The Correlations between the Intensity of Histopathological Ubiquitin-Specific Protease 11 Staining and Progression of Prostate Cancer.

BACKGROUND: Ubiquitin-specific protease 11 (USP11), one of the principal phosphatase and tensin homolog (PTEN) deubiquitinases, can reserve PTEN polyubiquitination to maintain PTEN protein integrity and inhibit PI3K/AKT pathway activation. The aim of the current study was to investigate the associations between immunohistochemical USP11 staining intensities and prognostic indicators in individuals with prostate cancer. METHODS: Tissue microarrays (TMAs) were performed for human prostate cancer and normal tissue (control) samples. Data on patient's age, Gleason score, plasma prostate-specific antigen (PSA) titer, disease stage, and presence of seminal vesicles, lymph nodes, and surgical margin involvement were collected. A pathologist who was blinded to the clinical outcome data scored the TMA for USP11 staining intensity as either positive or negative. RESULTS: Cancerous tissues exhibited lower USP11 staining intensity, whereas the neighboring benign peri-tumoral tissues showed higher USP11 staining intensity. The degree of USP11 staining intensity was lower in patients with a higher PSA titer, higher Gleason score, or more advanced disease stage. Patients who showed positive USP11 staining were more likely to have more optimal clinical and biochemical recurrence-free survival statistics. CONCLUSIONS: USP11 staining intensity in patients with prostate cancer is negatively associated with several prognostic factors such as an elevated PSA titer and a high Gleason score. It also reflects both biochemical and clinical recurrence-free survival in such patients. Thus, USP11 staining is a valuable prognostic factor in patients with prostate cancer.

The correlation between the expression of ubiquitin-conjugating enzyme 2C and prostate cancer prognosis.

PURPOSE: Ubiquitin-conjugating enzyme E2 C (UBE2C) is known to show a causal relationship with cancer development and advancement. The role of UBE2C is to control the mitotic spindle checkpoint. Excess UBE2C has been identified in patients with advanced prostate cancer. The objective of the present study was to examine positive connections between the expression of UBE2C and prognostic factors for prostate cancer. METHODS: Prostate cancer patients' clinical data were analysed. Tissue microarrays (TMAs) were also performed for human prostate cancer tissues (n = 335) and adjacent non-neoplastic tissues (n = 22). TMA slides were incubated with antibodies against UBE2C. Cores were scored by a pathologist who was blind to cancer results. RESULTS: Of 335 prostate cancer patients, 200 could be assessed for biochemical recurrence, clinical recurrence, and overall survival. Human prostate cancer tissues showed higher expression of UBE2C than adjacent non-neoplastic tissues. High expression level of UBE2C showed a strong positive relationship with a high prostate-specific antigen (PSA), Gleason's score, and pathological stage of prostate cancer. Patients with a higher UBE2C grade demonstrated greater lymphatic engagement of prostate cancer than those with a lower UBE2C grade. CONCLUSION: The expression of UBE2C has positive correlations with several prognostic factors for prostate cancer. Thus, investigating the expression level of UBE2C staining is a promising tool for predicting prostate cancer prognosis.

Robot-Assisted Laparoscopic Paravaginal Repair and Sacrocolpopexy in Patients With Pelvic Organ Prolapse.

OBJECTIVE: To evaluate the surgical effects of robotic paravaginal repair and sacrocolpopexy in patients diagnosed with lateral cystocele due to paravaginal defect. PATIENTS AND METHODS: Robotic paravaginal repair and sacrocolpopexy were performed contemporaneously in 43 patients with high-grade pelvic organ prolapse combined with a lateral or mixed cystocele. To objectively evaluate prolapse correction, the Pelvic Organ Prolapse Quantification (POP-Q) test was performed at the 12-month visit and the results compared to those of the preoperative period. Subjective satisfaction was scored using the Patient Global Impression of Improvement (PGI-I) questionnaire. RESULTS: POP-Q measurement results before and after surgery, an objective indicator of surgery, the Ba and C scores improved significantly from 2.1 ± 1.2 preoperatively to -2.0 ± 1.1 postoperatively (P <.01), and from 0.3 ± 1.3 preoperatively to -4.3 ± 1.1 postoperatively (P <.01), respectively. In PGI-I questionnaire, the numbers of patients who awarded scores of 1 and 2 (evidencing high-level symptom improvement) were 33 at 1 month (76.7%), 30 at 3 months (69.8%), and 28 (65.1%) at 12 months. When respondents awarding 3 points (a little improvement) were included, the numbers rose to 38 (88.4%) at 1 and 3 months and 35 (81.4%) at 12 months, indicating satisfaction with symptom improvement. There were no critical complications during and after surgery, but complications such as de novo stress urinary incontinence that lower patient satisfaction occurred in some cases. CONCLUSION: Robot-assisted paravaginal repair and sacrocolpopexy can be safely performed in patients with cystocele-predominant pelvic organ prolapse and good surgical results can be expected with excellent effects.

ß-Defensin 2, an Antimicrobial Peptide, as a Novel Biomarker for Ulcerative Interstitial Cystitis; Can ß-Defensin 2 Suspect the Dysbiosis of Urine Microbiota?

As urine is not sterile, inflammatory reactions caused by dysbiosis of the urinary microbiota may induce interstitial cystitis. A study was conducted to determine whether ß-defensin 2 (BD-2), a specific antimicrobial peptide in the bladder, could be used as a novel diagnostic marker for ulcerative interstitial cystitis (IC). Urine samples from three female groups were examined: healthy controls (n = 34, Control group), non-Hunner type IC (n = 40, NHIC group), and Hunner type IC (n = 68, HIC group). Urine samples were collected via a transurethral catheter and assayed for BD-2 levels using enzyme linked immunosorbent assay. Under general or regional anesthesia, cystoscopy with diagnostic and therapeutic hydrodistension was performed in NHIC and HIC groups patients. These patients underwent a biopsy of the bladders. Based on the urinary specimens from 142 patients, BD-2 expression was found to be 18-fold higher in patients with Hunner type IC than in patients with non-Hunner type IC. The enhanced secretion of BD-2 exhibited a strong correlation with increased mast cell counts associated with bladder IC pathology. Enhanced urinary secretion of the antimicrobial peptide BD-2 from Hunner type IC patients associated with clinical phenotypes and demonstrated relatively robust levels to be used as a potential biomarker. Moreover, the increased urinary level of BD-2 may suggest a new possibility of biomarkers caused by dysbiosis of the urinary microbiota in ulcerative IC.

The Positive Correlations between the Expression of Histopathological Ubiquitin-Conjugating Enzyme 2O Staining and Prostate Cancer Advancement.

BACKGROUND: The mTOR signaling pathway is inactivated by AMPK's tumor-suppressing function. It is recognized that ubiquitin conjugating enzyme 2O (UBE2O), which directly targets AMPK for ubiquitination and degradation, is intensified in human cancers. METHODS: This study investigated the clinical data about prostate cancer. Examination was also carried out into tissue microarrays (TMA) of human prostate cancer (n = 382) and adjacent non-neoplastic tissues around prostate cancer (n = 61). The TMA slides were incubated with antibodies against UBE2O, and the cores were scored by the pathologist blind to cancer results. RESULTS: Very strong positive correlations were identified between the expression of UBE2O staining and high PSA and pathological stage of prostate cancer. Cox's proportional hazard analysis established correlations between the following: (1) positive surgical margin and biochemical recurrence free survival, (2) PSA grade and clinical recurrence free survival, (3) regional lymph node positive and clinical recurrence free survival, (4) adjuvant treatment and overall survival, and (5) pathological T stage and overall survival. CONCLUSION: There is a positive correlation between the expression of UBE2O staining and prognosis for prostate cancer. Thus, a prostate cancer prognosis can be assessed with the expression of UBE2O staining.

Urinary Microbiome Characteristics in Female Patients with Acute Uncomplicated Cystitis and Recurrent Cystitis.

Traditionally, the diagnostic mainstay of recurrent urinary tract infection has been urinary culture. However, the causative uropathogen of recurrent cystitis has not been well established. Urine DNA next-generation sequencing (NGS) can provide additional information on these infections. Herein, we compared urine NGS results and urine cultures in patients with acute uncomplicated cystitis (AUC) and recurrent cystitis (RC), and evaluated the difference in microbiome patterns in the NGS results. Patients who underwent urine culture and NGS due to AUC or RC were retrospectively reviewed. All urine samples were collected via a transurethral catheter and studied utilizing a type of NGS called 16S ribosomal RNA gene amplification and sequencing. The sensitivity of urine NGS was significantly higher than that of conventional urine culture (69.0% vs. 16.7%, p < 0.05). The detection rate of urine NGS was slightly lower in the RC group than in the AUC group (67.7% vs. 72.7%). Microbiome diversity was significantly higher in the RC group compared to the AUC group (p = 0.007), and the microbiome composition was significantly different between the AUC and RC groups. In the urine NGS results, Pseudomonas, Acinetobacter, and Enterobacteriaceae were found in the AUC group, and Sphingomonas, Staphylococcus, Streptococcus, and Rothia spp. were detected in the RC group. Urine NGS can significantly increase the diagnostic sensitivity compared to traditional urine culture methods, especially in RC patients. AUC and RC patients had significant differences in bacterial diversity and patterns. Therefore, recurrent cystitis might be approached from a different perspective.

Long-term outcomes of ulcerative interstitial cystitis after complete transurethral resection with therapeutic hydrodistention.

PURPOSE: We analyzed the long-term efficacy of simultaneous transurethral resection (TUR) and therapeutic hydrodistention in patients with ulcerative interstitial cystitis (IC) who did not experience recurrence on long-term follow-up. METHODS: We studied 132 female patients (mean age = 56.45 ± 11.56 years) who underwent TUR followed by hydrodistention to treat ulcerative IC between January 2010 and January 2017, and who were available for follow-up, for more than 36 months (mean = 52.3 ± 10.51 months). Of the 132 patients, those who did not suffer recurrence within 36 months after surgery were allocated to group I and those who had a recurrence within the same period were assigned to group II. Preoperative factors, including age, were compared between the groups. In group I, improvements in pain and voiding symptoms were recorded using a 10-point visual analog pain scale (VAS) and a 3-day micturition chart. A global response assessment (GRA) was used to evaluate patient satisfaction. RESULTS: In group II, the maximum functional bladder capacity (FBC) was smaller, and voiding frequency was higher, than in group I. Follow-up of patients in group I for more than 3 years showed that pain decreased after surgery. The 10-point VAS scores were 9.68 before surgery, and 1.54, 0.93, 0.55, and 0.46 at 1, 6, 12, and 36 months after surgery (p < 0.001), respectively. Maximum FBCs were 174.82 mL before surgery and 237.14, 250.71, and 254.46 mL at 1, 12, and 36 months after surgery (p < 0.001), respectively; thus, FBC increased after surgery. Urination frequency decreased significantly after surgery; the number of daily urinations was 12.77 before surgery, and 9.88, 9.21, and 9.25 at 1, 12, and 36 months after surgery (p < 0.001), respectively. Overall patient satisfaction improved after surgery; the GRA scores were 2.39, 2.71, and 2.8 points at 1, 12, and 36 months after surgery (p < 0.001), respectively. CONCLUSION: Upon simultaneous performance of TUR and therapeutic hydrodistention in patients with ulcerative IC, 49.2% showed favorable outcomes for 3 years.

The microbiome in urological diseases.

Due to the rapid development of next-generation sequencing, it has become possible to obtain information on the sequences of all genes in a specific microbiome. The detection of bacteria in patients with no urinary tract infections indicated that the dogma that "urine is sterile" was false, leading to active research regarding the roles of the urinary microbiome in the human urinary tract. Here, we present a review of the current literature regarding the role of the microbiome in urology.

Readjustable midurethral sling (REMEEX system) in obese women.

Purpose: To evaluate the success rate and patient satisfaction with the readjustable midurethral sling (REMEEX system) for the treatment of stress urinary incontinence (SUI) with intrinsic sphincter deficiency (ISD) or recurrent SUI in obese and non-obese women. Materials and Methods: Between August 2009 and August 2015, 70 patients who treated with the REMEEX system were stratified into normal, overweight and obesity groups according to body mass index. Objective surgical outcomes were evaluated using a 1-hour pad test that was performed 3 months after surgery. The subjective outcomes and degree of patient satisfaction were evaluated 3 months and 1 year after surgery. Results: Twenty-six normal weight, 31 overweight, and 13 obese women were included in the study. The objective cure rate determined using the 1-hour pad test revealed that 11 women (42.3%) were cured and 15 (57.7%) had improved in the normal weight group, respectively, compared with 16 (51.6%) and 15 (48.4%) in the overweight group and 6 (46.2%) and 7 (53.8%) in the obese group, respectively (p=0.78). One year after surgery, the subjective success rate was 91.5% in the normal weight group, 93.5% in the overweight group and 92.3% in the obese group. A total of 84.7%, 77.4%, and 77.0% of normal weight, overweight and obese women were very satisfied or satisfied 1 year after surgery, respectively. All groups showed similar success rates and satisfaction. Conclusions: The REMEEX procedure is equally effective in obese and normal weight women with ISD-type SUI or recurrent SUI.

Landscape of Actionable Genetic Alterations Profiled from 1,071 Tumor Samples in Korean Cancer Patients.

PURPOSE: With the emergence of next-generation sequencing (NGS) technology, profiling a wide range of genomic alterations has become a possibility resulting in improved implementation of targeted cancer therapy. In Asian populations, the prevalence and spectrum of clinically actionable genetic alterations has not yet been determined because of a lack of studies examining high-throughput cancer genomic data. MATERIALS AND METHODS: To address this issue, 1,071 tumor samples were collected from five major cancer institutes in Korea and analyzed using targeted NGS at a centralized laboratory. Samples were either fresh frozen or formalin-fixed, paraffin embedded (FFPE) and the quality and yield of extracted genomic DNA was assessed. In order to estimate the effect of sample condition on the quality of sequencing results, tissue preparation method, specimen type (resected or biopsied) and tissue storage time were compared. RESULTS: We detected 7,360 non-synonymous point mutations, 1,164 small insertions and deletions, 3,173 copy number alterations, and 462 structural variants. Fifty-four percent of tumors had one or more clinically relevant genetic mutation. The distribution of actionable variants was variable among different genes. Fresh frozen tissues, surgically resected specimens, and recently obtained specimens generated superior sequencing results over FFPE tissues, biopsied specimens, and tissues with long storage duration. CONCLUSION: In order to overcome, challenges involved in bringing NGS testing into routine clinical use, a centralized laboratory model was designed that could improve the NGS workflows, provide appropriate turnaround times and control costs with goal of enabling precision medicine.

Extrinsic Apoptosis Pathway Altered by Glycogen Synthase Kinase-3ß Inhibitor Influences the Net Drug Effect on NSC-34 Motor Neuron-Like Cell Survival.

Glycogen synthase kinase-3ß (GSK-3ß) inhibitors have been suggested as a core regulator of apoptosis and have been investigated as therapeutic agents for neurodegenerative diseases, including amyotrophic lateral sclerosis. However, GSK-3ß has an interesting paradoxical effect of being proapoptotic during mitochondrial-mediated intrinsic apoptosis but antiapoptotic during death receptor-mediated extrinsic apoptosis. We assessed the effect of low to high doses of a GSK-3ß inhibitor on survival and apoptosis of the NSC-34 motor neuron-like cell line after serum withdrawal. Then, we identified changes in extrinsic apoptosis markers, including Fas, Fas ligand, cleaved caspase-8, p38α, and the Fas-Daxx interaction. The GSK-3ß inhibitor had an antiapoptotic effect at the low dose but was proapoptotic at the high dose. Proapoptotic effect at the high dose can be explained by increased signals in cleaved caspase-8 and the motor neuron-specific p38α and Fas-Daxx interaction. Our results suggest that GSK-3ß inhibitor dose may determine the summation effect of the intrinsic and extrinsic apoptosis pathways. The extrinsic apoptosis pathway might be another therapeutic target for developing a potential GSK-3ß inhibitor.

A multicenter real-life study of the efficacy of an alpha-blocker with or without anticholinergic agent (imidafenacin) treatment in patients with lower urinary tract symptoms/benign prostatic hyperplasia and storage symptoms.

AIMS: To evaluate the efficacy and safety of combination therapy comprising a short-acting anticholinergic, imidafenacin and an alpha-blocker compared with monotherapy with an alpha-blocker only in men with lower urinary tract symptoms (LUTS) and storage symptoms. METHODS: The 12-week, prospective, double-blind, randomised trial enrolled men with LUTS and storage symptom. The inclusion criteria were a total International Prostate Symptom Score (IPSS) ≥12, an IPSS question 4 score ≥2, ≥8 micturitions in 24 hours, and a prostate volume >20 mL. The primary outcome was a change in the micturition number from baseline. Bladder diary variables, Patient Perception of Intensity of Urgency Scale (PPIUS) scores, IPSS and safety were assessed. RESULTS: Of 260 patients screened, 221 completed the study. Patients were randomly assigned to receive an alpha-blocker only (n=111, group 1) or combination therapy comprising an alpha-blocker and an anticholinergic (n=110, group 2) for 12 weeks. Group 1 and 2 showed significant improvement in their 24-hour micturition numbers (-1.87 and -2.08, respectively), nocturia episodes (-0.48 and -0.53, respectively), total IPSS (-9.9 and -8.8, respectively), and PPIUS scores (-0.19 and -0.24, respectively). Micturition number per 24 hours, daytime frequency, urgency, the PPIUS score, the IPSS question 4 score and IPSS QoL score improved significantly in the combination therapy group, but changes in total IPSS, nocturia episodes, and safety outcomes did not differ significantly between the groups. CONCLUSIONS AND CLINICAL IMPLICATIONS: Compared with treatment with an alpha-blocker alone, combination therapy comprising an anticholinergic and an alpha-blocker showed superior efficacy and its safety was similar in patients with LUTS and storage symptoms.

Altered nucleocytoplasmic proteome and transcriptome distributions in an in vitro model of amyotrophic lateral sclerosis.

Aberrant nucleocytoplasmic localization of proteins has been implicated in many neurodegenerative diseases. Evidence suggests that cytoplasmic mislocalization of nuclear proteins such as transactive response DNA-binding protein 43 (TDP-43) and fused in sarcoma (FUS) may be associated with neurotoxicity in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration. This study investigated the changes in nucleocytoplasmic distributions of the proteome and transcriptome in an in vitro model of ALS. After subcellular fractionation of motor neuron-like cell lines expressing wild-type or G93A mutant hSOD1, quantitative mass spectrometry and next-generation RNA sequencing (RNA-seq) were performed for the nuclear and cytoplasmic compartments. A subset of the results was validated via immunoblotting. A total of 1,925 proteins were identified in either the nuclear or cytoplasmic fractions, and 32% of these proteins were quantified in both fractions. The nucleocytoplasmic distribution of 37 proteins was significantly changed in mutant cells with nuclear and cytoplasmic shifts in 13 and 24 proteins, respectively (p<0.05). The proteins shifted towards the nucleus were enriched regarding pathways of RNA transport and processing (Dhx9, Fmr1, Srsf3, Srsf6, Tra2b), whereas protein folding (Cct5, Cct7, Cct8), aminoacyl-tRNA biosynthesis (Farsb, Nars, Txnrd1), synaptic vesicle cycle (Cltc, Nsf), Wnt signalling (Cltc, Plcb3, Plec, Psmd3, Ruvbl1) and Hippo signalling (Camk2d, Plcb3, Ruvbl1) pathways were over-represented in the proteins shifted to the cytoplasm. A weak correlation between the changes in protein and mRNA levels was found only in the nucleus, where mRNA was relatively abundant in mutant cells. This study provides a comprehensive dataset of the nucleocytoplasmic distribution of the proteome and transcriptome in an in vitro model of ALS. An integrated analysis of the nucleocytoplasmic distribution of the proteome and transcriptome demonstrated multiple candidate pathways including RNA processing/transport and protein synthesis and folding that may be relevant to the pathomechanism of ALS.

Alterations of Macrophage Migration Inhibitory Factor Expression in the Nervous System of the Rat Cystitis Model.

OBJECTIVE: We evaluated the changes in the migration inhibitory factor (MIF) expression with time in the bladder and spinal cord of a Sprague-Dawley rat cystitis model. METHODS: The bladder created by injecting lipopolysaccharide (LPS) and the lumbosacral spinal cord were removed at 4, 24, and 48 h, and 7 days after the induction of chronic cystitis, and 24 h after the induction of acute cystitis. The MIF expression was estimated using immunohistochemical staining, and the MIF mRNA was quantitatively analyzed using real-time polymerase chain reaction. RESULTS: The MIF expression in the urothelial cell was lowest at 24 h after LPS injection. As the degree of inflammation decreased, the MIF expression in the urothelial cell gradually increased 48 h and 7 days. The quantitative analysis of the MIF mRNA showed that the MIF expression was highest in both the bladder and the lumbosacral spinal cord 24 h after the cystitis became most severe. In chronic cystitis, the MIF mRNA expressions in the bladder and the lumbosacral spinal cord were 2.8 and 2.1 times significantly higher than in the normal control. CONCLUSION: MIF is involved in urinary symptoms and pain in cystitis, and in the mechanism that prolongs the symptoms of chronic cystitis by involving bladder tissue, and the nervous system.

Transurethral Resection Alone Vs Resection Combined With Therapeutic Hydrodistention as Treatment for Ulcerative Interstitial Cystitis: Initial Experience With Propensity Score Matching Studies.

OBJECTIVE: To compare the therapeutic efficacy of transurethral resection (TUR) alone with that of TUR combined with therapeutic hydrodistention in patients with ulcerative interstitial cystitis (IC). METHODS: The study subjects were 44 female patients newly diagnosed with IC who underwent TUR to treat ulcerative IC and who were available for follow-up, without recurrence of disease for 12 months. We retrospectively studied both patients who underwent TUR alone (group I) and those who underwent TUR combined with therapeutic hydrodistention (group II). Improvements in pain and voiding symptoms were retrospectively evaluated using a 10-point visual analog scale for pain and a 3-day micturition chart. RESULTS: Group I included 22 patients and group II included 22 patients of mean ages 58.45 ± 11.01 and 56.27 ± 11.86 years, respectively. Use of a 10-point visual analog scale showed that pain decreased after the procedures in both groups, but the improvement did not differ between groups. The maximum functional bladder capacities of patients in group I were 161.36, 192.47, and 204.12 mL, respectively, before, at 6 months, and at 12 months after the operation; the maximum functional bladder capacities of patients in group II were 175.45, 263.14, and 291.17 mL, respectively. The voiding frequencies of group I were 12.59, 10.67, and 9.89 times daily, respectively, before, at 6 months, and at 12 months after the operation; the voiding frequencies of group II were 12.95, 9.5, and 8.29 times daily, respectively. CONCLUSION: TUR combined with therapeutic hydrodistention increased bladder capacity and improved voiding symptoms more so than did TUR alone for ulcerative IC.

Intraoperative Motor-Evoked Potential Disappearance versus Amplitude-Decrement Alarm Criteria During Cervical Spinal Surgery: A Long-Term Prognosis.

BACKGROUND AND PURPOSE: We studied the clinical significance of amplitude-reduction and disappearance alarm criteria for transcranial electric muscle motor-evoked potentials (MEPs) during cervical spinal surgery according to different lesion locations [intramedullary (IM) vs. nonintramedullary (NIM)] by evaluating the long-term postoperative motor status. METHODS: In total, 723 patients were retrospectively dichotomized into the IM and NIM groups. Each limb was analyzed respectively. One hundred and sixteen limbs from 30 patients with IM tumors and 2,761 limbs from 693 patients without IM tumors were enrolled. Postoperative motor deficits were assessed up to 6 months after surgery. RESULTS: At the end of surgery, 61 limbs (2.2%) in the NIM group and 14 limbs (12.1%) in the IM group showed MEP amplitudes that had decreased to below 50% of baseline, with 13 of the NIM limbs (21.3%) and 2 of the IM limbs (14.3%) showing MEP disappearance. Thirteen NIM limbs (0.5%) and 5 IM limbs (4.3%) showed postoperative motor deficits. The criterion for disappearance showed a lower sensitivity for the immediate motor deficit than did the criterion for amplitude decrement in both the IM and NIM groups. However, the disappearance criterion showed the same sensitivity as the 70%-decrement criterion in IM (100%) and NIM (83%) surgeries for the motor deficit at 6 months after surgery. Moreover, it has the highest specificity for the motor deficits among diverse alarm criteria, from 24 hours to 6 months after surgery, in both the IM and NIM groups. CONCLUSIONS: The MEP disappearance alarm criterion had a high specificity in predicting the long-term prognosis after cervical spinal surgery. However, because it can have a low sensitivity in predicting an immediate postoperative deficit, combining different MEP alarm criteria according to the aim of specific instances of cervical spinal surgery is likely to be useful in practical intraoperative monitoring.

Effect of peripheral nerve tetanic stimulation on the inter-trial variability and accuracy of transcranial motor-evoked potential in brain surgery.

OBJECTIVES: The aim of this study was to evaluate and compare the advantages of post-tetanic motor-evoked potential (p-MEP) and conventional motor-evoked potential (c-MEP) in terms of MEP inter-trial variability and accuracy. METHODS: c-MEP and p-MEP were quantified in subjects who underwent brain surgery. c-MEP was generated by transcranial electrical stimulation (TES). p-MEP was generated using a preconditioning process involving tetanic stimulation at the left tibial nerve followed by TES. The presence of significant MEP deterioration was monitored during major surgical process. An additional 5-8 MEP obtained after major surgical process were used to analyze amplitude parameters such as mean, standard deviation, range, coefficient of variation (CV), and range to mean ratio. RESULTS: When only irreversible MEP deteriorations were considered as positive results, the false-positive rate was identical for p-MEP and c-MEP. When total MEP deteriorations were considered as positive results, the false-positive rate of p-MEP was lower and p-MEP had higher specificity than c-MEP. The mean amplitude of p-MEP was significantly higher than that of c-MEP. The CV and range to mean ratio of p-MEP were less than those of c-MEP. CONCLUSION: The p-MEP technique is useful for augmenting MEP amplitude and reducing inter-trial variability. SIGNIFICANCE: p-MEP has clinical significance as a useful technique for intraoperative monitoring.