1.Analysis of temperature-dependent abnormal bursting patterns of neurons in Aplysia
Nam Gyu HYUN ; Kwangho HYUN ; Saecheol OH ; Kyungmin LEE
The Korean Journal of Physiology and Pharmacology 2020;24(4):349-362
Temperature affects the firing pattern and electrical activity of neurons in animals, eliciting diverse responses depending on neuronal cell type. However, the mechanisms underlying such diverse responses are not well understood. In the present study, we performed in vitro recording of abdominal ganglia cells of Aplysia juliana , and analyzed their burst firing patterns. We identified atypical bursting patterns dependent on temperature that were totally different from classical bursting patterns observed in R15 neurons of A. juliana . We classified these abnormal bursting patterns into type 1 and type 2; type 1 abnormal single bursts are composed of two kinds of spikes with a long interspike interval (ISI) followed by short ISI regular firing, while type 2 abnormal single bursts are composed of complex multiplets. To investigate the mechanism underlying the temperature dependence of abnormal bursting, we employed simulations using a modified Plant model and determined that the temperature dependence of type 2 abnormal bursting is related to temperaturedependent scaling factors and activation or inactivation of potassium or sodium channels.
2.Analysis of temperature-dependent abnormal bursting patterns of neurons in Aplysia
Nam Gyu HYUN ; Kwangho HYUN ; Saecheol OH ; Kyungmin LEE
The Korean Journal of Physiology and Pharmacology 2020;24(4):349-362
Temperature affects the firing pattern and electrical activity of neurons in animals, eliciting diverse responses depending on neuronal cell type. However, the mechanisms underlying such diverse responses are not well understood. In the present study, we performed in vitro recording of abdominal ganglia cells of Aplysia juliana , and analyzed their burst firing patterns. We identified atypical bursting patterns dependent on temperature that were totally different from classical bursting patterns observed in R15 neurons of A. juliana . We classified these abnormal bursting patterns into type 1 and type 2; type 1 abnormal single bursts are composed of two kinds of spikes with a long interspike interval (ISI) followed by short ISI regular firing, while type 2 abnormal single bursts are composed of complex multiplets. To investigate the mechanism underlying the temperature dependence of abnormal bursting, we employed simulations using a modified Plant model and determined that the temperature dependence of type 2 abnormal bursting is related to temperaturedependent scaling factors and activation or inactivation of potassium or sodium channels.
3.Comparison of Conventional Surgical Tracheostomy and Percutaneous Dilatational Tracheostomy in the Neurosurgical Intensive Care Unit
Sungdae LIM ; Hyun PARK ; Ja Myoung LEE ; Kwangho LEE ; Won HEO
Korean Journal of Neurotrauma 2022;18(2):246-253
Objective:
Tracheostomy is a necessary procedure for patients admitted to the neurosurgery intensive care unit (ICU) with severe brain injury, because mechanical ventilation must be maintained for a long time following neurologic failure. The purpose of this study was to compare conventional surgical tracheostomy (CST) and percutaneous dilatational tracheostomy (PDT) performed at the bedside in critically ill neurosurgery patients requiring tracheostomy to determine which procedure has comparative advantages.
Methods:
This retprospective study was conducted between January 2019 and December 2020. PDT was performed on 52 patients and CST was performed on 44 patients. The baseline characteristics, procedural characteristics, and clinical outcomes were recorded.
Results:
The mean operative time in the CST group was 25.5±6.5 minutes and that in the PDT group was 15.1±2.5 minutes; the difference was statistically significant (p<0.01). Four patients in the CST group and none in the PDT group experienced bleeding requiring transfusion. However, there was no significant difference in total ICU mortality or length of hospital stay. There were no statistical differences in the individual complication categories between the 2 study groups.
Conclusion
There were fewer procedure-induced complications among patients receiving PDT than among those receiving CST. In addition, the treatment time for PDT was shorter than that for CST treatment.
4.Surgical Treatment of Ruptured Aneurysms of Lateral Spinal Artery Presenting as Intracranial Subarachnoid Hemorrhage : Case Series and Literature Review
Yonghun SONG ; Kwangho LEE ; Hyun PARK ; Soo Hyun HWANG ; Hye Jin BAEK ; In Sung PARK
Journal of Korean Neurosurgical Society 2024;67(5):586-592
Lateral spinal artery (LSA) aneurysms are extremely rare lesions that can rupture and cause subarachnoid hemorrhage (SAH) even though the spinal arteries communicate directly with the subarachnoid space. To date, six cases of LSA aneurysms have been reported in the literature. Herein, three such cases are reported. All patients presented to the emergency department with headaches. The patients in the first two cases were confirmed to have SAH and LSA aneurysms on a brain computed tomography (CT) angiography performed at the hospital. Two patients had prior instances of cerebral infarction and coronary disease, respectively, and were undergoing antiplatelet therapy. The antiplatelet medication was stopped for 2 weeks and 1 week, respectively, while conservative care was provided. Subsequently, a suboccipital craniectomy was performed, followed by aneurysm clipping. Following the surgery, both patients were discharged without any significant neurological deficits. Regarding the third patient, no aneurysm was found on brain CT angiography, and cerebral angiography was performed during the patient’s hospital stay. She was hospitalized, where she received medication and conservative care, and was discharged with an improvement in bleeding without neurological symptoms. Subsequently, a LSA aneurysm was identified on a brain CT angiography performed at an outpatient clinic; however, the patient was transferred because she wanted to be treated at another hospital. LSA aneurysms are difficult to visualize using CT angiography; therefore, careful angiographic studies are required. Surgical clipping is the treatment of choice if the aneurysm is inaccessible by the endovascular treatment.
5.Surgical Treatment of Ruptured Aneurysms of Lateral Spinal Artery Presenting as Intracranial Subarachnoid Hemorrhage : Case Series and Literature Review
Yonghun SONG ; Kwangho LEE ; Hyun PARK ; Soo Hyun HWANG ; Hye Jin BAEK ; In Sung PARK
Journal of Korean Neurosurgical Society 2024;67(5):586-592
Lateral spinal artery (LSA) aneurysms are extremely rare lesions that can rupture and cause subarachnoid hemorrhage (SAH) even though the spinal arteries communicate directly with the subarachnoid space. To date, six cases of LSA aneurysms have been reported in the literature. Herein, three such cases are reported. All patients presented to the emergency department with headaches. The patients in the first two cases were confirmed to have SAH and LSA aneurysms on a brain computed tomography (CT) angiography performed at the hospital. Two patients had prior instances of cerebral infarction and coronary disease, respectively, and were undergoing antiplatelet therapy. The antiplatelet medication was stopped for 2 weeks and 1 week, respectively, while conservative care was provided. Subsequently, a suboccipital craniectomy was performed, followed by aneurysm clipping. Following the surgery, both patients were discharged without any significant neurological deficits. Regarding the third patient, no aneurysm was found on brain CT angiography, and cerebral angiography was performed during the patient’s hospital stay. She was hospitalized, where she received medication and conservative care, and was discharged with an improvement in bleeding without neurological symptoms. Subsequently, a LSA aneurysm was identified on a brain CT angiography performed at an outpatient clinic; however, the patient was transferred because she wanted to be treated at another hospital. LSA aneurysms are difficult to visualize using CT angiography; therefore, careful angiographic studies are required. Surgical clipping is the treatment of choice if the aneurysm is inaccessible by the endovascular treatment.
6.Surgical Treatment of Ruptured Aneurysms of Lateral Spinal Artery Presenting as Intracranial Subarachnoid Hemorrhage : Case Series and Literature Review
Yonghun SONG ; Kwangho LEE ; Hyun PARK ; Soo Hyun HWANG ; Hye Jin BAEK ; In Sung PARK
Journal of Korean Neurosurgical Society 2024;67(5):586-592
Lateral spinal artery (LSA) aneurysms are extremely rare lesions that can rupture and cause subarachnoid hemorrhage (SAH) even though the spinal arteries communicate directly with the subarachnoid space. To date, six cases of LSA aneurysms have been reported in the literature. Herein, three such cases are reported. All patients presented to the emergency department with headaches. The patients in the first two cases were confirmed to have SAH and LSA aneurysms on a brain computed tomography (CT) angiography performed at the hospital. Two patients had prior instances of cerebral infarction and coronary disease, respectively, and were undergoing antiplatelet therapy. The antiplatelet medication was stopped for 2 weeks and 1 week, respectively, while conservative care was provided. Subsequently, a suboccipital craniectomy was performed, followed by aneurysm clipping. Following the surgery, both patients were discharged without any significant neurological deficits. Regarding the third patient, no aneurysm was found on brain CT angiography, and cerebral angiography was performed during the patient’s hospital stay. She was hospitalized, where she received medication and conservative care, and was discharged with an improvement in bleeding without neurological symptoms. Subsequently, a LSA aneurysm was identified on a brain CT angiography performed at an outpatient clinic; however, the patient was transferred because she wanted to be treated at another hospital. LSA aneurysms are difficult to visualize using CT angiography; therefore, careful angiographic studies are required. Surgical clipping is the treatment of choice if the aneurysm is inaccessible by the endovascular treatment.
7.Surgical Treatment of Ruptured Aneurysms of Lateral Spinal Artery Presenting as Intracranial Subarachnoid Hemorrhage : Case Series and Literature Review
Yonghun SONG ; Kwangho LEE ; Hyun PARK ; Soo Hyun HWANG ; Hye Jin BAEK ; In Sung PARK
Journal of Korean Neurosurgical Society 2024;67(5):586-592
Lateral spinal artery (LSA) aneurysms are extremely rare lesions that can rupture and cause subarachnoid hemorrhage (SAH) even though the spinal arteries communicate directly with the subarachnoid space. To date, six cases of LSA aneurysms have been reported in the literature. Herein, three such cases are reported. All patients presented to the emergency department with headaches. The patients in the first two cases were confirmed to have SAH and LSA aneurysms on a brain computed tomography (CT) angiography performed at the hospital. Two patients had prior instances of cerebral infarction and coronary disease, respectively, and were undergoing antiplatelet therapy. The antiplatelet medication was stopped for 2 weeks and 1 week, respectively, while conservative care was provided. Subsequently, a suboccipital craniectomy was performed, followed by aneurysm clipping. Following the surgery, both patients were discharged without any significant neurological deficits. Regarding the third patient, no aneurysm was found on brain CT angiography, and cerebral angiography was performed during the patient’s hospital stay. She was hospitalized, where she received medication and conservative care, and was discharged with an improvement in bleeding without neurological symptoms. Subsequently, a LSA aneurysm was identified on a brain CT angiography performed at an outpatient clinic; however, the patient was transferred because she wanted to be treated at another hospital. LSA aneurysms are difficult to visualize using CT angiography; therefore, careful angiographic studies are required. Surgical clipping is the treatment of choice if the aneurysm is inaccessible by the endovascular treatment.
8.Persistent Primitive Trigeminal Artery That Mimics Persistent Primitive Otic Artery on Cerebral Angiography.
Kwangho LEE ; Hyun PARK ; Insung PARK ; Jongwoo HAN
Journal of Cerebrovascular and Endovascular Neurosurgery 2016;18(2):120-123
Persistent primitive trigeminal artery (PPTA) is the most common carotid-basilar anastomosis; on the other hand, persistent primitive otic artery (PPOA) is extremely rare. PPTA is often misdiagnosed as PPOA on cerebral angiography. We present a case of PPTA that mimicked PPOA on cerebral angiography. We further describe the utility of brain computed tomography angiography for differential diagnosis of PPTA from PPOA, together with a review of previous literature.
Angiography
;
Arteries*
;
Brain
;
Central Nervous System Vascular Malformations
;
Cerebral Angiography*
;
Diagnosis, Differential
;
Hand
9.ischVascular Calcification in Patients Undergoing Total Knee Arthroplasty: Frequency and Effects on the Surgery
Ju-Hyung YOO ; Jin-Gyu KIM ; Kwangho CHUNG ; Seung Hyun LEE ; Hyun-Cheol OH ; Sang-Hoon PARK ; Sang-Ok SEOK
Clinics in Orthopedic Surgery 2020;12(2):171-177
Background:
This study aims to investigate the frequency of distal femoral and popliteal arterial calcification and to evaluate the intraoperative and postoperative effects of arterial calcification in patients undergoing total knee arthroplasty using a tourniquet.
Methods:
The records of 5,438 patients who had undergone primary total knee arthroplasty between January 2003 and January 2017 were retrospectively reviewed. We examined the preoperative radiographs of the knee from all patients for calcifications of the femoral and popliteal arteries. Vascular calcification was identified on preoperative radiographs in 223 cases. Intraoperative and postoperative complications were investigated among these patients. Postoperative complications were analyzed from the time of surgery to the last follow-up (minimum 1-year follow-up).
Results:
Vascular calcification of the arteries around the knee was found in 223 cases (4.1%). The mean patient age was 70.6 years in the non-calcification group and 73.8 years in the calcification group (p > 0.05). The calcification group was classified into medial, intimal, or mixed subgroups according to the morphology of calcification on preoperative radiographs. The medial type included 46 cases (20.6%); intimal type, 161 cases (72.2%); and mixed type, 16 cases (2.7%). There was no statistically significant difference in demographic and surgical data among the three groups. There were intraoperative complications in two cases in the medial type group, both of which involved tourniquet failure. There was also a postoperative complication in one case in the medial type group, which involved wound dehiscence at 2 weeks postoperatively. No other postoperative complications were identified during 1-year follow-up.
Conclusions
Despite the presence of calcifications in the arteries around the knee, total knee arthroplasty (using a tourniquet) can be performed without serious complications.
10.Y-configuration Stent-assisted Coil Embolization for Wide-necked Intracranial Bifurcation Aneurysms.
Kwangho LEE ; Hyun PARK ; Insung PARK ; Sukh Que PARK ; O Ki KWON ; Jongwoo HAN
Journal of Cerebrovascular and Endovascular Neurosurgery 2016;18(4):355-362
OBJECTIVE: The objective of this study was to determine the efficiency and safety of Y configuration stent-assisted coiling with double-closed stents for wide-necked intracranial aneurysms located at arterial bifurcations thorough analysis of a multicenter case series. MATERIALS AND METHODS: A retrospective chart review was done on 10 patients who underwent endovascular treatment of wide-necked intracranial aneurysms with Y-configuration stent-assisted coil embolization in three centers from August 2011 to March 2014. The degree of aneurysmal occlusion was assessed using the Raymond scale. Clinical outcomes were assessed before operation, at discharge, and at the last follow-up visit using the Glasgow outcome scale. RESULTS: The 10 patients included 6 females and 4 males with a mean age of 58.6 years. Indications for treatment included 6 unruptured intracranial aneurysms and 4 ruptured intracranial aneurysms. Five aneurysms were located at the basilar artery bifurcation, four aneurysms were located in an anterior communicating artery, and one aneurysm was in the pericallosal artery. The mean size of the 10 aneurysms was 9.7 mm. All aneurysms had a dome-to-neck ratio of < 1.5 (mean, 0.89). Immediate complications included one thromboembolic event out of the 10 cases. Immediate posttreatment angiograms showed complete occlusion in 1 aneurysm and residual necks in 9 aneurysms. Follow-up results showed 8 complete occlusions and 2 residual necks. No delayed complications were observed during the follow-up period (mean: 20 months). CONCLUSION: Y configuration using double-closed cell stents is feasible and safe in selected patients. This method is an acceptable option for managing complex wide-necked bifurcations.
Aneurysm*
;
Arteries
;
Basilar Artery
;
Embolization, Therapeutic*
;
Female
;
Follow-Up Studies
;
Glasgow Outcome Scale
;
Humans
;
Intracranial Aneurysm
;
Male
;
Methods
;
Neck
;
Retrospective Studies
;
Stents