A Bolus Dose of Ketamine Reduces the Amplitude of the Transcranial Electrical Motor-evoked Potential: A Randomized, Double-blinded, Placebo-controlled Study

BACKGROUND

A low-dose bolus or infusion of ketamine does not affect transcranial electrical motor-evoked potential (MEP) amplitude, but a dose ≥1 mg/kg may reduce MEP amplitude. We conducted a randomized, double-blinded, placebo-controlled study to evaluate the effect of ketamine (1 mg/kg) on transcranial electrical MEP.

METHODS

Twenty female patients (aged 12 to 18 y) with adolescent idiopathic scoliosis scheduled to undergo posterior spinal fusion were randomly allocated to receive ketamine or saline. General anesthesia was induced and maintained with continuous infusions of propofol and remifentanil. MEP was elicited by supramaximal transcranial electrical stimulation. MEP recordings were obtained at baseline and then at 2, 4, 6, 8, and 10 minutes after administration of ketamine (1 mg/kg) or saline (0.1 ml/kg). The primary endpoint was the minimum relative MEP amplitude (peak-to-peak amplitude, % of baseline value) recorded from the left tibialis anterior muscle. The baseline amplitude recorded before test drug administration was defined as 100%.

RESULTS

Medians (interquartile range) minimum MEP amplitudes in the left tibialis anterior muscle in the ketamine and saline groups were 26% (9% to 34%) and 87% (55% to 103%) of the baseline value, respectively (P<0.001). MEP amplitudes in other muscles were significantly reduced by ketamine. The suppressive effect of ketamine lasted for at least 10 minutes in each muscle.

CONCLUSION

A 1-mg/kg bolus dose of ketamine can reduce MEP amplitude. Anesthesiologists should consider the dosage and timing of intravenous ketamine administration during MEP monitoring.

Cortical Distribution of Fragile Periventricular Anastomotic Collateral Vessels in Moyamoya Disease: An Exploratory Cross-Sectional Study of Japanese Patients with Moyamoya Disease

BACKGROUND AND PURPOSE

Collateral vessels in Moyamoya disease represent potential sources of bleeding. To test whether these cortical distributions vary among subtypes, we investigated cortical terminations using both standardized MR imaging and MRA.

MATERIALS AND METHODS

Patients with Moyamoya disease who underwent MR imaging with MRA in our institution were enrolled in this study. MRA was spatially normalized to the Montreal Neurological Institute space; then, collateral vessels were measured on MRA and classified into 3 types of anastomosis according to the parent artery: lenticulostriate, thalamic, and choroidal. We also obtained the coordinates of collateral vessel outflow to the cortex. Differences in cortical terminations were compared among the 3 types of anastomosis.

RESULTS

We investigated 219 patients with Moyamoya disease, and a total of 190 collateral vessels (lenticulostriate anastomosis, n = 72; thalamic anastomosis, n = 21; choroidal anastomosis, n = 97) in 46 patients met the inclusion criteria. We classified the distribution patterns of collateral anastomosis as follows: lenticulostriate collaterals outflowing anteriorly (P < .001; 95% CI, 67.0-87.0) and medially (P < .001; 95% CI, 11.0-24.0) more frequently than choroidal collaterals; lenticulostriate collaterals outflowing anteriorly more frequently than thalamic collaterals (P < .001; 95% CI, 34.0-68.0); and choroidal collaterals outflowing posteriorly more frequently than thalamic collaterals (P < .001; 95% CI, 14.0-34.0). Lenticulostriate anastomoses outflowed to the superior or inferior frontal sulcus and interhemispheric fissure. Thalamic anastomoses outflowed to the insular cortex and cortex around the central sulcus. Choroidal anastomoses outflowed to the cortex posterior to the central sulcus and the insular cortex.

CONCLUSIONS

Cortical distribution patterns appear to differ markedly among the 3 types of collaterals.

SAT0010 ANTI-CD30 IMMUNOTHERAPY AMELIORATES BONE AND CARTILAGE DESTRUCTION IN EXPERIMENTAL MODEL OF RHEUMATOID ARTHRITIS IN MICE

Background:

CD30 is a member of the TNF-receptor family and commonly expressed on lymphocytes of Hodgkin lymphoma and anaplastic large cell lymphoma. It has been reported that levels of soluble CD30 in serum and joint fluid is significantly elevated in rheumatoid arthritis (RA). Although RA patients may develop lymphoproliferative disorders (LPD) as a result of immunosuppression by MTX or bDMARDs, safety medications after the regression of LPD for RA have not yet been established.

Objectives:

To explore the potential of CD30 targeting therapy for RA.

Methods:

(1) Immuno-histological staining of CD30 was performed for fresh synovial tissues of RA and osteoarthritis (OA). In addition, double immunofluorescence staining of CD30 with CD3, CD20, CD68, CD138 were performed on RA synovial tissue. (2) Brentuximab vedotin (BV) is an anti-CD30 antibody conjugated with monomethyl auristatin E, designed to induce apoptosis of CD30 expressing cells. A multiple myeloma cell line (RPMI8226) was used as a non-lymphoma cell line and plasma cell-like cell line. Immuno-cytological staining for CD30 was performed on RPMI8226. Cells were cultured and harvested on days 0, 1, and 3 to evaluate the effects of BV (50 μl / ml per well). Cytospin specimens were stained by May-Grunwald-Giemsa (MGG) staining for cell counting and by FIFC-terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining for detection of apoptosis. (3) Collagen antibody induced arthritis (CAIA) was induced in DBA/1 mice by arthritogenic cocktail of monoclonal antibodies against type II collagen. BV was administered to the treatment groups (30mg/kg and 70mg/kg n=4 each) and evaluated clinical score, histological findings and levels of SAA, IL-6, and TNFα in serum by ELISA. Student’st-test (two-tailed) was used to determine statistical significance for analysis of synovial tissues and cell line assay. Two way ANOVA with Dunnett’s post hoc analysis was used for multiple comparisons of mice model.

Results:

(1) The number of CD30-positive cells was significantly higher in RA synovial tissue than in OA synovial tissue (p<0.01) (Fig. 1). CD30-positive cells were detected around the lymphoid follicles. Double immunofluorescence showed CD30 and CD138 double-positive cells in the synovial tissue of RA, suggesting CD30 is predominantly expressed by plasma cells. (2) RPMI8226 cells expressed CD30. BV caused apoptosis of RPMI8226 cells, and the number of cells treated with BV decreased to 95% compared to controls. (3) All control mice (n=4) developed severe arthritis, and their scores reached a peak (score: 13.3) on day 10. In the mice of treatment group of 30 mg/kg, paw swelling was slightly decreased, their clinical score reached a peak (score: 9.3) on day 10. In contrast, paw swelling was significantly reduced in the 70 mg/kg treatment group. The peak of the clinical score was 4.3 on day 10 (Fig.2). Histological score evaluated synovitis with infiltration of inflammatory cells, pannus formation, and erosion of bone and cartilage. Histological score of hind paws were 3.0 ± 0.8 for the control group, 2.7 ± 1.0 for 30 mg/kg group, and 0.7 ± 1.1 for 70 mg/kg group (p<0.01), respectively. The serum levels of SAA and IL-6 of treatment group were lower than those of no treatment group (p<0.01).

Conclusion:

We showed the expression of CD30 on synovial tissue of RA and the expression of CD30 on plasma cells. In addition, the current study provides the first evidence that BV depletion of CD30-positive cells suppressed arthritis and osteochondral destruction in CAIA mice. Our results may provide an important clue for the development of an effective treatment for RA with iatrogenic immunodeficiency-related LPD.

Disclosure of Interests:

Minami Matsuhashi: None declared, Keiichiro Nishida Grant/research support from: K. Nishida has received scholarship donation from CHUGAI PHARMACEUTICAL Co., Eisai Co., Mitsubishi Tanabe Pharma and AbbVie GK., Speakers bureau: K. Nishida has received speaking fees from CHUGAI PHARMACEUTICAL Co., Eli Lilly, Janssen Pharmaceutical K.K., Eisai Co. and AYUMI Pharmaceutical Corporation., Yoshihisa Nasu: None declared, Ryuichi Nakahara: None declared, Masahito Watanabe: None declared, Yoshifumi Hotta: None declared, Toshifumi Ozaki: None declared

SAT0068 THE RECENT INCIDENCE OF SURGICAL SITE INFECTION AND DELAYED WOUND HEALING AFTER ELECTIVE ORTHOPAEDIC SURGERIES FOR PATIENTS WITH RHEUMATOID ARTHRITIS WHO TREATED WITH B/TSDMARDS

Background:

In Japan, Methotrexate (MTX) has been approved in 1999, the first biologic DMARD (bDAMRD) in 2003, and the Janus kinase (JAK) inhibitors have been used since 2013. Although it is expected that the recent advancement of drug therapy would contribute the decrease in the incidence of orthopaedic surgeries by preventing structural damages1, 2), we are still facing a considerable number of patients who require surgical interventions3).

Objectives:

To investigate the recent trends of patient’s background who underwent the orthopaedic surgery for rheumatoid arthritis, number of orthopaedic intervention, and the type of the surgery.

Methods:

We reviewed the records of 1569 patients with RA who underwent orthopedic surgeries between 2004 and 2019 in our institution. The mean age of patients was 62.8 (22-88) years-old with disease duration of 20.9 (0.5-64) years. Data of these patients such as age, disease duration, medication (Glucocorticoid; GC, MTX, b/tsDMARD), type of surgeries (total joint replacement; TJR, hand surgery, foot surgery, spine surgery, and others), and preoperative serum CRP level were collected. We analyzed the annual change of these demographic and clinical data. Then, we compared them between CRP negative (<1.5g/l) and CRP positive group. Cochran-Armitage trend test,χ square test, or unpaired T-test was performed for statistical analysis. P <0.05 was considered significant.

Results:

Among all cases, 426 cases (27.2%) were treated with b/tsDMARDs at the time of operation. MTX and GC were used in 937 cases (59.7%) and 1015 cases (64.7%), respectively. The mean age and disease duration of RA showed an increasing trend, although the CRP level was dramatically decreased during the study period. While the rate of MTX use has not changed significantly (p=0.102), the number of cases treated by b/ts DMARD increased significantly to 46.7% (p<0.001). In contrast, the rate of GC use dicreased significantly (p<0.001). Although the annual number of surgeries have not changed, the proportion of cases who performed TJR decreased dramatically (59.6% in 2011, 29.5% in 2019), and the surgeries for hand and foot increased significantly (p<0.001) (Fig 1). The annual mean preoperative CRP level also decreased from 18.8±1.95 to 4.89±0.81 (Fig2). Compared to CRP positive group (n=1,113), the patients in CRP negative group (n=446) showed significantly younger age(p<0.001), shorter disease duration (p=0.031), lower late of GC use, and a higher rate of b/tsDAMRD use. The proportion of patients who underwent TJR was significantly higher in CRP positive group (p<0.001).

Conclusion:

Along with the increasing use of b/tsDMARD, the preoperative disease control of RA, as well as the type of demanded surgeries have dramatically changed.

References:

[1] Yamanaka H, Tanaka E, Nakajima A, et al. A large observational cohort study of rheumatoid arthritis, IORRA: Providing context for today’s treatment options.Mod Rheumatol2020;30:1-6.

[2] Matsumoto T, Nishino J, Izawa N, et al. Trends in Treatment, Outcomes, and Incidence of Orthopedic Surgery in Patients with Rheumatoid Arthritis: An Observational Cohort Study Using the Japanese National Database of Rheumatic Diseases.J Rheumatol2017;44:1575-82.

[3] Momohara S, Tanaka S, Nakamura H, et al. Recent trends in orthopedic surgery performed in Japan for rheumatoid arthritis.Mod Rheumatol2011;21:337-42.

Disclosure of Interests:

Yoshifumi Hotta: None declared, Yoshihisa Nasu: None declared, Keiichiro Nishida Grant/research support from: K. Nishida has received scholarship donation from CHUGAI PHARMACEUTICAL Co., Eisai Co., Mitsubishi Tanabe Pharma and AbbVie GK., Speakers bureau: K. Nishida has received speaking fees from CHUGAI PHARMACEUTICAL Co., Eli Lilly, Janssen Pharmaceutical K.K., Eisai Co. and AYUMI Pharmaceutical Corporation., Minami Matsuhashi: None declared, Masahito Watanabe: None declared, Ryuichi Nakahara: None declared, Toshifumi Ozaki: None declared

SAT0023 THE ROLE OF ADAM12 UPREGULATED PROLIFERATION OF SYNOVIAL MEMBRANE IN RHEUMATOID ARTHRITIS

Background:

ADAM12 is a member of a disintegrin and metalloproteinase family and has been reported to participate in the development of a variety of tumors by degrading ECM and shed precursors, thus promoting cell proliferation, invasion, and metastasis1). Additionally, ADAM12 is involved in chondrocyte differentiation from osteoarthritis (OA) patients by regulation of TGFβ1-induced IGF-1 and RUNX-2 expressions2). However, there is no report on the role of ADAM12 for rheumatoid arthritis (RA).

Objectives:

To investigate the expression and role of ADAM12 in the synovial tissue of RA.

Methods:

(1) The expression of ADAM12 in synovial tissues from RA (18 cases), OA (5 cases) and healthy control (HC) (3 cases) was examined by immunohistochemistry. The synovial tissues of HC were obtained during surgery of hemiarthroplasty for bone tumors. Three researchers evaluated the positive cell ratio. The samples were scored according to the percentage of positive staining: 0 points (weak positive, positive expression was less than 5%), 1 point (moderate positive, positive expression was between 5% and 50%) and 2 points (strong positive, positive expression was greater than 50%). In addition, the samples were scored according to the staining intensity: 0 points (weak intensity), 1 point (moderate intensity) and 2 points (high intensity). (2) The cultured synovial fibroblasts obtained from RA patients at the surgery (RASF) were stimulated by TNFα (1, 5, 10 ng/mL), TGFβ1 (1, 5, 10 ng/mL), PDGF-BB (1, 5, 10 ng/mL) and TNFα+TGFβ1+PDGF-BB (all 10 ng/mL), and the expression levels of ADAM12 relative mRNA was examined by real-time PCR. (3) siADAM12 was transfected in RASF, and the proliferation was examined by WST-1 assay, and the expression of ADAM12 protein was examined by western blotting.

Results:

(1) ADAM12 positive cells were found in synovial lining cells, plasma cells, and vascular endothelial cells. ADAM12 was highly expressed in RA synovial tissues. The immunostaining scores of RA, OA, and HC were 3.9±0.01, 1.9±0.27, and 0.8±0.18, respectively. (2) Stimulation by TNFα, TGFβ1, and PDGF-BB resulted in the upregulation of the expression of ADAM12 relative mRNA in RASF, and TGFβ1 stimulation notably tended to increase the expression by about 5 to 6 times. (3) siADAM12 successfully suppressed the expression of ADAM12 protein and simultaneously suppressed the proliferation of RASF.

Conclusion:

ADAM12 might be involved in the pathogenesis of RA, promoting the cell proliferation of RASF.

References:

[1] Kyeiborg M, Albrechtsen R, Couchman J, et al., Cellular roles of ADAM12 in health and disease, Int J Biochem Cell Biol, 2008

[2] Masahiro H, Keiichiro N, Joe H, et al., Involvement of ADAM12 in Chondrocyte Differentiation by Regulation of TGF-beta1-Induced IGF-1 and RUNX-2 Expressions, Calcif Tissue Int, 2019

Disclosure of Interests:

Masahito Watanabe: None declared, Keiichiro Nishida Grant/research support from: K. Nishida has received scholarship donation from CHUGAI PHARMACEUTICAL Co., Eisai Co., Mitsubishi Tanabe Pharma and AbbVie GK., Speakers bureau: K. Nishida has received speaking fees from CHUGAI PHARMACEUTICAL Co., Eli Lilly, Janssen Pharmaceutical K.K., Eisai Co. and AYUMI Pharmaceutical Corporation., Yoshihisa Nasu: None declared, Ryuichi Nakahara: None declared, Minami Matsuhashi: None declared, Yoshifumi Hotta: None declared, Toshifumi Ozaki: None declared

FRI0523 THE RECENT TREND OF ORTHOPAEDIC SURGERIES FOR RHEUMATOID ARTHRITIS. AN ANALYSIS OF 1569 CASES FROM 2004 TO 2019

Background:

In Japan, Methotrexate (MTX) has been approved in 1999, the first biologic DMARD (bDAMRD) in 2003, and the Janus kinase (JAK) inhibitors have been used since 2013. Although it is expected that the recent advancement of drug therapy would contribute the decrease in the incidence of orthopaedic surgeries by preventing structural damages1, 2), we are still facing a considerable number of patients who require surgical interventions3).

Objectives:

To investigate the recent trends of patient’s background who underwent the orthopaedic surgery for rheumatoid arthritis, number of orthopaedic intervention, and the type of the surgery.

Methods:

We reviewed the records of 1569 patients with RA who underwent orthopedic surgeries between 2004 and 2019 in our institution. The mean age of patients was 62.8 (22-88) years-old with disease duration of 20.9 (0.5-64) years. Data of these patients such as age, disease duration, medication (Glucocorticoid; GC, MTX, b/tsDMARD), type of surgeries (total joint replacement; TJR, hand surgery, foot surgery, spine surgery, and others), and preoperative serum CRP level were collected. We analyzed the annual change of these demographic and clinical data. Then, we compared them between CRP negative (<1.5g/l) and CRP positive group. Cochran-Armitage trend test,χ square test, or unpaired T-test was performed for statistical analysis. P <0.05 was considered significant.

Results:

Among all cases, 426 cases (27.2%) were treated with b/tsDMARDs at the time of operation. MTX and GC were used in 937 cases (59.7%) and 1015 cases (64.7%), respectively. The mean age and disease duration of RA showed an increasing trend, although the CRP level was dramatically decreased during the study period. While the rate of MTX use has not changed significantly (p=0.102), the number of cases treated by b/ts DMARD increased significantly to 46.7% (p<0.001). In contrast, the rate of GC use dicreased significantly (p<0.001). Although the annual number of surgeries have not changed, the proportion of cases who performed TJR decreased dramatically (59.6% in 2011, 29.5% in 2019), and the surgeries for hand and foot increased significantly (p<0.001) (Fig 1). The annual mean preoperative CRP level also decreased from 18.8±1.95 to 4.89±0.81 (Fig 2). Compared to CRP positive group (n=1,113), the patients in CRP negative group (n=446) showed significantly younger age(p<0.001), shorter disease duration (p=0.031), lower late of GC use, and a higher rate of b/tsDAMRD use. The proportion of patients who underwent TJR was significantly higher in CRP positive group (p<0.001).

Conclusion:

Along with the increasing use of b/tsDMARD, the preoperative disease control of RA, as well as the type of demanded surgeries have dramatically changed.

References:

[1] Yamanaka H, Tanaka E, Nakajima A, et al. A large observational cohort study of rheumatoid arthritis, IORRA: Providing context for today’s treatment options.Mod Rheumatol2020;30:1-6.

[2] Matsumoto T, Nishino J, Izawa N, et al. Trends in Treatment, Outcomes, and Incidence of Orthopedic Surgery in Patients with Rheumatoid Arthritis: An Observational Cohort Study Using the Japanese National Database of Rheumatic Diseases.J Rheumatol2017;44:1575-82.

[3] Momohara S, Tanaka S, Nakamura H, et al. Recent trends in orthopedic surgery performed in Japan for rheumatoid arthritis.Mod Rheumatol2011;21:337-42.

Disclosure of Interests:

Yoshifumi Hotta: None declared, Yoshihisa Nasu: None declared, Keiichiro Nishida Grant/research support from: K. Nishida has received scholarship donation from CHUGAI PHARMACEUTICAL Co., Eisai Co., Mitsubishi Tanabe Pharma and AbbVie GK., Speakers bureau: K. Nishida has received speaking fees from CHUGAI PHARMACEUTICAL Co., Eli Lilly, Janssen Pharmaceutical K.K., Eisai Co. and AYUMI Pharmaceutical Corporation., Minami Matsuhashi: None declared, Masahito Watanabe: None declared, Ryuichi Nakahara: None declared, Toshifumi Ozaki: None declared

AB0216 POWER DOPPLER SCORE IS USEFUL TO PREDICT JOINT DESTRUCTION OF HAND AND WRIST JOINT IN RHEUMATOID ARTHRITIS PATIENTS

Background:

Several studies demonstrated that total power Doppler (PD) signal can predict radiographic progression as a change in total van der Heijde-modified total Sharp score (mTSS) in rheumatoid arthritis (RA) patients. However, in some studies, radiographic progression was observed in a different joint compared with the site of a positive PD signal at baseline in many cases.

Objectives:

The aim of this study was to identify the clinical factor of RA patients in association with radiographic progression of hands and wrists and to investigate which joint showed radiographic progression in RA patients. We focused on the correlation of the site of a positive PD signal and the site of radiographic progression.

Methods:

We examined retrospectively of 70 RA patients (67 women, three men) who underwent ultrasonography (US) examination at 32 regions on bilateral hands and wrists from 2014 to 2016. Radiographs of the hands were taken at baseline and at least one year after US (mean, 19.9 months), and radiographic progression was assessed using mTSS system. We performed multivariate logistic regression analysis to investigate the association between baseline factors and radiographic progression. The relationships between radiographic progression of the individual joint and total/each joint PD score were assessed by ROC analysis and Fisher’s exact test.

Results:

Nineteen patients (37.3%) experienced progression of mTSS of hands and wrists. DAS28-CRP (P=0.02) and total PD score (P=0.01) were associated with radiographic progression, and total PD score was significantly associated with radiographic progression (OR 1.22; 95% CI 1.04-1.36; P=0.006) by multivariate logistic regression analysis (Table 1).

Table 1.

Association between the demographic and clinical findings at baseline and radiographic progression over 12 months

a.univariate analysisNo radiographicprogression(n = 51)Radiographicprogression(n = 19)P-valueAge, years63.4 ± 12.758.1 ± 10.60.61Duration of RA, years24.4 ± 13.620.0 ± 5.00.28Usage of Bio, %42.240.40.57Amount of MTX, mg/week4.8 ± 3.34.5 ± 4.30.77Amount of PSL, mg1.5 ± 2.11.8 ± 2.20.73DAS28-CRP2.5 ± 0.72.9 ± 0.60.02*CRP, mg/dl0.4 ± 0.50.7 ± 0.70.10Total PD score2.4 ± 3.36.6 ± 6.10.01*b.multivariate analysisodds ratio95% CIP-valueDAS28-CRP1.630.72 - 3.710.238Total PD score1.191.04 - 1.360.010*

Predictive performance of total PD score was good for radiographic progression of MCP joint (AUC-ROC 0.91) and wrist joint (AUC-ROC 0.85), although poor for PIP joint (AUC-ROC 0.57).

PD score of wrist joint, MCP joint, and PIP joint were significantly associated with radiographic progression of each joint (P<0.01). The sensitivity, specificity, positive predictive value, and negative predictive value of wrist joint PD score were 100%, 57.0%, 8.0%, and 100%, MCP joint PD score were 85.7%, 90.5%, 8.0%, 99.8%, and 8.3%, and PIP joint PD score were 30.0%, 97.2%, 13.6%, and 99.0%, respectively.

Conclusion:

Total PD score of hands and wrists was a strong predictor of radiographic progression, especially in MCP and wrist joint. Evaluation of PD signal in individual joint is a clinically useful method to predict radiographic progression of the same joint, however there are some differences in sensitivity and specificity.

References:

[1]Brown AK, et al. Arthritis & Rheumatism. 2008;58:2958-2967.

[2]McQueen F, et al. Annals of the Rheumatic Diseases. 2011;70:241-244.

Disclosure of Interests:

Shunji Okita: None declared, Ryuichi Nakahara: None declared, Minami Matsuhashi: None declared, Masahito Watanabe: None declared, Yoshihisa Nasu: None declared, Keiichiro Nishida Grant/research support from: K. Nishida has received scholarship donation from CHUGAI PHARMACEUTICAL Co., Eisai Co., Mitsubishi Tanabe Pharma and AbbVie GK., Speakers bureau: K. Nishida has received speaking fees from CHUGAI PHARMACEUTICAL Co., Eli Lilly, Janssen Pharmaceutical K.K., Eisai Co. and AYUMI Pharmaceutical Corporation., Toshifumi Ozaki: None declared

Marked attenuation of the amplitude of transcranial motor-evoked potentials after intravenous bolus administration of ketamine: a case report

Background

It is believed that ketamine does not affect motor-evoked potential amplitude, whereas various anesthetic drugs attenuate the amplitude of transcranial motor-evoked potential. However, we encountered a patient with marked attenuation of motor-evoked potential amplitude after intravenous bolus administration of ketamine.

Case presentation

A 15-year-old Japanese girl with a diagnosis of adolescent idiopathic scoliosis was admitted to our hospital to undergo posterior spinal fusion at T4–L3. After induction of general anesthesia using a continuous infusion of propofol and remifentanil, we confirmed that transcranial electrical motor-evoked potentials were being recorded correctly. Ketamine 1.25 mg/kg was administered intravenously for intraoperative and postoperative analgesia. About 3 minutes later, the motor-evoked potential amplitude was markedly attenuated. No other drugs were administered except for ketamine. The patient’s vital signs were stable, and the surgery had not yet started. The motor-evoked potential amplitude was recovered at about 6 minutes after administration of ketamine. The surgery was performed uneventfully, and the patient had no neurologic deficit when she emerged from general anesthesia.

Conclusions

Although there is a widely held belief in the field of anesthesiology that ketamine does not affect motor-evoked potential amplitude, it has been suggested that ketamine could affect its monitoring.

Free radical scavenger edaravone produces robust neuroprotection in a rat model of spinal cord injury

We used a multimodal approach to evaluate the effects of edaravone in a rat model of spinal cord injury (SCI). SCI was induced by extradural compression of thoracic spinal cord. In experiment 1, 30 min prior to compression, rats received a 3 mg/kg intravenous bolus of edaravone followed by a maintenance infusion of 1 (low-dose), 3 (moderate-dose), or 10 (high-dose) mg/kg/h edaravone. Although both moderate- and high-dose edaravone regimens promoted recovery of spinal motor-evoked potentials (MEPs) at 2 h post-SCI, the effect of the moderate dose was more pronounced. In experiment 2, moderate-dose edaravone was administered 30 min prior to compression, at the start of compression, or 10 min after decompression. Although both preemptive and coincident administration resulted in significantly improved spinal MEPs at 2 h post-SCI, the effect of preemptive administration was more pronounced. A moderate dose of edaravone resulted in significant attenuation of lipid peroxidation, as evidenced by lower concentrations of the free radical malonyldialdehyde in the spinal cord 3 h post-SCI. Malonyldialdehyde levels in the high-dose edaravone group were not reduced. Both moderate- and high-dose edaravone resulted in significant functional improvements, evidenced by better Basso-Beattie-Bresnahan (BBB) scores and better performance on an inclined plane during an 8 week period post-SCI. Both moderate- and high-dose edaravone significantly attenuated neuronal loss in the spinal cord at 8 weeks post-SCI, as evidenced by quantitative immunohistochemical analysis of NeuN-positive cells. In conclusion, early administration of a moderate dose of edaravone minimized the negative consequences of SCI and facilitated functional recovery.

Preceding haemorrhagic shock as a detrimental risk factor for respiratory distress after excessive allogeneic blood transfusion

BACKGROUND AND OBJECTIVES

Whether transfusion-associated circulatory overload arises as a simple result of over-transfusion or requires another trigger remains unclear. Here, we examined whether respiratory distress could be reproduced by massive transfusion alone in an animal model.

MATERIALS AND METHODS

A total of 20 anaesthetized swine were equipped with monitors. Allogeneic blood was obtained from 10 donor swine. A 4-stage loading protocol with each stage equivalent to 25% of the blood volume (BV) in the recipient swine was then used to infuse crystalloid (CR), hydroxyethyl starch (HES) or allogeneic blood (TR) (n = 5 each). The five remaining animals were subjected to a haemorrhagic shock (HS) prior to an allogeneic blood transfusion (TRS).

RESULTS

The PaO₂ /FiO₂ (P/F) ratio did not decrease to the level of respiratory distress in either the CR group or the HES group after loading with a volume corresponding to 100% of the recipient BV. However, the TRS and TR groups exhibited significant reductions in the P/F ratio after fluid overloading (227 ± 29 and 267 ± 133, respectively). Blood transfusion after HS expanded the blood volume, but over-transfusion alone did not. HS was accompanied by an increase in the white blood cell count.

CONCLUSION

The lung and the heart can tolerate volume overloads with HES, CR and even transfused blood. However, a preceding HS may induce an inflammatory response, making the lung vulnerable to subsequent blood overloads. In this study, a preceding haemorrhagic shock mediated respiratory distress following massive transfusion in a swine model. (247 words).

The frequencies of human neutrophil alloantigens among the Japanese population

Human neutrophil antigens (HNAs) play an important role in a variety of clinical conditions including immune-mediated neutropenia, non-hemolytic transfusion reactions, and transfusion-related acute lung injury. The aim of this study was to investigate the frequency distribution of HNAs-1 to -5 among the Japanese population. We analyzed samples from 570 healthy Japanese by molecular and serologic techniques to estimate the gene frequencies of HNAs-1 to -5. DNA samples were obtained and typed for the HNA-1 (n = 523), -3 (n = 570), -4 (n = 570), and -5 (n = 508), by molecular techniques. The HNA-1 genotype was determined by using a commercial polymerase chain reaction-reverse sequence-specific oligonucleotide probes (PCR-rSSOP) kit. The HNA-3 to -5 genotypes were determined by the PCR-sequence specific primer (PCR-SSP), previously described, with a small modification. The HNA-2a phenotype was determined in 301 donors by granulocyte immunofluorescence test. In Japanese, the gene frequencies of HNA-1a, -1b, and -1c were 0.623, 0.377, and 0.000, respectively. The frequency of HNA-2a phenotype was 0.987, and the gene frequencies of HNA-3a and -3b were 0.654 and 0.346, respectively. HNA-4a and -4b were found at 1.000 and 0.000, respectively, and HNA-5a and -5b at 0.840 and 0.160, respectively. We describe, for the first time, the frequencies of all HNAs (HNA-1 to -5) among the Japanese population. This study will be helpful for the prediction of the risk of alloimmunization to HNA, especially to determine the risk of HNA alloantibody production by transfusion of HNA incompatible blood and feto-maternal incompatibility.

Subregions of human MT complex revealed by comparative MEG and direct electrocorticographic recordings

OBJECTIVE

To locate the visual motion complex (MT+) and study its response properties in an epilepsy surgery patient.

METHODS

A 17-year-old epilepsy patient underwent invasive monitoring with subdural electrodes in the right temporo-parieto-occipital area. MT+ was investigated by cortical electric stimulation and by epicortical visual evoked potentials time-locked to motion onset of sinusoidal gratings (motion VEP). Motion-related visual evoked magnetic field (motion VEF) was also recorded before the electrode implantation to complement the invasive recording.

RESULTS

Motion VEPs revealed two subregions within MT+, generating early and late potentials respectively. The early activity with a peak around 130 ms was localized at a single electrode situated immediately caudal to the initial portion of the ascending limb of the superior temporal sulcus (AL-STS). The late activity, peaking at 242-274 ms, was located ventro-rostrally over three electrodes. Among the four electrodes with motion VEPs, cortical stimulation at the most caudal pair elicited motion-in-depth perception involving the whole visual field. In addition to two subregions revealed on the gyral crown, magnetoencephalography (MEG) demonstrated another subregion with a late motion VEF in AL-STS immediately rostral to the electrode with the early motion VEP.

CONCLUSIONS

In combination with MEG recording, the present invasive exploration demonstrated human MT+ in a focal area of the temporo-parieto-occipital junction and delineated possible three subregions as indicated by the different latencies and distributions of the motion VEP/VEFs.

SIGNIFICANCE

Comparative MEG and direct electrocorticographic recordings delineated possible subregions within the human MT complex.

Surgical treatment of seizures from the peri-Sylvian area by perinatal insult: a case report of ictal hypersalivation

OBJECTIVES AND IMPORTANCE: It is important to evaluate the seizure manifestation of epilepsy before surgical planning. A patient with partial epilepsy manifesting hypersalivation who underwent resection of the epileptogenic foci with satisfactory postoperative seizure control is reported.

CLINICAL PRESENTATION AND INTERVENTION

A 26-year-old man, with a history of perinatal asphyxia, started having medically intractable partial epilepsy at the age of 10 years. His seizure was characterized by throat discomfort followed by hypersalivation. Brain MRI showed an atrophic lesion around the peri-Sylvian area. Scalp recorded EEG did not demonstrate robust epileptiform activity localized enough to define the epileptogenic zone. The patient underwent invasive recording by multiple subdural electrode grids, which showed that the seizure arose from the left anterior frontal operculum. After resection of epileptogenic opercular cortex, the seizures disappeared with no additional neurological deficits.

CONCLUSION

Although the responsible sites for ictal drooling are distributed in multiple areas including insula, medial temporal area and operculum, the seizure can be successfully controlled by focus resection of the frontal opercular area in a selected patient with careful presurgical evaluation.

Intracarotid propofol test for speech and memory dominance in man

OBJECTIVE

To evaluate the usefulness of propofol as an alternative drug to amobarbital for the Wada test.

METHODS

The authors analyzed 67 right-handed patients out of 123 patients who were candidates for neurosurgical therapy and thus underwent the Wada test as a preoperative evaluation. Twelve were tested with propofol and 55 were tested with amobarbital. Test conditions of the Wada test, recovery time of muscle power to manual muscle testing (MMT) Grade 3 (T3/5) and Grade 5 (T5/5), onset time of the first verbal response (Tverb) after injection and that of the first nonverbal response (Tnon-verb), were compared between the two groups. Power spectrum analysis of EEG background activity during the Wada test was performed and the time and spatial distribution of polymorphic slow activities were also compared in three cases.

RESULTS

With propofol injection, lateralities of language and memory function were identified in 12 and 9 of 12 patients in comparison to amobarbital (52 and 41 of 55 patients detection in language and memory function). No complications with direct intracarotid injection of propofol were observed. T3/5 and T5/5 with propofol injection were shorter while Tverb and Tnon-verb were longer compared to amobarbital. Absolute power of polymorphic slow EEG waves gradually increased and then rapidly decreased with propofol, which was in contrast to amobarbital injection.

CONCLUSIONS

With direct intracarotid propofol injection, the Wada test was satisfactorily performed in all 12 patients and 2 more patients with left-handedness or with different injection dose for each side without any complications. Clinical usefulness of propofol as an alternative drug to amobarbital for the Wada test was indicated.

Seizures arising from the inferior parietal lobule can show ictal semiology of the second sensory seizure (SII seizure)

A 52-year-old right handed man presented with medically intractable partial seizures consisting of numbness on the left upper back spreading to the left upper as well as lower limbs. Head computed tomography and magnetic resonance imaging showed a round calcified lesion in the depth of the superior ramus of the right sylvian fissure. Ictal electrocorticographic recording with chronically implanted subdural electrodes showed low voltage fast activities starting exclusively from an electrode located on the right inferior parietal lobule. No apparent ictal activities were observed from the depth electrodes inserted in the parietal operculum. Somatosensory evoked potentials of 75 ms to 145 ms latency were recorded from the ictal onset zone, which was 2 cm caudal to the perisylvian area corresponding to the second somatosensory area. Seizures arising from the inferior parietal lobule including the angular and supuramarginal gyri can produce partial seizures whose ictal semiology and scalp electroencephalography are indistinguishable from the ones originating from the second somatosensory area.

Maturational change of parallel auditory processing in school-aged children revealed by simultaneous recording of magnetic and electric cortical responses

OBJECTIVES

To elucidate the maturational change of cortical auditory processing, we analyzed simultaneously recorded auditory evoked potentials (AEPs) and magnetic fields (AEFs) in school-aged children.

METHODS

Simultaneous recording of AEP and AEF were performed in 32 healthy children of age ranging from 6 to 14 years and 10 adults. Tone bursts of 1 kHz were presented to the left and right ears alternately with 3 different within-ear stimulus onset asynchronies (SOAs) (1.6, 3.0 and 5.0 s for each ear) under attention-distracted condition.

RESULTS

All subjects showed clear N100 and N100m peaks under the longest SOA condition (5.0 s). Under the shortest SOA condition (1.6 s), 4 out of 19 subjects under 12 years (21%) failed to show the N100m component. By contrast, N250 and N250m were observed in the majority of children (29/32: 91%) while those were detected in only 4 out of 10 adults (40%). The spatial distribution of N100 in children under 9 years differed from that in older subjects, whereas the dipole orientation of N100m was constant among age groups, suggesting that radially oriented sources might make additional contribution to the generation of N100 in early childhood. N250 was significantly larger in children than in adults. The strength of N250 was suppressed with longer SOAs, whereas that of N100 was enhanced. The dipole of N250m was located around Heschl's gyrus on the superior temporal plane which was significantly medial, anterior and inferior to that of N100m.

CONCLUSIONS

Dissociation of maturational change between the tangential and radial components of N100 suggests that auditory processing at around 100 ms consists of multiple parallel pathways which mature independently. Furthermore, a negative peak at around 250 ms specifically seen in children has different generators from N100 and might represent a special auditory processing which takes an active part until acquisition of the efficient cortical networks of the adult brain.