• Biomedical Science Letters
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• v.11 no.2
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• pp.211-219
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• 2005

Trigeminovascular system plays an important role for the cerebral memodynamics. The aim of this study was to investigate the alterations in cerebrovascular reactivity by trigeminovascular system injury in rats. Trigeminovascular system of male Sprague-Dawley rats was injured by either denervation of nasocilliary nerve or neonatal capsaicin treatment. Trigeminovascular system was stimulated by controlled hemorrhagic hypotension or somatosensory (whisker) stimulation. Changes in regional cerebral blood flow (rCBF) and pial arterial diameter were continuously measured by laser-Doppler flowmetry and videomicroscopy, respectively. Nitric oxide synthase (NOS) activity in cerebral cortex was determined by measuring the conversion of $L-^3H-arginine\;to\;L-^3H-citrulline$. Cyclic GMP levels in cerebral cortex and pial artery were determined using the cyclic GMP $^{125}I$ scintillation proximity assay system. rCBF autoregulation was impaired or almost abolished by trigeminovascular system injury. rCBF response to whisker stimulation was significantly attenuated by trigeminovascular system injury. NOS activity as well as cyclic GMP level in cerebral cortex and pial artery were significantly reduced in the group of trigeminovascular system injury. These results suggest that trigeminovascular system injury causes prominent alterations in cerebrovascular reactivity, and that NO, which is generated by neuronal NOS in the trigeminovascular system, is implicated in the regulation of rCBF.

• Journal of Korean Neurosurgical Society
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• v.58 no.1
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• pp.76-78
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• 2015

This report details a case of unexpected, severe post-operative cerebral edema following cranioplasty. We discuss the possible pathological mechanisms of this complication. A 50-year-old female was admitted to our department with sudden onset of stuporous consciousness. A brain computed tomography (CT) revealed a subarachnoid hemorrhage with intracranial hemorrhage and subdural hematoma. Emergency decompressive craniectomy and aneurysmal neck clipping were performed. Following recovery, the decision was made to proceed with an autologous cranioplasty. The cranioplasty procedure was free of complications. An epidural drain was placed and connected to a suction system during skin closure to avoid epidural blood accumulation. However, following the procedure, the patient had a seizure in the recovery room. An emergency brain CT scan revealed widespread cerebral edema, and the catheter drain was clamped. The increased intracranial pressure and cerebral edema were controlled with osmotic diuretics, corticosteroids, and antiepileptic drugs. The edema slowly subsided, but new low-density areas were noted in the brain on follow-up CT 1 week later. We speculated that placing the epidural drain on active suction may have caused an acute decrease in intracranial pressure and subsequent rapid expansion of the brain, which impaired autoregulation and led to reperfusion injury.

• 대한예방의학회:학술대회논문집
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• 1993.10a
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• pp.63-64
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• 1993

• Journal of Korean Neurosurgical Society
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• v.51 no.2
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• pp.117-119
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• 2012

The sinking skin flap syndrome is a rare complication after a large craniectomy. It consists of a sunken skin above the bone defect with neurological symptoms such as severe headache, mental changes, focal deficits, or seizures. In patient with sinking skin flap syndrome, cerebral blood flow and cerebral metabolism are decreased by sinking skin flap syndrome, and it may cause the deterioration of autoregulation of brain. We report a case of a patient with sinking skin flap syndrome who suffered from reperfusion injury after cranioplasty with review of pertinent literature.

• Journal of Haehwa Medicine
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• v.15 no.2
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• pp.263-272
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• 2006

Purpose Brain vessles have autoregulation function, so even when perfusion pressure drops, cerebral blood flow remain stable by vasodilation. Latest research on this reserve of cerebral vessels is being done using TCD, which measures the reserve of the vessels. We did a research comparing cerebral vessel and peripheral vessel reserve between Taeumin, who are more likely to suffer CVA, and the normal. We observed blood flow of Internal carotid artery siphon and radial indicis artery of the two group with TCD. Method We picked 20 people out of patients diagnosed as cerebral infarction at Cheon-An Oriental hospital of Daejeon University. They were diagnosed as Taeumin with QSCCII questionnaire and constitutional differentiation. Using TCD, we measured highest blood flow rate, mean blood flow and asymmetric counting blood flow of Internal carotid artery siphon and radial indicis artery at rest. And then we measured again after stimulating cerebral vessels, by triggering hypercapnia by self apnea and peripheral vessels by palm heating. Result At rest, mean blood flow rate of Internal carotid artery siphon showed significant decrease compared to control group. Blood flow rate of Internal carotid artery siphon after hypercapnia showed significant decline in highest blood flow rate and mean blood flow compared to control group. Cerebral vessel reaction after the hypercapnia induction showed great change in experiment group than the control group. Peripheral vessel reaction after palm heating showed significant decline in experiment group compared to control group. Conclusion In conclusion, measuring the alteration of blood flow used in diagnosing cerebral infarction, is more sensitive when vessel stimulation is done. Non-invasive TCD is effective especially in case of Taeumin who are more likely to suffer vascular disorder than others.

• Neonatal Medicine
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• v.28 no.1
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• pp.14-21
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• 2021

Purpose: Premature infants have immature respiratory control and cerebral autoregulation. We aimed to investigate changes in cerebral oxygenation during apnea with and without peripheral oxygen desaturation in premature infants. Methods: This prospective observational study was conducted at Inha University Hospital. Near-infrared spectroscopy (NIRS)-monitored regional cerebral oxygen saturation (rScO₂) and pulse oximeter-monitored peripheral oxygen saturation (SpO₂) were assessed during the first week of life in 16 stable, spontaneously breathing preterm infants. Apneic episodes that lasted for ≥20 seconds or were accompanied by desaturation or bradycardia were included for analysis. The average rScO₂ value during the 5-minute prior to apnea (baseline), the lowest rScO₂ value following apnea (nadir), the time to recover to baseline (recovery time), the area under the curve (AUC), and the overshoot above the baseline after recovery were analyzed. Results: The median gestational age and birth weight of the infants were 29.2 weeks (interquartile range [IQR], 28.5 to 30.5) and 1,130 g (IQR, 985 to 1,245), respectively. A total of 73 apneic episodes were recorded at a median postnatal age of 2 days (IQR, 1 to 4). The rScO₂ decreased significantly following apneic episodes regardless accompanied desaturation. There were no differences in baseline, nadir, or overshoot rScO₂ between the two groups. However, the rScO₂ AUC for apnea with desaturation was significantly higher than that for apnea without desaturation. Conclusion: Cerebral oxygenation can significantly decrease during apnea, especially when accompanied by reduced SpO₂. These results add the evidence for the clinical utility of NIRS in monitoring premature infants.

• Clinical and Experimental Pediatrics
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• v.46 no.10
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• pp.983-988
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• 2003

Purpose : Syncope appears to be common. However, the mechanism of syncope is not clear. Increased vagal activity and withdrawal of sympathetic stimulation cause hypotension, bradycardia and finally loss of consciousness. The purpose of this study was to evaluate changes of cerebral blood flow velocity, blood pressure, and heart rate during tilt test in children with vasovagal syncope. Methods : Sixty four children with a past history of syncope were evaluated. The stand up test was performed for 15 minutes after a rest at supine position for 10 minutes, followed by an $80^{\circ}$ tilt test lasting 45 minutes. If presyncope(lightheadedness, nausea, blurred vision, or sweating) or syncope occurred, the study was discontinued. 12-lead electrocardiography, echocardiography, and electroencephalography were performed. Transcranial Doppler study was performed at the middle cerebral artery with 2 MHz continuous Doppler probe in 10 children with positive tilt test. Systolic, diastolic, mean cerebral blood flow velocity, integral, and pulsatility index were measured with blood pressure, heart rate, and $O_2$ saturation. Results : The positive rate of tilt test was 31.3%(20/64). Systolic, diastolic, and mean cerebral blood flow velocity decreased significantly in absence of hypotension or bradycardia during presyncope. Time velocity integral of cerebral artery also decreased significantly. Conclusion : Decreased cerebral blood flow velocity can predict the presyncope manifestation. Impairment of autoregulation of cerebral blood flow might play an important role in the pathophysiology of vasovagal syncope.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.13 no.2
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• pp.108-113
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• 2017

Moyamoya disease is a disorder in which certain arteries in the brain are constricted. Blood flow can be blocked by the constriction and blood clots. The patients frequently experience transient ischemic attacks (TIA), cerebral hemorrhage, or may not experience any symptoms at all. It is reported that they have a higher risk of recurrent stroke and a distinct underlying pathophysiology. A 3-year-8-month old boy with moyamoya disease experienced cerebral infarctions five times, and he underwent a cerebrovascular anastomosis surgery four years ago. He showed swallow disturbance, general delayed development, hemiplegia, and strabismus. Also he had hypocalcified teeth with or without multiple caries lesions in all dentitions. Dental treatment under general anesthesia using sevoflurane was performed due to his lack of cooperation. Moyamoya disease is associated with various medical conditions requiring a thoughtful deliberation and a careful examination before and during dental treatment. Pain and anxiety control during dental treatment is important because hyperventilation induced by crying has been seen to trigger TIA. Both isoflurane and sevoflurane are commonly used in patients with MMD, but dynamic autoregulation is better preserved during sevoflurane than isoflurane anesthesia. So sevoflurance general anesthesia may be recommendable to manage dental patients having multiple caries with moyamoya disease.