Sungmin Cho

Neuregulin 1 up-regulates the expression of nicotinic acetylcholine receptors through the ErbB2/ErbB3-PI3K-MAPK signaling cascade in adult autonomic ganglion neurons

We investigated effects of Neuregulin 1 (NRG1) on the expression of nicotinic acetylcholine receptor (nAChR) in major pelvic ganglion (MPG) from adult rat. MPG neurons were found to express transcripts for type I and III NRG1s as well as α and β‐type epidermal growth factor (EGF)‐like domains. Of the four ErbB receptor isoforms, ErbB1, ErbB2, and ErbB3 were expressed in MPG neurons. Treating MPG with NRG1β significantly increased the transcript and protein level of the nAChR α3 and β4 subunits. Consistent with these molecular data, nicotinic currents (IACh) were significantly up‐regulated in NRG1β‐treated sympathetic and parasympathetic MPG neurons. In contrast, the type III NRG1 and the α form of the NRG1 failed to alter the IACh. Inhibition of the ErbB2 tyrosine kinase completely abolished the effects of NRG1β on the IACh. Stimulation of the ErbB receptors by NRG1β activated the phosphatidylinositol‐3‐kinase (PI3K) and mitogen‐activated protein kinase (MAPK). Immunoblot analysis revealed that PI3K‐mediated activation of Akt preceded Erk1/2 activation in NRG1β‐treated MPG neurons. Furthermore, specific PI3K inhibitors abrogated the phosphorylation of Erk1/2, while inhibition of MEK did not prevent the phosphorylation of Akt. Taken together, these findings suggest that NRG1 up‐regulates nAChR expression via the ErbB2/ErbB3‐PI3K‐MAPK signaling cascade and may be involved in maintaining the ACh‐mediated synaptic transmission in adult autonomic ganglia.

Middle Meningeal Artery Embolization in Recurrent Chronic Subdural Hematoma Combined with Arachnoid Cyst.

Chronic subdural hematoma (CSDH) is a collection of old blood and its breakdown products between the surface of the brain parenchyma and the outermost layer called the dura. The most common treatment option for primary CSDH is burr-hole trephination; however, the treatment method for recurrent CSDH is still widely debated. An arachnoid cyst (AC) is a sac filled with cerebrospinal fluid located between the brain or spinal cord and the arachnoid membrane, which is one of the three meninges covering the brain or spinal cord. Although it is rare, the cyst is associated with CSDH in juveniles, and the recurrence rate of CSDH increases in such cases. Much of the literature has supported the preventive role of middle meningeal artery (MMA) embolization in recurrent CSDH. We report a 13-year-old male patient with recurrent CSDH and AC where the early intervention of MMA embolization was proven effective in preventing the further recurrence of CSDH.

Retrieval of Unintended Migrated Detached Coil: Case Report

Owing to the rapid development of intervention techniques and devices, endovascular coil embolization of cerebral arteries has become standardized. It is particularly preferred when a patient presents with an unruptured intracranial aneurysm of the posterior communicating artery (PcomA). However, the risk of thrombogenic complications of the coil migration may also result in a large cerebral infarction. When coil migration occurs during embolization, a procedure for removal of the embolic coil should be performed immediately. We experienced a clinically rare case of migration of a framing coil to the distal middle cerebral artery aneurysm during endovascular embolization of an unruptured PcomA aneurysm. The migrated coil was barely retrieved using snare techniques.

Factors Affecting Optimal Time of Cranioplasty: Brain Sunken Ratio

Objective After a rigorous management of increased intracranial pressure by decompressive craniectomy (DC), cranioplasty (CP) is usually carried out for functional and cosmetic purposes. However, the optimal timing of CP remains controversial. Our study aims to analyze the relationship between the optimal timing of CP and the post-operative complications. Methods From January 2013 to December 2015, ninety patients who underwent CP in a single institution were analyzed. We set the independent variables as follows: 1) patient characteristics; 2) the time interval between the DC and CP; 3) operation time; 4) anesthesia time; and 5) pre-operative computed tomography (CT) findings such as a degree of sunken brain by ratio of A (the median length from scalp to midline) to B (the length from midline to inner table of skull at this level). The dependent variables of this study are the event of post-operative complications. Results The overall complication rate was 33.3%. There was no statistical significance in the time interval between the DC and CP in the groups with and without complications of CP (p=0.632). However, there was a significant statistical difference in the degree of sunken brain by ratio (A/B) between the two groups (p<0.001). Conclusion From this study, we conclude that it is better to determine the optimal timing of CP by the pre-operative CT finding than by the time interval between the DC and CP. Hereby, we suggest a potentially useful determinant of optimal timing of CP.

Endovascular Treatment of Giant Serpentine Aneurysm of the Middle Cerebral Artery

Giant serpentine aneurysms are uncommon types of aneurysmal disease and have angiographically authentic features. We report a case of a 44-year-old male with headache and seizure. He presented a giant serpentine aneurysm arising from the middle cerebral artery (MCA). It was a large intracranial aneurysm thrombosed as a mass-like lesion while it maintained its outflow drainage into the distal MCA branches. The balloon occlusion test (BOT) was performed to test the tolerance of temporary collateral circulation. Following routine cerebral angiography, we performed an endovascular embolization on the proximal artery of MCA. He was discharged from the hospital with alert mental status and mild Gerstmann syndrome. The short-term follow-up imaging studies showed the decreased mass effect, and the patient presented an improved Gerstmann syndrome. After a careful evaluation of BOT, an endovascular embolization can be one of the powerful therapeutic instruments for giant serpentine aneurysm.

Cranial Nerve Palsy after Onyx Embolization as a Treatment for Cerebral Vascular Malformation

The Onyx liquid embolic system is a relatively safe and commonly used treatment for vascular malformations, such as arteriovenous fistulas and arteriovenous malformations. However, studies on possible complications after Onyx embolization in patients with vascular malformations are limited, and the occurrence of cranial nerve palsy is occasionally reported. Here we report the progress of two different types of cranial nerve palsy that can occur after embolization. In both cases, Onyx embolization was performed to treat vascular malformations and ipsilateral oculomotor and facial nerve palsies were observed. Both patients were treated with steroids and exhibited symptom improvement after several months. The most common types of neuropathy that can occur after Onyx embolization are facial nerve palsy and trigeminal neuralgia. Although the mechanisms underlying these neuropathies are not clear, they may involve traction injuries sustained while extracting the microcatheter, mass effects resulting from thrombi and edema, or Onyx reflux into the vasa nervorum. In most cases, the neuropathy spontaneously resolves several months following the procedure.

Clinical Outcome of Acute Epidural Hematoma in Korea: Preliminary Report of 285 Cases Registered in the Korean Trauma Data Bank System

Objective The aim of this preliminary collaborative study was to assess the clinical characteristics, management, and outcome of epidural hematoma (EDH) based on the data collected and registered in the Korean Trauma Data Bank System (KTDBS). Methods Of 2,698 patients registered in the KTDBS between September 2010 and March 2014, 285 patients with EDH were analyzed. Twenty-three trauma centers participated in the study voluntarily to collect data. We subcategorized the patients into two groups with good and poor outcomes. Various clinical characteristics and the time intervals with regard to treatment course were investigated to determine the relationship between these parameters and the functional outcome. Results Of multiple parameters for this analysis, older age (p=0.0003), higher degree of brain injury (p<0.0001), cases of surgical EDH (p<0.0001), time interval from trauma to hospital before 6 hours, and the decreasing pattern of Glasgow Coma Scale (GCS) between and initial and final GCS were strongly associated with poor outcome. Use of prophylactic anticonvulsant did not affect the functional outcome. There was an interesting difference in the use of mannitol in treating EDH between the urban and rural regions (p<0.0001). Conclusion This is the first multi-center analysis of etiology of injury, pre-hospital care, treatment, and functional outcome of EDH in Korea. The degree of brain injury and the GCS difference were notable factors that were significant in determining the functional outcome of EDH.

Clinical Analysis of Delayed Surgical Epidural Hematoma.

Objective A small epidural hematoma (EDH) that has been diagnosed to be nonsurgical by initial brain computed tomography (CT) can increase in size and need surgical removal, resulting in a poor prognosis. However, there have been few studies, which focused delayed operated EDH. Therefore, we analyzed the clinical factors to determine the predicting factors of delayed operated EDH. Methods Between January 2011 and January 2014, 90 patients, who were admitted due to EDH, were enrolled in this study. None of the patients were indicated for operation initially. Based on the presence of surgery, we classified the patients into a delayed-surgery group (DG) and a non-surgical group (NG). Additionally, we analyzed them according to the following: time interval between the trauma and the initial CT, gender, age, medical history, drinking, change of mean arterial pressure (MAP), volume of EDH and other traumatic brain lesion. Results Among the 90 patients, the DG was 19 patients. Compared with NG, the DG revealed increased MAP, less presence of drinking, and a short time interval (DG vs. NG: +9.684 mm Hg vs. -0.428 mm Hg, 5.26% vs. 29.58%, 1.802 hours vs. 5.707 hours, respectively, p<0.05). Analyzing the time interval with receiver operating characteristic, there was 88.2% sensitivity and 68.3% specificity at the 2.05-hour cut-off value (area under the curve=0.854). Conclusion According to our results, the time interval between the trauma and the initial CT along with blood pressure change are potential predicting factors in the cases of delayed operation of EDH.