Isolated intracranial Rosai-Dorfman disease in a child, a case report and review of the literature.

BACKGROUND: Rosai-Dorfman disease (RDD), otherwise known as sinus histiocytosis with massive lymphadenopathy (SHML), usually affects young adults and commonly presents with massive painless cervical lymphadenopathy. Extranodal disease is present in a third of patients, and it is recognised that this can involve the central nervous system. Intracranial RDD is rare in adults and fewer than 10 paediatric cases have been reported. CASE: A 10-year-old boy with isolated intracranial RDD presents with a painless forehead mass. The management is discussed and the literature reviewed. CONCLUSION: This case of isolated intracranial RDD highlights the importance of considering RDD in the differential of paediatric intracranial mass lesions and outlines the diagnostic and treatment challenges faced when managing this rare condition.

Relationship between guideline adherence and outcomes in severe traumatic brain injury.

INTRODUCTION: Traumatic brain injury (TBI) is a leading cause of death and morbidity worldwide. Evidence-based guidelines for managing severe TBI have been available for over 25 years. However, adherence to guidelines remains variable despite evidence highlighting improvement in outcomes with individual recommendations. There is limited evidence to support a superior outcome with compliance to whole sets of recommendations. The aim of this review was to determine whether adherence to TBI guidelines as a package improves outcomes in adults and paediatric patients with severe TBI. METHODS: A structured literature search was conducted using the MEDLINE®, Embase™, PubMed and CINAHL® (Cumulative Index to Nursing and Allied Health Literature) databases. Studies were considered eligible for inclusion in this review if they were quantitative studies investigating the use of TBI guidelines in relation to one or more of the following outcomes: mortality, functional outcome and length of hospital stay. RESULTS: Nine cohort studies were identified that fulfilled the inclusion criteria and answered the clinical question. A review of these papers was conducted. CONCLUSIONS: Mortality after severe TBI improves with increasing adherence to evidence-based guidelines in both adults and children. The evidence also suggests that compliance with guideline recommendations results in improved functional outcomes and reduced length of hospital stay.

Recognition memory for emotionally negative and neutral words: an ERP study.

Scalp recorded event-related potentials were used to investigate the neural activity elicited by emotionally negative and emotionally neutral words during the performance of a recognition memory task. Behaviourally, the principal difference between the two word classes was that the false alarm rate for negative items was approximately double that for the neutral words. Correct recognition of neutral words was associated with three topographically distinct ERP memory 'old/new' effects: an early, bilateral, frontal effect which is hypothesised to reflect familiarity-driven recognition memory; a subsequent left parietally distributed effect thought to reflect recollection of the prior study episode; and a late onsetting, right-frontally distributed effect held to be a reflection of post-retrieval monitoring. The old/new effects elicited by negative words were qualitatively indistinguishable from those elicited by neutral items and, in the case of the early frontal effect, of equivalent magnitude also. However, the left parietal effect for negative words was smaller in magnitude and shorter in duration than that elicited by neutral words, whereas the right frontal effect was not evident in the ERPs to negative items. These differences between neutral and negative words in the magnitude of the left parietal and right frontal effects were largely attributable to the increased positivity of the ERPs elicited by new negative items relative to the new neutral items. Together, the behavioural and ERP findings add weight to the view that emotionally valenced words influence recognition memory primarily by virtue of their high levels of 'semantic cohesion', which leads to a tendency for 'false recollection' of unstudied items.

Neural activity associated with episodic memory for emotional context.

To address the question of which brain regions subserve retrieval of emotionally-valenced memories, we used event-related fMRI to index neural activity during the incidental retrieval of emotional and non-emotional contextual information. At study, emotionally neutral words were presented in the context of sentences that were either negatively, neutrally or positively valenced. At test, fMRI data were obtained while participants discriminated between studied and unstudied words. Recognition of words presented in emotionally negative relative to emotionally neutral contexts was associated with enhanced activity in right dorsolateral prefrontal cortex, left amygdala and hippocampus, right lingual gyrus and posterior cingulate cortex. Recognition of words from positive relative to neutral contexts was associated with increased activity in bilateral prefrontal and orbitofrontal cortices, and left anterior temporal lobe. These findings suggest that neural activity mediating episodic retrieval of contextual information and its subsequent processing is modulated by emotion in at least two ways. First, there is enhancement of activity in networks supporting episodic retrieval of neutral information. Second, regions known to be activated when emotional information is encountered in the environment are also active when emotional information is retrieved from memory.

Face processing impairments after encephalitis: amygdala damage and recognition of fear.

Face processing and facial emotion recognition were investigated in five post-encephalitic people of average or above-average intelligence. Four of these people (JC, YW, RB and SE) had extensive damage in the region of the amygdala. A fifth post-encephalitic person with predominantly hippocampal damage and relative sparing of the amygdala (RS) participated, allowing us to contrast the effects of temporal lobe damage including and excluding the amygdala region. The findings showed impaired recognition of fear following bilateral temporal lobe damage when this included the amygdala. For JC, this was part of a constellation of deficits on face processing tasks, with impaired recognition of several emotions. SE, YW and RB, however, showed relatively circumscribed deficits. Although they all had some problems in recognizing or naming famous faces, and had poor memory for faces on the Warrington Recognition Memory Test, none showed a significant impairment on the Benton Test of Facial Recognition, indicating relatively good perception of the face's physical structure. In a test of recognition of basic emotions (happiness, surprise, fear, sadness, disgust and anger), SE, YW and RB achieved normal levels of performance in comparison to our control group for all emotions except fear. Their results contrast with those of RS, with relative sparing of the amygdala region and unimpaired recognition of emotion, pointing clearly toward the importance of the amygdala in the recognition of fear.

Electrophysiological correlates of the retrieval of emotional and non-emotional context.

In two experiments, words were presented in negatively or neutrally valenced sentences. At test, subjects made old/new recognition judgments to these words. In Experiment 2 only, for words judged old, subjects also indicated whether the words had been studied in a neutral or a negative context. In Experiment 1, left parietal old/new event-related brain potential (ERP) effects were larger and more sustained when elicited by words that had been studied in negative sentences, and a right frontal old/new effect was elicited by these words exclusively. In Experiment 2, the left parietal and right frontal effects elicited by old words correctly assigned to their study context were equivalent in size regardless of the nature of the context; a third ERP old/new effect, maximal over posterior scalp regions, was seen only for words from negative contexts. The findings indicate that incidental retrieval of emotional context gives rise to greater activation in neural systems supporting conscious recollection than does retrieval of nonemotional context. When contextual retrieval is intentional, recollection of emotional and non-emotional information are associated with equivalent engagement of these systems. The findings from Experiment 2 suggest that additional neural circuitry may be activated selectively by emotionally valenced episodic information.

Antiparkinsonian activity and dyskinesia risk of ropinirole and L-DOPA combination therapy in drug naïve MPTP-lesioned common marmosets (Callithrix jacchus).

De novo administration of long-acting dopamine agonists, such as ropinirole, to patients with Parkinson's disease or to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated subhuman primates produces a lower incidence of dyskinesia than occurs with L-DOPA. This study compares the intensity of dyskinesia produced by combinations of L-DOPA and ropinirole and by these drugs alone, using the MPTP-treated common marmoset model of Parkinson's disease. The objective is to determine the optimum therapeutic strategy for the long-term control of Parkinson's disease with a minimal risk of dyskinesia. MPTP-treated marmosets received either L-DOPA alone, ropinirole alone, or one of two combinations of these drugs (either L-DOPA dominant or ropinirole dominant) daily for 28 days in doses titrated to produce a similar improvement in disability and increase in locomotion. In the group receiving L-DOPA alone, there was a trend for peak dose locomotor activity to increase and the duration of drug effect to decline over the period of the study. L-DOPA alone induced marked dyskinesia over the period of treatment, in contrast to ropinirole which produced a low intensity of involuntary movements. The L-DOPA dominant combination initially produced little dyskinesia, but this became increasingly intense as the study progressed. In contrast, the ropinirole dominant combination produced no greater intensity of dyskinesia than was produced by ropinirole alone. These data suggest that in early Parkinson's disease, the use of ropinirole alone or in combination with a low-dose L-DOPA might delay the induction of dyskinesias while improving motor performance.