogenic headache patients were divided into two groups (a myofascial relaxation group, a placebo group). Pain levels were measured using a visual analog scale (VAS). Transcranial Doppler (TCD) ultrasound recordings were used to measure blood flow velocity in the cranial artery. Results: Cervicogenic headache patients exhibited a significantly lower blood flow velocity in the middle cerebral artery. The patients who received an intervention had a significantly higher blood flow velocity in the left middle cerebral artery, right vertebral artery and basilar artery. Compared to the placebo group, the myofascial relaxation group exhibited a significantly decreased level of pain. Conclusion: Cervicogenic headache is pain referred to the head from a source in the cervical spine. Manual therapy affect to cervical spine and soft tissue as well as the passage of these vessels and nerves to recover because it is thought to be able to help.

Effectiveness and Safety of Mechanical Thrombectomy with Stent Retrievers in Basilar Artery Occlusion : Comparison with Anterior Circulation Occlusions

  • Hu, Soo Young;Yi, Ho Jun;Lee, Dong Hoon;Hong, Jae Taek;Sung, Jae Hoon;Lee, Sang Won
    • Journal of Korean Neurosurgical Society
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    • v.60 no.6
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    • pp.635-643
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    • 2017
  • Objective : Acute basilar artery occlusion (BAO) is associated with severe neurological dysfunction and high mortality rates. The benefits of mechanical thrombectomy in BAO have not been explored in recent clinical trials. Therefore, we analyzed outcomes of stent retriever mechanical thrombectomy for BAO, and compared with anterior circulation occlusions (ACO). Methods : In total, 161 consecutive patients (24 BAO, 137 ACO) who underwent mechanical thrombectomy with the stent retriever between January 2013 and August 2016 enrolled in our study. All patients underwent clinical assessment with the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin scale (mRS). Radiological results were used to evaluate thrombolysis in cerebral infarction (TICI) scores and successful recanalization was defined by TICI 2b or 3. Results : Mean NIHSS scores at 24 hours and 30 days were significantly higher in the BAO group than the ACO group (p=0.021, p=0.001). mRS at 90 days was significantly higher in the BAO group (4.2) compared with the ACO group (3.0) (p=0.003). The BAO group (2.0) performed fewer stent retriever passages than the ACO group (2.7) (p=0.049). There were no significant differences between the two groups in terms of complications, but the BAO patients experienced a higher mortality (16.6%) rate than ACO patients (5.8%) (p=0.001). In subgroup analysis of BAO, patients with short procedure times achieved successful recanalization (p=0.001) and successfully recanalized patients exhibited more favorable mRS at 90 days (p=0.027). Conclusion : In our study, mechanical thrombectomy of BAO patients showed worse clinical outcome and higher mortality rate than ACO patients. However, mechanical thrombectomy with a stent retriever in BAO is an effective treatment, because successfully recanalized patients showed good clinical outcome in BAO patients.

Congenital Hypoplasia of Internal Carotid Artery Accompanying with Cerebral Aneurysms

  • Baek, Geum-Seong;Koh, Eun-Jeong;Lee, Woo-Jong;Choi, Ha-Young
    • Journal of Korean Neurosurgical Society
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    • v.41 no.5
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    • pp.343-346
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    • 2007
  • Hypoplasia of the internal carotid artery is a rare congenital anomaly. Agenesis, aplasia, and hypoplasia of the internal carotid artery [ICA] are frequently associated with cerebral aneurysms in the circle of Willis. Authors report two cases with congenital hypoplasia of the ICA accompanying with the aneurysms. Transfemoral cerebral angiography [TFCA] in one patient identified nonvisualization of the left ICA. Bilateral anterior cerebral artery [ACA] and middle cerebral artery [MCA] were supplied from the right ICA accompanying with two aneurysms at anterior communicating artery [AcoA] and A1 portion of the left ACA. TFCA in another patient demonstrated hypoplastic left ICA and left ACA filled from the right ICA accompanying with AcoA aneurysm. Left MCA was filled from basilar artery via posterior communicating artery [PcoA]. Skull base computed tomography [CT] in two patients showed hypoplastic carotid canal. Authors performed direct aneurysmal neck clipping. Follow up CT angiography [CTA] at one year after surgery did not show regrowth or new development of the aneurysm. In patients with hypoplastic ICA, neurosurgeons should be aware of the possibility of development of the aneurysms, presumably because of hemodynamic process. Direct aneurysmal neck clipping is a good treatment modality. After operation, regular CTA, magnetic resonance angiography [MRA] or TFCA is needed to find progressive lesion and to prevent cerebrovascular attack [CVA].

Persistent Trigeminal Artery Variant Detected by Conventional Angiography and Magnetic Resonance Angiography -Incidence and Clinical Significance-

  • Rhee, Sun-Joo;Kim, Myoung-Soo;Lee, Chae-Heuck;Lee, Ghi-Jai
    • Journal of Korean Neurosurgical Society
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    • v.42 no.6
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    • pp.446-449
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    • 2007
  • Objective : Persistent trigeminal artery variant (PTAV) is an anastomosis between the internal carotid artery (ICA) and the cerebellar artery without any interposing basilar artery segment. We discuss its probable embryological origin and emphasize clinical implications. Methods : Retrospectively 1250 conventional cerebral angiograms and 2947 cranial magnetic resonance angiographies (MRAs) were evaluated for the patients with PTAV. Results : Five patients (four men and one woman, 23 to 76 years of age, median age 65 years) had a PTAV. Three patients who underwent MRA had a PTAV (3/2947=0.1%). Four of the patients who underwent cerebral angiography had a PTAV (4/1250=0.32%). Two of 143 patients who underwent both conventional angiography and cranial MRA showed PTAV. The PTAV was an incidental finding in all five patients. The PTAV originated from the cavernous segment of the left ICA in four patients and from the cavernous segment of the right ICA in one patient. The terminal branch of the PTAV was the anterior inferior cerebellar artery (AICA) and superior cerebellar artery (SCA) in two patients and the AICA only in the other three patients. Conclusion : Neurosurgeons should be aware of possible presence of PTAV. Manipulation of this vessel during a surgical approach to the parasellar region and percutaneous gasserian ganglion procedure may result in hemorrhage or ischemia.

The Technique and Normal Values of Transcranial Doppler Ultrasonography(TCD) (Transcranial Doppler Ultrasonography (TCD)의 시행 방법 및 정상치)

  • Sohn, Young Ho
    • Annals of Clinical Neurophysiology
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    • v.1 no.1
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    • pp.39-46
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    • 1999
  • Transcranial doppler ultrasonography (TCD) is a new, non-invasive and easily applicable method to evaluate cerebral hemodynamics. Last 10 years, its use in Korea has been dramatically expanded, but the qualification of TCD laboratory has yet to be settled. Since duplex sonography is seldom used in Korea, we have to depend totally on TCD to evaluate cerebral hemodynamic changes. Thus, all of the available data from every detectabler cerebral arteries has to be obtained for accurate interpretation of TCD measurements. Moreover, flow direction and wave form should be concerned in addition to the flow velocity. In this article, I present technique to measure the anterior, meddle and posterior cerebral arteries, the internal carotid artery siphon and at cervical level, and the vertebral and the basilar artery, and normal values for these measurements which is essential for the adequate interpretation.

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