When does less yield more? The impact of severity upon implicit recognition in pure alexia

Pure alexia (PA) is characterised by strong effects of word length on reading times and is sometimes accompanied by an overt letter-by-letter (LBL) reading strategy. Past studies have reported “implicit recognition” in some individual PA patients. This is a striking finding because such patients are able to perform semantic classification and lexical decision at above chance levels even when the exposure duration is short enough to prevent explicit identification. In an attempt to determine the prevalence of this “implicit recognition” effect, we assessed semantic categorisation and lexical decision performance using limited exposure durations in 10 PA cases. The majority of the patients showed above chance accuracy in semantic categorisation and lexical decision. Performance on the lexical decision test was influenced by frequency and imageability. In addition, we found that the extent to which patients showed evidence of “implicit recognition” in both tasks was inversely related to the severity of their reading disorder. This result is consistent with hypotheses which suggest that this effect does not constitute an implicit form of unique word identification but is a reflection of the degree of partial activation within the word recognition system. These results also go some way towards explaining the individual variation in the presence of this effect observed across previous case-study investigations in the literature.     

Bradycardic and hypotensive responses to microinjection of -glutamate into the lateral aspect of the commissural NTS are blocked by an NMDA receptor antagonist

Baroreflex activation by phenylephrine infusion produces a bradycardic response while microinjection of -glutamate into the most lateral aspect of the commissural nucleus tractus solitarius (NTS, 0.8 mm lateral to the midline) produces bradycardic and hypotensive responses. In the present study we investigated the role of NMDA receptors in the lateral aspect of the commissural NTS (0.8 mm lateral to the midline) in the bradycardic and hypotensive responses to microinjection of -glutamate as well as in the processing of the bradycardic response to the baroreflex activation. The hypotensive and bradycardic responses to -glutamate microinjection into the NTS were blocked by methyl-atropine (intravenous, i.v.), indicating that the hypotensive response was secondary to the bradycardia. Microinjection of -glutamate (1 nmol/50 nl) into the NTS was performed before and after microinjection of increasing doses of phosphonovaleric acid (AP-5, a selective NMDA antagonist) at the same site. The microinjection of AP-5 [0.5 (n=9), 2.0 (n=8) and 10.0 nmol/50 nl (n=7)] into the NTS (0.8 mm lateral to the midline) produced a dose-dependent blockade of the bradycardic and hypotensive responses to -glutamate. In a specific group of rats the microinjection of 10 nmol/50 nl of AP-5 produced a significant reduction in baroreflex sensitivity 2 min after microinjection into the lateral NTS [gain=−1.48±0.12 vs. −0.5±0.2 beats/mmHg, (n=5)], which was reversible. The data show that the bradycardic responses produced by microinjection of -glutamate into the most lateral aspect of the commissural NTS or by activation of the baroreflex were blocked by microinjection of AP-5, indicating that the neurotransmission of the parasympathetic component of the baroreflex in the neurons of the lateral aspect of the commissural NTS involves NMDA receptors.     

Effect of rikkunshito on gastric sensorimotor function under distention

Background The herbal medicine rikkunshito is effective for the treatment of gastrointestinal symptoms in patients with functional dyspepsia. Although some basic studies on the effects of rikkunshito have been reported in rats, its effects on human gastric function have not yet been clarified. Psychosocial stress induces visceral hypersensitivity and elements of rikkunshito may reasonably affect or suppress this process. We conducted a study to verify the hypothesis that rikkunshito improves stress‐induced gastric hypersensitivity and/or changes in gastric wall tone. Methods Nine healthy volunteers (five males, four females) participated in the study. The counterbalanced regimen consisted of a 2‐week period of oral administration of 7.5 g day^?1 rikkunshito, then a 2‐week period without treatment. Fundic sensorimotor function was examined using a gastric barostat twice on the day after each period. Virtual reality stress was imposed during the measurements of gastric tone and electrocardiogram. Key Results Stress induced a significant increase in heart rate (P = 0.041), gastric volume (P = 0.008), and phasic volume events (P = 0.049) and a decrease in sensory (P = 0.038), discomfort (P = 0.011), and pain (P = 0.041) thresholds of the stomach. Rikkunshito significantly reduced epigastric fullness (P = 0.037) and perceived stress (P = 0.034) following stimulation of the pain threshold, regardless of stress without the drug. Stress reduced gastric volume at the sensory threshold and increased anxiety at the discomfort threshold, and these responses were significantly inhibited by rikkunshito (P = 0.026, P = 0.022, respectively). Conclusions & Inferences These findings suggest that rikkunshito may improve symptoms and impaired gastric accommodation under distention stimuli of the proximal stomach superimposed by stress.     

Production and perception of mandarin tone in adults with cerebral palsy

The primary objective of the present study was to document tone production and intelligibility deficits in Mandarin‐speaking persons with cerebral palsy (CP). Spastic, athetoid, and mixed types of CP were studied, along with a control group, to investigate the possibility of tone production and intelligibility deficits that were differentially affected by type of CP. Speakers produced a 78‐word list that included contrasts for all four Mandarin tones. Intelligibility data were obtained for these words from 26 native speakers of Mandarin, and F0 contour analyses were implemented in CSpeech (Milenkovic) for a subset of the words. Mean tone intelligibility for speakers with CP was 73%, significantly different from the 91% value for control speakers. F0 contour analysis showed that speakers with CP maintained some contrast among the F0 contours for the four tones, but with less distinction than contrasts observed for control speakers. Discussion focuses on the role of tone in a model of the dysarthria associated with CP.     

Thymoma and pure red cell aplasia with hypoplasia of megakaryocytopoiesis: A rare and life-treating condition

Thymic tumors are rare diseases with an incidence of 0.15 cases per 100,000 person-years. They can be associated with a variety of other syndromes, such as Myasthenia Gravis or autoimmune disorders. Among them, pure red cell aplasia is a hemato-pathological condition characterized by anemia, reticulocytopenia and erythroid cell hypoplasia of bone marrow. Here, we reported a case of a 62-year-old female with a long history of neurologic symptoms due to Myasthenia Gravis. She was diagnosed with thymoma, with mediastinal mass and pleural thickening. After chemoradiotherapy treatment, she was surgically resected successfully, but she developed anemia and severe thrombocytopenia, worsening in respiratory failure requiring intubation. A bone marrow biopsy was performed resulting in a red-cell aplasia with marked hypoplasia of megakaryocytopoiesis compatible with pure red cell aplasia with acquired thrombocytopenia. Considering that there are no standard treatments, clinical condition improvement was achieved only after some lines of medical treatment. Our data, together with the few already published, help to raise the attention towards acquired cytopenias and the need to optimize the treatment for a potentially life-threatening condition.     

气导声刺激前庭诱发肌源性电位在正常儿童中的表现

目的 探讨研究正常儿童中气导声刺激诱发的眼性前庭诱发肌源性电位(oVEMP)和颈性前庭肌源性诱发电位(cVEMP)的各项参数指标,并对正常值进行统计学处理分析。 方法 选择4~10岁听力正常健康儿童52例,以500 Hz短纯音作为刺激音,分别行 oVEMP和cVEMP检测,记录左、右耳引出率及波形参数,并采用SPSS统计软件进行统计学处理分析。 结果 双耳皆未引出oVEMP 2例,单耳可引出oVEMP4例,oVEMP总体引出率为92%。双耳皆未引出cVEMP 2例,cVEMP总体引出率为96%。oVEMP与cVEMP的P1潜伏期分别为(17.07±0.89)ms、(15.55±1.58)ms;N1潜伏期分别为(12.39±0.91)ms、(23.10±2.29)ms;N1P1间期分别为(4.68±0.88)ms、(7.83±1.56)ms;oVEMP与cVEMP的振幅分别为(7.24±4.79)μV、(197.40±118.37)μV。双耳间oVEMP及cVEMP振幅不对称比分别为(19.03±12.50)%、(22.16±18.64)%。患儿左右耳的潜伏期,P1N1间期及振幅差异无统计学意义(P>0.05)。 结论 绝大部分正常儿童经气导声刺激可引出oVEMP与cVEMP。该检测患儿依从性高,可用来评估儿童前庭功能。此研究结果可为我国的儿童气导VEMP提供正常参考值范围。     

耳鸣患者1/24倍频程精细化纯音测试结果分析

目的了解精细化匹配耳鸣位点与听损最大点之间的关系,分析耳鸣患者听力及临床特征与耳鸣的关系。方法对常频听力正常及异常组均进行1/24倍频程精细化纯音测听,寻找听损最大点及耳鸣位点;两组患者均进行病史分析,分析耳鸣患者听力及临床特征与耳鸣的关系。结果常频听力正常的患者38例行1/24倍频程精细化听力测试,检出听力损失者12例;两组患者127例均进行1/24倍频程听力精细化测试及耳鸣位点精细化评估,其中36例患者听力损失最大点和耳鸣位点一致。将常频听力正常组和异常组临床特征对比分析,常频听力异常组高血压、脑供血不足、睡眠障碍的发病率高于常频听力正常组。结论常频听力正常的患者行1/24倍频程精细化纯音测听可提高耳鸣声治疗的“靶向性”。     

Heart rate turbulence and other autonomic risk markers for arrhythmia risk stratification in dilated cardiomyopathy

Background

Noninvasive arrhythmia risk stratification in patients with nonischemic dilated cardiomyopathy (DCM) using autonomic markers have yielded disappointing results. Heart rate turbulence is a new method to assess cardiac autonomic function.

Aim

The aim of the study was to compare the predictive value of heart rate turbulence with those of conventional autonomic risk markers for ventricular tachyarrhythmic events in patients with DCM.

Methods

The predictive value of heart rate turbulence, baroreflex sensitivity (phenylephrine method), and heart rate variability was assessed in patients with symptomatic congestive heart failure due to DCM who were in sinus rhythm and had a 24-hour Holter recording. Patients were followed for a combined end point of ventricular tachyarrhythmic events.

Results

A total of 114 patients (mean left ventricular ejection fraction, 28 ± 11%), included in the Frankfurt DCM database between 1996 and 2000, fulfilled the criteria for inclusion in this study. Determinate test results were obtained for heart rate variability in 98%, for baroreflex sensitivity in 90%, and for heart rate turbulence in 75% of patients (P = .008). Correlation between the different autonomic markers were only modest (r values, 0.36-0.43). During a follow-up of 22 ± 17 months, an end point event occurred in 15 patients. On univariate analysis, left ventricular ejection fraction and baroreflex sensitivity were significant predictors of arrhythmic events. On multivariate analysis, only baroreflex sensitivity remained an independent predictor (χ² = 3.17; P = .07).

Conclusion

Reliable analysis of heart rate turbulence is possible in approximately 75% of eligible patients with DCM. Whereas blunted baroreflex sensitivity is a predictor of arrhythmic events, heart rate variability and turbulence do not yield predictive power in these patients.