Browsing by Author "Mirzai, H"

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    Neurotoxicity of chronic epidural somatostatin administration in rabbits
    Tekin, I; Mirzai, H; Yentur, EA; Ates, U; Baka, M; Yurtseven, M
    The central administration of somatostatin (SMS) in humans became a subject of controversy on the issue of potential neurotoxicity on the spinal cord. The study was aimed at the assessment of the neurodegenerative effects of chronic epidural SMS administration in rabbits. Rabbits were randomly assigned to two groups: the SMS and the control group. The SMS group received 100 mug SMS and the control group received isotonic saline by epidural catheter for 15 consecutive days. Then, laminectomy was performed and the spinal cord was removed. Light and electron microscopic examinations were performed. In the control group, a mild dural inflammatory response and in the SMS group, loss of Nissl bodies at the pericarion, chromatolysis and shrinking at nucleus membranes were observed in all animals at different degrees in light microscopy. In electron microscopy, mitochondrial swellings, irregularities in both nucleus and cell membrane, splitting at myelin lamellae, degeneration at myelin sheath and shrinking of axolemma were found in the SMS group. Our results showed the neurotoxic effects of chronic administration of SMS in rabbits both in light and electron microscopy even in a quite low doses. However, there were no significant clinical findings for the neurological effects during long term follow up.
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    Histological discrepancies in malignant glioneuronal tumors: A report of 4 cases
    Isisag, A; Nese, N; Demirtas, E; Tunakan, M; Rezanko, T; Temiz, C; Mirzai, H
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    Repeated epidural injections of ketamine with preservative benzethonium chloride produce evidence for neurotoxicity in rabbits
    Yentur, EA; Mirzai, IT; Mirzai, H; Ates, U; Baka, M; Yurtseven, M
    Background and objectives: In this study, we investigated whether repeated doses of 1% ketamine with preservative benzethonium chloride, administered into the epidural space of the rabbit, caused direct neurotoxicity. Methods: Twelve rabbits were randomly assigned to two groups (ketamine and control). After the animals were anesthetized, lumbar epidural catheters were placed for repeated epidural drug delivery. The ketamine group received 1% ketamine with preservative benzethonium chloride (0.5 ml) and the control group received isotonic saline (0.5 ml) once a day for 14 consecutive days. The day after the last injection, the animals were reanaesthetized, the left and right ventricles were cannulated and perfused with 2% glutaraldehyde, 1% formaldehyde mixture, in 0.1 mol/l phosphate buffer. Then, laminectomy was performed. A five centimetre segment of the spinal cord was removed and examined by light and electron microscopy to observe possible histological changes. Microscopic examinations were performed by coding each animal by a neuro-histologist who was blinded as to the source of each specimen. Results: Ketamine-treated rabbits showed significant histological changes at light and electron microscopy findings compared with the control group (p < 0.05). Conclusions: These changes suggested a neurotoxic effect of ketamine with preservative benzethonium chloride following chronic epidural administration.
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    Perioperative use of corticosteroid and bupivacaine combination in lumbar disc surgery - A randomized controlled trial
    Mirzai, H; Tekin, I; Alincak, H
    Study Design. A prospective and controlled study of perioperative use of combined local anesthetic and corticosteroid in lumbar disc surgery. Summary of Background Data. The anti-inflammatory mechanism of corticosteroids is considered to be caused by the inhibition of phospholipase A(2), which plays an important role in the pain mechanism of lumbar disc problems. Although some authors have demonstrated that the use of intramuscular bupivacaine during lumbar discectomy resulted in a marked reduction of postoperative back pain, others have reported that the key intervention was probably the administration of epidural corticosteroid. The coadministration of these two drugs in lumbar disc surgery for the relief of postoperative back pain has yet not been studied adequately. Objectives. Assessment of the combined use of perioperative corticosteroids and bupivacaine for the relief of postoperative pain after lumbar disc surgery. Methods. Forty-four selected patients had acute-onset single-level unilateral herniated nucleus pulposus that were refractory to conservative management. All patients underwent lumbar disc surgery under standard general anesthesia. Before surgical incision, the skin and subcutaneous tissues were infiltrated with 10 mL of 1% lidocaine with 1:200,000 adrenaline to produce local vasoconstriction. During wound closure, 20 mL 0.9% saline in Group 1 (n = 22) and 20 mL 0.25% bupivacaine in Group 2 (n = 22) were injected into the paravertebral muscles band subcutaneus tissues. In addition, a piece of autologous fat taken from the wound was first soaked in 40 mg of methylprednisolone for 10 minutes, then placed over the exposed nerve root, and the remaining steroid was flushed into the wound in Group 2. The wound was closed after drug administration in both groups. In the postoperative period, all patients received 100 mg of meperidine intramuscularly when needed and were allowed to receive a second dose at least 4 hours later than the first dose for postoperative analgesia. Postoperative back pain intensity, heart rate, and mean arterial pressure were assessed 1, 3, 6, and 12 hours after the conclusion of surgery. Results. Visual analog scale pain scores for the postoperative recordings were lower in Group 2 than in Group 1, but these findings were not statistically significant. Patients in Group 1 received 77.3 +/- 48.8 mg meperidine, and those in Group 2 received 31.8 +/- 45.5 mg meperidine, for pain medication in the first 12 hours (P < 0.05). Heart rate and mean arterial pressure were not significantly different between the two groups in all recording periods. Conclusion. It is concluded that the perioperative use of bupivacaine and corticosteroids during lumbar discectomy maintains effective postoperative analgesia and decreases opioid usage without complications.
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    The results of nucleoplasty in patients with lumbar herniated disc: a prospective clinical study of 52 consecutive patients
    Mirzai, H; Tekin, I; Yaman, O; Bursali, A
    BACKGROUND CONTEXT: Nucleoplasty is a minimally invasive, percutaneous procedure that uses radiofrequency energy to ablate nuclear material and create small channels within the disc. PURPOSE: To evaluate the efficacy of nucleoplasty technique in patients with leg pain caused by radicular encroachment. STUDY DESIGN/SETTING: A prospective clinical study of subjects with lumbar disc herniation, and radicular pain resistant to previous medical treatment and physiotherapy for a period of at least 3 months. PATIENT SAMPLE: Fifty-two consecutive patients with leg pain and magnetic resonance imaging evidence of small and medium-sized herniated discs correlating with the patient's symptoms (contained disc herniation <6 mm, with a disc height >= 50% in comparison to normal adjacent discs) were included. OUTCOME MEASURES: Visual analogue scale (VAS) was administered and Oswestry disability questionnaires were filled out at preprocedure and postprocedure 2 weeks, 6 months, and 1 year. Reduction of analgesic treatment and the patients' satisfaction were also recorded. METHODS: All procedures were performed under local anesthesia and fluoroscopic guidance on an outpatient basis. Patients underwent discography to evaluate annular integrity just before nucleoplasty. Channels were created in the nucleus by advancing the radiofrequency probe (ablating) and withdrawing it (coagulation). In all patients six channels were created. RESULTS: Thirty-four patients had one and 18 had two discs treated; a total of 70 procedures were performed. Mean age of patients was 44.8 +/- 8.6 years. The mean follow-up period was 12.1 +/- 1.6 months. Mean VAS reduced from preprocedure 7.5 to 3.1 at postprocedure 6 months and to 2.1 at the latest follow-up. Mean Oswestry index decreased from 42.2 to 24.8 at 6 months and to 20.5 at the latest examination. Analgesic consumption was stopped or reduced in 42 patients (85%) at 6 months and in 46 patients (94%) 1 year after the procedure. Overall patient satisfaction was 81% at 2 weeks, 85% at 6 months, and 88% at the latest follow-up. There were no complications related to the procedures. CONCLUSIONS: Our results encourage us to use nucleoplasty in carefully selected patients with leg pain caused by radicular encroachment. We recommend applying this minimally invasive technique only in those patients with small (<6 mm) contained disc herniations, with a disc height of >= 50% and with annular integrity. (C) 2007 Elsevier Inc. All rights reserved.
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    Ultra fast resolution of acute post-traumatic subdural haematoma
    Mirzai, H; Yaldiz, C; Eminoglu, M; Orguc, S
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    Are drains useful for lumbar disc surgery? A prospective, randomized clinical study
    Mirzai, H; Eminoglu, M; Orguc, S
    Objective: In this prospective, observer-masked clinical study, we evaluated if insertion of a drain had a significant role in decreasing the existence and the size of postoperative epidural hematoma, which is believed to be a factor causing epidural fibrosis in patients undergoing lumbar discectomy. Method: Fifty patients undergoing lumbar disc surgery were randomly assigned to two groups: with or Without insertion of a drain in the epidural space. A drain was inserted in 22 patients, whereas 28 were left without a drain. All patients were evaluated, by means of magnetic resonance imaging (MRI) oil the first postoperative day, specifically looking for the existence and the size of epidural hematoma. The size of epidural hematoma was graded as none, minimal, moderate, or prominent. The patients were clinically examined preoperatively and at the follow-up of 6 months by Oswestry Disability Index and recurrence of pain. A follow-up MRI was repeated at 6 months, and the subsequent development of epidural fibrosis was evaluated. Results: Epidural hematoma was detected in 36% of patients with a drain and in 89% of patients without a drain (P = 0.000). There were significant less number of minimum, moderate, and prominent sized hematomas in the group with a drain (P = 0.000). On the 6-month follow-up, epidural fibrosis was found in 58.3% of patients without a drain and in 31.6% of patients with a drain (P = 0.08). Late clinical outcome (improvement in Oswestry Index and no recurrent pain) was better in the group with drain, but not statistically significant (P = 0.4). Conclusions: Occurrence of hematoma in the epidural space is common after lumbar disc surgery even if meticulous hemostasis has been achieved. Insertion of a drain decreases both the incidence and the size of hematoma on the first postoperative day as detected by MRL This may have practical implications for the prevention of significant postoperative fibrosis and obtaining better surgical outcome.
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    Effect of propofol and clonidine on cerebral blood flow velocity and carbon dioxide reactivity in the middle cerebral artery
    Mirzai, H; Tekin, I; Tarhan, S; Ok, G; Goktan, C
    This study was designed to evaluate the effects of propofol alone and propofol-clonidine combination on human middle cerebral artery blood flow velocity (Vmca) and cerebrovascular carbon dioxide (CO,) response by using transcranial Doppler ultrasonography. Mean Vmca in response to changes in arterial partial pressure of CO2 (Paco(2)) was determined under the following conditions: awake (group 1), propofol anesthesia (group 2), and combined propofolclonidine anesthesia (group 3). Nonnocapnic, hypercapnic, and hypocapnic values of heart rate, mean arterial pressure, partial end-tidal CO2 pressure, Paco(2), and Vmca were obtained. The mean Vmca in groups 2 and 3 was significantly lower than that in group 1 at each level of Paco(2). The calculated Vmca at each level of Paco(2) was not different between groups 2 and 3. There was a correlation between Paco(2), and Vmca in all groups, but in the anesthetized groups the effect of Paco(2) on Vinca was attenuated. The present data demonstrated that clonidine-propofol does not change CO2 reactivity compared with propofol alone, but both anesthetics attenuate cerebral blood flow compared with awake controls.
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    A comparison of conventional and pulsed radiofrequency denervation in the treatment of chronic facet joint pain
    Tekin, I; Mirzai, H; Ok, G; Erbuyun, K; Vatansever, D
    Objectives: The goal of this study was to compare the effects of conventional radiofrequency (CRF) and pulsed RF (PRF) denervation to medial branches of dorsal rami in the treatment of facet joint pain. Methods: The patients greater than 17-year old, with continuous low back pain with or without radiating pain with focal tenderness over the facet joints, pain on hyperextension, absence of neurologic defect, unresponsiveness to conservative treatment, no radicular syndrome, and no indication for low back surgery were included in the study. Local anesthetic was applied in the control group (n = 20), whereas 80 degrees C CRF were applied in the CRF (n = 20) and 2 Hz PRF were applied in the PRF group (n = 20). Pain relief was evaluated by visual analog scale (VAS) and Oswestry Disability Index (ODI) at preprocedure, at procedure, at 6 months and 1 year after the procedure. Reduction in analgesic usage, patients' satisfaction, and complications were assessed. Results: Mean preprocedural VAS and ODI scores were higher than postprocedural scores in all groups. Both VAS and ODI scores of PRIF and CRF groups were lower than the score of the control group at the postprocedural evaluation. Although decrease the pain score was maintained in the CRF group at 6 months and 1-year period, this decrease discontinued in the PRIF group at the follow-up periods. The number of patients not using analgesics and patient satisfaction were highest in CRF group. Discussion: PRF and CRF are effective and safe alternatives in the treatment of facet joint pain but PRF is not as long lasting as CRF.
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    Tuberculoma of the cervical spinal canal mimicking en plaque meningioma
    Mirzai, H
    A previously healthy, HIV-negative, 40-year-old man presented with a 2-month history of progressive weakness of his left arm. Magnetic resonance imaging revealed an intradural, extra medullary plaque-shaped lesion at C6-T1 levels with high contrast enhancement. Based on the patient's clinical and radiologic findings, it was believed that the patient had an en plaque meningioma, and he was operated on. Histologic examination of the mass revealed granulomas with multinucleated and Langhans-type giant cells, typical of a tuberculoma. Intradural extramedullary tuberculomas should be considered in the differential diagnosis of en plaque meningioma as a rare entity.