The association between abcb1 gene polymorphism and clopidogrel response variability in stroke ischemic: a cross sectional study.

BACKGROUND: Clopidogrel has been the primary choice of antiplatelet in ischemic stroke that inhibits adenosine diphosphate (ADP)-induced platelet aggregation. P-glycoprotein (P-gp) multidrug resistance-1 (MDR1) is a transmembrane efflux transporter in intestinal cells that plays a significant role in clopidogrel absorption, therefore may affect platelet aggregation. P-gp is encoded by the ABCB1 gene. This study aims to evaluate the effect of ABCB1 polymorphism on clopidogrel response variability in ischemic stroke patients and its genotype frequency. METHODS: A cross-sectional study was conducted in ischemic stroke patients who received clopidogrel between 2020 and 2023 in RSUI/RSCM. All subjects were assessed for ABCB1 polymorphisms C3435T and C1236T. Platelet aggregation were measured using VerifyNow PRU. Clopidogrel response variability was classified into unresponsive (> 208 PRU), responsive (95-208 PRU), and bleeding risk (< 95 PRU). RESULTS: 124 subjects enrolled in this study, with 12,9% of subjects classified as non-responsive/resistant, 49,5% as responsive, and 41,9% as bleeding risk. ABCB1 C1236T homozygote wildtype (CC) was associated with 3,76 times higher bleeding risk than other variants (p = 0,008; 95%CI 1,41 - 10,07). Genotype frequency of ABCB1 C3435T homozygote wildtype, heterozygote, and homozygote variants were 35,9%, 43,5% and 16,9%, respectively; while the genotype frequency of ABCB1 C1236T were 17,8%, 39,5%, and 42,7%, respectively. CONCLUSION: ABCB1 C1236T homozygote wildtype was associated with 3,76 times higher bleeding risk than other variants. The most common genotype frequency of ABCB1 C1236T was homozygote variant; while for ABCB1 C3435T was heterozygote.

Pedicle screw position changing policy for nerve injury problems during screw insertion on thoracolumbar compression fractures.

INTRODUCTION: Intraoperative neurophysiologic monitoring (IONM) had important role related to the complications in spinal surgery. Somatosensory Evoked Potential (SSEP), Transcranial electric Muscle Evoked Potentials (tceMEPs), and free run EMG are parameters used to asses functional integrity of the nervous system during surgical procedures. Once warning signal was recognized, surgeon have to make a precise decision to overcome that problem. PRESENTATION OF CASE: We present a 47-year old male with back pain due to compression fracture of thoracic vertebra T12 and lumbar vertebrae L1. While stabilizing through the posterior approach on the T11 and 12 as well as L2 and L3, the SSEP monitor showed 50% reduction in the waveform as the pedicle screw was inserted at the left side of T12. The instrumentation was changed into vertebra thoracal T10, T11, and vertebrae lumbar L2, L3. The SSEP normalized and post operatively pain decreased. After surgery there was no neurological deficit. DISCUSSION: Acute trauma as a result of spine instrumentation may provoke significant edema, with mass effect causing neurophysiological dysfunction. Administration of intravenous steroid would do at this stage, followed by constant infusion for following 24-48h, may help ameliorating the mass effect and improving the neurologic outcome. Alternatively, immediate pedicle screw changing policy showed absolute recovery of nerve injury. CONCLUSION: Insertion of pedicle screw in spinal surgery has a risk of complication that could be treated by pedicle screw changing policy.

Preservation and Tissue Handling Technique on Iatrogenic Dural Tear with Herniated Nerve Root at Cauda Equina Level.

Iatrogenic or incidental dural tear is a relatively common complication in lumbar decompression surgery. Although mostly there are no changes that occurred in long-term result following an incidental durotomy, the sequelae are not always benign especially when the herniated nerve root is involved. Preservation and tissue handling is paramount in order to prevent further injury. Two cases of dural tear with herniated nerve root complicating the lumbar decompression surgery are presented. Direct watertight repair was performed using the preservation and tissue handling concept. Assessing the relative size between the dural tear and the root mass is the key in determining whether enlargement of tear is needed. Whenever feasible, the tear will not be enlarged. Opening the vent by using a suture anchor and manually repositioning the nerve root with a fine instrument is the key for an atraumatic handling of the herniated nerve root. Clinical and neurophysiology examination was performed postoperatively and no further neurologic deficit occurred despite the iatrogenic injury. Although some debate on a few intraoperative and postoperative details still persists, tissue handling and preservation concept should be applied in all cases.

Intradural Intramedullary Mixed Type Hemangioma: Optimizing the Surgical Management through Intraoperative Neurophysiological Monitoring.

Intradural intramedullary mixed type hemangioma is a rare histotype of primary spinal cord tumors, though it can carry a severe clinical burden leading to limb dysfunction or motor and sensory disturbances. Timely intervention with radical resection is the hallmark of treatment but achieving it is not an easy task even for experienced neurosurgeons. We herein present an exemplificative case presenting with sudden paraplegia in which total resection was achieved under intraoperative neurophysiology monitoring. A thorough discussion on the operative technique and the role of neuromonitoring in allowing a safe surgical management of primary spinal cord tumors is presented.