Trans-Pars Interarticularis Approach for Lumbar Interbody Fusion: An Efficient, Straightforward, and Minimally Invasive Surgery for Lumbar Spondylolisthesis and Stenosis.

PURPOSE: Lumbar interbody fusion is a commonly applied surgical treatment for spondylolisthesis. For this procedure, various minimally invasive approaches have been developed, including posterior lumbar interbody fusion, transforaminal lumbar interbody fusion (TLIF), oblique lumbar interbody fusion, and anterior lumbar interbody fusion. OBJECTIVE: In this study, we characterized the features of a minimally invasive (MIS) trans-pars interarticularis approach for lumbar interbody fusion (TPLIF) and compared its surgical outcomes with those of MIS-TLIF. METHODS: This study included 89 and 44 patients who had undergone MIS-TPLIF and MIS-TLIF, respectively, between September 2016 and December 2022. The following clinical outcomes were analyzed: operative time, blood loss, and hospitalization duration. RESULTS: For the MIS-TPLIF and MIS-TLIF groups, the average operative time, blood loss, and hospitalization duration were, respectively 98.28 and 191.15 min, 41.97 and 101.85 mL, and 5.8 and 6.9 days. CONCLUSION: The MIS-TPLIF approach for lumbar spondylolisthesis or other degenerative diseases involves the use of the commonly available and cost-effective instrument Taylor retractor, thus enabling posterior lumbar interbody fusion to be performed with minimal invasion. This approach also confers the benefits of a short learning curve and an intuitive approach. Our results suggest that although MIS-TPLIF is noninferior to MIS-TLIF, it is easier to learn and perform than MIS-TLIF.

Risk factors for bone cement dislodgement following balloon kyphoplasty for osteoporotic vertebral compression fracture.

OBJECTIVE: The study aimed to determine the incidence and risk factors associated with bone cement dislodgement in patients with osteoporotic vertebral compression fracture following balloon kyphoplasty treatment. METHODS: A retrospective study was conducted on 203 patients who underwent kyphoplasty in 255 vertebral bodies between January 2017 and December 2021. The patients were categorized into two groups: the bone cement dislodgment group (n = 16) and the non-bone cement dislodgement group (n = 239). Various patient characteristics and radiologic parameters were evaluated. Statistical analysis involved the assessment of the background homogeneity of the group by using independent sample t tests, chi-square tests, and Fisher's exact. Univariate and multivariate logistic regression analyses were performed to explore the impact of background variables on cement dislodgement. RESULTS: The results revealed that split-type fracture (χ2 = 31.706, p < 0.001), DISH (χ2 = 18.827, p = 0.011), pedicle fracture (χ2 = 22.246, p < 0.001), endplate deficit (χ2 = 14.023, p < 0.001), posterior wall injury (χ2 = 29.124, p < 0.001), and intervertebral vacuum cleft (χ2 = 21.469, p < 0.001) were the factors that significantly differed between the two groups. The multivariate logistic regression analysis revealed posterior wall injury (OR = 12.983, p = 0.025) and intervertebral vacuum cleft (OR = 5.062, p = 0.024) to be independent risk factors. CONCLUSION: The incidence of bone cement dislodgement in our study was 6.3%. This study underscores the importance of using preoperative radiologic parameters to predict the risk of bone cement dislodgement following balloon kyphoplasty.

Combining Laminoplasty With Artificial Disc Replacement for the Treatment of Cervical Spondylotic Myelopathy With Congenital Cervical Stenosis.

BACKGROUND: Cervical spondylotic myelopathy (CSM) is a very common and devastating spinal disease. Congenital cervical stenosis (CCS) is the most common cause. We aimed to elucidate the security, effectivity, and feasibility of surgery combining laminoplasty with artificial disc replacement (ADR) to treat CSM patients with radiculopathy, especially for preserving the range of motion (ROM) of the cervical spine. METHOD: Between August 2008 and April 2019, 39 patients with multiple CSM caused by CCS were enrolled in the present study. All patients received laminoplasty first and then ADR. We used a retrospective collection of data for evaluating the functional and radiologic outcomes, especially regarding preservation of ROM. RESULTS: Each patient underwent at least a 2-year postoperative follow-up. The Japanese Orthopedic Association score showed great improvements at 6 months. The ADR index-level ROM was preserved during follow-up. The subaxial Cobb angle could also be retained in the whole cervical spine, and the spinal canal diameter could be expanded by more than 52.6%. There were no severe complications or side effects, and no patients needed secondary surgery. CONCLUSIONS: We aimed to treat multiple levels of CSM with adequate decompression without too many intervertebral disc replacements. We were able to expand the spinal canal directly for these patients with CCS and needed only 1- or 2-level ADR to treat them with associated radiculopathy. This combined surgical strategy was secure, effective, and was able to preserve the ROM of the cervical spine.

Aging-Associated Thyroid Dysfunction Contributes to Oxidative Stress and Worsened Functional Outcomes Following Traumatic Brain Injury.

The incidence of traumatic brain injury (TBI) increases dramatically with advanced age and accumulating evidence indicates that age is one of the important predictors of an unfavorable prognosis after brain trauma. Unfortunately, thus far, evidence-based effective therapeutics for geriatric TBI is limited. By using middle-aged animals, we first confirm that there is an age-related change in TBI susceptibility manifested by increased inflammatory events, neuronal death and impaired functional outcomes in motor and cognitive behaviors. Since thyroid hormones function as endogenous regulators of oxidative stress, we postulate that age-related thyroid dysfunction could be a crucial pathology in the increased TBI severity. By surgically removing the thyroid glands, which recapitulates the age-related increase in TBI-susceptible phenotypes, we provide direct evidence showing that endogenous thyroid hormone-dependent compensatory regulation of antioxidant events modulates individual TBI susceptibility, which is abolished in aged or thyroidectomized individuals. The antioxidant capacity of melatonin is well-known, and we found acute melatonin treatment but not liothyronine (T3) supplementation improved the TBI-susceptible phenotypes of oxidative stress, excitotoxic neuronal loss and promotes functional recovery in the aged individuals with thyroid dysfunction. Our study suggests that monitoring thyroid function and acute administration of melatonin could be feasible therapeutics in the management of geriatric-TBI in clinic.

Brain abscess caused by Parvimonas micra: A rare case report and literature review.

Brain abscesses mostly develop due to direct infection caused by a nearby infectious lesion or hematogenous spread and are rarely caused by an odontogenic infection. We report a 47-year-old woman who presented with high fever, disturbed consciousness, headache, and neck pain. Imaging studies revealed a ring-shaped enhanced mass in the left frontal lobe causing a mass effect and midline shift. Magnetic resonance spectroscopy revealed a peak alanine concentration of 1.5 ppm. Supraorbital keyhole surgery with abscess removal was performed, and a bacterial culture confirmed a diagnosis of Parvimonas micra infection. After undergoing 6-week antibiotic treatment, the patient's symptoms resolved completely. No recurrence of abscess was observed during the follow-up period. Although brain abscess caused by P. micra has rarely been reported, an odontogenic origin should be investigated, especially when a patient has a history of periodontal infection or tooth extraction.

Cystic artery pseudoaneurysm: A case report.

BACKGROUND: Cystic artery pseudoaneurysm is a condition rarely encountered by clinicians; this, its etiology and presentation as well as appropriate treatments are not well studied. Although it is treated by removal of the diseased gallbladder and cystic artery, such surgery can be difficult and risky if acute inflammation with bleeding occurs, and not every patient can tolerate the surgery. CASE SUMMARY: An 81-year-old man complained of epigastric pain and tarry stool passage that lasted for 3 d. He had a medical history of poor cardiopulmonary function. The computed tomographic scan of abdomen showed cystic artery pseudoaneurysm and dilatation of gallbladder. Because of high adverse outcomes related to general anesthesia, the patient was successfully managed with endovascular embolization for this cystic artery pseudoaneurysm and percutaneous drainage for the distended gallbladder. CONCLUSION: A patient with cystic artery pseudoaneurysm may quickly deteriorate with the occurrence of concurrent arterial bleeding and sepsis. This report presents the case of a patient who did not undergo surgery due to multiple cardiopulmonary comorbidities and whose condition was managed successfully with embolization and biliary drainage. Endovascular embolization and biliary drainage may provide an alternative option to manage this complicated condition.

Supratentorial hemangioblastoma: A rare case report and literature review.

Hemangioblastomas are rare and benign tumors of the central nervous system. They account for 1.5%-2.5% of all intracranial tumors and have an incidence of 3.2%. The resemblance of hemangioblastomas to other tumors renders preoperative diagnosis and management challenging. Herein, we report a case of a supratentorial hemangioblastoma accompanied by extensive reactive gliosis and diagnosed through magnetic resonance imaging. In addition, we review the relevant literature.

Two-dimensional C-arm robotic navigation system (i-Navi) in spine surgery: a pilot study.

PURPOSE: Pedicle screws placement is very common procedure in spinal surgery. Robotic assisted surgery has been widely used in this operation. We assessed the accuracy of thoracolumbar spine trans-pedicle screws (TPS) implantation utilizing a noval robotic navigation system (i-Navi robotic navigation system) by planning with two-dimensional (2-D) C-arm. METHODS: This study was approved by the Institutional Review Board of the Cathay General Hospital on June 21, 2018 (IRB number: CGH-P 106,092), and written informed consents were obtained from all the patients. There are 18 patients were enrolled in the study. All the patients received the posterior fusion with TPS insertion under the assistant of our robotic navigation system. RESULTS: There are 18 patients were included into our study, there are 2 patients were quitted from the study due to the equipment setup was not complete. Other 16 patients completed the entire procedure successfully. There is total 88 pedicle screws were inserted through i-Navi robotic navigation system. There are 79 of 88 screws were graded A, and 9 screws were graded B; no screws were graded C or D. No vascular or nerve injuries were noted after the operations. CONCLUSION: We present our i-Navi robotic navigation system, by planning with 2-D C-arm imaging and pre-operative CT scans. According to the results of study, we think it can provide a reliable and easy tool to perform the TPS in thoracic lumbar spine surgery.

Pneumatosis intestinalis after systemic chemotherapy for colorectal cancer: A case report.

BACKGROUND: Pneumatosis intestinalis (PI), also known as intramural gas in the small intestine, is a rare condition encountered by patients with cancer after receiving chemotherapy. CASE SUMMARY: A 78-year-old man with a history of colorectal cancer developed epigastric pain and diarrhea after receiving combination chemotherapy of fluorouracil, leucovorin, irinotecan, and cetuximab. Abdomen radiography revealed intramural air in the small intestinal wall. A computed tomography scan of the abdomen revealed the features of PI with air expanding into the mesentery. After surgery, the patient remained symptom-free throughout a 9 mo follow-up period during which he received chemotherapy of fluorouracil, leucovorin, and irinotecan. CONCLUSION: Although chemotherapy-induced PI is rare among patients with cancer, the differential diagnosis of PI and fulminant complications (such as ischemia, infarction, and perforation of the gastrointestinal tract) should be conducted, in which case an urgent surgical intervention is required.

TDP-43 is essential for Eph receptor-class-specific spinal motor axon trajectory into the limb.

During the neural circuit formation, neuronal growth cones must be guided precisely to their neuronal or muscle targets, which can be achieved by the activation of membrane-bound guidance receptors at the periphery. However, the mechanisms that regulate the temporal availability of these receptors remain largely unknown. TAR DNA binding protein-43 (TDP-43) has been proposed to bind with the mRNAs of guidance receptors, thus prompting us to investigate its role in axon guidance of the spinal lateral motor column (LMC) neurons into the limb mesenchyme. We first identified the TDP-43 expression in the LMC neurons at the stage of axons growth into the limb using in situ mRNA hybridization. The loss and gain of TDP-43 function in chick LMC neurons redirected their axon trajectory with opposite effects. In mice, a spinal motor neuron-specific TDP-43 deletion led to the misrouting of LMC axons. Further, ectopic TDP-43 expression increased EphB protein levels in LMC neurons, suggesting that TDP-43 mediates LMC pathfinding by regulating EphB expression. Finally, TDP-43 levels influenced the growth preference of LMC neurites against ephrin-B, but not Netrin-1 and Semaphorin ligands. Our results demonstrate that TDP-43 is essential for the ephrinB:EphB signaling-mediated axon trajectory selection of LMC subtypes into the limb.

Advances in Antibody-Based Therapeutics for Cerebral Ischemia.

Cerebral ischemia is an acute disorder characterized by an abrupt reduction in blood flow that results in immediate deprivation of both glucose and oxygen. The main types of cerebral ischemia are ischemic and hemorrhagic stroke. When a stroke occurs, several signaling pathways are activated, comprising necrosis, apoptosis, and autophagy as well as glial activation and white matter injury, which leads to neuronal cell death. Current treatments for strokes include challenging mechanical thrombectomy or tissue plasminogen activator, which increase the danger of cerebral bleeding, brain edema, and cerebral damage, limiting their usage in clinical settings. Monoclonal antibody therapy has proven to be effective and safe in the treatment of a variety of neurological disorders. In contrast, the evidence for stroke therapy is minimal. Recently, Clone MTS510 antibody targeting toll-like receptor-4 (TLR4) protein, ASC06-IgG1 antibody targeting acid sensing ion channel-1a (ASIC1a) protein, Anti-GluN1 antibodies targeting N-methyl-D-aspartate (NMDA) receptor associated calcium influx, GSK249320 antibody targeting myelin-associated glycoprotein (MAG), anti-High Mobility Group Box-1 antibody targeting high mobility group box-1 (HMGB1) are currently under clinical trials for cerebral ischemia treatment. In this article, we review the current antibody-based pharmaceuticals for neurological diseases, the use of antibody drugs in stroke, strategies to improve the efficacy of antibody therapeutics in cerebral ischemia, and the recent advancement of antibody drugs in clinical practice. Overall, we highlight the need of enhancing blood-brain barrier (BBB) penetration for the improvement of antibody-based therapeutics in the brain, which could greatly enhance the antibody medications for cerebral ischemia in clinical practice.

Cervical myeloradiculopathy as an initial presentation of pseudogout.

Pseudogout, also known as calcium pyrophosphate deposition disease, is an inflammatory arthropathy that primarily occurs in the peripheral joints, such as the knee or elbow. Spinal pseudogout is uncommon, and neck pain is its most common clinical manifestation. However, cervical myeloradiculopathy as an initial presentation of pseudogout attack of the ligamentum flavum has rarely been reported in the literature. We report a case of a 65-year-old woman who presented with neck pain, bilateral finger numbness, and left-sided upper extremity weakness. Magnetic resonance images showed an epidural mass at the C4-5 level, compressing the spinal cord. Following laminectomy with removal of the calcified mass, the profound neurologic deficits gradually recovered. A pathological examination confirmed the diagnosis of cervical pseudogout.

Extrahepatic pseudocyst in an adult.

Ventriculoperitoneal (VP) shunts are commonly used in neurosurgical procedures to treat hydrocephalus. Although shunt-associated abdominal complications are well documented, extrahepatic pseudocysts are a rare shunt complication in adult patients. Therefore, we herein report the case of a 54-year-old male patient who presented with a bulging mass around the previous surgical site at the right upper quadrant of the abdomen. He had a 4-year history of VP shunt surgery for posthemorrhagic hydrocephalus. A computed tomographic scan revealed a large extrahepatic pseudocsyt. Our case represented a rare entity of extrahepatic pseudocyst in adult patients underwent VP shunt surgery. The clinical presentation, diagnostic tools, and treatment methods were discussed.

Association between cranial asymmetry severity and chronic subdural hematoma laterality.

OBJECTIVE: To analyze the association between cranial asymmetry severity and chronic subdural hematoma (CSDH) laterality. METHODS: We retrospectively assessed 120 patients with surgically treated unilateral CSDH from January 2009 to December 2018. Preoperative computed tomography images were used to determine occipital vault angles, bilateral cranium areas, and cranial index of symmetry (CIS) ratios. RESULTS: The male sex (70%) was the predominant factor promoting CSDH pathogenesis. In the overall study population (mean age, 71.3 years; left-sided CSDH, 58/120 [48%] patients; right-sided CSDH due to right-sided flat cranium, 38 patients; left-sided CSDH due to right-sided flat cranium, 37 patients). Flat cranial asymmetry was nonsignificantly associated with CSDH laterality (p-value=.689). However, most CSDH patients (86.7% of 120 patients) presented dominant-sided nonoverlapping areas on the left side. Thirteen (81.3%) patients presenting right-dominant nonoverlapping areas had right-sided CSDH, and 55 (52.9%) patients had left-dominant nonoverlapping area had left-sided CSDH (p-value=0.01). The CIS ratio was significantly higher in patients with right-dominant nonoverlapping areas than in those with left-dominant nonoverlapping areas (97.2% vs 95.9%, p-value<0.0001). CONCLUSION: Left-sided hematoma predominance is not associated with a flat cranium and laterality of unilateral CSDH. Moreover, more asymmetric crania with lower CIS ratios may predict left-sided CSDHs, whereas the right-sided CSDHs may be more common in symmetric crania with higher CIS ratios. The CSDH laterality is potentially attributable to cranial asymmetry severity.

Gastric perforation by a ventriculoperitoneal shunt in an adult.

Ventriculoperitoneal (VP) shunt operation is a common neurosurgical procedure applied for managing intracranial hydrocephalus. Migration of a distal catheter is an uncommon complication, and related gastric perforation is rarely reported. Herein, we report the case of gastric perforation in a patient with VP shunt who presented with fever. The distal catheter within the stomach was confirmed by preoperative computed tomographic scan of abdomen and gastric endoscopy. Surgical intervention and appropriate antibiotics management enabled patient recovery. This case emphasizes the importance of early recognition and surgical intervention in this rare complication related to the shunt procedure.

Interleukin-1 receptor antagonist ameliorates the pain hypersensitivity, spinal inflammation and oxidative stress induced by systemic lipopolysaccharide in neonatal rats.

Perinatal inflammation-induced reduction in pain threshold may alter pain sensitivity to hyperalgesia or allodynia which may persist into adulthood. In this study, we investigated the anti-inflammatory protective effect of interleukin-1 receptor antagonist (IL-1ra), an anti-inflammatory cytokine, on systemic lipopolysaccharide (LPS)-induced spinal cord inflammation and oxidative stress, thermal hyperalgesia, and mechanical allodynia in neonatal rats. Intraperitoneal (i.p.) injection of LPS (2 mg/kg) or sterile saline was performed in postnatal day 5 (P5) rat pups, and IL-1ra (100 mg/kg) or saline was administered (i.p.) 5 min after LPS injection. Pain reflex behavior, spinal cord inflammation and oxidative stress were examined 24 h after LPS administration. Systemic LPS exposure led to a reduction of tactile threshold in the von Frey filament tests (mechanical allodynia) and pain response latency in the tail-flick test (thermal hyperalgesia) of P6 neonatal rats. Spinal cord inflammation was indicated by the increased numbers of activated glial cells including microglia (Iba1+) and astrocytes (GFAP+), and elevated levels of pro-inflammatory cytokine interleukin-1ß (IL-1ß), cyclooxygenase-2 (COX-2), and prostaglandin E2 (PGE2) 24 h after LPS treatment. LPS treatment induced spinal oxidative stress as evidenced by the increase in thiobarbituric acid reactive substances (TBARS) content in the spinal cord. LPS exposure also led to a significant increase in oligodendrocyte lineage population (Olig2+) and mature oligodendrocyte cells (APC+) in the neonatal rat spinal cord. IL-1ra treatment significantly reduced LPS-induced effects including hyperalgesia, allodynia, the increased number of activated microglia, astrocytes and oligodendrocytes, and elevated levels of IL-1ß, COX-2, PGE2, and lipid peroxidation (TBARS) in the neonatal rat spinal cord. These data suggest that IL-1ra provides a protective effect against the development of pain hypersensitivity, spinal cord inflammation and oxidative stress in the neonatal rats following LPS exposure, which may be associated with the blockade of LPS-induced pro-inflammatory cytokine IL-1ß.

Systemic Lipopolysaccharide-Induced Pain Sensitivity and Spinal Inflammation Were Reduced by Minocycline in Neonatal Rats.

In this study, we investigated the effects of minocycline, a putative suppressor of microglial activation, on systemic lipopolysaccharide (LPS)-induced spinal cord inflammation, allodynia, and hyperalgesia in neonatal rats. Intraperitoneal (i.p.) injection of LPS (2 mg/kg) or sterile saline was performed in postnatal day 5 (P5) rat pups and minocycline (45 mg/kg) or vehicle (phosphate buffer saline; PBS) was administered (i.p.) 5 min after LPS injection. The von Frey filament and tail-flick tests were performed to determine mechanical allodynia (a painful sensation caused by innocuous stimuli, e.g., light touch) and thermal hyperalgesia (a condition of altered perception of temperature), respectively, and spinal cord inflammation was examined 24 h after the administration of drugs. Systemic LPS administration resulted in a reduction of tactile threshold in the von Frey filament tests and pain response latency in the tail-flick test of neonatal rats. The levels of microglia and astrocyte activation, pro-inflammatory cytokine interleukin-1ß (IL-1ß), cyclooxygenase-2 (COX-2), and prostaglandin E2 (PGE2) in the spinal cord of neonatal rats were increased 24 h after the administration of LPS. Treatment with minocycline significantly attenuated LPS-induced allodynia, hyperalgesia, the increase in spinal cord microglia, and astrocyte activation, and elevated levels of IL-1ß, COX-2, and PGE2 in neonatal rats. These results suggest that minocycline provides protection against neonatal systemic LPS exposure-induced enhanced pain sensitivity (allodynia and hyperalgesia), and that the protective effects may be associated with its ability to attenuate LPS-induced microglia activation, and the levels of IL-1ß, COX-2, and PGE2 in the spinal cord of neonatal rats.

Accuracy and Safety of Using Customized Guiding Templates for Cervical Pedicle Screw Insertion in Severe Cervical Deformity, Fracture, and Subluxation: A Retrospective Study of 9 Cases.

OBJECTIVE: To assess accuracy and safety of self-developed customized guiding templates for cervical pedicle screw (CPS) insertion surgery. METHODS: From July 2016 to December 2017, 57 screws were implanted in 9 patients with the assistance of customized guiding templates. Customized guiding templates were manufactured from acrylonitrile-butadiene-styrene plastic material using a three-dimensional printer after establishing pedicle screw trajectories for each vertebra with the assistance of a virtual surgical planning software program, developed by our team, for the insertion of CPSs. RESULTS: CPSs were evaluated using the following grading system: grade 0 (contained), grade 1 (exposure), grade 2 (perforation), and grade 3 (penetration). Each patient underwent postoperative computed tomography to evaluate accuracy of screw position. Of 57 screws, 54 were graded 0, and 3 were graded 1; no screws were graded 2 or 3. No vascular or nerve injuries were noted after the operations. CONCLUSIONS: CPSs, which provide strong biologic strength, are especially suitable for treating osteoporosis and severe deformity. However, CPS insertion remains a challenging procedure with high incidences of vascular and nerve injuries reported. The results of this study indicate that use of customized guiding templates can improve safety of CPS insertion surgery.

Impact of Intraoperative 3-Dimensional Volume-Rendering Rotational Angiography on Clip Repositioning Rates in Aneurysmal Surgery.

OBJECTIVE: Three-dimensional (3D) rotational angiography (RA), a gold standard imaging tool for the evaluation of cerebral aneurysms after clipping, can currently be performed intraoperatively in a hybrid operating room (OR). However, its role in intraoperative aneurysmal surgery is unclear. We aimed to study the value of intraoperative 2-dimensional digital subtraction angiography (2D-DSA) and 3D-RA for the evaluation of aneurysms after clipping, in terms of clip repositioning. METHODS: We included patients with cerebral aneurysms who were treated with microsurgical clipping in a hybrid OR. After aneurysmal clipping and indocyanine green video angiography assessment, intraoperative 2D-DSA and 3D-RA with volume-rendering (VR) images of the clipped aneurysm were obtained. The incidence rate of clip repositioning was determined, and aneurysm-related factors associated with suboptimal clipping that required clip revision after intraoperative angiography evaluation were analyzed. RESULTS: Between September 2016 and August 2017, 24 consecutive patients with 35 aneurysms were treated with microsurgical clipping. A clip repositioning rate of 17.1% was revealed after intraoperative 3D-VR imaging and initial indocyanine green-video angiography. 3D-VR was able to demonstrate all aneurysmal remnants, whereas 2D-DSA helped confirm flow stagnation in compromised vessels. Challenging aneurysms of size >7 mm (P = 0.043) and neck width >4 mm (P = 0.012) were significantly associated with a higher incidence of suboptimal aneurysmal clipping. CONCLUSIONS: A hybrid OR, with angiography facilities for high-resolution 2D-DSA and 3D-VR images, allows neurosurgeons to perform high-quality surgery. The routine use of intraoperative 3D-RA may not be necessary; however, it is invaluable for treating challenging aneurysms.