Investigation of the existence of and a block technique for the inferior lateral genicular nerve: cadaveric study.

Background: Among the four genicular nerves innervating the anterior aspect of the knee, the inferior lateral genicular nerve has been omitted as a target of blocking. Some authors have suggested that the inferior lateral genicular nerve of the knee might pass beneath the lateral collateral ligament of knee. The authors aimed to study the location of the inferior lateral genicular nerve and the spread of injectate during the inferior lateral genicular nerve block. Methods: In ten knees from fresh frozen cadavers, the authors performed on each an ultrasound-guided block of the inferior lateral genicular nerve of the knee just below the lateral collateral ligament. The needle was inserted below the lateral collateral ligament, and 2 mL of blue dye was injected. A week later, the cadavers were dissected, and the existence of the inferior lateral genicular nerve and the spread of dye around it was investigated. Results: The proportion of inferior lateral genicular nerves branching from the common peroneal nerve was found in 8 of 10 (80.0%) cadavers. Of these eight cadavers with inferior lateral genicular nerve, five specimens (62.5%) were stained with blue dye. The common peroneal nerve was not infiltrated with dye in any specimens. Conclusions: When 2 mL of dye was inserted inferiorly to the lateral collateral ligament, the inferior lateral genicular nerve could be blocked in 62.5% of specimens. Because the common peroneal nerve was not involved in any specimen, motor weakness would be avoided with this method.

Pilot Study to Evaluate the Efficacy of Polynucleotide Sodium Compared to Sodium Hyaluronate and Crosslinked Sodium Hyaluronate in Patients with Knee Osteoarthritis.

Degenerative arthritis of the knee joint has become a major social problem worldwide due to population aging. There are several treatment options for knee osteoarthritis, and the intraarticular injection of sodium hyaluronate is commonly selected by many clinicians as a nonsurgical treatment. However, the efficacy of the treatment is controversial. In this pilot study, we aimed to compare polynucleotide sodium (Conjuran®) with sodium hyaluronate (Hyruan Plus®) and 1,4-butanediol diglycidyl ether-crosslinked sodium hyaluronate (Synovian®) in terms of analgesic efficacy after intraarticular injection in patients with knee osteoarthritis. One of the three intraarticular agents was selected according to what agents were available for outpatients when each patient was enrolled in the study. The 15 enrolled patients were subdivided into 3 groups of 5 patients each. Three injections were performed under ultrasound guidance at a 1-week intervals over a total of 3 weeks. The visual analog scale (VAS) score, the Korean version of the Western Ontario and McMaster Universities Arthritis Index (K-WOMAC), the EuroQol five-dimension scale (EQ-5D) score, and the Korean version of the painDETECT Questionnaire (K-PDQ) score were evaluated before injection and at 1, 2, and 6 weeks after the start of the treatment protocol. The primary endpoint was the change in weight-bearing pain at 4 weeks after the last injection. Secondary endpoints included pain at rest and during walking and the K-WOMAC, EQ-5D, and K-PDQ scores. Weight-bearing pain decreased significantly more from pretreatment to 6 weeks after the start of the treatment protocol in the polynucleotide sodium-treated patients than in the patients who were treated with other agents (p = 0.006, one-way ANOVA). There were no significant between-group differences in the other secondary endpoints. No adverse events occurred. In conclusion, polynucleotide sodium could effectively reduce weight-bearing pain in the patients with knee osteoarthritis compared to standard hyaluronic acid viscosupplementation.

Efficacy and Safety of the Controlled-release Pregabalin Tablet (GLA5PR GLARS-NF1) and Immediate-release Pregabalin Capsule for Peripheral Neuropathic Pain: A Multicenter, Randomized, Double-blind, Parallel-group, Active-controlled, Phase III Clinical Trial.

PURPOSE: This study compared the efficacy and safety of controlled-release pregabalin (GLA5PR GLARS-NF1 tablets) with those of an immediate-release pregabalin capsule after 12 weeks' administration to patients with peripheral neuropathic pain. METHODS: In this multicenter, randomized, double-blind, active-controlled, parallel-group, Phase III study, the primary outcome was to confirm that a single treatment with the study drug (after the evening meal) is clinically noninferior to the control drug (BID regimen) at improving the mean Daily Pain Rating Scale score for treating peripheral neuropathic pain. Secondary outcomes were the Daily Sleep Interference Scale, Medical Outcomes Study Sleep Scale, Hospital Anxiety and Depression scale, and frequency of rescue medication use. The safety and tolerability of GLA5PR GLARS-NF1 tablets were also evaluated. The total daily dose of pregabalin is 150-600 mg. FINDINGS: Of the 352 randomized subjects, 261 (n = 130, study group; n = 131, control group) were analyzed. The difference in adjusted mean Daily Pain Rating Scale scores between the groups was -0.11 (95% confidence interval, -0.05 to 0.30), indicating that the study group is noninferior to the control group. There was no statistically significant difference in Daily Sleep Interference Scale, Medical Outcomes Study Sleep Scale, and Hospital Anxiety and Depression scale scores between the groups at treatment termination. Logistic regression analysis revealed no significant difference in the use of rescue medication between the groups (P = 0.217). The overall adverse event profile of the groups was similar, and no serious adverse drug reactions were observed. IMPLICATIONS: GLA5PR GLARS-NF1 tablets can be effectively and safely administered to patients with peripheral neuropathic pain. Furthermore, we found that sleep, anxiety, and depression were improved with pain control. Owing to the once-daily administration, treatment effects can be maximized by improved treatment compliance. ClinicalTrials.gov identifier: NCT03221907.

Relationship Between Epidural Steroid Dose and Suppression of Hypothalamus-Pituitary-Adrenal Axis.

BACKGROUND: The suppression of hypothalamic-pituitary-adrenal (HPA) axis is a common complication associated with epidural steroid injections (ESIs). However, the effect of different doses is unknown. OBJECTIVES: The primary objective was to compare the differences in the duration of HPA suppression following treatment with different doses of ESI; triamcinolone acetate (TA) 40 mg and TA 20 mg. The secondary objectives were to compare the extent of salivary cortisol (SC) reduction, the incidence of adrenal insufficiency (AI), and the differences in a numeric rating scale (NRS) depending on the varying levels of TA dose used for ESI. STUDY DESIGN: A double-blind, parallel-group, randomized controlled trial. SETTING: Pain clinics in a university hospital. METHODS: The patients were treated with TA epidurally and divided into 2 groups (T20 and T40) depending on the dose of TA (20 mg and 40 mg). The SC concentration was measured before and after ESI to calculate the duration of HPA axis suppression, the extent of SC concentration reduction, and the SC recovery rate. Additionally, NRS and adrenocorticotropic hormone stimulation tests were used. RESULTS: Thirty patients were analyzed. The T40 group showed longer HPA suppression (19.7 ± 3.1 days) compared with that of the T20 group (8.0 ± 2.4 days). The recovery rate of the T40 group was lower than that of the T20 group (P < 0.015). However, there was no difference in the extent of reduction in SC concentration after ESI, the occurrence of AI, and pain reduction. LIMITATIONS: There were selection bias and no placebo control. CONCLUSIONS: Although the difference in pain relief according to the ESI dose is not significant, the HPA suppression is prolonged with a higher dose than a lower dose, and the recovery is slower. Therefore, the time interval between consecutive ESIs should be adjusted depending on the steroid dose to ameliorate the adverse effects of steroids.

Predictors of Response to a Medial Branch Block: MRI Analysis of the Lumbar Spine.

The aim of this study was to determine the association between radiologic spinal pathology and the response to medial branches block (MBB). This retrospective observational study compared 165 patients. A successful response was defined as ≥30% or a 2-point reduction in the numeric rating scale (NRS) compared with the baseline at the 1-month follow-up. The facet angle, facet angle difference, facet joint degeneration, disc height and spondylolisthesis grade were analyzed from an MRI at the L3 to S1 levels. Univariate and multivariate logistic regression analyses were used to evaluate independent factors associated with a successful response of MBB. In the univariate analysis, the disc height at L5-S1 and facet angle difference at L3-4 were lower in the positive responders (p = 0.022 and p = 0.087, respectively). In the multivariate analysis, the facet angle difference at L3-4 and disc height at L5-S1 were independent factors associated with a successful response (odds ratio = 0.948; p = 0.038 and odds ratio = 0.864; p = 0.038, respectively). In patients with a degenerative disc at L5-S1, MBB can lead to a good response for at least one month. In patients with facet tropism at L3-4 level, the response to MBB after one month is likely to be poor.

Clinical outcome of percutaneous lumbar foraminoplasty using a safety-improved device in patients with lumbar foraminal spinal stenosis.

Lumbar foraminal spinal stenosis (LFSS) is defined as the narrowing of the nerve root exit associated with a herniated intervertebral disc, osteoarthritic changes in the facet joints, or a hypertrophied ligamentum flavum, which can provoke neurogenic claudication. To achieve effective and safe decompression of the lumbar spinal foramen, a specially designed instrument (Claudicare, SEAWON Meditech, Bucheon-si, Gyeonggi-do, Republic of Korea) for percutaneous lumbar foraminoplasty (PLF) was invented. The purpose of this study was to evaluate the clinical efficacy and safety of the newly devised instrument in patients with LFSS.PLF was performed for LFSS by a single pain physician. For each patient, an 11-point numerical rating scale (NRS) pain score-the Oswestry Disability Index (ODI)-and the duration of walking without radicular pain were evaluated at the 3-month follow-up. The successful responder percentage was defined as ≥50% reduction from the baseline NRS score with improvement in ODI and duration of walking.Among 24 patients who underwent PLF, 15 patients showed successful responses. The NRS pain score and duration of walking without radicular pain were improved significantly from baseline at the 3-month follow-up (P < .01). The ODI was also decreased, but the difference was not statistically significant (P = .09). The NRS pain score and walking duration without pain at 3 months were statistically significantly different between the groups (P < .001 and P = .01, respectively), whereas there was no statistically significant difference in improvement in ODI between the groups (P = .23). No serious adverse events occurred in the study.In conclusion, PLF using the Claudicare device may be an optimal and safe option for managing intractable LFSS on an outpatient basis.

Predictive Factors of Successful Percutaneous Cervical Nucleoplasty for the Treatment of Pain with Cervical Herniated Disk.

BACKGROUND: Percutaneous cervical nucleoplasty (PCN) is an effective treatment for cervical herniated intervertebral disc (C-HIVD). In this retrospective study, we evaluated clinical predictors that affect the successful outcome of PCN. METHODS: Fluoroscopically guided PCN was conducted for C-HIVD by one pain physician. Successful outcome was defined as a combination of greater than 50% pain relief on the numerical rating scale pain score, no increase in analgesics, and no cervical epidural steroid injection during the 3-month follow-up period. The relationship between outcomes and independent variables, including patient demographics, comorbid diseases, pain duration, type of disc herniation, presence of spinal stenosis, pain location, analgesics, and shape of the PCN needle tip, were investigated using multivariable analyses. RESULTS: Of 201 patients, 134 experienced a successful outcome after PCN. In the positive outcome group, shorter pain durations, rarer central canal stenosis, increased unilateral radiculopathy versus axial pain, and more frequent use of the curved tip technique, were reported. Multivariable analyses revealed that unilateral radiculopathy (P = 0.013) and use of the curved-tip technique (P = 0.027) were independent positive predictors of successful PCN outcomes; conversely, longer pain duration (P = 0.014) and concurrent spinal stenosis (P < 0.001) were negative predictors. No serious complications related to PCN occurred. CONCLUSIONS: In this study, the success rate of PCN was 66.7% in patients with C-HIVD. Shorter pain duration, the absence of cervical central canal stenosis, pain location (i.e., unilateral radiculopathy vs. axial pain), and the use of the curved-tip technique were positive predictors of successful PCN.

Axillary approach versus the infraclavicular approach in ultrasound-guided brachial plexus block: comparison of anesthetic time.

BACKGROUND: With ultrasound guidance, the success rate of brachial plexus block (BPB) is 95-100% and the anesthetic time has become a more important factor than before. Many investigators have compared ultrasound guidance with the nerve stimulation technique, but there are few studies comparing different approaches via the same ultrasound guidance. We compared the axillary BPB with the infraclavicular BPB under ultrasound guidance. METHODS: Twenty-two ASA physical status I-II patients presenting with elective forearm surgery were prospectively randomized to receive an axillary BPB (group AX) or an infraclavicular BPB (group IC) with ultrasound guidance. Both groups received a total of 20 ml of 1.5% lidocaine with 5 µg/ml epinephrine and 0.1 mEq/ml sodium bicarbonate. Patients were then evaluated for block onset and block performance time was also recorded. RESULTS: Group IC demonstrated a reduction in performance time vs. group AX (622 ± 139 sec vs. 789 ± 131 sec, P < 0.05). But, the onset time was longer in group IC than in group AX (7.7 ± 8.8 min vs. 1.4 ± 2.3 min, P < 0.05). All blocks were successful in both groups. CONCLUSIONS: Under ultrasound guidance, infraclavicular BPB was faster to perform than the axillary approach. But the block onset was slower with the infraclavicular approach.

The effect of low fresh gas flow rate on sevoflurane consumption.

BACKGROUND: In an era of medical cost containment, cost-effectiveness has become a major focus in healthcare. The effect of a new policy on the use of low fresh gas flow during maintenance of general anesthesia with volatile anesthetics was evaluated. METHODS: The numbers and duration of general anesthesia cases using sevoflurane 5 weeks prior to and 15 weeks after policy implementation were retrieved from the electronic medical records database. The number of sevoflurane bottles consumed was also assessed. The anesthesia hours per bottle of sevoflurane were compared before and after policy implementation. RESULTS: The number of anesthesia hours performed per bottle of sevoflurane increased by 38.3%. The effect varied over time and tended to fade with time. CONCLUSIONS: The implementation of a low fresh gas flow rate policy effectively reduces the amount of sevoflurane consumed for the same duration of anesthesia.

The results of cervical nucleoplasty in patients with cervical disc disorder: a retrospective clinical study of 22 patients.

BACKGROUND: Nucleoplasty is a minimally invasive spinal surgery using a Coblation® technique that creates small voids within the disc. The purpose of this study was to evaluate the efficacy of cervical nucleoplasty in patients with cervical disc disorder. METHODS: Between March 2008 and December 2009, 22 patients with cervical disc disorders were treated with cervical nucleoplasty after failed conservative treatment. All procedures were performed under local anesthesia, and fluoroscopic guidance and voids were created in the disc with the Perc™ DC Spine Wand™. Clinical outcomes were evaluated by the Modified Macnab criteria and VAS score at preprocedure, postprocedure 1 month, and 6 months. RESULTS: Six patients had one, eight patients had two and eight patients had three discs treated; a total of 46 procedures was performed. Mean VAS reduced from 9.3 at preprocedure to 3.7 at postprocedure 1 month and to 3.4 at postprocedure 6 months. There was no significant complication related to the procedure within the first month. Outcomes were good or excellent in 17/22 (77.3%) cases. Postprocedure magnetic resonance imaging was acquired in two patients after two months showing morphologic evidence of volume reduction of protruded disc material in one patient but not in the other. CONCLUSIONS: Percutaneous decompression with a nucleoplasty using a Coblation® technique in the treatment of cervical disc disorder is a safe, minimally-invasive and less uncomfortable procedure, with an excellent short-term clinical outcome.

Immunohistochemical localization of insulin-like growth factor binding protein 2 in the central nervous system of SOD1(G93A) transgenic mice.

In the present study, we performed immunohistochemical studies to investigate the changes of insulin-like growth factor binding protein 2 (IGFBP2) in the central nervous system of SOD1(G93A) mutant transgenic mice as an in vivo model of amyotrophic lateral sclerosis (ALS). Decreased immunoreactivity for IGFBP2 was observed in the cerebral cortex, hippocampus and brainstem of SOD1(G93A) transgenic mice. In the cerebral cortex, the number of IGFBP2-positive cells was decreased in the somatomotor area, somatosensory area, auditory area, visual area, entorhinal area, piriform area and prefrontal area. In the hippocampal formation, IGFBP2 immunoreactivity was significantly decreased in the CA1-3 areas and the dentate gyrus. In the brainstem, few IGFBP2-immunoreactive cells were observed in the medullary and pontine reticular formation, vestibular nucleus, trigeminal motor nucleus, facial nucleus, hypoglossal nucleus and raphe nucleus. In the spinal cord, IGFBP2 immunoreactivity was not significantly decreased in SOD1(G93A) transgenic mice. This study showing decreased IGFBP2 in different brain regions of SOD1(G93A) transgenic mice may provide clues for understanding differential susceptibility of neural structures in ALS.