Clinical and electroencephalographic data indicative of brain tumours in a seizure population

Magnetically-Guided Self-Assembly of Fibrin Matrices with Ordered Nano-Scale Structure for Tissue Engineering

The development of effective biological scaffold materials for tissue engineering and regenerative medicine applications hinges on the ability to present precise environmental cues to specific cell populations to guide their position and function. Natural extracellular matrices have an ordered nano-scale structure that can modulate cell behaviors critical for developmental control, including directional cell motility. Here we describe a method for fabricating fibrin gels with defined architecture on the nanometer scale in which magnetic forces are used to position thrombin-coated magnetic micro-beads in a defined 2-dimensional array and thereby guide the self-assembly of fibrin fibrils through catalytic cleavage of soluble fibrinogen substrate. Time-lapse and confocal microscopy confirmed that fibrin fibrils nucleate near the surface of the thrombin-coated beads and extend out in a radial direction to form these gels. When controlled magnetic fields were used to position the beads in hexagonal arrays, the fibrin nano-fibrils that polymerized from the beads oriented preferentially along the bead--bead axes in a geodesic (minimal path) pattern. These biocompatible scaffolds supported adhesion and spreading of human microvascular endothelial cells, which exhibited co-alignment of internal actin stress fibers with underlying fibrin nano-fibrils within some membrane extensions at the cell periphery. This magnetically-guided, biologically-inspired microfabrication system is unique in that large scaffolds may be formed with little starting material, and thus it may be useful for in vivo tissue engineering applications in the future.

Anthropometric measurements of the facial framework in adulthood: age-related changes in eight age categories in 600 healthy white North Americans of European ancestry from 16 to 90 years of age

The aim of this cross-sectional anthropometric study was to determine the age-related changes in the facial framework during adulthood in healthy white North Americans of European ancestry (261 male subjects and 339 female subjects). Five measurements, four horizontal and one vertical, defining the framework were taken from the skin and bony surface of the face in the maturation period (16-20 years) and in 10-year age categories of adulthood (21-90 years). As well, the thickness of the soft-tissue cover between these two anatomical levels was measured. The categories between 21 and 40 years represented early adulthood, those between 41 and 70 years represented middle adulthood, and those between 71 and 90 years represented late adulthood. The forehead width in both sexes increased significantly on the skin and bony surface from the maturation period to early adulthood. In middle adulthood, the changes were significant only sporadically. In late adulthood, the upper and lower jaw showed a harmonious change with age, mostly increasing on both the skin and bony surface. The face width proved to be the most stable measurement and had the thinnest soft-tissue cover. No consistent pattern emerged during adulthood in increases or decreases within the facial framework; however, an unexpected harmony was noted between the values of the measurements in early and late adulthood in both sexes on both the skin and bony surface. The thickness of the soft-tissue cover at the bony landmarks was greatest in the midface, with a moderately decreasing tendency in both sexes. In the lower jaw, the soft tissue showed significant increases in thickness in early adulthood and moderate to large decreases in late adulthood. Anthropometric analysis of the facial framework in adulthood marks only the first step in establishing the morphological changes of the aging face. Quantitative evaluation of changes within the facial framework of the aging population must be carried out in more detail. Increased worldwide migration results in a mixing of people of various racial/ethnic origins and necessitates a general anthropometric analysis of the aging face to provide more reliable guidelines for therapy.

The localization of spontaneous brain activity: first results in patients with cerebral tumors

OBJECTIVE

From EEG studies, it is known that structural brain lesions are accompanied by abnormal rhythmic electric activity. With the better spatial resolution of MEG, MEG dipole analysis can extend the knowledge based on EEG power spectra. This study presents the first results of a completely automatic analysis method applied to spontaneous MEG.

METHODS

Spontaneous MEG data of 5 patients with cerebral brain tumors and 4 controls were collected using a whole-head MEG system. Signals were bandpass-filtered with cut-off frequencies according to standard EEG bands. A moving dipole model was fitted to samples with at least twice the average sample power. Dipoles explaining 90% or more of the magnetic variance were projected onto a matched MR scan.

RESULTS

In controls, dipole distributions are symmetrical with respect to the mid-sagittal plane whereas distributions in patients often are asymmetrical to it. Dipoles describing gamma activity were located contralateral, and dipoles describing delta and theta activity were located ipsilateral to lesions.

CONCLUSIONS

The automatic method gives plausible 3-dimensional information about generator foci of abnormal slow waves and other rhythms with respect to lesion foci and thereby adds physiological knowledge to that derived from EEG power spectra.

Surgical management of pediatric tumor-associated epilepsy

Brain tumors are a common cause of seizures in children. Early surgical treatment can improve seizure outcome, but controversy exists regarding the most appropriate type of surgical intervention. Some studies suggest tumor resection alone is sufficient, while others recommend mapping and resection of the surrounding epileptogenic foci to optimize seizure outcome. To address this issue, we reviewed the charts of 34 pediatric patients aged 18 months to 20 years with medically intractable epilepsy and primary brain tumors. The average age at operation was 12.6 years, and patients had seizures for an average of 6.4 years. The majority of tumors were located in the temporal lobe. Seventeen patients, because of tumor location near an eloquent area, underwent extraoperative mapping using subdural electrode grids prior to definitive tumor resection. Fourteen of these patients had a gross total tumor resection, yet only two had a distinct zone of ictal onset identified and resected. The remaining 17 patients had tumors either in the nondominant hemisphere or far removed from speech-sensitive areas, and therefore did not undergo extraoperative subdural electroencephalograph mapping. Fourteen of these patients also had a gross total tumor resection, while none had intraoperative electrocorticography to guide the resection of additional nontumoral tissue. Overall, of the 28 patients treated with a gross total tumor resection, 24 (86%) are seizure free, while the other four are significantly improved. Of the six patients who had a subtotal tumor removal, five have persistent seizures. The mean follow-up was 3.6 years. We conclude that in children and adolescents, completeness of tumor resection is the most important factor in determining seizure outcome. The routine mapping and resection of epileptogenic foci might not be necessary in the majority of patients. As a corollary, the use of subdural electrode grids in pediatric patients with tumor-associated epilepsy should be limited to cases requiring extraoperative cortical stimulation for localization of nearby eloquent cortex.

Involuntary movement disorders associated with felbamate

Two children developed involuntary movements while taking felbamate as an adjunct to their antiepileptic regimen. One exhibited choreoathetosis and the other an acute dystonic reaction. In both children the symptoms resolved with no recurrence after felbamate discontinuance.

Causes of late onset epilepsy in Saudi Arabia: the role of cerebral granuloma

Cerebral granulomas, due to infections, have been rarely reported as a cause of late onset epilepsy. The incidence of cerebral granulomas was 7% in this prospective study of 56 consecutive patients with onset of seizures after the age of 20 years. Other main causes included cerebral tumours (20%), arteriovenous malformations (5%) and cerebrovascular disease (15% amongst patients with onset of seizures above the age of 40 years). The incidence of structural abnormalities was higher with increasing age at the onset of seizures and declined with long duration of history of epilepsy. Simple partial seizures were strongly associated with structural abnormalities (86%) as opposed to complex partial (33%) and generalised tonic-clonic seizures (33%).

Late onset epilepsy. A prospective study

253 cases of late onset epilepsy were studied prospectively. 27 cases (10.7%) had space-occupying lesion, 19 cases (7.5%) had cerebrovascular disease, 13 cases (5.1%) cerebral cysticercosis and 4 cases (1.6%) had diffuse cerebral atrophy. No cause could be detected in 190 cases (75.1%). Analysis of clinical data and radiological studies showed that a majority (85%) of patients with 'tumour' who presented with epilepsy had focal neurological deficit and/or papilloedema. Focal slow-wave abnormality in EEG also gave an indication of an organic lesion. Patients who had epilepsy for more than 1 year, infrequent attacks and partial complex seizures, were less likely to have a tumour. The role of careful clinical examination is stressed.