Ipsilateral Muscle Research Articles

Three Episodes of Presumed Culture-Negative Septic Arthritis Following Intramuscular Antipsychotic Injections: A Case Report.

We present a male patient of low socioeconomic status and Māori ethnicity who experienced 3 episodes of presumed culture-negative septic arthritis of the native hip between ages 43 and 52 years. Each episode occurred within 3 weeks of intramuscular antipsychotic injection into the ipsilateral gluteal muscles. The right hip was involved in 2 presentations and the left hip in 1 presentation. No coexisting infection or underlying immune suppression was identified, and at follow-up 2 years after the last episode, he has no sequelae of septic arthritis. This report describes 3 episodes of presumed culture-negative septic arthritis after intramuscular antipsychotic injection.

Improvement in health-related quality of life with Botulinum toxin A injection in acquired superior oblique palsy.

This study aimed to investigate the outcomes of Botulinum toxin A (BTA) injection into the inferior oblique (IO) muscle for the management of unilateral acute acquired superior oblique palsy (SOP) and to evaluate changes in health-related quality of life post-injection using the Adult Strabismus-20 (AS-20) questionnaire. A prospective cohort study was performed in patients with unilateral acute acquired SOP who received BTA injections. Four units of BTA were injected into the ipsilateral IO muscle. Ocular examinations were performed pre-and post-injection, including alignment, ocular movement, and cyclotorsion deviation. The patients' AS-20 questionnaire scores were analyzed. A total of 21 patients with acute acquired SOP were included. The initial median vertical deviation was 5 PD (range 1-16), which was improved to 0 PD (range 0-10) at both 1 and 6 months post-injection (p < 0.001 and p < 0.001, respectively). The median torsional deviation was 7° (range 2-18) at baseline and resolved to 0 degrees (range -3-5) at the 1-month and 0° (range -2-7) at the 6-month follow-up (p < 0.001 and p < 0.001, respectively). There were significant increases in the overall score (OAS), psychosocial subscale score (PSS), and functional subscale score (FSS) from baseline values at both the 1-month (p < 0.001, p < 0.001, and p = 0.001, respectively) and 6-month follow-up (all p < 0.001). Injecting BTA into the ipsilateral IO muscle successfully resolved vertical and torsional deviations and significantly improved quality-of-life scores. Our findings show that BTA treatment, as an early treatment for acute acquired SOP, can help patients by significantly improving their quality of life.

Neuromuscular adjustments to unweighted running: the increase in hamstring activity is sensitive to trait anxiety.

Introduction: Originally developed for astronauts, lower body positive pressure treadmills (LBPPTs) are increasingly being used in sports and clinical settings because they allow for unweighted running. However, the neuromuscular adjustments to unweighted running remain understudied. They would be limited for certain lower limb muscles and interindividually variable. This study investigated whether this might be related to familiarization and/or trait anxiety. Methods: Forty healthy male runners were divided into two equal groups with contrasting levels of trait anxiety (high, ANX+, n = 20 vs. low, ANX-, n = 20). They completed two 9-min runs on a LBPPT. Each included three consecutive 3-min conditions performed at 100%, 60% (unweighted running), and 100% body weight. Normal ground reaction force and electromyographic activity of 11 ipsilateral lower limb muscles were analyzed for the last 30s of each condition in both runs. Results: Unweighted running showed muscle- and stretch-shortening cycle phase-dependent neuromuscular adjustments that were repeatable across both runs. Importantly, hamstring (BF, biceps femoris; STSM, semitendinosus/semimembranosus) muscle activity increased during the braking (BF: +44 ± 18%, p < 0.001) and push-off (BF: +49 ± 12% and STSM: +123 ± 14%, p < 0.001 for both) phases, and even more so for ANX+ than for ANX-. During the braking phase, only ANX+ showed significant increases in BF (+41 ± 15%, p < 0.001) and STSM (+53 ± 27%, p < 0.001) activities. During the push-off phase, ANX+ showed a more than twofold increase in STSM activity compared to ANX- (+119 ± 10% vs. +48 ± 27, p < 0.001 for both). Conclusion: The increase in hamstring activity during the braking and push-off phases may have accelerated the subsequent swing of the free-leg, likely counteracting the unweighting-induced slowing of stride frequency. This was even more pronounced in ANX+ than in ANX-, in an increased attempt not to deviate from their preferred running pattern. These results highlight the importance of individualizing LBPPT training and rehabilitation protocols, with particular attention to individuals with weak or injured hamstrings.

Can exostoses of the external occipital protuberance and superior nuchal lines cause headache? A report of two cases

Compression of the occipital nerves can cause occipital headache. Several potential compression points have been identified along their course. One of these points is the hitherto undescribed instance of exostoses of anatomic structures of the occipital bone. A 34-year-old man with a prominent external occipital tuberance and superior nuchal lines complained of headache in the area of distribution of the greater occipital nerve with tenderness near the bony protrusion on palpation. A 44-year old woman experienced stabbing pain in the lateral orbital region with pressure on the ossified insertion of the ipsilateral trapezius muscle near the external occipital protuberance. Local nerve block achieved temporary relief of pain. Exostosis of the external occipital protuberance and superior nuchal lines may impinge on the greater and third occipital nerves. The characteristics of the pain in our cases differ in some aspects from those of occipital neuralgia.

A Pilot Study of Ratiometric Creatine CEST MRI Assessment of Rabbit Skeletal Muscle Energy Metabolism at 3 T.

pH MRI may provide useful information to evaluate metabolic disruption following ischemia. Radiofrequency amplitude-based creatine chemical exchange saturation transfer (CrCEST) ratiometric MRI is pH-sensitive, which could but has not been explored to examine muscle ischemia. To investigate skeletal muscle energy metabolism alterations with CrCEST ratiometric MRI. Prospective. Seven adult New Zealand rabbits with ipsilateral hindlimb muscle ischemia. 3 T/two MRI scans, including MRA and CEST imaging, were performed under two B1 amplitudes of 0.5 and 1.25 μT after 2 hours of hindlimb muscle ischemia and 1 hour of reperfusion recovery, respectively. CEST effects of two energy metabolites of creatine and phosphocreatine (PCrCEST) were resolved with the multipool Lorentzian fitting approach. The pixel-wise CrCEST ratio was quantified by calculating the ratio of the resolved CrCEST peaks under a B1 amplitude of 1.25 μT to those under 0.5 μT in the entire muscle. One-way ANOVA and Pearson's correlation. P < 0.05 was considered statistically significant. MRA images confirmed the blood flow loss and restoration in the ischemic hindlimb at the ischemia and recovery phases, respectively. Ischemic muscles exhibited a significant decrease of PCr at the ischemia (under both B1 amplitudes) and recovery phases (under B1 amplitude of 0.5 μT) and significantly increased CrCEST from normal tissues at both phases (under both B1 levels). Specifically, CrCEST decreased, and PCrCEST increased with the CrCEST ratio. Significantly strong correlations were observed among the CrCEST ratio, and CrCEST and PCrCEST under both B1 levels (r > 0.80). The CrCEST ratio altered substantially with muscle pathological states and was closely related to CEST effects of energy metabolites of Cr and PCr, suggesting that the pH-sensitive CrCEST ratiometric MRI is feasible to evaluate muscle injuries at the metabolic level. 2 TECHNICAL EFFICACY STAGE: 1.

Cirugía monocular de 4 músculos extraoculares para la exotropía monocular de gran ángulo

IntroductionRecurrent exotropia is common following surgery for monocular large angle constant sensory exotropia. Surgery is usually limited to operations on the affected eye. Simultaneous oblique weakening surgery may enhance the effect of the horizontal rectus muscles surgery by decreasing the abducting forces. We report the results of simultaneous oblique muscle weakening procedures combined with ipsilateral horizontal rectus muscle surgery constant monocular exotropia greater than 35 prism diopters (PD). MethodsRetrospective case series of patients who underwent unilateral lateral rectus recession combined with medial rectus muscle resection and simultaneous weakening of both ipsilateral oblique muscles. Primary outcome measure was ocular alignment in primary position. ResultsTwelve eyes of 12 patients were included. The mean preoperative exotropia improved from 57.9±15.1 (range 35–80; median 60PD) to 3.3±5.5 (range 0–16; median 0PD) postoperatively (p<0.005). Two (66%) patients with a pre-existing vertical deviation had resolution of their vertical misalignment postoperatively. At the last postoperative follow up 92% of the patients had an exodeviation of 10PD or less (range 0–16PD median 0PD), and 7 (58%) measured near and distance orthotropia. Postoperative abduction measured −0.6±1 (0 to −3) and adduction −0.4±0.7 (0 to −2). ConclusionWeakening the ipsilateral oblique muscles may enhance the effect of the horizontal rectus muscles surgery by decreasing the abducting vectorial forces when operating for a large angle monocular exotropia. As an additional potential advantage, oblique muscle surgery may be used simultaneously to address associated vertical deviations.

The Cortical Silent Period in the Cricothyroid Muscle as a Neurophysiologic Feature for Dystonia Observation: E-Field-Navigated Transcranial Magnetic (TMS) Study.

The cortical silent period (cSP) is a period of electrical silence following a motor-evoked potential (MEP) in the electromyographic signal recorded from a muscle. The MEP can be elicited by transcranial magnetic stimulation (TMS) over the primary motor cortex site corresponding with the muscle. The cSP reflects the intracortical inhibitory process mediated by GABAA and GABAB receptors. The study aimed to investigate the cSP in the cricothyroid (CT) muscle after applying e-field-navigated TMS over the laryngeal motor cortex (LMC) in healthy subjects. Then, a cSP as a neurophysiologic feature for laryngeal dystonia was observed. We applied a single-pulse e-field-navigated TMS to the LMC over both hemispheres with hook-wire electrodes positioned in the CT muscle in nineteen healthy participants, which triggered the elicitation of contralateral and ipsilateral corticobulbar MEPs. The subjects were engaged in a vocalization task, and then we assessed the following metrics: LMC intensity, peak-to-peak MEP amplitude in the CT muscle, and cSP duration. The results showed that the cSP duration from the contralateral CT muscle was distributed from 40 ms to 60.83 ms, and from the ipsilateral CT muscle, from 40 ms to 65.58 ms. Also, no significant difference was found between the contralateral and ipsilateral cSP duration (t(30) = 0.85, p = 0.40), MEP amplitude in the CT muscle (t(30) = 0.91, p = 0.36), and LMC intensity (t(30) = 1.20, p = 0.23). To conclude, the applied research protocol showed the feasibility of recording LMC corticobulbar MEPs and observing the cSP during vocalization in healthy participants. Furthermore, an understanding of neurophysiologic cSP features can be used to study the pathophysiology of neurological disorders that affect laryngeal muscles, such as laryngeal dystonia.

Unilateral four muscle surgery for extra-large monocular exotropia

IntroductionRecurrent exotropia is common following surgery for monocular large angle constant sensory exotropia. Surgery is usually limited to operations on the affected eye. Simultaneous oblique weakening surgery may enhance the effect of the horizontal rectus muscles surgery by decreasing the abducting forces. We report the results of simultaneous oblique muscle weakening procedures combined with ipsilateral horizontal rectus muscle surgery constant monocular exotropia greater than 35 prism diopters (PD). MethodsRetrospective case series of patients who underwent unilateral lateral rectus recession combined with medial rectus muscle resection and simultaneous weakening of both ipsilateral oblique muscles. Primary outcome measure was ocular alignment in primary position. ResultsTwelve eyes of 12 patients were included. The mean preoperative exotropia improved from 57.9 ± 15.1 (range 35–80; median 60 PD) to 3.3 ± 5.5 (range 0–16; median 0 PD) postoperatively (p < 0.005). Two of 3 patients with a pre-existing vertical deviation had resolution of their vertical misalignment postoperatively. At the last postoperative follow up 92% of the patients had an exodeviation of 10 PD or less (range 0–16 PD median 0 PD), and 7 (58%) measured near and distance orthotropia. Postoperative abduction measured −0.6 ± 1 (0 to −3) and adduction −0.4 ± 0.7 (0 to −2). ConclusionWeakening the ipsilateral oblique muscles may enhance the effect of the horizontal rectus muscles surgery by decreasing the abducting vectorial forces when operating for a large angle monocular exotropia. As an additional potential advantage, oblique muscle surgery may be used simultaneously to address associated vertical deviations.

Palpebral Fissure Changes in the Contralateral Eye in Duane Retraction Syndrome

Duane retraction syndrome (DRS) is a congenital cranial dysinnervation disorder that is characterized by paradoxical lateral rectus muscle innervation of the affected eye by axons meant to innervate the ipsilateral medial rectus muscle, with resultant varying degrees of co-contraction. It is characterized by severe abduction deficiency, variable limitation of adduction, globe retraction with narrowing of the palpebral fissure, and oblique elevation or depression on adduction. A total of 16 patients with unilateral DRS were identified. The mean age was 13 ± 8 years (range: 6 to 28 years). There were 5 males and 11 females. The cohort included 8 patients with DRS type I, 3 patients with DRS type II, 4 patients with DRS type III, and 1 patient with synergistic divergence (DRS type IV). The mean width of the palpebral fissure in primary gaze was 9.95 ± 0.25 mm, increased in abduction to 11.11 ± 1.16 mm, and changed on adduction to 10.03 ± 1.19 mm. The mean reduction in the size of the palpebral fissure on adduction was 11.7 ± 10.2% (range: 0 to 30%). The difference in the palpebral fissure width between adduction and abduction was statistically significant (P = .0018). Of the 16 patients, 8 (50%) showed narrowing of the palpebral fissure of the contralateral eye on adduction compared to abduction of more than 10%. In this case series of unilateral Duane retraction syndrome, there was a common association between widening of the palpebral fissure of the unaffected eye and adduction of the eyes with DRS in DRS types II, III, and IV and DRS type I with upshoot or downshoot. [J Pediatr Ophthalmol Strabismus. 2023;60(3):e22-e25.].

Is the risk of chronic pain after total temporomandibular joint replacement independent of its indications? A prospective cohort study

Chronic pain is a possible long-term complication after alloplastic temporomandibular joint reconstruction (TMJR). This study was developed to evaluate various subjective and objective measurements to determine the presence and degree of TMJ pain in patients treated with TMJR regardless of the indication for the operation. A prospective, single-centre study was performed. Data on 36 patients (56 TMJR) were collected preoperatively and at follow up two to three years postoperatively. The primary outcome variable was subjective TMJ pain (none/mild, moderate/severe) at follow up. The predictor variables were objective pressure pain thresholds (PPTs) at the ipsilateral joint(s) and muscle(s), functional parameters (incisal range of motion, maximum voluntary clenching), subjective oral health-related quality of life (OHRQoL), and demographic and surgical variables. The number of patients with moderate/severe pain decreased from 17 preoperatively to 10 at follow up. Self-reported TMJ pain was significantly reduced in the entire group (p = 0.001). Patients with moderate/severe pain at follow up were more restricted in their OHRQoL but did not differ in PPT and functional parameters from the no/mild pain group. Moderate/severe TMJ pain at follow up was associated with unilateral TMJR and more preoperative pain. This study provides preliminary evidence that despite good pain reduction in most patients, persistent pain after TMJR is common and, in rare cases, may even worsen regardless of the original diagnosis. At follow up there was a close relation between OHRQoL and TMJ pain. TMJ pain after TMJR cannot be confirmed by objective measurement methods (PPTs and functional parameters).

The Effects of Kinesio Taping® on Muscle Interplay within the Lumbo–Pelvic–Hip Complex: A Randomized Placebo-Controlled Trial

Coordination of muscle activity is determined by the recruitment order of agonists and synergists that results from their onset times. Motor recruitment deficits are possible. This study examined the acute and prolonged effects of three different techniques of the kinesio taping method in optimizing the intermuscular coordination within the lumbo-pelvic-hip complex. The sample consisted of 56 healthy participants of both genders, randomly divided into equal groups by kinesio taping muscle facilitation, muscle inhibition and functional correction technique, and placebo kinesio taping condition. The onsets of the ipsilateral and contralateral erector spinae muscles, in relation to the semitendinosus muscle of the tested leg, were measured using the surface electromyography, during the active performance of the prone hip extension test. Time span was also determined. Measurements were performed at baseline, 60 min, and 48 h post-intervention. For the control group, we did not find statistically significant differences in the onset between the measurement points (p > 0.05), while in the experimental groups, there was a significant delay in the onset of the contralateral erector spinae (p < 0.001) in the second and third measurement points. These results indicate that the kinesio taping method can optimize the intermuscular coordination, with the potential for primary injury prevention.

Implementing a Novel Orthopedic Polytraumatic Injury Model in Laboratory Mice

Background/Objective: Traumatic injury is consistently the leading cause of death up to middle age and is the largest factor in reducing the United States economic productivity. Currently, there are few murine models that emulate orthopedic polytraumatic injury. Existing models typically require sophisticated vascular access resulting in higher costs. We have identified the need for a simple and easily reproducible model. Therefore, we developed a new polytrauma mouse model which included femoral fracture, quadriceps muscle crush, andhemorrhagic shock.&#x0D; Methods: Sixty 12-week-old, C57BL/6 female mice were used in this study. Briefly, a mid-shaft femur fracture was surgically induced on the right leg of each mouse and was stabilized by an intramedullary wire. Next, the ipsilateral quadriceps muscle underwent an interval of crushing injury. Then, to create hemorrhagic shock, mice had approximately 400μL removed through the retroorbital sinus. Lasty, mice were resuscitated with intraperitoneal 1.6 ml of saline 90 minutes later. Other mice served as uninjured controls. Splenocytes were harvested in the control group and at 0-, 1-, 4-, and 24-hours post-trauma (n=12/group). Flow cytometric analyses and animal survival were examined.&#x0D; Results: Of the 48 C57BL/6 mice undergoing the polytrauma model, all survived to their respective time point. There was a significant increase (p&lt;0.05) in neutrophils from the 4-hour cohort compared to the control. There were also significant increases in the 24-hour group in natural killer (NK) cells compared to control (p&lt;0.05), 0-hour (p&lt;0.0001),1-hour (p&lt;0.0001), and 4-hour groups (p&lt;0.05).&#x0D; Conclusion: The survival of all of the mice shows the effectiveness of this model to emulate non-fatal, poly-traumatic injuries. Additionally, increased levels of neutrophils, and NK cells, along with steady levels of B cells are consistent with the known immunologic traumatic response, further validating this model’s ability to create survivable polytrauma conditions.

The application study of dual-energy CT nonlinear blending technique in pulmonary angiography*

Abstract Objective This study aimed to explore the feasibility of enhancing image quality in computed tomography (CT) pulmonary angiography (CTPA) and reducing radiation dose using the nonlinear blending (NLB) technique of dual-energy CT. Methods A total of 61 patients scheduled for CTPA were enrolled, and 30 patients underwent dual-energy scanning. Nonlinear blending images (NLB group) and three groups of linear blending images (LB group, 80 kV group, and 140 kV group) were reconstructed after scanning; 31 patients underwent single-energy scanning (120 kV group). The CT values and standard deviations of the pulmonary trunk, left and right pulmonary arteries, and ipsilateral back muscle at the bifurcation level of the left and right pulmonary arteries were measured. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the five groups were calculated. The subjective image quality of the five groups was assessed. The radiation doses of the dual- and single-energy groups were recorded and calculated. Results The CNR and SNR values of blood vessels in the NLB group were significantly higher than those in the LB, 140 kV, and 80 kV groups (CNR of pulmonary artery trunk: t = 3.50, 4.06, 7.17, all P &lt; 0.05; SNR of pulmonary trunk: t = 3.76, 4.71, 6.92, all P &lt; 0.05). There were no statistical differences in the CNR and SNR values between the NLB group and 120 kV group (P &gt; 0.05). The effective radiation dose of the dualenergy group was lower than that of the single-energy group (t = -4.52, P &lt; 0.05). The subjective scores of images in the NLB group were the highest (4.28 ± 0.74). Conclusion The NLB technique of dual-energy CT can improve the image quality of CTPA and reduce the radiation dose, providing more reliable imaging data for the clinical diagnosis of pulmonary embolism.

Observation study of using a small dose of rituximab treatment for thyroid-associated ophthalmopathy in seven Chinese patients: One pilot study.

To report the efficacy, long-term safety, and tolerability of using a small dose (125 mg/m2 weekly for 4 weeks) of rituximab to treat Chinese patients with thyroid-associated ophthalmopathy (TAO). Seven patients with active moderate-to-severe TAO were prospectively recruited in this study. A small dose of rituximab (125mg/m2 body surface area) was given weekly with a duration of four weeks. Thyroid function, thyrotropin receptor antibody (TRAb), B cell and T cell subsets, ophthalmological examination, magnetic resonance imaging derived parameters, and adverse reactions were recorded at each visit. Seven patients were followed for an average of 224 weeks. B-cell depletion was observed in all patients following rituximab infusion. The clinical activity score (CAS) decreased from 4.86 ± 0.69 to 3.00 ± 0.82 at 5 weeks after treatment (P = 0.033) and remained significantly lower than baseline values at the end of follow-up (P = 0.001). Compared to baseline values, significant decreases in exophthalmos of the right eye, the thickness of extraocular muscles with maximum signal intensity, and the highest signal intensity ratio (SIR) of extraocular muscle to ipsilateral temporal muscle values were observed at the last follow-up (all P < 0.05). Disease progressions or recurrences were not observed during follow-up. Only mild fatigue was observed after the first infusion as a side effect (n = 1). Small dose of rituximab may be a promising option with adequate safety, tolerability, and long-term efficacy for patients with active moderate-to-severe TAO.

Morphological Changes in Paraspinal Muscles on MR Imaging in Chronic Low Back Pain Patients with Unilateral Lumbar Disc Herniation: A Cross-sectional Study

Introduction: Low Back Pain (LBP) caused by Lumbar Disc Herniation (LDH) is a major cause of chronic disability worldwide. The management of LDH depends on clinical assessment and Magnetic Resonance Imaging (MRI) findings. Atrophy or fatty replacement of paraspinous muscles has a negative impact on the outcomes of both conservative and surgical treatment for LBP due to LDH. Aim: To analyse the morphological changes in paraspinous muscles using MRI in patients with chronic LBP and unilateral LDH. Materials and Methods: A cross-sectional study was conducted at Vardhman Mahavir Medical College and Safdarjung Hospital in New Delhi, India, from December 2020 to May 2022. A total of 59 patients, aged 21-65 years, with chronic LBP and unilateral LDH on MRI, were included in the study. The morphological changes in the Multifidus Muscle (MM) and Erector Spinae Muscle (EM) were analysed. The Cross-Sectional Area (CSA) of MM and EM, as well as the Signal Intensity (SI) of MM on the herniated side of the lumbar disc, were recorded and compared to the contralateral side at the same level. Continuous variables were expressed as mean±SD, median, and interquartile range, while categorical variables were presented as numbers and percentages. The Mann-Whitney test was used to compare continuous variables, and a p-value of &lt;0.05 was considered statistically significant. Results: The mean age of the study participants was 39.17±12.82 years, with 59.3% male and 40.7% female participants. The CSA of MM on the side of disc herniation was 5.84±1.53 cm2 , compared to 6.52±1.69 cm2 on the unaffected side (p=0.02). The CSA of EM on the side of unilateral disc herniation was 13.08±3.04 cm2 , compared to 14.29±3.22 cm2 on the unaffected side (p=0.01). The SI of MM on the affected side was 175.84±100.99, compared to 147.70±83.50 on the unaffected side (p=0.02). Conclusion: Chronic LBP due to unilateral LDH resulted in a reduction in the Cross-Sectional Area (CSA) and fatty infiltration of the ipsilateral paraspinous muscles.

MORPHOMETRIC ANALYSIS OF THE SURGICAL CORRIDOR IN THE PRE-PSOAS APPROACH: AN MRI STUDY IN THE BRAZILIAN POPULATION

ABSTRACT Objective: This study aims to perform a morphometric analysis and explore the characteristics of the surgical corridor of the anterior to psoas approach in the Brazilian population through magnetic resonance imaging (MRI). Methods: Two hundred spinal MRI scans of patients aged between 18 and 80 years were evaluated using axial cuts at L2-L5 levels and a sagittal cut, T2 weighted. The relationship between the left psoas muscle and the abdominal aorta or the left common iliac artery was analyzed. The anterior to psoas corridor was defined as the shortest distance between the posterolateral aspect of the aorta or inferior vena cava or the nearest iliac vessel and the anteromedial aspect of the ipsilateral psoas muscle. Results: 104 females and 96 males with a mean age of 49,68±2.04 (range 18–80) years. The mean anterior to psoas distance at the L2-L3 level was 14,17±0.75mm; at the L3-L4 level was 12,08±0.77m,m and at the L4-L5 level was 9,12±0.77mm. The surgical corridors at all levels were larger in the older population. Conclusion: In most Brazilian patients, the anterior to psoas approach can be a good alternative for lumbar intervertebral fusions. As a routine in preoperative examination and surgical planning, lumbar MRI is fundamental in preoperative evaluation for anterior to psoas approach surgery. Level of Evidence IV; Descriptive study.

Strabismus Surgery in Orthophoric Patients With Symptomatic, Asymmetric Vertical or Horizontal Incomitance

To report the indications, operative strategies, and surgical outcomes of patients who undergo vertical and horizontal rectus muscle surgery for incomitant strabismus despite being orthophoric in primary gaze. Retrospective, interventional case series. The setting for this study was an academic practice at Boston Children's Hospital. The patient population comprised 8 orthophoric patients who underwent strabismus surgery to treat vertical/horizontal incomitance. Observation procedures included review of surgical strategies, strabismus measurements in diagnostic gaze positions, and development of postoperative diplopia. The main outcome measures were preserved single vision in primary gaze, comitance, reoperation rate, and patient/surgeon satisfaction. Surgical strategies included the following: (1) simultaneous recession of ipsilateral antagonist rectus muscles; (2) recession or resection of 1 rectus muscle with balancing surgery on the fellow eye; (3) restricting the range of 1 muscle (combined resection and recession or posterior fixation suture); and (4) creating an acceptable deviation in primary gaze. Mean follow-up was 5.4 months (median, 2 months; range, 2-25 months). No patient had new-onset primary gaze diplopia. The median incomitance improved by 9.5 prism diopters. No patient required additional surgery. Patient satisfaction and surgeon assessment of outcomes were high. Although the risk of operating on orthophoric patients with incomitant strabismus may discourage surgeons from offering treatment, the use of specific strategies to address incomitance can preserve alignment in primary gaze while improving patient satisfaction. These strategies may also benefit patients with incomitant strabismus that is symptomatic in primary gaze.

The morphological characteristics of paraspinal muscles in young patients with unilateral neurological symptoms of lumbar disc herniation

ObjectiveThe objective of this study was to explore the morphological characteristics of paraspinal muscles in young patients with unilateral neurological symptoms of lumbar disc herniation.MethodsThis study retrospectively analyzed young patients aged 18–40 years who were hospitalized for lumbar disc herniation in our hospital from June 2017 to June 2020. Data on sex, age, body mass index (BMI), subcutaneous fat tissue thickness (SFTT) at the L1-L2 level, duration of symptoms, degree of lumbar disc herniation, visual analog scale (VAS) for the lower back, Mo-fi-disc score, relative cross-sectional area (RCAS) of the paravertebral muscles (psoas major [PM], multifidus [MF], and erector spinae [ES]), and degree of fat infiltration (DFF) of the paravertebral muscles were collected. The VAS was used to evaluate the intensity of low back pain. Patients with VAS-back >4 points were defined as the low back pain group, and patients with ≤4 points were defined as the control group. The demographic characteristics, as well as the bilateral and ipsilateral paravertebral muscles, of the two groups were compared and analyzed.ResultA total of 129 patients were included in this study (52 patients in the LBP group and 77 patients in the control group). There were no significant differences in sex, BMI, or Pfirrmann grade of lumbar disc herniation between the two groups (P > 0.05). The age of the LBP group (33.58 ± 2.98 years) was greater than that of the control group (24.13 ± 2.15 years) (P = 0.002), and the SFTT at the L1-L2 level (13.5 ± 7.14 mm) was higher than that of the control group (7.75 ± 6.31 mm) (P < 0.05). Moreover, the duration of symptoms (9.15 ± 0.31 months) was longer than that of the control group (3.72 ± 0.48 months) (P < 0.05), and the Mo-fi-disc score (8.41 ± 3.16) was higher than that of the control group (5.53 ± 2.85) (P < 0.05). At L3/4 and L5/S1, there was no significant difference in the RCSA and DFF of the bilateral and ipsilateral paraspinal muscles between the LBP group and the control group. At L4/5, there was no significant difference in the RCSA and DFF of the paraspinal muscles on either side in the LBP group (P > 0.05). In the control group, the RCSA of the MF muscle on the diseased side was smaller than that on the normal side (P < 0.05), and the DFF of the MF muscle on the diseased side was larger than that on the normal side (P < 0.05). In addition, there was no significant difference in the ES and PM muscles on both sides (P > 0.05). At L4/5, the RCSA of the MF muscle on the normal side was significantly smaller in the LBP group than in the control group (P < 0.05), and the DFF of the MF muscle on the normal side was significantly larger in the LBP group than in the control group (P < 0.05). There was no significant difference in the ES and PM muscles on the same side between the two groups (P > 0.05).ConclusionIn young patients with unilateral neurological symptoms of lumbar disc herniation, symmetrical atrophy of the bilateral MF muscle is more prone to causing low back pain. Older age, higher SFTT at the L1-L2 levels, longer symptom duration, higher Mo-fi-di score, and greater muscle atrophy on the normal side of the MF increased the incidence of low back pain in young patients with unilateral lumbar disc herniation.

Non-Invasive Optical Characterization of Tissue Hemodynamics in Sickle Cell Patients Undergoing Treatment with Isoquercetin

Sickle Cell Disease (SCD) is an inherited hemoglobin disorder which causes a mutation in the β subunit of hemoglobin (HbA), thus producing hemoglobin S (HbS) (Williams and Thein, 2018). When HbS is deoxygenated, red blood cells (RBC) can polymerize, which promotes increased rigidity and microvascular occlusions. The presence of mutated HbS increases the likelihood of recurrent venous thromboembolism (VTE). There is an unmet need for real-time, non-invasive methods of assessing microvascular hemodynamics and endothelial dysfunction. Near-Infrared Spectroscopy (NIRS), is a non-invasive, optical technique which measures tissue absorption and scattering between 650-1100 nm in subcutaneous tissue. NIRS has the capability to quantitatively measure the concentration of oxy- and deoxy- hemoglobin as well as blood flow. To determine the sensitivity of NIRS to changes in hemodynamics in SCD patients, we evaluated a cohort of SCD patients undergoing treatment with Isoquercetin (IQ), a flavonoid antithrombotic agent, and correlated the findings with D-dimer, a marker for blood clot degradation. We recruited a sub-cohort of 17 of 46 patients participating in a randomized, double-blind, placebo-controlled trial of IQ and performed an optical hemodynamic assessment at baseline and 4 weeks post-treatment. We used the commercial, multi-modal NIRS device (MetaOx, ISS Inc) which combines frequency-domain NIRS (FD-NIRS) and diffuse correlation spectroscopy (DCS) to acquire optical markers of tissue composition and blood flow, respectively. NIRS testing included resting baseline measurements and a brachial cuff occlusion. As seen in Figure 1A, a blood pressure cuff was wrapped around the bicep and the NIRS probe was placed on the ipsilateral forearm muscle. The challenge consisted of a 3-minute baseline, 3-minute cuff occlusion at 200 mmHg, and a 3-minute recovery. The decay constant τc of the intensity autocorrelation function g2(τ), which is an indicator of the bulk displacement of scattering particles (i.e. RBCs) in the forearm, was fitted from the DCS data. We compared the mean τc during the last 30s of the occlusion to D-dimer levels for all 17 patients at baseline and at 4 weeks follow up. Following a data quality review, 8 patients had NIRS data for baseline and follow up visits. D-dimer levels were 1.875 mcg/mL ± 0.869 mcg/mL at baseline and 1.449 mcg/mL ± 0.874 mcg/mL at 4 weeks follow up. Among the 8 patients with good quality data, 5/8 showed an average decrease in τc by 0.424 ms at 4 weeks follow up and an average decrease in D-dimer levels by 0.768 mcg/mL. The patient in Figure 1B showed 42.0% decrease in τc and 46.6% decrease in D-dimer levels from baseline to 4 weeks follow up. 2/8 patients showed an increase in τc by an average of 0.139 ms and an average increase in D-dimer levels by 0.320 mcg/mL. 1/8 patient showed a decrease in the τc with no change in D-dimer levels. We found that 7/8 patients with baseline and follow up visits had matching trends between D-dimer levels and τc. As demonstrated, a larger τc signified less movement of scattering particles, such as RBCs, due to increased blood coagulation. The remaining 9/17 patients had data from one visit of acceptable quality and were excluded from this analysis. The results of this initial analysis demonstrate autocorrelation decay time could be a promising metric that is reflective of blood coagulation and rheology. While this analysis focused on the changes observed in optical blood flow markers, further work will be performed to both expand upon this analysis and to integrate the compositional data acquired from the FD-NIRS portion of the measurements. NIRS can potentially complement traditional blood biomarkers when assessing anti-thrombotic effects of SCD treatments, such as Isoquercetin. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Interindividual differences in upper limb muscle synergies during baseball throwing motion in male college baseball players

Throwing is a fundamental human motor behavior that has evolved to aid hunting and defense against predators. In modern humans, accurate throwing is an important skill required in many sports. However, the spatiotemporal coordination of muscles during baseball throwing has not been fully elucidated. We herein aimed to identify the muscle synergies involved in baseball throwing and determine whether their spatiotemporal patterns are shared among individuals. Ten college baseball players participated in this study. Electromyographic activity was recorded from 13 ipsilateral upper limb muscles during throwing using full effort. Non-negative matrix factorization was used to extract the motor module composition and temporal activation patterns during baseball throwing, followed by k-means analysis to cluster the extracted motor modules based on their similarity. Four motor modules were extracted for each player. These were classified into four clusters (Clusters 1–4), each reaching the peak activity sequentially from the early cocking phase to ball release. Spatiotemporal interindividual similarity in the muscle synergy cluster comprising the muscles activated during the transition from early cocking to late cocking (Cluster 2) was significantly lower than that in the other clusters. There was no individual-specific muscle synergy. These results suggest that the skilled baseball throwing motion acquired through years of practice may consist of four basic muscle synergies that are common among individuals with some differences in their spatiotemporal patterns.