Neurotoxic effects of local anesthetics on the mouse neuroblastoma NB2a cell line.

Local anesthetics are used clinically for peripheral nerve blocks, epidural anesthesia, spinal anesthesia and pain management; large concentrations, continuous application and long exposure time can cause neurotoxicity. The mechanism of neurotoxicity caused by local anesthetics is unclear. Neurite outgrowth and apoptosis can be used to evaluate neurotoxic effects. Mouse neuroblastoma cells were induced to differentiate and generate neurites in the presence of local anesthetics. The culture medium was removed and replaced with serum-free medium plus 20 µl combinations of epidermal growth factor and fibroblast growth factor containing tetracaine, prilocaine, lidocaine or procaine at concentrations of 1, 10, 25, or 100 µl prior to neurite measurement. Cell viability, iNOS, eNOS and apoptosis were evaluated. Local anesthetics produced toxic effects by neurite inhibition at low concentrations and by apoptosis at high concentrations. There was an inverse relation between local anesthetic concentrations and cell viability. Comparison of different local anesthetics showed toxicity, as assessed by cell viability and apoptotic potency, in the following order: tetracaine > prilocaine > lidocaine > procaine. Procaine was the least neurotoxic local anesthetic and because it is short-acting, may be preferred for pain prevention during short procedures.

The spontaneous umbilical perforation of the distal end of ventriculoperitoneal shunt.

We present a case of umbilical perforation of the distal end of ventriculoperitoneal shunt as a rare complication of ventriculoperitoneal shunts including an umbilical abscess and an infection related with ventriculoperitoneal shunt. The ventriculoperitoneal catheter was removed, the umbilical abscess was drained and appropriate medication was employed for infection with successful outcome. Possible factors that might predispose to these complications of ventriculoperitoneal shunting are suggested.

Widespread post-traumatic acute spinal subdural haematoma: case report and review of the literature.

STUDY DESIGN: A case report of acute post-traumatic spinal subdural haematoma (ASSH). OBJECTIVE: To report a rare post-traumatic problem. SETTING: Dicle University Hospital, Diyarbakir, Turkey. METHOD: A 3-year-old boy was admitted to our clinic with paraplegia 24 h after falling from a height of about 5 meters. Investigation revealed an acute spinal subdural haematoma. RESULTS: Following surgery there was marked improvement. The rehabilitation of the patient continues. CONCLUSION: MRI is the most valuable diagnostic method. In each case diagnosed as ASSH, prompt evacuation should be performed before irreversible neurological damage occurs.

Gigantic intracranial mass of hydatid cyst.

A child (8 years old) with a gigantic mass of intracranial hydatid cysts (95x90x75 mm) is presented. The first manifestation was difficulty in walking, which was followed by symptoms of raised intracranial pressure. A craniotomy was performed, and more than 25 hydatid cysts were removed. The literature is reviewed and the incidence of gigantic mass of cerebral hydatid cyst is compared in the published reports.

The curly tail mouse model of human neural tube defects demonstrates normal spinal cord differentiation at the level of the meningomyelocele: implications for fetal surgery.

The paralysis associated with lumbosacral meningomyelocele has been attributed both to myelodysplasia and to degeneration of the exposed neural tissue. Surgically created dysraphism shows that exposure of an intact spinal cord in a genetically normal animal results in degeneration of the normal nervous tissue and subsequent paralysis. Our objective was to study neuronal differentiation in the curly tail mouse mutant model, which develops lumbosacral meningomyelocele naturally and is a phenocopy of nonsyndromic human neural tube defects. Prenatal repair of meningomyelocele assumes that the normal neuronal differentiation program occurs despite failure of neurulation. Here we demonstrate that this most suitable animal model has normal differentiation of neuronal structures at the level of the meningomyelocele. TuJ1, an antibody to neuronal specific class III beta-tubulin, an early marker of neuronal differentiation, was used to stain paraffin-embedded sections of curly tail mouse embryo meningomyelocele. Embryos were examined at embryonic day 13.5 (E13.5). The inbred mouse strain, C57BL6/J, which is genetically similar to the curly tail mouse, was used as a control in these studies. We show that early neuronal differentiation appears intact within the meningomyelocele. TuJ stains structures within the open neural tube. Motor neurons are present in the ventral horn and ventral roots. Dorsal root ganglia are present and of similar size to controls. The staining pattern is similar to that seen in the C57BL/6J control mouse, although dorsal structures are laterally displaced in the curly tail meningomyelocele. Based on this model, fetal surgery to repair human meningomyelocele may preserve neurological function in those cases where there is not an inherent genetic defect of the neural tissue.

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

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 mal-development.

Role of magnetic resonance imaging in children with voiding dysfunction: retrospective analysis of 81 patients.

OBJECTIVES: To investigate the role of magnetic resonance imaging (MRI) in children with voiding dysfunction and a normal neuro-orthopedic assessment. The differential diagnosis of neurogenic and non-neurogenic voiding dysfunction, particularly in children with occult neurogenic pathologic findings without a clinically demonstrable neurologic defect, is a commonly encountered problem. METHODS: Eighty-one children with voiding dysfunction, including a history of diurnal incontinence, frequency, urgency, urge incontinence, incomplete bladder emptying, recurrent urinary tract infection, and persistent vesicoureteral reflux, constituted our study group. A detailed neuro-orthopedic evaluation was performed in all patients. The urologic evaluation consisted of a detailed history (including bowel function disturbances), renal sonography or excretory urography, spinal x-ray, urinalysis and culture, voiding cystourethrography, and multichannel water cystometry. In all cases, lumbosacral spinal axial and sagittal T1- and T2-weighted MRI performed with a 1.5-Tesla surface coil was reviewed by one neuroradiologist. RESULTS: MRI revealed pathologic findings in 17 (38.6%) of 44 patients who had voiding dysfunction and a normal neuro-orthopedic assessment. All these patients underwent early surgical intervention in our pediatric neurosurgery department. In the postoperative period, objective and/or subjective improvement in voiding symptoms within short (6 months) and long (14 months) periods was observed in 8 (47.0%) and 5 (29.4%) patients, respectively. Ten (58.8%) of those 17 patients had a history of voiding dysfunction refractory to conservative management. CONCLUSIONS: Our results revealed that MRI of the lower spinal cord is a valuable tool in the diagnosis of occult spinal cord disorders, especially in patients with voiding dysfunction refractory to conservative management strategies and normal neurologic and orthopedic assessments.

Management of tight filum terminale syndrome with special emphasis on normal level conus medullaris (NLCM).

BACKGROUND: Tethered cord syndrome is classically defined as having the tip of the conus medullaris below the body of L2, instead of at the normal L1-2 disc space level. The syndrome presents most commonly with urinary incontinence. In a patient with urinary incontinence and a low-lying conus medullaris, tethered cord syndrome can be diagnosed without difficulty. 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 on magnetic resonance imaging, diagnosing a tethered cord can be challenging. We hypothesized that patients with hyperreflexive neurogenic bladders have a neurologic basis for their bladder dysfunction, probably secondary to tethering by a tight filum terminale, despite having a normally positioned conus medullaris. METHODS: We investigated 13 patients with tethered cord syndrome with urinary incontinence. All patients underwent urodynamic tests, somatosensory-evoked potentials (SSEPs), and magnetic resonance imaging. All had normal neurologic exams including lower extremity motor, sensory, and reflex functions. To minimize disturbance of the normal anatomy, we used a flavotomy approach and transected the tight filum terminale to release the tethered conus medullaris. RESULTS: We show that urodynamic studies appear to be more predictive of a tight filum terminale than SSEPs. However, pathological SSEP results seem to correlate with poor surgical outcomes. Ninety-three percent of operated patients were continent by the first post-surgical day. However, disappointingly, almost half lost continence within the first month after surgery. CONCLUSION: In cases of incontinence with a normal level conus medullaris, but urodynamic studies showing a hyperreflexic neurogenic bladder, we believe that sectioning of the filum terminale often improves continence.

Mature teratoma of the lateral ventricle: report of two cases.

In this paper, two cases with mature teratoma of the lateral ventricle are presented. Teratomas are rare intracranial tumours and the most common location is in the midline pineal region. Lateral ventricle as the site of location is very rare. Between the years 1975 and 1996, 120 cases were operated on for lateral ventricle tumours at the University of Ankara, Department of Neurosurgery, and only two cases (% 1.6) were histologically identified as mature teratomas. It is generally accepted that benign teratomas are radioresistant and total removal of these tumours results in cure. If mature teratoma of the lateral ventricle is totally removed, as done in our cases, the prognosis is usually good.

Level of conus medullaris in term and preterm neonates.

AIMS: To compare the levels of conus medullaris in preterm and term neonates; to show the time of ascent to normal; and to evaluate the babies with low conus medullaris levels for tethered cord syndrome. METHODS: Levels were assessed using ultrasonography in 41 preterm and 64 term neonates. RESULTS: In the preterm group the conus medullaris level in one infant (2.4%) was below L4. In three infants (7.2%) it was between L2 and L3 and in 37 infants (90.4%) it was above L2. In the term group it was below L4 in one baby (1.6%), between L2 and L3 in four (6.3%), and above L2 in 57 babies (92.1%). The difference in the conus medullaris levels between term and preterm neonates and genders was not significant. Two patients, one with a conus medullaris level at L4-L5, and the other at L2-L3, had Down's syndrome. CONCLUSION: The ascent of conus medullaris seems to occur early in life. It is important to follow up patients with conus medullaris levels at or below the 4th lumbar vertebra for the development of tethered cord syndrome.

Large craniopharyngioma extending to the posterior cranial fossa.

Craniopharyngiomas are most commonly located extra-axially in the sellar or suprasellar area. They are benign but aggressive neoplasms. This paper reports an 8-year-old girl with a large craniopharyngioma originating from the suprasellar region and extending to the posterior cranial fossa down to the region of the foramen magnum.

Effectiveness of radiofrequency thermocoagulation in recurrent trigeminal neuralgia after previous retrogasserian rhizotomy.

Between 1974 and 1984, 428 trigeminal neuralgia cases were treated by controlled radiofrequency thermocoagulation (RFTC). 29 had recurrent trigeminal neuralgia after intracranial surgery. 26 of the 29 patients were treated by retrogasserian rhizotomy and 3 by posterior fossa exploration. Among the 26 recurrent trigeminal neuralgia following retrogasserian rhizotomy, RFTC was effective in 23 cases (88.5%), and in 3 cases (11.5%) RFTC was effective for a short period. Repeated RFTC was unable to control the pain attacks which were later relieved by posterior fossa exploration and root section. Of the 3 recurrent trigeminal neuralgia following posterior fossa exploration, RFTC was effective in 2 cases (66.6%).

A giant meningioma of the fourth ventricle associated with Sturge-Weber disease.

A case of meningioma without dural attachment within the fourth ventricle associated with Sturge-Weber disease is reported. Review of the literature revealed that meningiomas arising from the choroid plexus of the fourth ventricle and lying totally within the fourth ventricle are very rare. Coexistence of Sturge-Weber disease with meningioma of the fourth ventricle has never been reported, as far as we could find out.