Comparison of the effects of octreotide and melatonin in preventing nerve injury in rats with experimental spinal cord injury.

In this study, we aimed to investigate the biochemical and histopathological protective effects of octreotide and melatonin in an experimental model of spinal cord injury. Fifty- six male albino Wistar rats were divided into four groups. Rats in the G1 group (n=7; control group) did not undergo any treatment except for anesthesia prior to being killed. Rats in the G2 group (n=7) underwent laminectomy and aneurysmal clip application at the T4-5 level. G3 group rats (n=14) were either treated with a 7.5 mg/kg intraperitoneal dose of melatonin (Sigma, St. Louis, MO, USA) immediately after laminectomy, then the same dose again on the day following injury (G3a), or given three equal doses over 10 days to achieve a total dose of 7.5 mg/kg/day (G3b). G4 group rats (n=14) were either treated with a 30microg/kg intraperitoneal dose of octreotide (Sandostatin; Novartis, Istanbul, Turkey) immediately after laminectomy, then the same dose again on the day following injury (G4a), or given three equal doses over 10 days to achieve a total dose of 30miocrog/kg/day (G4b). Rats in the G3 and G4 groups were sacrificed on days 1 and 10 after spinal cord injury (n=7 at each time point) and spinal cord samples were obtained. Tissue malonyldialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) levels were assayed. G3a, G3b and G4b had significantly lower levels of MDA than G2 (p<0.01). G3b had significantly higher SOD and GSH-Px levels than G2 (p<0.01). Histopathologically, melatonin significantly reduced necrosis and degeneration in both the initial and late stages (p<0.01). Octreotide had significant effects on necrosis and degeneration during the late stages, and on edema and congestion in both the initial and the late stages of injury (p<0.01). Melatonin was found to be superior to octreotide with respect to the prevention of congestion, edema, axonal degeneration and necrosis.

Intraoperative monitoring of lower cranial nerves in skull base surgery: technical report and review of 123 monitored cases.

The fundamental goal of skull base surgery is tumor removal with preservation of neurological function. Injury to the lower cranial nerves (LCN; CN 9-12) profoundly affects a patient's quality of life. Although intraoperative cranial nerve monitoring (IOM) is widely practiced for other cranial nerves, literature addressing the LCN is scant. We examined the utility of IOM of the LCN in a large patient series. One hundred twelve patients underwent 123 skull base operations with IOM between January 1994 to December 1999. The vagus nerve (n=37), spinal accessory nerve (n=118), and the hypoglossal nerve (n=83) were monitored intraoperatively. Electromyography (EMG) and compound muscle action potentials (CMAP) were recorded from the relevant muscles after electrical stimulation. This data was evaluated retrospectively. Patients who underwent IOM tended to have larger tumors with more intricate involvement of the lower cranial nerves. Worsening of preoperative lower cranial nerve function was seen in the monitored and unmonitored groups. With the use of IOM in the high risk group, LCN injury was reduced to a rate equivalent to that of the lower risk group (p>0.05). The immediate feedback obtained with IOM may prevent injury to the LCN due to surgical manipulation. It can also help identify the course of a nerve in patients with severely distorted anatomy. These factors may facilitate gross total tumor resection with cranial nerve preservation. The incidence of high false positive and negative CMAP and the variability in CMAP amplitude and threshold can vary depending on individual and technical factors.

Collet-Sicard syndrome associated with occipital condyle fracture and epidural hematoma.

A 31-year-old male was presented with a very rare case of ipsilateral palsies of the nerves IX through XII (Collet-Sicard syndrome) after a closed head injury. An occipital condyle fracture that was associated with epidural hematoma was diagnosed by computed tomography. The patient was conservatively managed, and following the treatment, partial neurological recovery ensued. The phenomenon of occipital condyle fracture involving the last four cranial nerve palsies is relatively rare. Although 3 cases of Collet-Sicard syndrome that were caused by an occipital condyle fracture has been reported, the association between condyle fracture and epidural hematoma has never been described before.

Review of complications due to foramen ovale puncture.

We aim to evaluate the mechanisms responsible for complications during trigeminal rhizotomy via foramen ovale puncture. Ten dry skulls and 10 skull-base specimens were investigated in the present study. In cadaveric skull-base specimens, the anatomical relationships between the foramen ovale, mandibular nerve and Gasserian ganglion and the surrounding neurovascular structures were investigated intradurally. The distance between the foramen ovale and Gasserian ganglion was measured as 6 mm. The abducent nerve, adjacent to the anterior tail of the petrolingual ligament, was observed passing along the lateral wall of the cavernous sinus. Advancement of the catheter more than 10 mm from the foramen ovale is likely to damage the internal carotid artery and the abducent nerve at the medial side of the petrolingual ligament. Thermocoagulation of the lateral wall of the cavernous sinus may damage the cranial nerves by heat, giving rise to pareses.

Hemorrhage into the brain abscess cavity with Fallot's tetralogy.

Hemorrhage into the abscess cavity is a complication of brain abscess. It has been reported to be due to inflammation which results in the damage of the fragile neovasculature of the abscess wall. Hypoxia caused by Fallot's tetralogy or other congenital heart diseases facilitates the damage of these vessels with the lacking supportive tissues, and in turn intracavital bleeding.

Irrigation vs. closed drainage in the treatment of chronic subdural hematoma.

A number of different techniques are used to treat chronic subdural hematomas surgically. In this study, 70 chronic subdural hematomas were surgically treated and analyzed prospectively. Patients were classified according to clinical features and computed tomography images. Results of the cases that underwent burr-hole craniostomy-irrigation (group A; n=35) were compared with those undergoing burr-hole craniostomy-closed system drainage (group B; n=35). The most common etiological factor was trauma in both groups. Complete resolution in the early period was higher in group B compared to group A (60% vs. 40%). However, no difference was noted at the first month-follow-up. Recurrence rates were 17% in group A and 14% in group B. No significant difference was noted in terms of hospitalization duration or postoperative complications. In conclusion, we believe that the burr-hole craniostomy-irrigation technique is a reliable and effective method compared to burr-hole craniostomy-closed system drainage in the treatment of chronic subdural hematoma.

Seprafilm superior to Gore-Tex in the prevention of peridural fibrosis.

OBJECT: This is an investigation into the effects of two barrier membranes in the prevention of peridural fibrosis in an animal model. METHODS: Seprafilm or Gore-Tex was applied to a laminectomy defect overlying the dura mater in rats separated into treatment groups. A third group of rats underwent laminectomy only and served as controls. Two months postoperatively a histological study was performed to compare the amount of scar tissue in each group. The gross dissection demonstrated that both membranes created a controlled dissection plane, facilitated access to the epidural space, and provided a reduction in the amount of tissue adhering to the dura mater. Statistically, Seprafilm was superior to Gore-Tex in preventing peridural fibrosis (p < 0.05). CONCLUSIONS: Seprafilm can prevent peridural fibrosis better than Gore-Tex and can be used in humans in spinal surgery.

Observer variability based on the strength of MR scanners in the assessment of lumbar degenerative disc disease.

OBJECT: aim of this study was to analyse the observer variability in the diagnosis and definition of disc pathologies with low and high-field strength MR scanners. MATERIAL AND METHODS: 95 patients with low back pain or radicular pain who were referred from two different centers were included in the study. Fifty-seven patients were scanned with 0.3 T MR (group 1) and 38 patients with 1.5 T (group 2). The intraobserver and interobserver reliability were assessed with the cappa coefficient which was characterised as follows: values less than 0.0 = 'poor' agreement, values 0.01-0.2 = 'slight' agreement beyond chance, 0.21-0.4 = 'fair' agreement, 0.41-0.60 = 'moderate' agreement, 0.61-0.80 = 'substantial' agreement and 0.81-1.00 = 'almost perfect' agreement. RESULTS: intraobserver agreement in group 1 and group 2 for both readers was 'almost perfect' in differentiating normal and pathological discs; 'substantial-almost perfect' in defining the disc pathologies, 'moderate-substantial' in root compression, and 'moderate-substantial' in spinal stenosis. Interobserver agreement was 'almost perfect' in differentiating normal and pathological discs, 'substantial' in defining disc pathologies, 'moderate' in root compression and 'moderate' in spinal stenosis in the group 1, whereas in group 2, it was 'almost perfect' in differentiating normal and pathological discs, 'almost perfect' in defining disc pathologies, 'slight-substantial' in root compression and 'moderate' in spinal stenosis. CONCLUSION: in the diagnosis of root compression and spinal stenosis, the intra and interobserver agreements were relatively poor with both high and low-strength field MRIs, indicating a need for more objective criteria. In differentiating normal and pathologic appearance of disc, the interobserver agreement was considerably better with high-field compared to low-field strength MRI. In cases where this definition is important, high-field strength scanners should be preferred.

Meningocele with cervical dermoid sinus tract presenting with congenital mirror movement and recurrent meningitis.

Dermoid sinuses and meningoceles are seldom encountered in the cervical region. Besides, to the best of our knowledge, the coexistence of these types of congenital abnormalities with recurrent meningitis, as well as with mirror movement, has never been reported before. A 14-year-old female with the diagnosis of recurrent meningitis was referred to our clinic from the Department of Infectious Diseases. She had a cervical meningocele mass that was leaking cerebro-spinal fluid (CSF) and an associated mirror movement symptom. Spina bifida, dermoid sinus and meningocele lesions were demonstrated at the C2 level on computed tomography (CT) and magnetic resonance imaging (MRI). She underwent an operation to remove the sinus tract together with the sac, and at the same time the tethered cord between the sac base and the distal end of the spinal cord was detached. The diagnosis of dermoid sinus and meningocele was confirmed histopathologically. These kinds of congenital pathologies in the cervical region may also predispose the patient to other diseases or symptoms. Herein, a case of meningocele associated with cervical dermoid sinus tract which presented with recurrent meningitis and a rare manifestation of mirror movement is discussed. Neurosurgeons should consider the possible coexistence of mirror movement and recurrent meningitis in the treatment of these types of congenital abnormalities.

Radiation-induced meningiomas: clinical, pathological, cytokinetic, and cytogenetic characteristics.

OBJECT: Radiation-induced meningiomas are known to occur after high- and low-dose cranial radiation therapy. The goal of this study was to discern the distinguishing findings and characteristics of radiation-induced meningiomas. METHODS: The records of 16 patients (seven men and nine women) who fulfilled the criteria for radiation-induced meningiomas were retrospectively reviewed. Clinical, histopathological, cytokinetic, and cytogenetic findings as well as the patients' outcome were analyzed. The mean age of the patients was 38.8 years and the mean tumor latency was 26.5 years. Five patients had multiple meningiomas in the irradiated field. The recurrence rate was 100% after the initial resection; 62% of patients had a second recurrence and 17% had a third recurrence. Thirty-eight percent of patients had atypical or malignant histopathological findings. The presence of progesterone receptors and low proliferation indices in these patients did not correlate with benign tumor behavior. Cytogenetic analysis showed multiple clonal aberrations in all tumors studied. The most frequent aberrations were found on chromosomes 1p, 6q, and 22. Derivative, lost, or additional chromosome 1p was found in 89% of cases and loss or deletion on chromosome 6 was found in 67%. CONCLUSIONS: The age of patients at presentation with meningioma and the latency period of radiation-induced meningiomas are dose related. These tumors are more aggressive and are certain to recur, have a higher histopathological grade, and are associated with complex cytogenetic aberrations particularly involving 1p and 6q.

The mechanism of injury of the abducens nerve in severe head trauma: a postmortem study.

The aim of this study is to investigate the mechanism of injury of abducens nerve at petroclival region in severe head trauma. Twenty specimens provided from 10 autopsied cases due to severe head trauma were investigated macroscopically and histopathogically. The slices of the abducens nerve taken consecutively along its course at petroclival region were stained with Hematoxylline-Eosin and evaluated under light microscope. In addition, coexisting cervical injuries in these cases were assessed macroscopically. Edema and perineural hemorrhagia of abducens nerve were identified in all cases. Nerve injury was found more exaggerated at the sites of dural entry point and petrous apex than any other parts of the abducens nerve. Furthermore, microscopically, also remarkable perineural hemorrhage of the abducens nerve was observed at the site of its anastomoses with the sympathetic plexus on the lateral wall of the internal carotid artery (ICA). Abducens nerve is injured at the sites of dural entry point, petrous apex and lateral wall of the ICA, directly proportional with the severity of the trauma. This finding is also significant in verification of the severe head trauma.

Coexistence of rapidly resolving acute subdural hematoma and delayed traumatic intracerebral hemorrhage.

Rapid resolution of acute subdural hematoma is rare. Delayed traumatic intracerebral hematomas following medical or surgical treatment of increased intracranial pressure have also been reported. Coexistence of a quickly resolving acute subdural hematoma and a delayed traumatic intracerebral hemorrhage has not been reported before. A 13-month-old boy was admitted to our emergency department after a car accident. On CT, a thin acute subdural hematoma on the right frontotemporal region and a small epidural hematoma on the left frontal region could be seen. On 24-hour follow-up CT, the right subdural hematoma was found to be less dense but larger than it had been before. At 36 h after hospitalization, CT showed that the right acute subdural hematoma had completely disappeared; however, a delayed traumatic intracerebral hematoma on the left occipital region was identified. We think that the mechanism involved in the development of a delayed intracerebral hematoma in our case was similar to the one causing delayed traumatic intracerebral hematoma after treatment for increased intracranial pressure.

Protective effects of melatonin and vitamin E in brain damage due to gamma radiation: an experimental study.

Gamma radiation is known to cause serious damage in the brain, and many agents have been used for neuroprotection. In this study, lipid peroxidation levels and histopathological changes in brain tissues of whole-body irradiated rats with likely radiation injury were compared to those with melatonin and vitamin E protection. Forty rats in four equal groups were used. The control group received neither radiation nor medication. The remaining groups received doses of 720 cGy in two equal fractions 12 h apart. The second group received radiation but no medication, the third received radiation plus 100 mg/kg per day of vitamin E i.p., and the fourth received radiation plus 100 mg/kg per day of melatonin i.p. over 5 days. On the 10th postoperative day, all the rats were decapitated and specimens from parietal cortices were analyzed for tissue malondialdehyde (MDA) levels and histopathological changes. Increases in MDA were relatively well prevented by melatonin treatment but less so with vitamin E therapy. On histopathological examination, melatonin significantly reduced the rates of edema, necrosis, and neuronal degeneration, whereas vitamin E reduced only necrosis. Neither substance was capable of preventing vasodilatation. In conclusion, melatonin may be useful in preventing the pathological changes of secondary brain damage as a result of free oxygen radicals generated by irradiation.

Giant aneurysm of the azygos pericallosal artery: case report and review of the literature.

BACKGROUND: Pericallosal aneurysms are encountered less than 6.7%, and giant aneurysms among them even less. Giant azygos pericallosal artery aneurysm at the callosomarginal bifurcation is extremely rare, and our case presented herein is the second one. The case is discussed with thorough review of the literature. METHODS: A 65-year-old woman presented with an extremely rare giant aneurysm on the azygos pericallosal artery manifesting as subarachnoid hemorrhage in World Federation of Neurosurgical Societies Grade 3. Computed tomography (CT), magnetic resonance angiography (MRA), and four vessel angiography revealed a giant azygos pericallosal artery aneurysm associated with a second aneurysm at the left M1. RESULTS: After recovery to Grade 2, she underwent surgery via the right frontal interhemispheric approach for the azygos artery aneurysm on the 17th day after bleeding. The true dimensions of the aneurysm were greater than indicated by angiography because of partial thrombosis. Trilobulate aneurysm was carefully dissected from the surrounding structures. Postoperative cerebral angiography showed no filling of the clipped aneurysm and preservation of circulation. CONCLUSIONS: The treatment of distal anterior cerebral artery aneurysms is often difficult, because of their broad-based irregular configurations and adherence to surrounding tissue, tendency to bleed irrespective of size and the coexistence of other cerebral aneurysms. However, excellent outcomes can be obtained based on thorough preoperative radiologic evaluation, including magnetic resonance imaging (MRI), and correct selection of surgical approach.

Effects of prostaglandin E1, melatonin, and oxytetracycline on lipid peroxidation, antioxidant defense system, paraoxonase (PON1) activities, and homocysteine levels in an animal model of spinal cord injury.

STUDY DESIGN: Investigation of the effects of prostaglandin E1, melatonin, and oxytetracycline on lipid peroxidation, antioxidant and paraoxonase activities, and homocysteine levels in an experimental model of spinal cord injury. OBJECTIVES: To determine the antioxidant efficacy of prostaglandin E1, melatonin, and oxytetracycline and whether paraoxonase and homocysteine can be used as monitoring parameters in the acute oxidative stress of spinal cord injury. SUMMARY OF BACKGROUND DATA: Melatonin has been found useful in spinal cord injury in previous studies. No study exists investigating the effects of melatonin, prostaglandin E1, and oxytetracycline as well as the response type of paraoxonase enzyme and homocysteine levels in the acute oxidative stress of spinal cord injury. METHODS: Sixty-three male albino Wistar rats were anesthetized with 400 mg/kg chloral hydrate and divided into 5 groups. The G1 (n = 7) control group provided the baseline levels. G2-G5 underwent T3-T6 total laminectomies and spinal cord injuries by clip compression at the T4-T5 levels. Medications were applied to G3-G5 right after clip compression. Hence, G2 constituted laminectomy + injury, G3 laminectomy + injury + prostaglandin E1; G4 laminectomy + injury + melatonin, and G5 laminectomy + injury + oxytetracycline groups. Animals were decapitated either the first or fourth hour after injury. Spinal cord tissue and blood malonyldialdehyde and plasma homocysteine levels, plasma glutathione peroxidase, superoxide dismutase, paraoxonase activities were assayed. The SPSS 9.0 program was used for statistical analysis and graphics. Intergroup comparisons were made by Bonferroni corrected Mann Whitney U test (P < 0.025) and intragroups comparisons by Wilcoxon Rank test (P < 0.03). RESULTS: In injury groups, plasma homocysteine levels decreased and paraoxonase activities increased as erythrocyte superoxide dismutase levels and plasma glutathione peroxidase activities decreased in parallel to increases of tissue and blood malonyldialdehyde levels. These alterations were relatively suppressed by prostaglandin E1, melatonin, and oxytetracycline administrations in varying degrees. Melatonin was the most powerful agent, particularly at the fourth hour. Oxytetracycline was also effective, both at the first and fourth hour. Prostaglandin E1 was effective in comparison to injury group, but not as much as melatonin and oxytetracycline. CONCLUSIONS: Melatonin and oxytetracycline are effective in preventing lipid peroxidation in spinal cord injury. Paraoxonase and homocysteine can be used in monitoring the antioxidant defense system as well as superoxide dismutase and plasma glutathione peroxidase, both in injury and medicated groups.

Asymptomatic interval in delayed traumatic intracerebral hemorrhage: report of two cases.

Delayed traumatic intracranial hemorrhage (DTICH) is seen mostly in trauma to the occipitoparietal region by countercoup mechanism. It is most encountered within the first posttraumatic 10 days, particularly in the first 3. Herein, two cases of delayed traumatic intracerebral hemorrhage were discussed, first one presented with headache and vomiting who had been asymptomatic for 168 days after head trauma and the other presented with dysarthria and hyperkynesias after 92 days of asymptomatic interval, either being longer than that of the previous cases reported in the literature. Despite a long time elapse, DTICH should be considered in the differential diagnosis in the patients with history of head trauma that manifests at later stages with intracranial pressure elevation symptoms such as headache, vomiting.

Laryngeal neurofibroma associated with neurofibromatosis type 2.

We present a case of laryngeal neurofibroma associated with neurofibromatosis type 2. Although laryngeal neurofibromas have previously been reported in cases of neurofibromatosis type 1, their presence has never been described in a patient with neurofibromatosis type 2.

Complete superior and inferior sagittal sinus thromboses with multiple cranial nerve pareses and transient ischemic attack--case report.

A 27-year-old woman with headache and right peripheral facial nerve paresis persisting for over 25 days, and left hemiparesis for 2 days, which had all been gradually improving, was admitted to our hospital as she suddenly developed horizontal and vertical diplopia. She had right fourth and sixth cranial nerve pareses, papilledema, and right orbital venous congestion, and also experienced a seizure on the day of admission. Magnetic resonance (MR) imaging and MR venography revealed complete superior and inferior sagittal sinus thromboses and significant collateral venous channels, but no parenchymal lesion. Fourth and seventh cranial nerve pareses and the left hemiparesis resolved completely within 2 days, but she concurrently developed an episode of right hemiparesis, which lasted for 30 minutes. The patient recovered with medical therapy. MR venography showed recanalization of both sinuses. She was neurologically intact except for minimal right abducens nerve paresis at discharge, 40 days after admission. Multiple cranial nerve pareses with transient ischemic attack is an extremely rare manifestation of superior sagittal sinus thrombosis. Transient functional disturbance due to temporary reduction of tissue perfusion caused by overload of the collateral channels is more likely to be responsible for the transient ischemic attack and reversible ischemic neurological deficit.

Effects of methylprednisolone and dextromethorphan on lipid peroxidation in an experimental model of spinal cord injury.

OBJECTIVE: This study examines the effects of agents purported to improve recovery following spinal cord trauma, methylprednisolone sodium succinate, dextromethorphan, and the combination of both, on the post-traumatic alterations of membrane lipid metabolism. METHODS: After sparing ten rats for a control group (G1) and performing T3-T6 laminectomies in 150 rats, spinal cord injuries were accomplished in 120 of 150 Wistar rats with an aneurysmal clip compression at the level of T4-5 for 30 sec. Hence the G2 group ( n 30) included the "only laminectomy/sham" group. The 120 injured animals were subdivided into four equal groups ( n 30 each). Group G3 underwent no therapy, G4 methylprednisolone (MP), G5 dextromethorphan (DM), and G6 MP+DM therapies. Groups G2-G6 were killed ten by ten at 10 min, 30 min, and 120 min after the operation. We measured tissue (MDA) and blood malonyldialdehyde (MDAb), (a product of lipid peroxidation) levels as an indicator of oxidative damage by thiobarbituric acid method and activity levels of antioxidant enzymes superoxide dismutase and glutathione peroxidase in erythrocytes. Intergroup and intragroup results were compared statistically. RESULTS: Methylprednisolone was able to keep the levels for all parameters close to baseline except for 30-min MDA, MDA(b), and SOD values. But their results were all different from those of G3. Dextromethorphan was successful in this respect at 30-min GSH-Px and 120-min SOD and GSH-Px, and all values were also different from G3 values except for 10-min MDA, SOD, and GSH-Px. Combined therapy was not able to keep levels close to baseline for all parameters, but they were different from G3's except for the GSH-Px values. Methylprednisolone values displayed minimal alterations according to baseline at 120 min. Dextromethorphan was relatively unsuccessful at 10 min. Combined therapy did not show benefit superior to MP/DM single therapies.

Chordoma of the thoracic spine--case report.

A 44-year-old woman presented with a thoracic chordoma with intrathoracic extension manifesting as complaints of lower extremity weakness, hypesthesia below the levels of T5-6, and sphincter incontinence. Almost total resection combined with anterior interbody fusion and stabilization was possible through a left transpleural transthoracic approach. She suffered recurrence after 2 years and was considered inoperable. Biopsy revealed a malignant chordoma with no sarcomatous differentiation. Chordoma is an uncommon malignant bone tumor originating from remnants of the embryonal notochord, occurring mostly along the axial skeleton, at the extremity of the vertebral spine, and is least common in the thoracic region. Differential diagnosis is problematic and biopsy is helpful particularly if considered inoperable. Thoracic chordomas of the malignant type manifest as cord or root compression. Classical malignant chordomas must be distinguished from chondroid, benign, or other types of chordomas, since the biological behavior and clinical features are distinct. However, the differential diagnosis cannot be based on histological examination, but long-term follow up is required. Most patients have extradural and intraspinal tissue extension at the time of diagnosis, which makes complete resection impossible. Aggressive surgery without violation of surgical borders is the best choice in the treatment of thoracic chordoma. Thoracic chordoma is a recurring neoplasm and is prone to dissemination and sarcomatous differentiation despite its slow-growing nature.