Konuralp Ilbay

Management of Persistent Cerebrospinal Fluid Leakage Following Thoraco-lumbar Surgery

Study Design This was a retrospective study of patients who had developed a dural tear after thoracic and lumbar spine surgery that was not recognized during the surgery, and was treated either by lumbar drainage or over-sewing of the wounds. Purpose To revisit the treatment strategies in postoperative dural leaks and present our experience with over-sewing of the wound and lumbar drainage. Overview of Literature Unintended durotomy is a frequent complication of spinal surgery. Management of subsequent cerebrospinal fluid leakage remains controversial. There is no distinct treatment guideline according to the etiology in the current literature. Methods The records of 368 consecutive patients who underwent thoracic and/or lumbar spine surgery from 2006 throug h 2010 were retrospectively reviewed. Seven cerebrospinal fluid fistulas and five pseudomeningoceles were noted in 12 (3.2%) procedures. Cerebrospinal fluid diversion by lumbar drainage in five pseudomeningoceles and over-sewing of wounds in seven cerebrospinal fluid fistulas employed in 12 patients. Clinical grading was evaluated by Wang. Results Of the 12 patients who had a dural tear, 5 were managed successfully with lumbar drainage, and 7 with oversewing of the wound. The clinical outcomes were excellent in 9 patients, good in 2, and poor in 1. Complications such as neurological deficits, or superficial or deep wound infections did not develop. A recurrence of the fistula or pseudomeningocele after the treatment was not seen in any of our patients. Conclusions Pseudomeningoceles respond well to lumbar drainage, whereas over-sewing of the wound is an alternative treatment option in cerebrospinal fluid fistulas without neurological compromise.

Intraventricular meningioma of the fourth ventricle

A rare case of meningioma of the fourth ventricle is reported. A review of the literature revealed only 24 reported cases of this type of tumor.

Topical application of mitomycin C prevents epineural scar formation in rats

The role of topically applied mitomycin C in preventing postoperative perineural fibrosis was examined by gross anatomical dissection and histological analysis in rats. The sciatic nerve was exposed bilaterally in 24 Wistar adult male rats, and an abrasion injury was produced on the exposed surface of the biceps femoris muscle in all animals. In the experimental group, cotton pads soaked with mitomycin C (0.5 mg/ml) were placed around the nerves for 5 min, whereas cotton pads soaked with saline were applied to the control group. Four weeks after surgery, the neurolysis sites were evaluated by blinded surgical dissection. Perineural adhesions were graded using a numerical grading scheme. The scar tissue formation index was also calculated, and a grading was made according to the number of fibroblasts/fibrocytes counted around the epineurium in histological evaluation. Mitomycin C-treated nerves showed significantly less perineural adhesions than controls. Quantification of the dense connective tissue surrounding the nerves revealed a statistically significant reduction around nerves treated with mitomycin C, and the number of fibroblast/fibrocytes was also significantly reduced. Application of topical mitomycin C might be effective in preventing epineural scar formation after neurolysis of peripheral nerves.

Reconstruction of the middle cerebral artery after excision of a giant fusiform aneurysm

A patient with a giant fusiform aneurysm of the left inferior trunkus of the middle cerebral artery (MCA) is presented. The size of the aneurysm was 5 cm at its largest diameter. Retrograde flow was well developed. After the application of temporary clips the aneurysm was excised and microsurgical reconstructions were undertaken. Adequate flow in the reconstructed MCA trunkus was maintained. This rare case is discussed in the light of the literature.

Doxorubicin for prevention of epineurial fibrosis in a rat sciatic nerve model: outcome based on gross postsurgical, histopathological, and ultrastructural findings.

OBJECT Epineural fibrosis may complicate peripheral nerve surgeries and currently is considered as one of the main factors responsible for failed surgeries. The authors investigated the postoperative antiscarring effects of topically applied doxorubicin (DXR) on rat sciatic nerves. METHODS The sciatic nerves were dissected from the surrounding tissue and exposed bilaterally in 20 Wistar albino adult male rats. Abrasion trauma was produced on the exposed surface of the biceps femoris muscle in the vicinity of the sciatic nerves and their main branches in all animals. In the DXR Group, cottonoid pads soaked with DXR (0.5 mg/ml) were placed around the nerves for 5 minutes, whereas cotton pads soaked with saline (0.9% NaCl) were applied to nerves of animals in the Control Group for the same duration. Twelve weeks after the procedure, all of the rats were killed and the sciatic nerves were examined. Epineural adhesions were evaluated histopathologically and ultrastructurally. Additionally, quantitative histological parameters, the scar tissue formation index and the scar density, were calculated in histological evaluation. RESULTS Gross postsurgical evaluation as well as histopathological and electron microscopic examination of involved nerve segments showed significantly less epineurial adhesions in the DXR Group than in the Control Group. Quantitative analysis of the epineurium revealed a statistically significant reduction in the density and amount of epineural scarring in specimens from the DXR Group than in those from the Control Group. CONCLUSIONS The results of gross postsurgical anatomical evaluation and histopathological and ultrastructural studies suggested that topical application of DXR effectively reduced epineural scar formation on rat sciatic nerves. These promising findings merit further experimental and clinical studies to determine the efficacy and safe applicability of DXR in human subjects.

Differentiation of two subtypes of adult hydrocephalus by mixture of experts.

This paper illustrates the use of mixture of experts (ME) network structure to guide model selection for diagnosis of two subtypes of adult hydrocephalus (normal-pressure hydrocephalus–NPH and aqueductal stenosis–AS). The ME is a modular neural network architecture for supervised learning. Expectation-Maximization (EM) algorithm was used for training the ME so that the learning process is decoupled in a manner that fits well with the modular structure. To improve classification accuracy, the outputs of expert networks were combined by a gating network simultaneously trained in order to stochastically select the expert that is performing the best at solving the problem. The classifiers were trained on the defining features of NPH and AS (velocity and flux). Three types of records (normal, NPH and AS) were classified with the accuracy of 95.83% by the ME network structure. The ME network structure achieved accuracy rates which were higher than that of the stand-alone neural network models.

Double myelomeningocele in a neonate: Case report and review of the literature

The presence of myelomeningocele at multiple levels along the spinal column is extremely rare. There are only a few cases of double myelomeningocele reported in the literature. We report the case of a newborn male who had two myelomeningoceles with one at the cervical level and the other at the lumbar level. This unusual case report as well as a review of the literature is presented.

Recurrent Neural Networks for Diagnosis of Carpal Tunnel Syndrome Using Electrophysiologic Findings

This paper presents the use of recurrent neural networks (RNNs) for diagnosis of carpal tunnel syndrome (CTS) (normal, right CTS, left CTS, bilateral CTS). The RNN is trained with the Levenberg-Marquardt algorithm. The RNN is trained on the features of CTS (right median motor latency, left median motor latency, right median sensory latency, left median sensory latency). The multilayer perceptron neural network (MLPNN) is also implemented for comparison the performance of the classifiers on the same diagnosis problem. The total classification accuracy of the RNN is significantly high (94.80%). The obtained results confirmed the validity of the RNNs to help in clinical decision-making.

Multiple sclerosis and coexisting intradural extramedullary spinal cord tumour: a case report.

Abstract. We report the coexistence of multiple sclerosis (MS) and an intradural extramedullary spinal cord tumour in a 46-year-old woman with a 2-year history of MS. The patient presented with right hemitrunk and lower extremity paraesthesias, urinary incontinence, and intermittent lower right back and abdominal pain, which did not respond to pulse steroid therapy. A spinal magnetic resonance imaging (MRI) study revealed an intradural extramedullary spinal cord tumour in the lower thoracic spine, later diagnosed as schwannoma. We call attention to this rare association of MS and a spinal cord tumour, and emphasize the need for scrutiny of new and uncommon symptoms during the follow-up of MS patients.

Prevention of Epidural Fibrosis in Rats by Local Administration of Mitomycin C or Daunorubicin.

AIM Epineural adhesion after peripheral nerve surgery is common. The purpose of this study was to evaluate the macroscopic and histopathologic effects of topical mitomycin C and daunorubicin on epineural scar formation. MATERIAL AND METHODS In this study, we used 15 rats (30 nerves). Two test groups and one control group were created. Sciatic nerve exposure was created bilaterally in each group (30 nerve examinations in total). In experimental group 1, cotton pads that had absorbed mitomycin C (0.5 mg/ml) were placed onto the nerves for 5 minutes while in experimental group 2, cotton pads that had absorbed daunorubicin (0.2 mg/ml) were placed onto the nerves for 5 minutes and cotton pads that had absorbed saline were applied to the control group. Eight weeks after the first surgery, surgical dissection was performed for the evaluation of neurolysis sites. Epineural adhesions were classified utilizing a numerical grading layout. RESULTS We did not find any adverse effect with topically applied mitomycin C and daunorubicin. Within the 3 groups, no significant difference was seen in skin and fascia-muscle cavity closure (p > 0.05). Macroscopically, mitomycin C and daunorubicin decreased the adhesion of sciatic nerve to adjacent structures. There was intensive epineural scar formation in the control group. Scar tissue thickness and fibroblast/fibrocyte cell number were less in the two test groups compared with the control group (p < 0.001). There was no statistical difference between the two test groups. CONCLUSION Epineural scar formation after peripheral nerve surgery may be reduced by using topical application of mitomycin C and daunorubicin.