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STUDY DESIGN A prospective analysis. OBJECTIVE To test if threshold-based monitoring of compound muscle action potentials (CMAPs) by stimulating the screw loaded to uninsulated extender sleeve provides a valid safety warning for percutaneous pedicle screw (PPS) placements in the lumbosacral spine. SUMMARY OF BACKGROUND DATA Utility of the CMAP monitoring to PPS procedures remains controversial. METHODS A series of 202 patients underwent a total of 1664 lumbosacral PPS placements under CMAP monitoring without fluoroscopic guidance. The monitoring consisted of stimulating the PPS assembled to uninsulated extender sleeve and recording CMAPs from the vastus medialis, biceps femoris, tibialis anterior, and medial gastrocnemius. Automated steps of a threshold hunting algorithm using 0.2-ms duration pulses of increasing intensities delivered at 2/s allowed quick determination of a minimum stimulation current to evoke >100-μV amplitude CMAPs. RESULTS At L2 through S1 spines, postoperative CT scans identified 51 medial or inferior pedicle wall breaches of 1536 screws (3.3%) without neurologic complications. The ROC curve analysis determined the critical cut-off threshold value of 27 mA (74% sensitivity and 95% specificity) for predicting 35 breaches of 627 screws (5.6%) at L2 and L3, and of 17 mA (100% sensitivity, 98% specificity) for 16 of 909 (1.8%) at L4 through S1. While advancing the screw, 3 breaches (5.9%) showed a particularly low threshold of ≤6-mA, allowing the surgeon to immediately redirect the screw and retest the new trajectory as safe. CONCLUSION Screw stimulation with threshold hunting algorithm has a distinct advantage over the time-consuming insulated pilot hole stimulation, allowing an uninterrupted flow of the surgery. The present findings have documented practical usefulness and reliability of CMAP monitoring using direct stimulation of the PPS assembled to uninsulated extender sleeve.Level of Evidence: 2.

The demand for intraoperative monitoring (IOM) of lumbar spine surgeries has escalated to accommodate more challenging surgical approaches to prevent perioperative neurologic deficits. Identifying impending injury of individual lumbar roots can be done by assessing free-running EMG and by monitoring the integrity of sensory and motor fibers within the roots by eliciting somatosensory (SEP), and motor evoked potentials. However, the common nerves for eliciting lower limb SEP do not monitor the entire lumbar plexus, excluding fibers from L1 to L4 roots. We aimed to technically optimize the methodology for saphenous nerve SEP (Sap-SEP) proposed for monitoring upper lumbar roots in the operating room. In the first group, the saphenous nerve was consecutively stimulated in two different locations: proximal in the thigh and distal close to the tibia. In the second group, three different recording derivations (10–20 International system) to distal saphenous stimulation were tested. Distal stimulation yielded a higher Sap-SEP amplitude (mean ± SD) than proximal: 1.36 ± 0.9 µV versus 0.62 ± 0.6 µV, (p

To study if spinal motor evoked potentials (SpMEPs), muscle responses after electrical stimulation of the spinal cord, can monitor the corticospinal tract. Study 1 comprised 10 consecutive cervical or thoracic myelopathic patients. We recorded three types of muscle responses intraoperatively: (1) transcranial motor evoked potentials (TcMEPs), (2) SpMEPs and (3) SpMEPs + TcMEPs from the abductor hallucis (AH) using train stimulation. Study 2 dealt with 5 patients, who underwent paired train stimulation to the spinal cord with intertrain interval of 50-60 ms for recording AH SpMEPs. We will also describe two illustrative cases to demonstrate the clinical value of AH SpMEPs for monitoring the motor pathway. In Study 1, SpMEPs and SpMEPs + TcMEPs recorded from AH measured nearly the same, suggesting the collision of the cranially evoked volleys with the antidromic signals induced by spinal cord stimulation via the corticospinal tracts. In Study 2, the first and second train stimuli elicited almost identical SpMEPs, indicating a quick return of transmission after 50-60 ms considered characteristic of the corticospinal tract rather than the dorsal column, which would have recovered much more slowly. Of the two patients presented, one had no post-operative neurological deteriorations as anticipated by stable SpMEPs, despite otherwise insufficient IONM, and the other developed post-operative motor deficits as predicted by simultaneous reduction of TcMEPs and SpMEPs in the face of normal SEPs. Electrical stimulation of the spinal cord primarily activates the corticospinal tract to mediate SpMEPs.

In this study, porous boron nitride (p-BN) with hexagonal phase boron nitride (h-BN) pore walls was synthesized using high-temperature calcination. Negligible variation in pore-wall structure can be observed in powder X-ray diffraction (XRD) profiles and infrared (IR) spectra. However, a highly stable p-BN with a stable pore structure even at 973 K under the oxidative conditions is obtained when synthesized at higher than 1573 K under nitrogen gas flow. For p-BN, this stability is obtained by generating h-BN microcrystals. Nitrogen adsorption–desorption isotherms at 77 K provide type-IV features and typical adsorption–desorption hysteresis, which suggests micropore and mesopore formation. Moreover, adsorption–desorption isotherms of Ar at 87 K are measured and compared with those of nitrogen. The relative adsorbed amount of nitrogen (i.e., the amount of nitrogen normalized by that of Ar at each relative pressure or adsorption potential value) on p-BN is considerably larger than that on microporous carbon at low-pressure regions, which suggests the existence of strong adsorption sites on the p-BN surface. In fact, the relative number of adsorbed nitrogen molecules to that of Ar on p-BN is, at most, 150%–200% larger than that on microporous carbon for the same adsorption potential state. Furthermore, additional adsorption enhancement to nitrogen between P/P0 = 10−5 and 10−3 can be observed for p-BN treated at 1673 K, which suggests the uniformly adsorbed layer formation of nitrogen molecules in the vicinity of a basal planar surface. Thus, unlike typical nanoporous sp2 carbons, p-BN materials have the potential to enhance adsorption for certain gas species because of their unique surface state.

Highlights • Myokymia with neuromyotonic discharges was originated from median nerve motor axons. • Inching studies with a concentric needle using a filter setting for single fiber electromyography detected a focal slowing near the distal crease at the wrist, an entrapment site occasionally seen in the carpal tunnel syndrome. • One injection of botulinum toxin type A eliminated the myokymia, which then recurred two and a half years later, showing less prominent muscle twitches., Objective We report a case of sustained atypical myokymia associated with short bursts of neuromyotonic discharges involving the abductor pollicis brevis (APB) muscle and describe a useful way of detecting a focal slowing involving a small number of median nerve motor fibers with a concentric needle using the filter setting for single fiber electromyography (EMG). Methods and Results A 62-year-old woman developed right thumb twitches at regular interval of 1.7–3.3 s (0.6–0.3 Hz), which continued for more than four months. Muscle twitches remained the same during altered hand position, psychological stress, or sleep. A concentric needle inserted in the active zone of the APB muscle revealed myokymic bursts with a characteristic of neuromyotonic discharges. Inching study, stimulating at 5 mm increment along the median nerve and recording with a concentric needle using a filter setting for single fiber EMG, revealed a focal slowing of the motor fibers at a point 5–10 mm distal from the distal crease of the wrist, an entrapment site occasionally seen in the carpal tunnel syndrome. One injection of botulinum toxin type A eliminated the myokymia, which then recurred two and a half years later, showing less prominent muscle twitches. Conclusions Sustained atypical myokymia seen in our case represented bursts of neuromyotonic discharges originated from a focal demyelinating lesion involving a few median nerve motor fibers.

Prophylactic splenectomy for hilar lymph node (#10) dissection has shown no survival benefit for patients with proximal advanced gastric cancer that does not invade the greater curvature. However, the survival benefit of prophylactic splenectomy for proximal advanced gastric cancer invading the greater curvature side, particularly for clinically negative #10 lymph node metastasis (#10[-]) cases remains controversial.This multi-institutional retrospective study enrolled 146 consecutive patients with proximal advanced gastric cancers invading the greater curvature side with clinical #10(-) who underwent R0 total gastrectomy. For 33 of these patients, splenectomy was performed, and the remaining 113 underwent spleen-preservation gastrectomy. Short- and long-term results were compared between the splenectomy and spleen-preservation groups, with the incidence of #10 metastasis in the splenectomy group and recurrence in the spleen-preservation group compared.In the splenectomy group, longer operative time, greater blood loss, more frequent postoperative abdominal infection, and longer hospital stay were observed than in the spleen-preservation group. The two groups exhibited no differences in median relapse-free survival time (31.1 vs 59.8 months; P = 0.684) or median overall survival time (64.9 vs 65.1 months; P = 0.765). The pathologic #10 lymph node metastasis rate was 3% in the splenectomy group, and the #10 lymph node recurrence rate was 2.7% in the spleen-preservation group.Prophylactic splenectomy showed more frequent postoperative morbidities and a longer hospital stay than spleen preservation, without any long-term survival benefits.

Objective To study the relationship between various electrodiagnostic modalities in acute facial palsy. Setting Academic tertiary care center. Patients One‐hundred and six patients who presented with traumatic or non‐traumatic acute facial paralysis (House‐Brackmann, HB, grade 6/6) between 2008 and 2017 and underwent acute electrodiagnostic testing. Intervention Electroneurography (ENoG) using nasolabial fold (NLF) or nasalis muscle (NM) methods, and volitional electromyography (EMG) in all patients. Main outcome measures Percent degeneration of ipsilateral facial nerve compound muscle action potentials (CMAP) on NLF‐ and NM‐ENoG, presence or absence of muscle unit potentials (MUPs) on EMG. Results Extent of facial nerve degeneration measured by NLF‐ and NM‐ENoG were highly correlated (r = 0.85, P, This is an original study that defines outcomes for electrodiagnostic testing in acute facial palsy and compares two methods. Electrodiagnostic testing is often used by clinicians to prognosticate outcomes for patients with acute facial palsy and determine candidacy for facial nerve decompression. This study describes one of the largest cohorts of patients to date with acute facial paralysis (House‐Brackmann 6/6) and detailed electrodiagnostic testing, consisting of two methods of electroneurography (ENoG) and electromyography (EMG).

To establish age-related characteristics and normative values of F waves in healthy Chinese infants.We studied median, ulnar and tibial nerves on one side distally in 229 healthy Chinese infants (108 males) ranging from 1 to 12 months old.Minimal F-wave latencies (Fmin) showed a strong negative correlation to the age for median, ulnar and tibial nerves (P 0.01) but no correlation to the height. Statistical analyses revealed a significant (P 0.01) decrease of Fmin during the second month of life and no change (P 0.05) thereafter. Dividing the infants into 1 month old (Group 1) and 2-12 months old (Group 2), normal values (Mean ± SD ms) of Fmin for tibial, median and ulnar nerves consisted of 23.38 ± 1.68, 17.19 ± 0.95 and 16.47 ± 1.06 for Group 1 and 21.42 ± 1.25, 14.50 ± 1.15 and 14.52 ± 0.90 for Group 2.F-wave latencies shorten in the 2nd month of life and change little thereafter when age-related maturation counters the concomitant growth of the nerve length.F waves can assess infantile neuropathies as a reliable measure, complementing the technically difficult conventional nerve conduction study in short limbs.

Highlights • Absence of F-waves in weak patients may be due to reduced F-wave excitability. • Re-emergence of F-waves was elicited after a 1-second train of 20 Hz supramaximal RNS. • “Re-awakening” of F-waves using RNS may help exclude AIDP as a cause of weakness., Aim Absence of the F-wave may represent the inability of spinal motor neurons to be excited after periods of inactivity. Repetitive stimulation in an otherwise immobile patient acts as a voluntary movement therefore allowing for the production of an F-wave in a patient with previously demonstrated absent F-waves. Through this case report, we attempt to highlight that the absence of the F-wave may result from inexcitability of spinal motor neurons after reduced mobilization. Case We present the case of a 48-year-old woman who had been hospitalized in an ICU setting for almost one month due to a subarachnoid hemorrhage, pancreatitis, and respiratory failure. An electromyogram and nerve conduction study (NCS) was performed for weakness in all four extremities. On routine NCS, her F-waves were absent, but after repetitive stimulation was performed, her F-waves appeared. Discussion This may be further evidence that the absence of the F-wave may result from inexcitability of spinal motor neurons after immobilization or reduced mobility rather than true pathology of the peripheral nerve. The ability to recover F-waves after an initial absence could assist in differentiating between inexcitability of the anterior horn cell and proximal nerve conduction block. This case presentation is an attempt to show that repetitive nerve stimulation may prove to be a useful technique to restore F-waves in patients who are unable to voluntarily contract their muscles, which may help exclude certain pathologic processes.

This chapter gives an overview on the historical development of shipbuilding technologies that facilitated the water transportation of commodities and people in the Maritime Silk Route trade. Maritime archaeological research has examined ship remains and wreck sites found in Southeast Asia and East Asia and clarified types of seagoing ships widely used for the early and medieval Maritime Silk Route trading activities. The trading ships with the seaworthiness and a large cargo-carrying capacity propelled merchants and seafarers from the Indian Ocean World and Southeast Asia to voyage actively to China during the Tang Dynasty. In medieval periods, the growth of ship construction techniques impacted on the advent of mass shipment by Chinese merchants in the long distance maritime trade.

The Maritime Silk Road foregrounds the numerous networks that have been woven across oceanic geographies, tying world regions together often far more extensively than land-based routes. On the strength of the new data which has emerged in the last two decades in the form of archaeological findings, as well as new techniques such as GIS modelling, the authors collectively demonstrate the existence of a very early global maritime trade. From architecture to cuisine, and language to clothing, evidence points to early connections both within Asia and between Asia and other continents—well before European explorations of the Global South. The human stories presented here offer insights into both the extent and limits of this global exchange, showing how goods and people travelled vast distances, how they were embedded in regional networks, and how local cultures were shaped as a result.