Semih Gungor

A Systematic Review of NMDA Receptor Antagonists for Treatment of Neuropathic Pain in Clinical Practice

Objective: To investigate the efficacy of N-methyl-D-aspartate receptor (NMDAR) antagonists for neuropathic pain (NeuP) and review literature to determine if specific pharmacologic agents provide adequate NeuP relief. Methods: Literature was reviewed on PubMed using a variety of key words for 8 NMDAR antagonists. These key words include: “Ketamine and Neuropathy,” “Ketamine and Neuropathic Pain,” “Methadone and Neuropathy,” “Methadone and Neuropathic Pain,” “Memantine and Neuropathic pain,” “Memantine and Neuropathy,” “Amantadine and Neuropathic Pain,” “Amantadine and Neuropathy,” “Dextromethorphan and Neuropathic Pain,” “Dextromethorphan and Neuropathy,” “Carbamazepine and Neuropathic Pain,” “Carbamazepine and Neuropathy,” “Valproic Acid and Neuropathy,” “Valproic Acid and Neuropathic Pain,” “Phenytoin and Neuropathy,” and “Phenytoin and Neuropathic Pain.” With the results, the papers were reviewed using the PRISMA (Preferred Reporting in Systematic and Meta-Analyses) guideline. Results: A total of 58 randomized controlled trials were reviewed among 8 pharmacologic agents, which are organized by date and alphabetical order. Of the trials for ketamine, 15 showed some benefit for analgesia. Methadone had 3 positive trials, while amantadine and memantine each only had 2 trials showing NeuP analgesic properties. Dextromethorphan and valproic acid both had 4 randomized controlled trials that showed some NeuP treatment benefit while carbamazepine had over 8 trials showing efficacy. Finally, phenytoin only had 1 trial that showed clinical response in treatment. Conclusions: There are a variety of NMDAR antagonist agents that should be considered for treatment of NeuP. Nevertheless, continued and further investigation of the 8 pharmacologic agents is needed to continue to evaluate their efficacy for treatment of NeuP.

Treatment of Chronic Pain With Various Buprenorphine Formulations: A Systematic Review of Clinical Studies

Clinical studies demonstrate that buprenorphine is a pharmacologic agent that can be used for the treatment of various types of painful conditions. This study investigated the efficacy of 5 different types of buprenorphine formulations in the chronic pain population. The literature was reviewed on PubMed/MEDLINE, EMBASE, Cochrane Database, clinicaltrials.gov, and PROSPERO that dated from inception until June 30, 2017. Using the population, intervention, comparator, and outcomes method, 25 randomized controlled trials were reviewed involving 5 buprenorphine formulations in patients with chronic pain: intravenous buprenorphine, sublingual buprenorphine, sublingual buprenorphine/naloxone, buccal buprenorphine, and transdermal buprenorphine, with comparators consisting of opioid analgesics or placebo. Of the 25 studies reviewed, a total of 14 studies demonstrated clinically significant benefit with buprenorphine in the management of chronic pain: 1 study out of 6 sublingual and intravenous buprenorphine, the only sublingual buprenorphine/naloxone study, 2 out of 3 studies of buccal buprenorphine, and 10 out of 15 studies for transdermal buprenorphine showed significant reduction in pain against a comparator. No serious adverse effects were reported in any of the studies. We conclude that a transdermal buprenorphine formulation is an effective analgesic in patients with chronic pain, while buccal buprenorphine is also a promising formulation based on the limited number of studies.

Postoperative transient blindness after general anesthesia and surgery: case report of conversion disorder

Postoperative acute visual loss due to organic pathology has been described after spinal surgery in the prone position. This report describes a case of transient postoperative blindness in a patient after general anesthesia and surgery in the prone position. Postoperative workup did not reveal any organic pathology. Unbeknown to the treating physicians, the patient had a comorbid untreated psychiatric history. Upon psychiatric consultation, the patient was diagnosed with conversion disorder as a cause of postoperative blindness. There was full recovery of vision after psychiatric intervention within a week.

Epidural hematoma development contralateral to dura after lumbar transforaminal epidural steroid injection

AIM To illustrate the anatomical and pathophysiological risks of epidural hematoma formation, other than direct needle trauma, after lumbar transforaminal epidural steroid injection in the setting of severe central canal stenosis. CASE REPORT This case report presents the development of an epidural hematoma after lumbar transforaminal epidural steroid injection in a patient who has anatomical risk factor of severe lumbar spinal stenosis. The anatomic location of epidural hematoma was at the injected level, but on the contralateral side of the dura at a distance from the needle path. Epidural vascular anatomy and the potential mechanisms of bleeding in the epidural space in the absence of direct needle trauma, including the importance of injection pressures are discussed. CONCLUSION This is the first reported case of an epidural hematoma on the contralateral side of the dura at a distance from the needle tip location, in the setting of severe central canal stenosis.

A Computed Tomography-Guided Demonstration of the Unilateral Distribution of Low-Volume Epidural Injectate

The primary objective of this case report was to demonstrate the unilateral distribution of the low volume injectate given in the epidural space when paramedian interlaminar approach is utilized under computed tomography guidance.

Changes in the Skin Conductance Monitor as an End Point for Sympathetic Nerve Blocks

Objective There is a lack of objective methods for determining the achievement of sympathetic block. This study validates the skin conductance monitor (SCM) as an end point indicator of successful sympathetic blockade as compared with traditional monitors. Methods This interventional study included 13 patients undergoing 25 lumbar sympathetic blocks to compare time to indication of successful blockade between the SCM indices and traditional measures, clinically visible hyperemia, clinically visible engorgement of veins, subjective skin temperature difference, unilateral thermometry monitoring, bilateral comparative thermometry monitoring, and change in waveform amplitude in pulse oximetry plethysmography, within a 30-minute observation period. Differences in the SCM indices were studied pre- and postblock to validate the SCM. Results SCM showed substantially greater odds of indicating achievement of sympathetic block in the next moment (i.e., hazard rate) compared with all traditional measures (clinically visible hyperemia, clinically visible engorgement of veins, subjective temperature difference, unilateral thermometry monitoring, bilateral comparative thermometry monitoring, and change in waveform amplitude in pulse oximetry plethysmography; P ≤ 0.011). SCM indicated successful block for all (100%) procedures, while the traditional measures failed to indicate successful blocks in 16-84% of procedures. The SCM indices were significantly higher in preblock compared with postblock measurements (P < 0.005). Conclusions This preliminary study suggests that SCM is a more reliable and rapid response indicator of a successful sympathetic blockade when compared with traditional monitors.

A Case of Spinal Cord Stimulator Recharging Interruption in Wound Healing

To illustrate the obstacles and problems with electrical fields (EFs) in treatment and management of skin wounds. Unlike the literature that gives evidence for EF promoting wound healing, there is relatively little research to illustrate the interference of wound healing with EFs.