Discharge patterns of neurons in the rostral superior colliculus of cat: activity related to fixation of visual and auditory targets

Neurons in the rostral superior colliculus (SC) of alert cats exhibit quasi-sustained discharge patterns related to the fixation of visual targets. Because some SC neurons also respond to auditory stimuli, we investigated whether there is a population of neurons in the rostral SC which is active in relation to fixation of both auditory and visual targets. We identified cells which were active with visual fixation and which continued to discharge if the fixation stimulus was briefly extinguished. The population of neurons exhibited similar discharge characteristics when the fixation stimulus was auditory. Few neurons were significantly more active during fixation of visual targets than during fixation of auditory targets. Most fixation neurons showed a diminished discharge rate during spontaneous (self-generated) saccadic eye movements away from a visual fixation stimulus, regardless of the direction of the saccade. this diminished discharge rate (or pause) typically began, on average, 12.2 ms before saccade onset and the duration of the pause was Ionger than the duration of the saccade. These observations are consistent with the hypothesis that increased discharge of these neurons is related to active fixation and that reductions in their activity are important for the generation of saccades. However, the lack of a precise relationship between pause duration and saccade duration implies that these neurons would be unlikely to project directly to the saccadic burst generator. The mean interval from the beginning of the pauses of fixation neurons to be beginning of the saccades away from fixation targets is also shorter than has been found in brainstem omnipause neurons. By analogy with the concept of a receptive field, agaze position error field depicts the range of gaze position error for which a cell is active. Although fixation neurons appear to encode the magnitude and direction of the error between visual targets and the visual axis, visual error fields at the end of fixating eye movements were significantly larger than those at stimulus onset. For auditory stimuli, this difference was not significant. These observations are compatible with a number of recent experiments indicating that neural signals of eye position are damped or delayed with respect to current eye position.     

Primary lymphoplasmacytoid lymphoma of the trachea with immunoglobulin G paraprotein

A primary tracheal lymphoma with immunoglobulin G (IgG)-associated monoclonal serum paraprotein treated with surgery and chemotherapy is reported. As far as we know this is the first lymphoplasmacytoid lymphoma reported in the tracheobronchial tree and the first with a serum and tissue IgG monoclonal paraprotein. Differential diagnosis must be made essentially with extramedullary plasmacytoma and mucosa-associated lymphoid tissue lymphoma. CD-45RB strong positivity and the absence of lymphoepithelial lesions may help to differentiate lymphoplasmacytoid lymphoma from them. We expand the spectrum of lymphoid lesions with plasmacytoid features that can occur in the tracheobronchial tract.     

Long-term outcome of allogeneic or autologous haemopoietic cell transplantation for acute lymphoblastic leukaemia in second remission in children. GETMON experience 1983-1998

We present a retrospective study of long-term outcome and predictive factors of survival and relapse in 219 paediatric patients with acute lymphoblastic leukaemia (ALL) in second remission. They received allogeneic (allo) or autologous (auto) haemopoietic cell transplantation (HCT) depending on the availability of a matched sibling donor. The probability of event-free survival (EFS) for the total patient group was 0.35+0.03 at 14 years. No significant differences were observed for EFS between allo- and auto-HCT: 0.39+0.05 vs 0.32+0.04 (P=0.43). A better EFS was seen in patients with a late relapse (LR) (P=0.06 and 0.02, for allogeneic and autologous respectively). Significantly better EFS was observed in allo-HCT patients under 10 years of age and in auto-HCT patients with leukocytes at diagnosis below 25 x 109/l and late relapse. Predictive factors of failure in both groups were early relapse (ER), medullary relapse and age over 10 years. The probability of relapse (RP) for the total group of patients was 0.57+0.03, and it was significantly higher in auto-HCT patients: 0.65+0.04 vs 0.42+0.06 (P=0.002). Factors predictive for relapse were medullary and early relapse, auto-HCT and WBC >25 x 109/l at diagnosis.     

Remote cerebellar hemorrhage after spinal procedures (part 2): a systematic review

A remote cerebellar hemorrhage (RCH) is a spontaneous bleeding in the posterior fossa, which can be rarely observed as a complication of spine surgery. As well as for RCH reported after supratentorial procedures, it shows a characteristic bleeding pattern defined “zebra sign”. Nowadays, RCH pathophysiology still remains unknown. We performed a comprehensive review, collecting all cases of RCH after spine surgery reported in literature in order to identify the procedures most frequently associated with RCH and the possible risk factors. We assessed percentages of incidence and 95 % confidence interval of all demographic, neuroradiological, and clinical features. Univariate and multivariate analyses were used to evaluate their association with outcome. We included 44 articles reporting 57 patients with mean age of 57.6?±?13.9 years and a male/female ratio of 23/34. A RCH was more frequently reported as a complication of decompressive procedures for spinal canal stenosis, particularly when associated with instrumented fusion, followed by spinal tumor debulking and disc herniation removal. In the majority of cases, RCH occurrence was characterized by progressive impairment of consciousness, whereas some patients complained non-specific symptoms. Coagulation disorders, hypertension, and placement of postoperative subfascial drainages were the most frequently reported risk factors. The occurrence of intraoperative dural lesions was described in about 93 % of patients. Zebra sign was the most common bleeding pattern (about 43 % of cases) followed by parenchymal hematoma (37.5 %) and mixed hemorrhage (about 20 %). Impairment of consciousness at clinical onset and intake of anticoagulants/antiplatelets appeared associated with poor outcome at univariate analysis. However, more than 75 % of patients showed a good outcome and a RCH often appeared as a benign and self-limiting condition, which usually did not require surgical treatment, but only prolonged clinical surveillance, unless of the occurrence of complications.     

Exaggerated Waiting Impulsivity Associated with Human Binge Drinking,and High Alcohol Consumption in Mice

There are well-established links between impulsivity and alcohol use in humans and animal models; however, whether exaggerated impulsivity is a premorbid risk factor or a consequence of alcohol intake remains unclear. In a first approach, human young (18–25 years) social binge and non-binge drinkers were tested for motor impulsivity and attentional abilities in a human version of the Five-Choice Serial Reaction Time Task (Sx-5CSRTT), modeled on the rodent 5CSRTT. Participants completed four variants of the Sx-5CSRT, in addition to being screened for impulsive traits (BIS-11 questionnaire) and impulsive behavior (by means of the Delay Discounting Questionnaire, Two-Choice Impulsivity Paradigm (TCIP), Stop Signal Reaction Time, and Time Estimation Task). Using a second approach, we compared one of these impulsivity measures, 5CSRTT performance, in two inbred strains of mice known to differ in alcohol intake. Compared with non-bingers (NBD; n=22), binge drinkers (BD, n=22) showed robust impairments in attention and premature responding when evaluated under increased attentional load, in addition to presenting deficits in decision making using the TCIP. The best predictors for high binge drinking score were premature responding in the Sx-5CSRTT, trait impulsivity in the BIS-11, and decision making in the TCIP. Alcohol-naïve C57BL/6J (B6) mice (alcohol preferring) were more impulsive in the 5CSRTT than DBA2/J (D2) mice (alcohol averse); the degree of impulsivity correlated with subsequent alcohol consumption. Homologous measures in animal and human studies indicate increased premature responding in young social BD and in the ethanol-preferring B6 strain of mice.Impulsivity has been consistently implicated as both a determinant and a consequence of alcohol abuse. Binge patterns of alcohol consumption, in particular, have been associated with impaired attentional function and executive function (Scaife and Duka, 2009; Townshend and Duka, 2005), and increased impulsive behavior in both humans and rodent models (Bell et al, 2013; Duka et al, 2003; Stephens and Duka, 2008). However, it is unclear whether high levels of impulsivity are a cause or consequence of alcohol intake.Given the prevalence of binge drinking in adolescence (Healey et al, 2014), the first aim of our study was to examine the relationship of binge drinking to measures of waiting impulsivity and attentional abilities in human adolescents (18–25 years old) and in rodents, which consume alcohol. Taking the rodent 5CSRTT (Robbins, 2002) as a model, we developed a novel, iPad-based task (Sussex 5CSRTT; Sx-5CSRTT), to assess both attentional performance and anticipatory behavior in humans. BD were also characterized in four additional measures of impulsivity, based on different operational definitions of the construct. The Stop Signal Task, used to assess ability to inhibit a prepotent response (Logan, 1994), served as an additional measure of ‘motoric impulsivity''. The Delay Discounting Questionnaire measured preference for immediate over-delayed rewards (Petry, 2001) and, combined with the Two-Choice Impulsivity paradigm (Dougherty et al, 2005), provided an index of ‘choice'' impulsivity or decision making; the fourth behavioral measure used was the Time Estimation Task. Although each of these five measures has been used in the clinical context as an index of impulsive behavior, the sensitivity of each task to characterize impulsive phenotype in young social BD, and their relationship to one another has not been explored. We anticipated binge drinking might be differentially associated with different aspects of impulsive behavior, but generally that high binge drinking scores would be associated with high levels of trait and behavioral motor impulsivity and aversion to delay.The role of premorbid impulsivity as a predictor of elevated alcohol intake cannot be easily disentangled in human studies, as impulsivity measures are almost inevitably assessed after a period of alcohol use. Animal models are more powerful tools in this respect as they allow the exclusion of alcohol experience as a potential contributor to impulsivity. Therefore, having established that 5CSRTT waiting impulsivity was associated with human binge drinking, we asked whether waiting impulsivity in alcohol-naïve mice predicted alcohol drinking in two widely used B6 and D2 inbred strains, that also differ in alcohol consumption (Crabbe et al, 1994). We have previously reported (Walker et al, 2011) that prior exposure to high alcohol concentrations over several weeks in adulthood has only transitory effects in increasing impulsivity in B6 mice. We predicted greater impulsivity in the high-ethanol-preferring mice indicating a potential causal relationship between waiting impulsivity and high alcohol consumption.Using homologous measures of impulsivity in mouse and humans, we provide evidence that waiting impulsivity is associated with binge drinking in young adult humans, and predicts alcohol consumption in mice.     

A combination of tests for the diagnosis of dementia had a significant diagnostic value

OBJECTIVE: To study the diagnostic parameters of a number of instruments for a diagnosis of dementia in general practice and the added diagnostic value of these tests. STUDY DESIGN AND SETTING: Cross-sectional diagnostic research in general practice. Participants: 152 persons aged 65 plus. The Mini-Mental State Examination (MMSE), the Clock Drawing Test, the ADMP scale, the Timed Up and Go Test, the Extrapyramidal Sign Scale, the Behavior Observation Scale, the Poon-Baro-Wens computer battery, and the Cognitive Drug Research Computerized Assessment System were evaluated against the Dutch version of the Cambridge Examination for Mental Disorders of the Elderly (CAMDEX-N). Diagnostic characteristics were calculated with their 95% CI. Using forward stepwise logistic regression analysis, a model was built with CAMDEX-N as the dependent variable and the tests under study as independent variables. Area under the curve was the main parameter for the comparisons. RESULTS: The main diagnostic gain results from age and ADMP, followed by the Clock Drawing Test. Subsequent addition of the MMSE and computer tests results in modest additional gain only. The final model including five tests has an area under the curve of 0.95. CONCLUSION: Sophisticated neuropsychological computerized tests have little added value in the diagnostic work-up of dementia in general practice. Basic clinical tests used in an appropriate sequence can be very valuable in establishing the diagnosis of dementia.