Agahan Unlu

Role of oxidative stress enzymes in open-angle glaucoma

PurposeTo investigate the role of oxidative stress and lipid peroxidation in the pathogenesis of primary open-angle glaucoma (POAG).Materials and methodsThe activities of myeloperoxidase (MPO), catalase (CAT), and the levels of plasma malondialdehyde (MDA) were measured in 40 (15 men and 25 women) patients with POAG and 60 (30 men and 30 women) healthy controls.ResultsThere was no significant difference in the activities of CAT and MPO between the POAG patients and the controls. However, the plasma MDA level was significantly higher in patients than the controls.ConclusionThe results of this preliminary study suggest that the possible alterations of plasma MDA levels may be associated with the pathogenesis of POAG, but further research is needed to understand the role of oxidative damage in this important disorder of aging.

The effect of intrathecal sodium nitroprusside on severe chronic vasospasm

The efficacy of sodium nitroprusside in resolving cerebral vasospasm was evaluated with multicisternal injections. Twelve animals received fresh, unheparinized arterial blood via three injections (15 ml total) into the cisterna magna. Selective vertebral arteriography was performed on Day 0, and blood injections were performed on the second and third days after the first injection. On the seventh day selective arteriography was performed to evaluate the diameter of the basilar artery. In the sodium nitroprusside group, intrathecal injections of the drug were started on Day 4 and continued for two days (25 micrograms/kg/day). The diameter of the basilar artery was reduced 72.98 +/- 11.07% in control experiments. For the animals treated with intrathecal sodium nitroprusside, the mean diameter of the basilar artery was reduced 29.25 +/- 4.54%. The effect of intrathecal sodium nitroprusside on intracranial pressure (ICP), blood pressure (BP) and electrocardiogram (ECG) was also evaluated in 14 animals. There were no prominent changes in ICP, BP, or ECG when sodium nitroprusside was given intrathecally, but BP decreased and ICP and heart rate increased with intravenous doses of sodium nitroprusside. These results support the hypothesis that sodium nitroprusside administered intrathecally is an effective treatment for cerebral vasospasm.

Patients with urinary incontinence often benefit from surgical detethering of tight filum terminale

Abstract We retrospectively reviewed 77 patients with a tethered spinal cord syndrome to evaluate the results of neurosurgical treatment. The patients were divided into two groups: in group 1 there were 17 patients with primary tethered cord who had normal level conus medullaris (NLCM) and normal thickness filum terminale (NTFT) with urinary incontinence, and group 2 was made up of 60 patients with secondary spinal cord tethering after a previous closure of a midline fusion defect who had a low-lying conus medullaris. Neurological examination, radiography, urodynamic tests and electrophysiological findings confirmed the diagnosis. Conventionally, tethered cord syndrome has been defined as a state in which the conus medullaris is located below the L1–2 disc space. However, in a patient with urinary incontinence and a hyperreflexive type of neurogenic bladder, in whom the conus medullaris is found to be at the normal level, there may still be cord tethering that is causing the incontinence. In this study the comparison was based on evaluation of the response to treatment and general characteristics of the syndrome in both groups of patients to draw attention to the general approach to this incapacitating maldevelopment.

CT-guided percutaneous Selective Cordotomy

SummaryIn this article the technique of CT-Guided Selective Cordotomy is described. The advantages of CT guidance in percutaneous cordotomy are the measurement of spinal cord diameters at the lesion site for each individual patient, direct visualization of target electrode relations, demonstration of spinal cord displacement during the procedure and localization of the electrode system in a specific part of the spinothalamic tract. Local destruction of the spinothalamic tract leads to selective cordotomy.Since 1987, CT-Guided Cordotomy has been applied to 54 cases of intractable cancer pain. In 33 of the 54 cases, the cordotomy was selective enough to be successful with a local denervation of the area where the pain was dominant. Except for one temporary hemiparesis and one temporary ataxia, no complications or side effects were observed.

Endoscopic Anatomy of Sphenoid Sinus for Pituitary Surgery

Endoscopic endonasal transsphenoidal approach to the sellar region yields an alternative to classical microsurgical approaches. Endoscopes provide images that differ from microscopic view. This study aimed to highlight surgical landmarks and their anatomical relationships for pituitary surgery through endoscopic perspective. Ten sides of five adult cadaveric heads with red‐colored latex injected arteries were evaluated. Endoscopic dissections were performed and measurements were done in the sphenoid sinuses before and after the removal of bony structures in all the aspects. Endoscopic vision of the sellar region enabled a wide panoramic perspective and detailed inspection. The measurements, in general, indicated the variations in the bony structures and soft tissues. The width of the pituitary, which is the distance between the medial margins of the carotid prominences, was measured as 21 ± 2.5 mm and the distance between the medial margin of the carotid prominences at the lower margin of the pituitary was 18 ± 3.1 mm. After the bony structures were removed, further measurements were done. The width of the pituitary, which is the distance between the medial margins of the anterior curvature of the ICA, was measured as 23.2 ± 3 mm, while the distance between the posterior curvature of the ICA was 19.7 ± 4.9 mm. Endoscopic view provided superior detailed visualization of the close relationships between pituitary gland, internal carotid arteries, and optic nerves. This facilitated exact evaluation for variations, which could result in more effective and safe surgery. However, these variations again emphasize the necessity of preoperative radiological evaluation in each case. Clin. Anat. 21:627–632, 2008.

Chiari Type I malformation presenting as glossopharyngeal neuralgia: case report.

OBJECTIVE AND IMPORTANCE Chiari Type I malformation is an important pathological state in which the brainstem is compressed by the cerebellar tonsil. We present a case of glossopharyngeal neuralgia caused by Chiari Type I malformation. CLINICAL PRESENTATION A 50-year-old male patient was admitted with glossopharyngeal neuralgia. Magnetic resonance imaging studies revealed caudal displacement of the left cerebellar tonsil. INTERVENTION Small occipital craniectomy and C1 laminectomy were performed. The left cerebellar tonsil was resected. CONCLUSION This glossopharyngeal neuralgia was caused by compression of the lower cranial nerves and brainstem by the displaced left cerebellar tonsil. Decompression and pain relief were obtained with resection of the cerebellar tonsil. The patient was pain-free 30 weeks after the operation.

Transclival Approach to Rabbit Basilar Artery for Experimental Induction of Chronic Vasospasm

SummaryAn experimental technique for producing delayed cerebral vasospasm in a rabbit model is described. The basilar artery is punctured via the transclival route and angiographic verification is illustrated.

Infection-related atlantoaxial subluxation in two adults: Grisel syndrome or not?

Summary. Grisels syndrome involves the subluxation of the atlanto-axial joint from inflammatory ligamantous laxity following an infectious process in the head or neck. It is a rare disease usually affecting children, but infrequent adult cases do occur. Today, due to the widened use of antibiotics and availability of MR imaging, some cases presenting with neck pain, resulting from the infectious inflammation of C1 and C2 but without pronounced subluxation, can be a challenging problem for most neurosurgeons. Several theories have been proposed to explain the pathogenesis of inflammatory subluxation. The primary treatment of Grisels syndrome is medical. The underlying infectious organism must be isolated and appropriate antibiotics must be prescribed. The subluxation is reduced in holter or skeletal traction. This paper reports two cases of infection-related atlanto-axial subluxation in two adults. The literature on this subject is briefly reviewed.

Spinal cord regeneration induced by a voltage-gated calcium channel agonist

Abstract Regeneration in the central nervous system (CNS) is prohibitive. This is likely due to an interplay of cellular (gene expression, growth factors) and environmental (inhibition by CNS myelin) factors. Calcium supports various intracellular functions, and multiple in vitro studies have shown a role of calcium in axonal growth. In this study, we examine the role of a calcium agonist, S(-)-Bay K 8644, in promoting or impeding CNS growth in vivo, in an effort to understand further the relationship between the voltage-gated L type calcium channel and regeneration. Using a well-established rat spinal cord model of regeneration, we have injected various doses of S(-)-Bay K 8644 (30-240 M) around the injured spinal cord. Our results demonstrate that S(-)-Bay K 8644 enhances regeneration in a dose-dependent fashion. In addition, at very specific concentrations, the same agonist has no effect on or even inhibits regeneration. We conclude that spinal regeneration is highly dependent on intracellular calcium concentration. Furthermore, depending on the dose used, the effect of calcium agonist supplementation on spinal regeneration can be supportive or inhibitory.

Resolution of cerebral vasospasm with trapidil; an animal model

Cerebral vasospasm and rebleeding are important clinical phenomena associated with a high mortality rate. Therefore, any promising finding in the laboratory deserves assessment in clinical practice. The present study was designed to examine the possible effects of trapidil on the basilar artery of the rabbit through a cerebral vasospasm model. This experimental study was carried out on 26 adult New Zealand albino rabbits of both sexes weighing 2.5-3.0 kg. A transclival exposure was performed. Vasospasm was produced by an intracisternal injection of autologous blood. After observation of the vasospasm, trapidil was locally applied in increasing concentrations (10(-5)-10(-4) M). The effect of each concentration was measured independently after 10 minutes for each application and was extended to three hours. Trapidil was shown to have a clear spasmolytic effect on the rabbits basilar artery. These data suggest that trapidil can have a potential use in the treatment of patients suffering from cerebral vasospasm.