Fibro-osseous disease: harmonizing terminology with biology

Classification systems and associated terminology are inherently slow in reflecting rapidly unfolding scientific discoveries in the mechanism and presentation of diseases. Misleading concepts, which often have historical value only, may become entrenched in the literature, leading to confusion and inaccurate communication. The purpose of this communication is to stimulate discussion and debate on inappropriate terminology associated with fibro-osseous disease that continues to be perpetuated in the literature. Use of the terms "cementum," "aggressive," "active," "gigantiform," and "maturation" are questioned, and the criteria applied to the interpretation of secondary changes in fibro-osseous lesions critically are evaluated.     

A Mirror in the Mind: A Case of Visual Allaesthesia in Homonymous Hemianopia

We report the case of a 61-year-old female patient with intracranial bleeding in left parietal and parieto-temporal regions and a history of epilepsy and migraine. MR images showed lesions of the optic radiation, but primary visual cortical areas were intact. Perimetric testing revealed an incomplete right hemianopia. The patient claimed that visual percepts from her intact field were projected as “mirror images” into the hemianopic field. The illusory images were weak and sometimes difficult to detect, but focusing spatial attention on the “mirror” image increased its saliency. Drawings the patient made of her pseudo-hallucinations revealed that the illusions were lateral transpositions instead of mirror images of real objects. The illusions were tilted in clockwise direction and were never colored, although color discrimination was unimpaired in the patient's left hemifield. We quantified the characteristics of the pseudohallucinations in several experiments: The patient was asked to adjust the position, rotation angle, and size of a white test card in her blind field so that it corresponded with the illusory projection of a card of standard size and position that was presented in the intact field. The test card was compressed in horizontal size by 20% and positioned 17° visual angle to the right of the standard, shifted 1.5° upward or downward, and rotated in clockwise direction by 22.6° on average. Large objects in the intact field were projected incompletely into the blind area. Our patient's symptoms are similar to those reported in earlier case studies of visual allaesthesia. We hypothesize that the “mirror image” is induced by sparse input from contralesional V1 via the corpus callosum upstream of the lesion site and a lack of inhibition or hyperexcitability of ipsilesional early visual areas after deafferentation. The rotation of the illusions may be induced by the parietal lesions causing faulty co-ordinate computations, e.g., an inability to integrate visual and otholitic input.     

Injury to the upper extremity caused by extravasation of contrast medium: A true emergency

This retrospective clinical study, over a period of four years, includes 16 patients who had extravasation of iopromidum 623 mg (Ultravist 300® in the upper extremity during computed tomography (CT). Although conservative management is sufficient in most cases, seven patients were operated on. The mean time between extravasation and operation was 155 minutes. The most complicated postoperative course occurred when the operation was delayed 300 minutes after extravasation. When patients were treated early, there was no permanent postoperative impairment. Extravasation of contrast is an increasing cause of potential complications in the forearm as a result of the use of power injectors in CT. Immediate assessment by an experienced plastic surgeon followed by either conservative treatment or quick intervention if necessary may avoid serious damage.     

Synaptic alterations in the rTg4510 mouse model of tauopathy

Synapse loss, rather than the hallmark amyloid‐β (Aβ) plaques or tau‐filled neurofibrillary tangles (NFT), is considered the most predictive pathological feature associated with cognitive status in the Alzheimer's disease (AD) brain. The role of Aβ in synapse loss is well established, but despite data linking tau to synaptic function, the role of tau in synapse loss remains largely undetermined. Here we test the hypothesis that human mutant P301L tau overexpression in a mouse model (rTg4510) will lead to age‐dependent synaptic loss and dysfunction. Using array tomography and two methods of quantification (automated, threshold‐based counting and a manual stereology‐based technique) we demonstrate that overall synapse density is maintained in the neuropil, implicating synapse loss commensurate with the cortical atrophy known to occur in this model. Multiphoton in vivo imaging reveals close to 30% loss of apical dendritic spines of individual pyramidal neurons, suggesting these cells may be particularly vulnerable to tau‐induced degeneration. Postmortem, we confirm the presence of tau in dendritic spines of rTg4510‐YFP mouse brain by array tomography. These data implicate tau‐induced loss of a subset of synapses that may be accompanied by compensatory increases in other synaptic subtypes, thereby preserving overall synapse density. Biochemical fractionation of synaptosomes from rTg4510 brain demonstrates a significant decrease in expression of several synaptic proteins, suggesting a functional deficit of remaining synapses in the rTg4510 brain. Together, these data show morphological and biochemical synaptic consequences in response to tau overexpression in the rTg4510 mouse model. J. Comp. Neurol., 521:1334–1353, 2013. © 2012 Wiley Periodicals, Inc.     

Neuron specific enolase and serum remain unaffected by ultra high frequency left prefrontal transcranial magnetic stimulation in patients with depression: a preliminary study

Serum levels of neuron specific enolase (NSE) and protein S-100 were analysed in 22 patients with depression, who got repetitive transcranial magnetic stimulation (rTMS) for 3 weeks with ultra high frequency stimulation or sham. NSE and S-100 at baseline and after 3 weeks did not differ between the groups. Neither in the ultra high frequency group, nor in the sham group a difference between baseline and end could be found. No evidence for a significant rise in brain damage markers in rTMS was found in this preliminary study.     

Aging‐related changes of cognitive performance and stress regulation in high functioning elderly individuals

This article aims to analyse long‐term changes in cognitive performance and psychophysiological stress regulation in a specific sample of 10 young‐old (age at pre‐test: M ± SD = 63.2 ± 1.5) and 12 old‐old (age at pre‐test: M ± SD = 69 ± 2) persons possessing a high psychosocial status and a physically active lifestyle. Psychophysiological parameters were recorded prior to, during, and after the administration of a cognitive performance test battery. The measurements took place three times within a 6‐month period, and again 6 years later in a follow‐up test. Considering practice and habituation effects, findings provide no compelling evidence of an aging‐associated cognitive decline in attention, multiple choice reaction performance, and information processing speed, either in the young‐olds, or in the old‐olds. Furthermore, psychophysiological stress regulation showed no long‐term alteration regarding skin conductance level and heart rate. Based on these findings, it is assumed that psychosocial health and physical activity might contribute to the preservation of cognitive abilities and stress regulation into the 70s. Finally, this study demonstrated the significance of considering practice and habituation effects elicited through test repetitions in order to estimate long‐term effects.     

Acute vestibular syndrome: is skew deviation a central sign?

Journal of Neurology - Skew deviation results from a dysfunction of the graviceptive pathways in patients with an acute vestibular syndrome (AVS) leading to vertical diplopia due to vertical ocular...