Chang Kyu Park

Trigeminal neuralgia caused by persistent primitive trigeminal artery.

A 66-year-old man presented with typical trigeminal neuralgia (TN). Magnetic resonance angiography (MRA) revealed a primitive trigeminal artery (PTA) that came into contact with the trigeminal nerve. Based on MRA, we performed microvascular decompression (MVD). In the operational field, we confirmed the PTA location and performed MVD successfully. Postoperatively, the patients pain subsided without any complications.

Prognostic ability of intraoperative electromyographic monitoring during microvascular decompression for hemifacial spasm to predict lateral spread response outcome

OBJECTIVE Abnormal lateral spread response (LSR) is a typical finding in facial electromyography (EMG) in patients with hemifacial spasm (HFS). Although intraoperative monitoring of LSR has been widely used during microvascular decompression (MVD), the prognostic value of this monitoring is still debated. The purpose of this study was to determine whether such monitoring exhibits prognostic value for the alleviation of LSR after treatment of HFS. METHODS Between January 2009 and December 2013, a total of 582 patients underwent MVD for HFS with intraoperative EMG monitoring at Kyung Hee University Hospital. The patients were categorized into 1 of 2 groups according to the presence of LSR at the conclusion of surgery (Group A, LSR free; Group B, LSR persisting). Patients were assessed for the presence of HFS 1 day, 6 months, and 1 year after surgery. Various parameters, including age, sex, symptom duration, offending vertebral artery, and offending perforating artery, were evaluated for their influence on surgical and electrophysiological results. RESULTS Overall, HFS was alleviated in 455 (78.2%) patients 1 day after MVD, in 509 (87.5%) patients 6 months after MVD, and in 546 (93.8%) patients 1 year after MVD. Patients in Group B were significantly younger than those in Group A (p = 0.022). Patients with a symptom duration of less than 1 year were significantly more likely to be classified in Group A than were patients whose symptoms had persisted for longer than 10 years (p = 0.023); however, analysis of the entire range of symptom durations did not reveal a significant effect (p = 0.132). A comparison of Groups A and B according to follow-up period revealed that HFS recovery correlated with LSR alleviation over a shorter period, but the same was not true of longer periods; the proportions of spasm-free patients were 80.6% and 71.1% (p = 0.021), 89.4% and 81.9% (p = 0.022), and 93.5% and 94.6% (p = 0.699) 1 day, 6 months, and 1 year after surgery in Groups A and B, respectively. CONCLUSIONS Although intraoperative EMG monitoring during MVD was beneficial for identifying the offending vessel and suggesting the most appropriate surgical end point, loss of LSR did not always correlate with long-term HFS treatment outcome. Because the HFS cure rate improved over time, revision might be considered for persistent LSR when follow-up has been performed for more than 1 year and the spasm remains despite adequate decompression.

Do Trunk Muscles Affect the Lumbar Interbody Fusion Rate?: Correlation of Trunk Muscle Cross Sectional Area and Fusion Rates after Posterior Lumbar Interbody Fusion Using Stand-Alone Cage

Objective Although trunk muscles in the lumbar spine preserve spinal stability and motility, little is known about the relationship between trunk muscles and spinal fusion rate. The aim of the present study is to evaluate the correlation between trunk muscles cross sectional area (MCSA) and fusion rate after posterior lumbar interbody fusion (PLIF) using stand-alone cages. Methods A total of 89 adult patients with degenerative lumbar disease who were performed PLIF using stand-alone cages at L4–5 were included in this study. The cross-sectional area of the psoas major (PS), erector spinae (ES), and multifidus (MF) muscles were quantitatively evaluated by preoperative lumbar magnetic resonance imaging at the L3–4, L4–5, and L5–S1 segments, and bone union was evaluated by dynamic lumbar X-rays. Results Of the 89 patients, 68 had bone union and 21 did not. The MCSAs at all segments in both groups were significantly different (p<0.05) for the PS muscle, those at L3–4 and L4–5 segments between groups were significantly different (p=0.048, 0.021) for the ES and MF muscles. In the multivariate analysis, differences in the PS MCSA at the L4–5 and L5–S1 segments remained significant (p=0.048, 0.043 and odds ratio=1.098, 1.169). In comparison analysis between male and female patients, most MCSAs of male patients were larger than females. Fusion rates of male patients (80.7%) were higher than females (68.8%), too. Conclusion For PLIF surgery, PS muscle function appears to be an important factor for bone union and preventing back muscle injury is essential for better fusion rate.

A Clinical Analysis of Secondary Surgery in Trigeminal Neuralgia Patients Who Failed Prior Treatment

Objective Although many treatment modalities have been introduced for trigeminal neuralgia (TN), the long-term clinical results remain unsatisfactory. It has been particularly challenging to determine an appropriate treatment strategy for patients who have responded poorly to initial therapies. We analyzed the surgical outcomes in TN patients who failed prior treatments. Methods We performed a retrospective analysis of 37 patients with recurrent or persistent TN symptoms who underwent surgery at our hospital between January 2010 and December 2014. Patients with follow-up data of at least one year were included. The prior treatment modalities of the 37 patients included microvascular decompression (MVD), gamma knife radiosurgery (GKRS), and percutaneous procedures such as radiofrequency rhizotomy (RFR), balloon compression, and glycerol rhizotomy (GR). The mean follow-up period was 69.9 months (range : 16–173). The mean interval between the prior treatment and second surgery was 26 months (range : 7–123). We evaluated the surgical outcomes using the Barrow Neurological Institute (BNI) pain intensity scale. Results Among the 37 recurrent or persistent TN patients, 22 underwent MVD with partial sensory rhizotomy (PSR), 8 received MVD alone, and 7 had PSR alone. Monitoring of the surgical treatment outcomes via the BNI pain intensity scale revealed 8 (21.6%) patients with a score of I, 13 (35.1%) scoring II, 13 (35.1%) scoring III, and 3 (8.2%) scoring IV at the end of the follow-up period. Overall, 91.8% of patients had good surgical outcomes. With regard to postoperative complications, 1 patient had transient cerebrospinal fluid rhinorrhea (2.7%), another had a subdural hematoma (2.7%), and facial sensory changes were noted in 8 (21.1%) patients after surgery. Conclusion Surgical interventions, such as MVD and PSR, are safe and very effective treatment modalities in TN patients who failed initial or prior treatments. We presume that the combination of MVD with PSR enabled us to obtain good short- and long-term surgical outcomes. Therefore, aggressive surgical treatment should be considered in patients with recurrent TN despite failure of various treatment modalities.

Revascularization as Treatment of a Ruptured Fusiform Aneurysm at the Cortical Segment of the Superior Cerebellar Artery: A Case Report and Literature Review

&NA; A fusiform aneurysm of the superior cerebellar artery (SCA) is rare and mainly occurs at the proximal segment. A 71‐year‐old female patient was admitted to our institution with a subarachnoid hemorrhage. Angiography revealed dominance of both SCAs with aplasia of both the posterior inferior cerebellar artery and a fusiform aneurysm at the cortical segment of the left SCA involving the bifurcation site. Bypass connecting the left occipital artery to the inferior branch of the left SCA was performed, followed by trapping and clipping of the proximal and distal parts of the aneurysm, respectively. Blood flow was maintained in a retrograde manner from the inferior branch to the superior branch. She was discharged with no neurologic deficits and continues to be followed up by our department as an outpatient. This is the first report of a treatment method for a fusiform aneurysm located in the cortical segment of the SCA.

Estimating Accurate Target Coordinates with Magnetic Resonance Images by Using Multiple Phase-Encoding Directions during Acquisition

Background: Stereotactic procedures are image guided, often using magnetic resonance (MR) images limited by image distortion, which may influence targets for stereotactic procedures. Objectives: The aim of this work was to assess methods of identifying target coordinates for stereotactic procedures with MR in multiple phase-encoding directions. Methods: In 30 patients undergoing deep brain stimulation, we acquired 5 image sets: stereotactic brain computed tomography (CT), T2-weighted images (T2WI), and T1WI in both right-to-left (RL) and anterior-to-posterior (AP) phase-encoding directions. Using CT coordinates as a reference, we analyzed anterior commissure and posterior commissure coordinates to identify any distortion relating to phase-encoding direction. Results: Compared with CT coordinates, RL-directed images had more positive x-axis values (0.51 mm in T1WI, 0.58 mm in T2WI). AP-directed images had more negative y-axis values (0.44 mm in T1WI, 0.59 mm in T2WI). We adopted 2 methods to predict CT coordinates with MR image sets: parallel translation and selective choice of axes according to phase-encoding direction. Both were equally effective at predicting CT coordinates using only MR; however, the latter may be easier to use in clinical settings. Conclusion: Acquiring MR in multiple phase-encoding directions and selecting axes according to the phase-encoding direction allows identification of more accurate coordinates for stereotactic procedures.

Puncture of Cerebellar Horizontal Fissure for Retrosigmoid Approach: A Prospective and Quantitative Analysis

BACKGROUND Cerebrospinal fluid (CSF) drainage is important in retrosigmoid approached surgery; however, in some cases, it is not feasible due to cerebellar swelling. OBJECTIVE To introduce a method, puncture of the horizontal fissure of the cerebellum, which can reduce the cerebellum to easily obtain a good operative corridor and slowly drain CSF. METHODS Between January and December 2014, we estimated the precise location of the horizontal fissure in 56 patients who underwent surgery via a retrosigmoid approach. Then, we collected and analyzed CSF drained by puncturing the horizontal fissure. We investigated whether a good operative corridor was obtained with this method. RESULTS The location of the precise horizontal fissure was a mean of 3.97 mm caudal to transverse sinus and the mean amount of CSF drained in 56 patients was 50.4 mL. A good corridor was obtained in 46 (82.1%) of 56 patients without additional cistern puncture. CONCLUSION The puncture of the horizontal fissure can be useful in retrosigmoid approach surgery. Moreover, inexperienced surgeons can use this method to effectively avoid injury of the cerebellum.

Cross-Sectional Area of the Lumbar Spine Trunk Muscle and Posterior Lumbar Interbody Fusion Rate: A Retrospective Study.

Study Design: A retrospective study. Objective: To investigate the relationship between trunk muscle cross-sectional area (MCSA) and fusion rate after posterior lumbar interbody fusion using pedicle screw fixation (PLIF-PSF). Summary of Background Data: Although trunk muscles of the lumbar spine contribute to spinal stability and alignment, effect of trunk muscles on spinal fusion rate and time to fusion is unclear. Methods: A total of 192 adult patients with degenerative lumbar disease who underwent PLIF-PSF at L3–L4 or L4–L5 were included. The MCSA of the flexor (psoas major, PS), extensor (erector spinae, ES; multifidus, MF) were measured using preoperative lumbar magnetic resonance imaging at 3 segments. Bone union was evaluated using lumbar dynamic plain radiography. Patients were divided into 2 groups according to the presence of bone fusion. Results: Most PS MCSAs in the fusion group were significantly larger than in the nonfusion group, except for MCSA at the L2–L3 segment (all P<0.05). In cases of ES and MF MCSAs, 4 of 6 segments were significantly large. Multivariate analysis revealed that the PS MCSA at L4–L5 was an independent factor for decreased possibility of nonfusion status in both segments (OR=0.812, P=0.028). Pearson analysis demonstrated that the most trunk MCSAs were negatively correlated with time to fusion for both segments and PS MCSAs exhibited a significant correlation with time to fusion except for MCSA at the L2–L3 segment. Conclusions: Trunk MCSAs were significantly larger for a fusion group than a nonfusion group. As trunk MCSAs increased, fusion timing decreased.