Dong-Keun Hyun

Time Course of Symptom Disappearance after Microvascular Decompression for Hemifacial Spasm

OBJECTIVE This study is to investigate time course of symptom disappearance in patients whose spasm relieved completely after microvascular decompression (MVD). METHODS Of 115 patients with hemifacial spasm (HFS) who underwent MVD from April 2003 to December 2006, 89 patients who had no facial paralysis after operation and showed no spasm at last follow-up more than 1.5 years after operation were selected. Symptom disappearance with time after MVD was classified into type 1 (symptom disappearance right after operation), type 2 (delayed symptom disappearance) and type 3 (unusual symptom disappearance). Type 2 was classified into type 2a (with postoperative silent period) and type 2b (without silent period). RESULTS Type 1, type 2a, type 2b and type 3 were 38.2%, 48.37%, 12.4% and 1.1%, respectively. Delayed disappearance group (type 2) was 60.7%. Post-operative symptom duration in all cases ranged from 0 to 900 days, average was 74.6 days and median was 14 days. In case of type 2, average post-operative symptom duration was 115.1 days and median was 42 days. Five and 3 patients required more than 1 year and 2 years, respectively, until complete disappearance of spasm. In type 2a, postoperative silent period ranged from 1 to 10 days, with an average of 2.4 days. CONCLUSION Surgeons should be aware that delayed symptom disappearance after MVD for HFS is more common than it has been reported, silent period can be as long as 10 days and time course of symptom disappearance is various as well as unpredictable.

Evidence for Rat Organic Anion Transporter 3 Association with Caveolin‐1 in Rat Kidney

The rat organic anion transporter 3 (rOAT3) has recently been identified as the third isoform of the OAT family. The mechanisms that regulate rOAT3s functions remain to be elucidated. rOAT3 contributes for moving a number of negatively charged organic compounds between cells and their extracellular milieu. Caveolin (Cav) also plays a role as a membrane transporter. To address the relationship of these two proteins, we investigated the protein‐protein interaction between rOAT3 and Cav‐1. The rOAT3 mRNA and protein expression were observed in the rat kidney, and the expressions of Cav‐1 mRNA and protein were also detected in the kidney. Confocal microscopy of the immuno‐cytochemistry experiments using primary cultured renal proximal tubular cells showed that rOAT3 and Cav‐1 were co‐localized at the plasma membrane. This finding was confirmed by Western blot analysis using isolated caveolae‐enriched membrane fractions from the rat kidney and immuno‐precipitation experimentation. When rOAT3s synthesized cRNA of rOAT3 along with the antisense oligo deoxynucleotide of Xenopus Cav‐1 were co‐injected into Xenopus oocytes, the [3H] estrone sulfate uptake was significantly decreased. These findings suggest that rOAT3 and caveolin‐1 share a cellular expression in the plasma membrane and Cav‐1 up‐regulates the organic anionic compound uptake via rOAT3 under normal physiological conditions. IUBMB Life, 57: 109‐117, 2005

Effects of carotid artery stenosis treatment on blood pressure

OBJECT The purpose of this study was to evaluate and compare the long-term effects of carotid endarterectomy (CEA) and carotid artery stenting (CAS) on blood pressure (BP). METHODS Between January 2003 and December 2009, 134 patients underwent 145 procedures for treatment of carotid artery stenosis. Patients with at least 1 year of clinical and radiographic follow-up after treatment were included in this study. A total of 102 patients met this criterion and were placed in the CEA group (n = 59) or the CAS group (n = 43) according to their treatment. The percentage change in BP decrement and the number of patients with a normotensive BP were evaluated and compared between the groups. RESULTS There were no significant differences between the groups with regard to baseline characteristics. Compared with the pretreatment BP, the follow-up BPs were significantly decreased in both groups. At the 1-year followup, the percentage change in the BP decrement was greater in the CAS group (percentage change: systolic BP 9.6% and diastolic BP 12.8%) than in the CEA group (percentage change: systolic BP 5.9% [p = 0.035] and diastolic BP = 8.1% [p = 0.049]), and there were more patients with a normotensive BP in the CAS group (46.5%) than in the CEA group (22.0%, p = 0.012). CONCLUSIONS Both CEA and CAS have BP-lowering effects. Carotid artery stenting seems to have a better effect than CEA on BP at the 1-year follow-up.

Technical Report of Free Hand Pedicle Screw Placement using the Entry Points with Junction of Proximal Edge of Transverse Process and Lamina in Lumbar Spine: Analysis of 2601 Consecutive Screws

Objective A variety of different pedicle screws entry point techniques are used for the lumbar pedicle screws placement. This study reported Kims entry point of lumbar pedicle screws with free hand technique and the accuracy of this technique. Methods We retrospectively reviewed the 584 cases with free hand placed lumbar pedicle screw placement. The diagnosis included 491 cases with degenerative spine, 59 cases with trauma, 29 cases with metastatic disease, and 5 cases with scoliosis. A total of 2601 lumbar pedicle screws were placed, and the entry points of lumbar pedicle screws were the junction of proximal edge of transverse process and lamina. Incidence and extent of cortical breach by misplaced pedicle screw was determined by review of intra-operative and post-operative radiographs and/or computed tomography. Results Among the total 2601 lumbar free hand placed pedicle screws, 114 screws (4.4%) in 79 patients (13.5%) were repositioned screws with suspected screw malposition during operation, and 37 screws (1.4%) in 31 patients (5.3%) were identified as moderate to severe breaching the pedicle after post-operative imaging studies. Among the patient with malpositioned screws, 3 patients showed nerve irritation sign of the lesion, and 2 cases were symptom improved after nerve block and conservative management, and 1 case was removed the screw after the failure of the treatment. Conclusion Free hand pedicle screw placement based on external landmark with the junction of proximal edge of transverse process and lamina showed acceptable safety and accuracy and avoidance of radiation exposure.

Surface Landmarks do not Correspond to Exact Levels of the Cervical Spine: References According to the Sex, Age and Height.

Objective A general orientation along the cervical spine could be estimated by external landmarks, and it was useful, quick and less exposable to radiation, but, sometimes it gave reference confusion of target cervical level. The authors reviewed the corresponding between the neck external landmarks and cervical levels. Methods Totally 1,031 cervical lateral radiographs of different patients were reviewed in single university hospital. Its compositions were 534 of males and 497 females; 86 of second decades (10-19 years-old), 169 of third decades, 159 of fourth decades, 209 of fifth decades, 275 of sixth decades, and 133 of more than seventh decades (>60 years-old). Reference external landmarks (mandible, hyoid bone, thyroid cartilage, and cricothyroid membrane) with compounding factors were reviewed. Results The reference levels of cervical landmarks were C2.13 with mandible angle, C3.54 with hyoid bone, C5.12 with thyroid cartilage, and C6.01 with cricothyroid membrane. The reference levels of cervical landmarks were differently observed by sex, age, and somatometric measurement (height) accordingly mandible angle from C1 to C3, hyoid bone from disc level of C2 and C3 to C5, thyroid cartilage from disc level of C3 and C4 to C7, and cricothyroid membrane from C4 to disc level of C7 and T1. Conclusion Surface landmarks only provide general reference points, but not correspond to exact levels of the cervical spine. Intraoperative fluoroscopy ensures a more precise placement to the targeted cervical level.

Cervical Arthroplasty for Moderate to Severe Disc Degeneration: Clinical and Radiological Assessments after a Minimum Follow-Up of 18 Months: Pfirrmann Grade and Cervical Arthroplasty

Purpose Clinical outcomes and radiologic results after cervical arthroplasty have been reported in many articles, yet relatively few studies after cervical arthroplasty have been conducted in severe degenerative cervical disc disease. Materials and Methods Sixty patients who underwent cervical arthroplasty (Mobi-C®) between April 2006 and November 2011 with a minimum follow-up of 18 months were enrolled in this study. Patients were divided into two groups according to Pfirrmann classification on preoperative cervical MR images: group A (Pfirrmann disc grade III, n=38) and group B (Pfirrmann disc grades IV or V, n=22). Visual analogue scale (VAS) scores of neck and arm pain, modified Oswestry Disability Index (mODI) score, and radiological results including cervical range of motion (ROM) were assessed before and after surgery. Results VAS and mean mODI scores decreased after surgery from 5.1 and 57.6 to 2.7 and 31.5 in group A and from 6.1 and 59.9 to 3.7 and 38.4 in group B, respectively. In both groups, VAS and mODI scores significantly improved postoperatively (p<0.001), although no significant intergroup differences were found. Also, cervical dynamic ROM was preserved or gradually improved up to 18 months after cervical arthroplasty in both groups. Global, segmental and adjacent ROM was similar for both groups during follow-up. No cases of device subsidence or extrusion were recorded. Conclusion Clinical and radiological results following cervical arthroplasty in patients with severe degenerative cervical disc disease were no different from those in patients with mild degenerative cervical disc disease after 18 months of follow-up.

Pneumocephalus in the absence of craniofacial skull base fracture.

W e report a rare case of intracerebral pneumocephalus. It was not accompanied by the typical craniofacial skull base fracture. A 77-year-old woman presented with pneumocephalus following a pedestrian traffic accident. Neurologic and physical examination revealed multiple extensive emphysemas, multiple rib fractures, and lung contusions, but no facial or skull bone fractures. Computed tomography (CT) and simple X-ray did not reveal a craniofacial skull base fracture, although both imaging methods showed an air shadow in the internal carotid artery (ICA) pathway. Pneumocephalus and pneumoventricle are defined as an intracranial gas collection, with several reports in the literature describing various portals of entry and clinical situations that favor the introduction of air to the skull. Our report presents the possibility that pneumoventricle and pneumocephalus can occur even in the absence of a bony skull fracture.

Early Decompression of Acute Subdural Hematoma for Postoperative Neurological Improvement: A Single Center Retrospective Review of 10 Years

Objective This study was conducted to investigate survival related factors, as well as to evaluate the effects of early decompression on acute subdural hematoma (ASDH). Methods We retrospectively reviewed cases of decompressive craniectomy (DC) for decade. In total, 198 cases of DC involved ASDH were available for review, and 65 cases were excluded due to missing data on onset time and a delayed operation after closed observation with medical care. Finally, 133 cases of DC with ASDH were included in this study, and various factors including the time interval between trauma onset and operation were evaluated. Results In the present study, survival rate after DC in patients with ASDH was shown to be related to patient age (50 years old, p=0.012), brain compression ratio (p=0.042) and brain stem compression (p=0.020). Sex, preoperative mental status, and time interval between trauma onset and operation were not related with survival rate. Among those that survived (n=78), improvements in Glasgow Coma Scale (GCS) score of more than three points, compared to preoperative measurement, were more frequently observed among the early (less than 3 hours between trauma onset and operation) decompressed cases (p=0.013). However, improvements of more than 4 or 5 points on the GCS were not affected by early decompression. Conclusion Early decompression of ASDH was not correlated with survival rate, but was related with neurological improvement (more than three points on the GCS). Accordingly, early decompression in ASDH, if indicated, may be of particular benefit.

Mysterious foreign body in transverse sinus.

This case report describes a patient who had a foreign body in transverse sinus. A 35-year-old Korean-Chinese man visited the emergency room with lacerated wound in left eyelid and a foreign body which was stumbled upon in the skull. On examination, there was right side hemianopsia in his left eye. He did not complain any headache or show any abnormal neurological signs, but there was a foreign body at left transverse sinus in computed tomography which was taken at another hospital. There was no intracranial abnormality except the foreign body in computed tomography. Because of the financial problem, additional evaluations were not possible. We herein report a strange case in which the pathway of a foreign body to locate in transverse sinus was ambiguous, and suggest that the foreign body located in transverse sinus might have been the penetrated along the anterior fontanelle and passed through the superior sagittal sinus.

Delayed Vertebral Artery Dissection after Posterior Cervical Fusion with Traumatic Cervical Instability: A Case Report

Vascular injury presented immediately after the penetration, but delayed onset of vascular symptom caused by an embolism or vessel dissection after cervical fusion or traumatic event is extremely rare. We present a case of a 56-year-old woman who underwent an operation for cervical fusion for type II Odontoid process fracture. She presented symptoms of seizure with hemiparesis in 6 days after the operation. Multifocal acute infarction due to an embolism from the left VA (V3 segment) dissection was observed without a definite screw breach the transverse foramen. We hereby reported the instructive case report of delayed onset of vertebral artery dissection after posterior cervical fusion with type II odontoid process fracture patient. When a cervical operation performed in the cervical trauma patient, even if no apparent VA injury occurs before and during the operation, the surgeon must take caution not to risk cerebral infarction because of the delayed VA dissection.