Evaluation of topical Dexmedetomidine administration in postlaminectomy epidural fibrosis rat model.

Epidural fibrosis is a challenging topic in spinal surgery. Numerous clinical and experimental studies have been focused on this issue to clarify problems faced in spinal procedures for the patient as well as the surgeon and find out new methodologies. Dense cytokines and growth factors which are released from inflammatory cells have been suggested to play a major role in the inception and progression of fibrosis. One of the most investigated and important actor in epidural fibrosis is assumed to be the transforming growth factor-1ß (TGF-1ß) formation. Studies showed that Dexmedetomidine (DEX) downregulates TGF-ß pathway with its anti-inflammatory and antioxidant effects. From this point of view, for the first time in the literature we try to observe if there will be an effect of topical DEX administration over epidural fibrosis in a rat model. We hypothesized that DEX might have preventive effects on epidural fibrosis via anti-inflammatory and antioxidant effects. Twenty-four adult male Wistar albino rats were randomly assigned to three groups (Topical DEX, Spongostan, Laminectomy). A total laminectomy was performed at the L3-L5 level and then the ligamentum flavum and epidural fat tissue were cleared away from the surgical site. Histopathological assessment was performed postoperatively after 4 weeks. Our study revealed that topical DEX administration may have effects on reducing epidural fibrosis. Topical DEX administration may be helpful in preventing epidural fibrosis after laminectomy in rats through multiple anti-inflammatory and antioxidant mechanisms as well as through TGF -1ß pathway.

Factors that influence recurrent lumbar disc herniation.

INTRODUCTION: The most common cause of poor outcome following lumbar disc surgery is recurrent herniation. Recurrence has been noted in 5% to 15% of patients with surgically treated primary lumbar disc herniation. There have been many studies designed to determine the risk factors for recurrent lumbar disc herniation. In this study, we retrospectively analysed the influence of disc degeneration, endplate changes, surgical technique, and patient's clinical characteristics on recurrent lumbar disc herniation. METHODS: Patients who underwent primary single-level L4-L5 lumbar discectomy and who were reoperated on for recurrent L4-L5 disc herniation were retrospectively reviewed. All these operations were performed between August 2004 and September 2009 at the Neurosurgery Department of Ataturk Education and Research Hospital in Ankara, Turkey. RESULTS: During the study period, 126 patients were reviewed, with 101 patients underwent primary single-level L4-L5 lumbar discectomy and 25 patients were reoperated on for recurrent L4-L5 disc herniation. Preoperative higher intervertebral disc height (P<0.001) and higher body mass index (P=0.042) might be risk factors for recurrence. Modic endplate changes were statistically significantly greater in the recurrent group than in the non-recurrent group (P=0.032). CONCLUSION: Our study suggests that patients who had recurrent lumbar disc herniation had preoperative higher disc height and higher body mass index. Modic endplate changes had a higher tendency for recurrence of lumbar disc herniation. Well-planned and well-conducted large-scale prospective cohort studies are needed to confirm this and enable convenient treatment modalities to prevent recurrent disc pathology.

Spectrofluorimetric Determination of α-Tocopherol in Capsules and Human Plasma.

A simple, sensitive and rapid spectrofluorimetric method for determination of α-tocopherol in pharmaceutical capsule and human plasma was developed and validated. The native fluorescence of α-tocopherol was measured at 334 nm with excitation at 291 nm, after extraction of α-tocopherol from human plasma hexane:dichloromethane mixture. The calibration curves were linear (R≥0.9993) in the concentration range of 0.25-2.5 µg/ml of α-tocopherol in both standard solutions and plasma samples. The developed method was directly and easily applied for determination of α-tocopherol in the plasma of healthy volunteers and different type of bladder cancer and stomach cancer patients and also pharmaceutical capsule.

Resolution of isolated syringomyelia after treatment of cervical disc herniation: association or coincidence?

BACKGROUND: Syringomyelia is a fluid-filled tubular cavity within the spinal cord. The exact pathophysiology of syringomyelia remains complex and uncertain. MATERIAL: We present a case of resolution of cervical syringomyelia after cervical disc operation in a follow-up time of 6 months. CONCLUSION: Restoration of cerebrospinal fluid flow dynamics between the syrinx and the subarachnoid space via removing the main pathology such as in our reported case, may contribute in resolution of the syrinx cavity (Fig. 3, Ref. 22).

Isolated abducens nerve palsy following lumbar puncture: case report and review of the mechanism of action.

Isolated abducens nerve palsy following lumbar puncture is a very rare condition. In this case we discussed the probable causes of abducens nerve palsy and review the mechanism of action in anatomical relevant literature. A 53-year old hypertensive female patient with a saccular aneursym on the left middle cerebral artery (MCA) bifurcation underwent emergency operation. Before the operation lumbar puncture (LP) was performed to the patient lying on the right lateral position to facilitate cerebral relaxation intraoperatively. The left MCA bifurcation aneurysm was clipped successfully with a left pterional-transsylvian approach. Postoperatively, she complained of visual diplopia and postural headache. In her neurological examination, isolated abducens nerve palsy was found on the left eye. The patient was treated with intravenous hydration, bed rest and non - steroid anti-inflamatuary drugs (NSAID) for postural headache. Her postural headache was resolved in the postoperative fifth day, but her abducens nerve palsy was present in the postoperative sixth month follow-up. Many classic textbooks have attributed the vulnerability of the abducens nerve to its long intracranial course, but it is now known that abducens nerves angulation points are the vulnerable parts of the nerve. We hypothesize that the petroclival dural entrance point is the entrapment point and lateral type abducens nerve, if present may be a factor that facilitates the injury of the nerve by lumbar puncture (LP).