Complications Following Burr Hole Craniostomy and Closed-System Drainage for Subdural Lesions / 대한신경손상학회지

OBJECTIVE: Burr hole craniostomy and closed-system drainage (BCD) is a common surgical procedure in the field of neurosurgery. However, complications following BCD have seldom been reported. The purpose of this study was to report our experiences regarding complications following BCD for subdural lesions. METHODS: A retrospective study of all consecutive patients who underwent BCD for presumed subdural lesions at one institute since the opening of the hospital was performed. RESULTS: Of the 395 patients who underwent BCD for presumed subdural lesions, 117 experienced surgical or nonsurgical complications. Acute intracranial hemorrhagic complications developed in 14 patients (3.5%). Among these, 1 patient died and 5 patients had major morbidities. Malposition of the drainage catheter in the brain parenchyma occurred in 4 patients, and opposite-side surgery occurred in 2 patients. Newly developed seizures after BCD occurred in 8 patients (2.0%), five of whom developed the seizures in relation to new brain lesions. Eighty-eight patients (22.3%) suffered from nonsurgical complications after BCD. Pulmonary problems (7.3%) were the most common nonsurgical complications, followed by urinary problems (5.8%), psychologic problems (4.3%), and cognitive impairments (3.8%). CONCLUSION: The incidence of complications after BCD for subdural lesions is higher than previously believed. In particular, catastrophic complications such as acute intracranial hematomas and surgical or management errors occur at rates that cannot be ignored, possibly causing medico-legal problems. Great caution must be taken during surgery and the postoperative period, and these complications should be listed on the informed consent form before surgery.

Simple Coiling versus Stent-Assisted Coiling of Paraclinoid Aneurysms: Radiological Outcome in a Single Center Study

OBJECTIVE: Paraclinoid aneurysms are a group of aneurysms arising at the distal internal carotid artery. Due to a high incidence of small, wide-necked aneurysms in this zone, it is often challenging to achieve complete occlusion when solely using detachable coils, thus stent placement is often required. In the present study, we aimed to investigate the effect of stent placement in endovascular treatment of paraclinoid aneurysms. METHODS: Data of 98 paraclinoid aneurysms treated by endovascular approach in our center from August 2005 to June 2016 were retrospectively reviewed. They were divided into two groups: simple coiling and stent-assisted coiling. Differences in the recurrence and progressive occlusion between the two groups were mainly analyzed. The recurrence was defined as more than one grade worsening according to Raymond-Roy Classification or major recanalization that is large enough to permit retreatment in the follow-up study compared to the immediate post-operative results. RESULTS: Complete occlusion was achieved immediately after endovascular treatment in eight out of 37 patients (21.6%) in the stent-assisted group and 18 out of 61 (29.5%) in the simple coiling group. In the follow-up imaging studies, the recurrence rate was lower in the stent-assisted group (one out of 37, 2.7%) compared to the simple coiling group (13 out of 61, 21.3%) (p=0.011). Multivariate logistic regression model showed lower recurrence rate in the stent-assisted group than the simple coiling group (odds ratio [OR] 0.051, 95% confidence interval [CI] 0.005–0.527). Furthermore there was also a significant difference in the rate of progressive occlusion between the stent-assisted group (16 out of 29 patients, 55.2%) and the simple coiling group (10 out of 43 patients, 23.3%) (p=0.006). The stent-assisted group also exhibited a higher rate of progressive occlusion than the simple coiling group in the multivariate logistic regression model (OR 3.208, 95% CI 1.106–9.302). CONCLUSION: Use of stents results in good prognosis not only by reducing the recurrence rate but also by increasing the rate of progressive occlusion in wide-necked paraclinoid aneurysms. Stent-assisted coil embolization can be an important treatment strategy for paraclinoid aneurysms when considering the superiority of long term outcome.

Traumatic Pseudoaneurysm Related to Calcified Nodules of Cerebral Convexity Dura Mater in an American College Football Player

Repeated concussion is common among football players; however, these minor blunt head trauma rarely result in serious complications. We report a case of a young college football player who presented acute subdural hematoma, cerebral edema, and seizure due to pseudoaneurysm rupture. The pseudoaneurysm, located at the cortical branch of the middle cerebral artery, was speculated to be formed by dural calcification and adhesion with the underlying brain, possibly due to repeated concussions. Following successful excision of the pseudoaneurysm and control of brain swelling, the patient recovered without sequelae and was discharged after a short while.

Relationship between Gyrus Rectus Resection and Cognitive Impairment after Surgery for Ruptured Anterior Communicating Artery Aneurysms

OBJECTIVE: The gyrus rectus (GR) is known as a non-functional gyrus; hence, its resection is agreed to be a safe procedure frequently practiced to achieve a better surgical view during specific surgeries. This study aimed at comparing the cognitive outcomes following GR resection in patients who underwent surgery for ruptured anterior communicating artery (ACoA) aneurysms. MATERIALS AND METHODS: From 2012 to 2015, 39 patients underwent surgical clipping for ruptured ACoA aneurysms. Mini-mental state examinations (MMSE) were performed in 2 different periods. The statistical relationship between GR resection and MMSE results was evaluated, and further analysis of MMSE subgroup was performed. RESULTS: Twenty-five out of the 39 patients (64.19%) underwent GR resection. Mean initial and final MMSE scores in the GR resection group were 16.3 ± 9.8 and 20.8 ± 7.3, respectively. In the non-resection group, the mean initial and final MMSE scores were 17.1 ± 8.6 and 21.9 ± 4.5, respectively. Neither group's scores showed a significant change. Subgroup analysis of initial MMSE showed a significant difference in memory recall and language (p = 0.02) but not in the final MMSE scores. CONCLUSION: There was no significant relationship between the GR resection and cognitive outcomes in terms of total MMSE scores after surgery for ruptured ACoA aneurysm. However, subgroup analysis revealed a temporary negative effect of GR resection in the categories of language and memory recall. This study suggests that GR resection should be executed superficially, owing to its close anatomical relationship with the limbic system.

Enhanced Efficacy of Human Brain-Derived Neural Stem Cells by Transplantation of Cell Aggregates in a Rat Model of Parkinson's Disease

OBJECTIVE: Neural tissue transplantation has been a promising strategy for the treatment of Parkinson's disease (PD). However, transplantation has the disadvantages of low-cell survival and/or development of dyskinesia. Transplantation of cell aggregates has the potential to overcome these problems, because the cells can extend their axons into the host brain and establish synaptic connections with host neurons. In this present study, aggregates of human brain-derived neural stem cells (HB-NSC) were transplanted into a PD animal model and compared to previous report on transplantation of single-cell suspensions. METHODS: Rats received an injection of 6-OHDA into the right medial forebrain bundle to generate the PD model and followed by injections of PBS only, or HB-NSC aggregates in PBS into the ipsilateral striatum. Behavioral tests, multitracer (2-deoxy-2-[18F]-fluoro-D-glucose ([18F]-FDG) and [18F]-N-(3-fluoropropyl)-2-carbomethoxy-3-(4-iodophenyl)nortropane ([18F]-FP-CIT) microPET scans, as well as immunohistochemical (IHC) and immunofluorescent (IF) staining were conducted to evaluate the results. RESULTS: The stepping test showed significant improvement of contralateral forelimb control in the HB-NSC group from 6-10 weeks compared to the control group (p<0.05). [18F]-FP-CIT microPET at 10 weeks posttransplantation demonstrated a significant increase in uptake in the HB-NSC group compared to pretransplantation (p<0.05). In IHC and IF staining, tyrosine hydroxylase and human beta2 microglobulin (a human cell marker) positive cells were visualized at the transplant site. CONCLUSION: These results suggest that the HB-NSC aggregates can survive in the striatum and exert therapeutic effects in a PD model by secreting dopamine.

Clinical Characteristics of Cerebral Venous Thrombosis in a Single Center in Korea

OBJECTIVE: The purpose of this study is to investigate the clinical characteristics of cerebral venous thrombosis (CVT) in a single center in Korea. METHODS: A total of 36 patients were diagnosed with CVT from August 2005 to May 2013. The patient data regarding age, sex, disease stage, pathogenesis, location, laboratory findings, radiological findings, and treatment modalities were retrospectively collected. The results were compared with those of previous studies in other countries. RESULTS: The patient group comprised 21 men and 15 women with a mean age of 46.9 years (ranging from three months to 77 years). The most common cause was a prothrombotic condition (8 patients, 22.2%). Within the patient group, 13 patients (36.1%) had a hemorrhagic infarction, whereas 23 (63.9%) had a venous infarction without hemorrhage. By location, the incidence of hemorrhagic infarction was the highest in the group with a transverse and/or sigmoid sinus thrombosis (n=9); however, the proportion of hemorrhagic infarction was higher in the cortical venous thrombosis group (75%) and the deep venous thrombosis group (100%). By pathogenesis, the incidence of hemorrhagic infarction was the highest in the prothrombotic group (n=6), which was statistically significant (p=0.016). CONCLUSION: According to this study, CVT was more prevalent in men, and the peak age group comprised patients in the sixth decade. The most common cause was a prothrombotic condition. This finding was comparable with reports from Europe or America, in which CVT was more common in younger women. Hemorrhagic infarction was more common in the prothrombotic group (p=0.016) than in the non-prothrombotic group in this study.

Glomus Tumor in the Femoral Nerve

The glomus tumor of the peripheral nerve is one of the mesenchymal tumors originating in the epineurium, and is extremely rare. A 56-year-old man presented complaining of lancinating pain on the left thigh, which was provoked by pressure or exercise. Subsequent image study revealed a mass in the femoral nerve. Total surgical excision with the aid of intraoperative ultrasonography was performed and the pain was successfully controlled. The authors report an unusual case of a patient diagnosed with glomus tumor in peripheral nerve, with a review of the clinical features, imaging, and pathological findings.

Galeal Tack-Up Sutures to Prevent Subgaleal Cerebrospinal Fluid Collection

OBJECTIVE: Postoperative subgaleal cerebrospinal fluid (CSF) collection is considered as one of the common minor surgical complication which can lead to prolonged hospitalization. We introduce "galeal tack-up suture" to prevent postoperative subgaleal CSF collection. METHODS: Galeal tack-up suture consists of various surgical techniques which aim to fix galea to cranium in order to prevent CSF pooling in subgaleal space. A total of 87 patients who underwent craniotomy were divided into two groups while closing the wound : group A with galeal tack-up suture and group B with routine wound closure without galeal tack-up suture. The patients were observed for postoperative subgaleal CSF collection. RESULTS: Among 87 cranitomy cases, galeal tack-up suture was performed in 32 cases and routine wound closure was done in 55 cases. Postoperative subgaleal CSF collection occurred in 13 cases (15%) in which 12 cases occurred in group B patients and 1 case occurred in group A patients (p=0.026). CONCLUSION: Galeal tack-up suture is an easy and effective technique in wound closure to prevent postoperative CSF collection.

Comparative Results of the Patients with Intracerebral and Intra-sylvian Hematoma in Ruptured Middle Cerebral Artery Aneurysms

OBJECTIVE: To clarify the prognosis of the patients with intra-sylvian hematoma (ISH) and intracerebral hematoma (ICH) in ruptured middle cerebral artery (MCA) aneurysms. METHODS: We categorized hematoma into ISH and ICH by the presence of intra-hematomal contrast enhancing vessel (IHCEV) on computed tomography angiography (CTA). Forty-four ruptured MCA aneurysm patients with ICH or ISH were grouped by the grading system proposed by the authors in our previous study. We investigated the relevance of the following factors: patient's age, gender, Hunt-Hess grade, Glasgow outcome scale (GOS) and changes in Glasgow coma scale (GCS) between pre-operation and 7 days after operation. RESULTS: There were no significant differences statistically in age, gender, Hunt-Hess grade, and GOS between the ISH and ICH groups. In their peri-operative GCS change, the ICH group showed greater improvement compared to the ISH group (p = 0.0391). The hematoma grade had a significant relevance with the patients' GOS. CONCLUSION: Although there were no significant statistic differences in the GOS of the 2 hematoma groups, there were prominent improvements of post-operative GCS in the ICH group. Unlike in the ISH group, effective removal of hematoma was possible in most patients of the ICH group. Thus although there is no difference in the prognosis of the 2 groups, early surgical evacuation of hematoma seems to be effective in improving the short-term GCS score in peri-operative period.

Comparative Results of the Patients with Intracerebral and Intra-sylvian Hematoma in Ruptured Middle Cerebral Artery Aneurysms

OBJECTIVE: To clarify the prognosis of the patients with intra-sylvian hematoma (ISH) and intracerebral hematoma (ICH) in ruptured middle cerebral artery (MCA) aneurysms. METHODS: We categorized hematoma into ISH and ICH by the presence of intra-hematomal contrast enhancing vessel (IHCEV) on computed tomography angiography (CTA). Forty-four ruptured MCA aneurysm patients with ICH or ISH were grouped by the grading system proposed by the authors in our previous study. We investigated the relevance of the following factors: patient's age, gender, Hunt-Hess grade, Glasgow outcome scale (GOS) and changes in Glasgow coma scale (GCS) between pre-operation and 7 days after operation. RESULTS: There were no significant differences statistically in age, gender, Hunt-Hess grade, and GOS between the ISH and ICH groups. In their peri-operative GCS change, the ICH group showed greater improvement compared to the ISH group (p = 0.0391). The hematoma grade had a significant relevance with the patients' GOS. CONCLUSION: Although there were no significant statistic differences in the GOS of the 2 hematoma groups, there were prominent improvements of post-operative GCS in the ICH group. Unlike in the ISH group, effective removal of hematoma was possible in most patients of the ICH group. Thus although there is no difference in the prognosis of the 2 groups, early surgical evacuation of hematoma seems to be effective in improving the short-term GCS score in peri-operative period.

Retrograde Stent Placement for Coil Embolization of a Wide-Necked Posterior Inferior Cerebellar Artery Aneurysm

Wide-necked aneurysms of the posterior inferior cerebellar artery (PICA) are infrequently encountered in cerebrovascular practice, and endovascular treatment is difficult or impossible even with the use of several neck remodeling techniques. We present the case of a patient with a wide-necked aneurysm of the PICA, which was treated by the retrograde stenting through the contralateral vertebral artery and vertebrobasilar junction with antegrade coil embolization.

Eosinophilic Myelitis in the Cervical Cord Mimicking Intramedullary Cord Tumor

Eosinophilic myelitis (EM) or atopic myelitis is a rare disease characterized by a myelitic condition in the spinal cord combined with allergic process. This disease has specific features of elevated serum IgE level, active reaction to mite specific antigen and stepwise progression of mostly the sensory symptoms. Toxocariasis can be related with a form of EM. This report describes two cases of cervical eosinophilic myelitis initially considered as intramedullary tumors. When a differential diagnosis of the intramedullary spinal cord lesion is in doubt, evaluation for eosinophilic myelitis and toxocariasis would be beneficial.

Grading of Intracerebral Hemorrhage in Ruptured Middle Cerebral Artery Aneurysms

OBJECTIVE: To propose grading of intracerebral hemorrhage (ICH) in ruptured middle cerebral artery (MCA) aneurysms, which helps to predict the prognosis more accurately. METHODS: From August 2005 to December 2010, 27 cases of emergent hematoma evacuation and aneurysm clipping for MCA aneurysms were done in the author's clinic. Three variables were considered in grading the ICH, which were 1) hematoma volume, 2) diffuse subarachnoid hemorrhage (SAH) that extends to the contralateral sylvian cistern, and 3) the presence of midline shifting from computed tomography findings. For hematoma volume of greater than 25 mL, we assigned 2 points whereas 1 point for less than 25 cc. We also assigned 1 point for the presence of diffuse SAH whereas 0 point for the absence of it. Then, 1 point was assigned for midline shifting of greater than 5 mm whereas 0 point for less than 5 mm. RESULTS: According to the grading system, the numbers of patients from grade 1 to 4 were 4, 6, 8 and 9 respectively and 5, 7, 8, 4 and 3 patients belonged to Glasgow Outcome Scale (GOS) 5 to 1 respectively. It was found that the patients with higher GOS had lower ICH grade which were confirmed to be statistically significant (p<0.01). Preoperative Hunt and Hess grade and absence of midline shifting were the factors to predict favorable outcome. CONCLUSION: The ICH grading system composed of above three variables was helpful in predicting the patient's outcome more accurately.

Optimization of MR Parameters of 3D TOF-MRA for Various Intracranial Stents at 3.0T MRI / 신경중재치료의학

PURPOSE: The in-stent signal reduction of the stented artery caused by susceptibility artifact or radiofrequency shielding artifact limited the use of time-of-flight MR angiography (TOF-MRA) as a follow-up tool after intracranial stenting. We showed the degree of an artifact according to different stent types, and optimized MR parameters for TOF-MRA in patients with intracranial stent on 3.0 T MRI. MATERIALS AND METHODS: Four stents (Neuroform, Wingspan, Solitaire, and Enterprise) were placed in a vascular flow phantom and imaged by changing flip angle (FA; 20degrees,30degrees,40degrees,50degrees and 60degrees) and bandwidth (BW; 31, 42 and 62.5 KHz) using TOF-MRA. Source data of each image set with different FA and BW were reconstructed with the maximal intensity projection (MIP) technique, and MIP images were used to evaluate the in-stent signal reduction of each stent according to the change of MR parameters. The in-stent signal reduction was assessed by calculating the relative in-stent signal (RIS) inside the stent as compared with background and signal intensity of the tube outside the stent. The optimal FA and BW of each stent were determined by comparing the RIS in each stent by one-sample t test. Finally, one neuroradiologist chose one image set with the best image quality. RESULTS: The mean RIS for Neuroform, Wingspan, Solitaire and Enterprise stent was 66.3 +/- 6.0, 44.2 +/- 5.8, 22.8 +/- 3.3 and 8.2 +/- 2.9, respectively. The significantly high RIS of each stent was obtained with FA/BW value of 20degrees/31 KHz (Neuroform), 20degrees/31 KHz and 30degrees/42 KHz (Wingspan), 40degrees/42 KHz and 50degrees/31 KHz (Solitaire) and 40degrees/31 KHz and 50degrees/31 KHz (Enterprise). Among these MIP images with significantly high RIS, images with FA/BW value of 20degrees/31 KHz (Neuroform and Wingspan) and 50degrees/31 KHz (Solitaire and Enterprise) had the best image quality. CONCLUSION: The degree of artifact was variable according to the design of each intracranial stent. The luminal visualization of closed-cell design stents such as Solitaire and Enterprise can be improved by higher FA. Thus, MR parameter should be adjusted according to the type of intracranial stents.

Time-Resolved 3D Contrast-Enhanced MRA on 3.0T: a Non-Invasive Follow-Up Technique after Stent-Assisted Coil Embolization of the Intracranial Aneurysm

OBJECTIVE: To evaluate the usefulness of time-resolved contrast enhanced magnetic resonance angiography (4D MRA) after stent-assisted coil embolization by comparing it with time of flight (TOF)-MRA. MATERIALS AND METHODS: TOF-MRA and 4D MRA were obtained by 3T MRI in 26 patients treated with stent-assisted coil embolization (Enterprise:Neuroform = 7:19). The qualities of the MRA were rated on a graded scale of 0 to 4. We classified completeness of endovascular treatment into three categories. The degree of quality of visualization of the stented artery was compared between TOF and 4D MRA by the Wilcoxon signed rank test. We used the Mann-Whitney U test for comparing the quality of the visualization of the stented artery according to the stent type in each MRA method. RESULTS: The quality in terms of the visualization of the stented arteries in 4D MRA was significantly superior to that in 3D TOF-MRA, regardless of type of the stent (p < 0.001). The quality of the arteries which were stented with Neuroform was superior to that of the arteries stented with Enterprise in 3D TOF (p < 0.001) and 4D MRA (p = 0.008), respectively. CONCLUSION: 4D MRA provides a higher quality view of the stented parent arteries when compared with TOF.

Serial Expression of Hypoxia Inducible Factor-1alpha and Neuronal Apoptosis in Hippocampus of Rats with Chronic Ischemic Brain

OBJECTIVE: The purpose of this study is to investigate serial changes of hypoxia-inducible factor 1alpha (HIF-1alpha), as a key regulator of hypoxic ischemia, and apoptosis of hippocampus induced by bilateral carotid arteries occlusion (BCAO) in rats. METHODS: Adult male Wistar rats were subjected to the permanent BCAO. The time points studied were 1, 2, 4, 8, and 12 weeks after occlusions, with n=6 animals subjected to BCAO, and n=2 to sham operation at each time point, and brains were fixed by intracardiac perfusion fixation with 4% neutral-buffered praraformaldehyde for brain section preparation. Immunohistochemistry (IHC), western blot and terminal uridine deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay were performed to evaluate HIF-1alpha expression and apoptosis. RESULTS: In IHC and western blot, HIF-1alpha levels were found to reach the peak at the 2nd week in the hippocampus, while apoptotic neurons, in TUNEL assay, were maximal at the 4th week in the hippocampus, especially in the cornu ammonis 1 (CA1) region. HIF-1alpha levels and apoptosis were found to fluctuate during the time course. CONCLUSION: This study showed that BCAO induces acute ischemic responses for about 4 weeks then chronic ischemia in the hippocampus. These in vivo data are the first to show the temporal sequence of apoptosis and HIF-1alpha expression.

Akinetic Mutism following Spontaneous Subarachnoid Hemorrhage: A Case Report / 대한뇌혈관외과학회지

Akinetic mutism (AM) is a rare complication of spontaneous subarachnoid hemorrhage (SAH). It is characterized by mutism and general hypokinesis in a patient superficially fully awake in that the eyes remain open and follow objects. Most common cause of AM in patients with SAH is secondary infarction in the distal anterior cerebral artery (DACA) territory. Sometimes post-SAH hydrocephalus has also been implicated in a delayed form of AM because of disruption of dopaminergic pathway. We report a case of 64-year-old woman who presented with sudden bursting headache without neurologic deficit. She was referred from the other hospital with a diagnosis of spontaneous SAH on head computed tomography (CT) which showed high density on sylvian, interhemispheric fissures and basal cistern. We performed computed tomographic cerebral angiography (CTA) and trans-femoral catheter cerebral angiography (TFCA), that revealed no definitive intracranial aneurysm, arterial dissection, or other vascular abnormality of the SAH. During admission period, she developed mutism and motor weakness of all limbs without spontaneous movement. We performed brain magnetic resonance (MR) image and RI cisternography. Also we prescribed levodopa. On the 33th hospital day, she had neurological recovery with drowsy mentality and grade 4 weakness of all limbs, but she was observed to suddenly develop general weakness and became cardiac arrest on the 55th hospital day. Efforts to resuscitate her failed, no more treatment could not be applied. In our case, we couldn't find infarction in the DACA terriority, midbrain or cerebellum except communicating hydrocephalus. This case may alert neurosurgeon to recognize the possibility of such rare complication after spontaneous SAH.

Angiographic Follow-up Result of Cerebral Aneurysms Treated with Coils Covered with Polyglycolic-Polylactic Acid Copolymer

OBJECTIVE: We evaluate the effect of the copolymer-coated coils on immediate occlusion of the aneurysm, preventing rupture, and decreasing compaction or re-growth. METHODS: Thirty-five aneurysms treated between September 2003 and December 2004 using Matrix detachable coil were reviewed. Study population consisted of 12 men and 23 women ranging in age from 34 to 75 years(mean, 55.1 years). Twentytwo aneurysms were ruptured and 23 aneurysms were located in the anterior circulation. Follow-up angiography was obtained in 16 patients after 6 months from the procedure. RESULTS: Initial complete occlusion was achieved in 17 aneurysms(48.6%), and the others remained as a residual neck in 8 aneurysms(22.8%) and residual sac in 10 aneurysms(28.6%). Among these incompletely occluded aneurysms, 7 aneurysms were performed follow-up angiography. And 6 of them converted into complete occlusion. In the other hands, among 17 aneurysms achieved complete occlusion initially, 9 aneurysms were performed follow-up angiography. Recurrence due to coil compaction occurred in one aneurysm and the others maintained complete occlusion. There was one mortality case due to thromboembolic complication. CONCLUSION: In spite of difficulty in achieving complete occlusion with Matrix coil system, there is no rupture or re-rupture during follow-up period. Follow-up angiography shows many conversions of residual sac into complete occlusion. Embolization using Matrix coil system is safe and effective, but the effects of PGLA copolymer need further investigation.

Endoscopic Release of Carpal Tunnel Syndrome; Temporal Correlation between Symptomatic and Electrophysiological Improvements in Postoperative Carpal Tunnel Syndrome

OBJECTIVE: We evaluate temporal correlations between postoperative symptomatic and electrophysiological improvements, and assessed the recovery time required for patients with carpal tunnel syndrome(CTS) before returning to routine activities. METHODS: 30 CTS patients were treated via the endoscopic monoportal approach, from March 2001 to September 2003. We assessed the symptoms (hyperesthesia in the finger tips, or abnormal sensations and painful numbness or night pain) and electrophysiological changes in the preoperative state, 1 month and 6 months after surgery. We marked the times at which patients became able to return to activities of daily living and work, after undergoing endoscopic carpal tunnel release. RESULTS: At the end of the follow-up period, high levels of achievement and good outcomes were observed, with respect to both the symptoms and electrophysiological studies. We discovered significant differences between the preoperative and postoperative periods, especially in terms of motor nerve onset latency from 4.50+/-1.43 to 3.97+/-0.69 and sensory nerve conduction velocity, the wrist-to-finger from 19.81+/-10.03 to 28.18+/-11.01 and wrist-to-palm from 23.34+/-13.40 to 31.79+/-13.38(p<0.05 for each comparison). The average time interval required before return to activities of daily living was 26.4 days, and time interval required before return to work was 48.08 days. CONCLUSION: Electrophysiological improvements are largely consistent with symptomatic relief, but there is some disparity between electrophysiological and symptomatic improvement.

GDC Embolization of Basilar Bifurcation Aneuryms; Consideration of Posterior Cerebral Artery Occlusion

OBJECTIVE: To access the risk factors of posterior cerebral artery(PCA) occlusion during endovascular treat-ment of basilar bifurcation aneurysm and importance of collateral circulation through posterior communicating artery(PCoA) after PCA occlusion, the authors review the results of 25 patients with basilar bifurcation aneurysms treated with Guglielmi detachable coils(GDCs). METHODS: Male to female ratio was 1: 3.2(6: 19) and the mean age of this group was 54. Nineteen patients were presented with subarachnoid hemorrhage, 1 patient had neurologic deficits of hemiplegia and dysarthria, and 5 patients had incidental aneurysms with headache and dizziness. All patients underwent GDC embolization and their clinical results were analyzed. RESULTS: Seven of nine patients who resulted in PCA occlusion had a collateral flow from the anterior circulation through PCoA. Six patients had a PCoA larger than 1mm and they had no symptoms of ischemia after PCA occlusion. One patient who had a PCoA with 0.53mm in diameter had transient ischemic symptoms. The PCA arouse from the aneurysm neck in seven patients, and six of them resulted in PCA occlusion. Four of five patients who had aneurysms with broad neck(<4mm) resulted in PCA occlusion. CONCLUSION: The aneurysm with either broad neck or PCA arising from the aneurysm neck have a high risk of PCA occlusion. After PCA occlusion, significant blood flow from anterior circulation through the PCoA larger than 1mm in diameter can minimize the ischemic result in PCA territories.