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Öğe Cephalocaudal Variations in the Horizontal and Vertical Diameters of the Pedicles of the Lumbar Spine in the Turkish Population(2001) Öğün, T. C.; Üstün, M. E.; Büyükmumcu, M.Purpose: Racial morphometric differences in the pedicular structure of the vertebrae must be taken into account when using international transpedicular screw systems. In this study, we tried to figure out the differences, if any, in the size of the pedicles in a sample of the Turkish population. Methods: The horizontal and vertical diameters of the pedicles of the lumbar vertebrae were measured from the standardized anteroposterior radiographs of the lumbar spine in 100 subjects, aged from 20 to 40 years. Results: The mean horizontal width of the pedicles in our sample of the Turkish population was smaller than the subjects in other studies. The vertical diameter did not differ widely. There was a cephalocaudal increase in the horizontal diameters in both sexes. The vertical diameters did not increase. Significant differences between the pedicle diameters of the males and the females were noted at L2, L3 and L4 levels. No significant age-related variations were observed. Conclusion: Awareness of the racial variations in the size of the pedicles is very important when using international transpedicular screw systems. Preoperative determination of especially the horizontal diameter of the pedicles to be used for screw implantation from standardized anteroposterior X-rays is the easiest way.Öğe Correlation of Magnetic Resonance Imaging Findings with Hexamethylpropyleneamine Oxime Brain Single Photon Emission Computed Tomography in Ischemic Stroke Patients in the Subacute Stage(Sage Publications Ltd, 2006) Kireşi, Demet; Taştekin, G.; Cengiz, Ş. L.; Üstün, M. E.; Yürüten, B.Purpose: To evaluate the correlation between magnetic resonance imaging (MRI) findings and Tc-99m-hexamethylpropyleneamine oxime (HMPAO) brain single photon emission computed tomography (SPECT) during the subacute stage in ischemic stroke patients. Material and Methods: The T1 and T2- weighted images and brain SPECT findings of 84 patients (mean age 60.69 +/- 12.47 years) with subacute cerebral ischemia during the period 1998-2004 were reviewed. All HMPAO SPECT and MRI studies were performed between 3 and 7 days (mean time delay 4.76 +/- 1.29 days) after the onset of stroke symptoms. Results: An ischemic lesion was seen both in T1 and T2- weighted images with perfusion defects above 60% (severe defect) according to count/pixel data of the lesion in HMPAO SPECT studies in 30 (90.9%) of 33 patients. Otherwise, the ischemic lesion was seen only on T2- weighted images with perfusion defects between 30% and 60% (moderate defect) in HMPAO SPECT studies in 25 (89.3%) of 28 patients. In 20 (87%) of 23 patients who had perfusion defects below 30% (mild defect) on HMPAO SPECT, only non-specific findings such as cerebral atrophy and/or periventricular ischemic-gliotic lesions could be seen in MRI. The difference between these ratios was statistically significant (P < 0.01). Conclusion: Brain Tc-99m-HMPAO SPECT findings indicate good correlation with MRI findings. When the ischemic lesions could be seen in both T1 and T2- weighted images, the patients frequently had severe perfusion defects. When only seen in T2- weighted images, the perfusion defect was moderate. When only non-specific findings were revealed by MRI, only mild perfusion defects were found by SPECT.Öğe Effects of Deferoxamine on Tissue Lactate and Malondialdehyde Levels in Cerebral Ischemia(Prous Science, Sa , 2003) Barışkaner, Hülagü; Üstün, M. E.; Ak, A.; Yosunkaya, Alper; Doğan, N.; Gürbilek, MehmetIn the present study, the effects of deferoxamine on tissue lactate and malondialdehyde (MDA) levels after cerebral ischemia at rabbits was studied. Rabbits were divided equally, into three groups: group 1: sham-operated group; group 2: cerebral ischemia produced by clamping bilateral common carotid arteries for 60 min: and group 3: deferoxamine 100 mg/kg i.v administered within 5 min after opening the clamps. EEG recordings were obtained in all groups before clamping and in group 2 and 3 60 min after clamping and 60 min after opening the clamps. One hour after opening the clamps and taking EEG recordings, brain cortices were resected and the concentrations of lactate and MDA were determined using the spectrophotometric enzymatic and thiobarbituric acid methods, respectively. There were significant differences between group I and the other groups in MDA and lactate levels (p < 0.05). There were no significant differences in lactate levels between groups 2 and 3. Preischemic EEG grades were the same at till groups. Preischemic (aid postischemic EEG values were significantly different (p < 0.05), but there were no significant differences between postischemic EEG grades in groups 2 and 3. There was also a correlation between postischemic EEG grades and lactate levels, but no correlation between postischemic EEG grades and MDA levels. These results demonstrate that cerebral ischemia leads to an increase in brain tissue lactate and MDA levels and deferoxamine suppresses the increase of MDA, but not lactate. Deferoxamine treatment caused no significant EEG changes. EEG grades correlated well with lactate levels.Öğe Effects of Magnesium Sulfate on Tissue Lactate and Malondialdehyde Levels After Cerebral Ischemia(Karger, 2003) Barışkaner, Hülagü; Üstün, M. E.; Ak, A.; Yosunkaya, Alper; Ulusoy, H. B.; Gürbilek, MehmetIn the present study, the effects of magnesium sulfate on tissue lactate and malondialdehyde (MIDA) levels after cerebral ischemia in rabbits were studied. The rabbits were divided equally into three groups. Group 1 (n = 8) was the sham-operated control group, in group 2 (n = 8) only cerebral ischemia was induced by clamping bilaterally the common carotid arteries for 60 min, and in group 3 (n = 8) magnesium sulfate was administered at a dose of 100 mg/kg im. within 5 min after opening the clamps. In group 1 EEG recordings were obtained immediately and 60 and 120 min after craniectomy. In groups 2 and 3 EEG recordings were obtained immediately after craniectomy but before clamping and 60 min after clamping. One hour after opening the clamps and taking EEG recordings, brain cortices were resected, and the concentrations of lactate and MIDA were determined using spectrophotometric/enzymatic and thiobarbituric acid methods, respectively. In all groups, there were significant differences between MDA and lactate levels (p < 0.05). There were no significant differences in lactate levels between groups 2 and 3 (p > 0.05), and also the preischemic EEG grades were the same in all groups. Preischemic and postischemic EEG values were significantly different (p < 0.05), and there were also significant differences between postischemic EEG grades in groups 2 and 3 (p < 0.05). There was a correlation between postischemic EEG grades and MIDA and lactate levels. These results demonstrate that cerebral ischemia-reperfusion injury leads to an increase in brain tissue lactate and MIDA levels, that magnesium sulfate suppresses the increase of MDA and lactate concentrations, and that magnesium sulfate, treatment improves the EEG changes. The EEG grades correlated well with MIDA and lactate levels.Öğe Effects of Nimodipine on Tissue Lactate and Malondialdehyde Levels in Experimental Head Trauma(2001) Ak, A.; Üstün, M. E.; Öğün, C. Ö.; Duman, A.; Bor, M. A.We studied the effects of nimodipine on brain tissue lactate and malondialdehyde (MDA) levels one hour after experimental head trauma in 25 New Zealand rabbits. Group 1 (n=5) was the sham operated group. Group 2 (n = 10) received head trauma without treatment and in group 3 (n=10) nimodipine was administered for 30 minutes intravenously (2 ?g/kg/min) immediately after head trauma. In groups 2 and 3, tissue samples from the non-traumatized side was named as "a" and traumatized side as "b". The lactate and malondialdehyde contents were significantly higher in groups 2a, 2b, 3a and 3b when compared with to group 1 (P<0.05). The differences between non-treated groups (2a, 2b) and nimodipine treated groups (3a, 3b) were not significant (P>0.05). The differences between the traumatized sides (2b, 3b) and non-traumatized sides (2a, 3a) were significant (P<0.05). These results demonstrated that nimodipine is ineffective in suppressing the increase of tissue lactate and malondialdehyde levels in the early period of experimental head trauma.Öğe Effects of Nimodipine on Tissue Lactate and Malondialdeyde Levels in Experimental Head Trauma(Australian Soc Anaesthetists, 2001) Ak, A.; Üstün, M. E.; Ogün, C. O.; Duman, A.; Bor, M. A.We studied the effects of nimodipine on brain tissue lactate and malondialdehyde (MDA) levels one hour after experimental head trauma in 25 New Zealand rabbits. Group 1(n=5) was the sham operated group. Group 2 (n=10) received head trauma without treatment and in group 3 (n=10) nimodipine was administered for 30 minutes intravenously (2 mug/kg/min) immediately after head trauma. In groups 2 and 3, tissue samples from the nontraumatized side was named as "a" and traumatized side as "b". The lactate and malondialdehyde contents were significantly higher in groups 2a, 2b, 3a and 3b when compared with to group 1 (P <0.05). The differences between non-treated groups (2a, 2b) and nimodipine treated groups (3a, 3b) were not significant (P >0.05). The differences between the traumatized sides (2b, 3b) and non-traumatized sides (2a, 3a) were significant (P <0.05). These results demonstrated that nimodipine is ineffective in suppressing the increase of tissue lactate and malondialdehyde levels in the early period of experimental head trauma.Öğe The Efficacy of Carbamazepine in the Treatment of the Pain Due to Lumbar Lateral Canal Stenosis(1997) Üstün, M. E.; Özerbil, O. M.; Güney, O.; Kocaoğullar, Y.In this study, we investigated whether carbamazepine which usually is used in many diseases characterized by neuropathy or neuralgia to reduce pain, has an analgesic effect in patients with lateral canal stenosis. 14 patients (7 women, 7 men) with lateral canal stenosis whose age ranged between 32 and 74 were included in the study. These patients had low back pain and/or sciatica at least for six months and they didn't respond to other medical drugs including nonsteroidal antiinflammatory drugs and analgesics. They were administered 400 mg/bid oral carbamazepine as initial dose for two weeks. When they didn't respond to that dose, it was increased to 800 mg/bid for four weeks. The patients pain were evaluated by the leg pain severity and overall functional disability score before and after treatment. After treatment, the pain was significantly reduced in these patients (p < 0.01, X2:10). In conclusion, we propose carbamazepine in the treatment of lateral canal stenosis as a new alternative drug.Öğe End-to-side Neurorrhaphy as a Salvage Procedure for Irreparable Nerve Injuries - Technical Note(Amer Assoc Neurological Surgeons, 2003) Öğün, T. C.; Özdemir, M.; Senaran, H.; Üstün, M. E.After a few reports on end-to-side nerve repair at the beginning of the last century, the technique was put aside until its recent reintroduction. The authors present their results in three patients with median nerve defects that were between 15 and 22 cm long and treated using end-to-side median-to-ulnar neurorrhaphy through an epineurial window. The follow-up times were between 32 and 38 months. Sensory evaluation involved superficial touch, pinprick, and two-point discrimination tests. Motor evaluation was completed by assessing the presence of opposition and by palpating the abductor pollicis brevis muscle. Sensory recovery was observed in all patients in the median nerve dermatome, and motor recovery was absent, except in Case 1. End-to-side nerve repair can be a viable alternative to nerve grafting in patients with long gaps between the ends of the injured nerve.Öğe Epidural Administration of Midasolam for Chronic Central Pain and Spasticity in Spinal Cord Injured Patients(1997) Özerbil, O. M.; Duman, A.; Yosunkaya, A.; Bayram, A.; Üstün, M. E.In the patients with spinal cord injury (SCI) chronic pain and spasticity affect significantly both the efficacy of rehabilitation and the quality of life. Recently it was shown that intrathecally and epidurally administered midasolam has analgesic and antispatic effects in both animals and humans so that it constitutes an alternative to be used in patients with SCI. In this study, four paraplegics who suffered from chronic central pain and spasticity in their lower extremities were given midasolan 6 times daily (dose 40 ?g/kg dose dissolved in 10 ml normal saline) via lumbar epidural catheter using pain management provider. Spasticity was monitored by means of a modified Ashwort scale, and pain evaluation was performed by face scale and VAS. The patients were hospitalized at least for two weeks and were observed for the efficacy of the drug. Although epidural administration of midasolam relieved both central pain and spasticity, it's efficacy on central pain was more pronounced. There were no significant side effects is any patient. We propose that midasolam may be given by epidural catheter or implantable drug pump for the treatment of central pain and/or spinal spasticity in spinal cord injured patients.Öğe Omental Transposition Decreases Ischemic Brain Damage Examined in a New Ischemia Model(Karger, 2003) Vatansev, Celalettin; Üstün, M. E.; Öğün, C. O.; Taştekin, G.; Karabacakoğlu, A.; Yılmaz, H.Purpose:The aim of this study was to determine whether omental transposition at the time of focal cerebral ischemia can decrease ischemic brain damage produced in dogs, in a new ischemia model, which had been described by us. Methods: In group 1 (n = 5), the left internal carotid artery and arterial circle of the brain (posterior communicating artery in humans) were occluded permanently. In group 2 (n = 5), additionally to this ischemia model, omental transposition was performed simultaneously. In the postoperative early period (first 24 h), single photon emission computed tomography (SPECT) and in the late period (72-96 h) SPECT and magnetic resonance imaging (MRI) of the brain were performed. Mann-Whitney U, paired t and Wilcoxon signed rank tests were used for statistical analyses, and p < 0.05 was considered significant. Results: The dogs had a neurological score (NS) of 3.6 +/- 0.5 and 3.4 +/- 0.5 in groups 1 and 2, respectively, in the early period (p > 0.05). In the late period, the dogs had an NS of 4.4 +/- 0.5 and 5.6 +/- 0.5 in groups 1 and 2, respectively (p < 0.05). The NS of each group differed significantly between the early and late period (p < 0.05). Early SPECT imaging showed 50 7.0% and 52 +/- 8.4% hypoperfusion corresponding to the left middle cerebral artery territory in groups 1 and 2, respectively (p > 0.05). In the late period, the degree of hypoperfusion decreased to 34 +/- 5.5% and 12 +/- 4.8% in groups 1 and 2, respectively (p < 0.05). The degree of hypoperfusion in both groups changed significantly between the early and late period (p < 0.05). In T-1- and T-2-weighted MRI images, the volume of the lesion in group 1 was significantly greater than in group 2 (p < 0.001). Conclusion: In our new ischemia model, simultaneous omental transposition is helpful in reversing the neurologic deficit and cerebral ischemic damage.
