Time experience in patients with schizophrenia and affective disorders

BackgroundThe experience of time, or the temporal order of external and internal events, is essential for humans. In psychiatric disorders such as depression and schizophrenia, impairment of time processing has been discussed for a long time.AimsIn this explorative pilot study, therefore, the subjective time feeling as well as objective time perception were determined in patients with depression and schizophrenia, along with possible neurobiological correlates.MethodsDepressed (n = 34; 32.4 ± 9.8 years; 21 men) and schizophrenic patients (n = 31; 35.1 ± 10.7 years; 22 men) and healthy subjects (n = 33; 32.8 ± 14.3 years; 16 men) were tested using time feeling questionnaires, time perception tasks and critical flicker-fusion frequency (CFF) and loudness dependence of auditory evoked potentials (LDAEP) to determine serotonergic neurotransmission.ResultsThere were significant differences between the three groups regarding time feeling and also in time perception tasks (estimation of given time duration) and CFF (the “DOWN” condition). Regarding the LDAEP, patients with schizophrenia showed a significant negative correlation to time experience in terms of a pathologically increased serotonergic neurotransmission with disturbed time feeling.ConclusionsImpairment of time experience seems to play an important role in depression and schizophrenia, both subjectively and objectively, and novel neurobiological correlates have been uncovered. It is suggested, therefore, that alteration of experience of time should be increasingly included in the current psychopathological findings.     

DEPRESSION: INFLUENCE ON TIME ESTIMATION AND TIME EXPERIENCE

Time studies are partly concerned with time estimation partly with time experience. In a study of depression both principles were applied. Depression did not influence time estimation, but, on the other hand, the patients did report a slowing down of time (change in time experience). An item analysis of Beck's and Hamilton's rating scales showed that the disturbance in time experience accompanies items referring mainly to mood changes, only to a small extent to somatic symptoms, and not at all to changes in the psychomotor activity.     

The influence of sacral nerve stimulation on gastrointestinal motor function in patients with fecal incontinence

Background Sacral nerve stimulation (SNS) is a well‐established treatment for fecal incontinence of various etiologies. However, the mechanism of action remains unclear. The aim of the present study was to determine whether SNS affects gastric emptying, small intestinal transit or colonic transit times. Methods Seven patients with a permanently implanted sacral nerve stimulator participated in a double‐blind randomized cross‐over study. The patients were allocated to stimulation ON or OFF for two 7‐day periods separated by at least 1 week. On days 4–7 of each 7‐day period, the patients were examined by gamma camera imaging to measure gastric emptying, small intestinal transit and colonic transit parameters of a radiolabeled, 1600 kJ mixed solid and liquid meal ingested on day 4. Key Results Sacral nerve stimulation did not change gastric retention at 15 min, gastric mean emptying time, gastric half emptying time, small intestinal mean transit time or colonic geometric center after 24, 48 and 72 h. Conclusions & Inferences Sacral nerve stimulation does not induce major changes in the propulsive capacity of the gastrointestinal tract in patients successfully treated for fecal incontinence with permanent sacral nerve stimulator.     

Delayed motor response correlates with striatal degeneration in Parkinson''s disease

OBJECTIVE: Studies on reaction time have suggested a selective deficit of slowness in motor readiness and motor programming in Parkinson's disease (PD). Objective of this study was the putative relation between delayed initiation and execution of movement and the striatal dopamine deficiency in PD. MATERIAL AND METHODS: We investigated 32 idiopathic, previously untreated parkinsonian patients to evaluate dopaminergic nigrostriatal degeneration by single photon emission tomography in combination with the radiotracer [123I]-beta-CIT and performed a simple reaction time paradigm on the same day. RESULTS: Significant relations between the [123I]-beta-CIT-SPECT-ratio striatum/cerebellum and reaction--and movement time appeared. Reaction time and movement time of parkinsonian patients were significantly longer compared to age-matched controls. CONCLUSIONS: We conclude that reaction- and movement-time is related to the dopaminergic nigrostriatal degeneration in untreated parkinsonian subjects.     

The influence of a concurrent cognitive task on lower limb reaction time among stroke survivors with right- or left-hemiplegia

Abstract

Objective:

To determine the impact of cognitive interference on foot pedal reaction time among stroke survivors with right- (RH) or left-hemiplegia (LH).

Design:

Cross-sectional comparison without randomization.

Subjects/patients:

10 patients post-stroke with RH, 10 with LH; 10 age-matched controls.

Methods:

Foot pedal response times were measured using three different reaction time (RT) paradigms: simple RT, dual-task RT (counting backward by serial 3 seconds), and choice RT (correct response contingent on stimuli to eliminate pre-programing). RH and LH used the non-paretic leg for all trials. Three 3 (RT task)?×?3 (group) mixed-model factorial ANOVAs were used to compare RT, movement time (MT), total response time (TRT).

Results:

Overall controls demonstrated faster RT than RH (332?±?73 versus 474?±?144?ms, P?<?0.001) or LH (402?±?127?ms, P?<?0.05); LH group demonstrated faster RT than those with RH (P?<?0.05). Control subjects demonstrated significantly faster RT than RH for all RT conditions (P?<?0.05 for all). In contrast, controls achieved significantly faster RT than LH for the choice RT condition only (P?<?0.05), but not for the simple (P?=?0.12) or dual-task RT conditions (P?=?0.25).

Conclusions:

Compared to controls, response time was significantly impaired among LH and RH when the response could not be pre-programmed. While current simple RT testing commonly employed by driver rehab specialists may be sufficient for detecting RT deficits in patients with RH, simple or dual-task RT tests alone may fail to detect RT deficiencies among LH, even when testing the non-paretic limb. Choice RT should be added to post-stroke driver fitness assessment, particularly for patients with LH.     

院内卒中救治绿色通道建立、优化及区域救治网络的建立

目的 机械取栓时代,探索如何因地制宜建立急性卒中救治体系,让更多急性卒中患者能在时间窗 内及时到达有条件的医院,从而提高区域性急性卒中急诊救治的整体水平。 方法 从2014年开始,在院内及医院所在的区域,由单位行政部门及区域卫生行政部门牵头协调, 制定卒中救治的相关政策、规定,陆军军医大学第一附属医院神经内科作为技术主导,开展卒中诊治 的培训及帮助各级部门、医院建立相应的卒中救治流程、规范。观察我院卒中救治的关键绩效指标 及协作单位救治水平的改善情况。 结果 ①院内急诊通道的建立：由院长亲自参与,院医疗科作为卫生行政部门进行督导、协调,院内 参与卒中救治的急救部、神经内科、神经外科、神经影像科、检验科、心电图室及护理保障中心积 极参与,使急性缺血性卒中的入院-静脉溶栓（door-to-needle time,DNT）时间由绿色通道建立前的 71 mi n缩短至53 mi n,入院-动脉穿刺（door-to-puncture time,DPT）时间由104 min缩短至82 min,入院-血 运重建（door-to-revascularization time,DRT）时间由144 min缩短至117 min。②区域性卒中救治网络的建 立：极大提高我院急性缺血性卒中的救治能力,2014年本科静脉溶栓及血管内治疗总病例数为7例, 2016年提高到112例,区域内初级卒中中心的卒中防治关键绩效指标明显改善。 结论 院内卒中救治绿色通道及区域性卒中救治网络的建立,能提高卒中救治水平及救治率,改善 区域性卒中救治水平。应进一步改进卒中救治通道及网络并进行更大范围的推广。     

Simple and choice reaction time in Parkinson's disease

Reaction-times were evaluated in 6 parkinsonian patients and 6 normal control subjects using a simple reaction task and 3 choice reaction tasks of differing complexity. Reaction-times were measured as the time from stimulus onset to the onset of electromyographic activity in the responding muscle. Reaction-time was significantly delayed in patients compared to controls in all tasks, but to a greater extent in the more difficult tasks. The relative magnitude of the change, however, was only 4% in the simple reaction task and 8% in the more difficult choice tasks. These results suggest that the deficit in Parkinson's disease is unlikely to represent a defect in preprogramming as suggested by some investigators. Instead, our results indicate a disturbance in the cerebral processing of the auditory stimuli after their occurrence and prior to the initiation of motor activity.     

Colour vision abnormalities and movement time in Parkinson''s disease

Visual system dysfunction has been reported in Parkinson's disease (PD). The objective of the present study was to evaluate a putative association of distorted colour vision and delayed initiation and execution of movement in PD. We performed the Farnsworth-Munsell 100-hue test and estimated the total error score in 30 previously untreated parkinsonian patients and 30 age- and sex-matched controls. We then determined slowness in motor readiness and motor programming in the parkinsonian subjects on the same day. Subjects were asked to press a start button and release it after the randomized appearance of a visual stimulus and to move their right index finger to a reaction button as quickly as possible. Reaction time was considered as elapsed time between onset of the stimulus light and release of the start button, movement time was the time period between release of the start button and the pressing of the reaction button. Significant differences appeared between parkinsonian patients' and controls' reaction times (P = 0.007), movement time (P = 0.001) and total error score (P = 2.23E-08). A significant relation (Spearman R = 0.473, P = 0.008) was found between movement time and total error score, but not between reaction time and total error score (Spearman R = 0.259, P = 0.166). We conclude, that visual dysfunction and execution of movement are more influenced by altered dopaminergic neurotransmission in PD in comparison to the initiation of movement.     

Identification of a new SERPINC1 mutation in a Kazak family that alters the heparin binding capacity of antithrombin

Introduction

Given its central role in mediating heparin-induced anti-coagulation, antithrombin (AT) gene mutations may result in heparin resistance. This study investigates the relationship between familial AT gene mutations and tolerance to heparin.

Methods

The medical history of a male patient with heparin resistance who received heart surgery and six of his family members was reviewed. Activated partial thromboplastin time (APTT), prothrombin time (PT), fibrinogen (Fib), D-dimer (D = D), and platelet count were determined to assess coagulation function. AT activity and the AT gene were also analyzed. For the newly identified gene mutations, polymorphisms were excluded in 120 healthy Kazak controls.

Results

Two mutations were identified in exon 7 of the AT gene, SERPINC1: g.1267G > A (p.A391T) found in five participants, including the index patient, and g.1334G > A, a silent mutation, in two family members. The g.1267G > A mutation may alter focal AT protein conformation. Neither of these mutations was observed in the healthy Kazak controls. Although all coagulation parameters and AT activity were within the normal ranges for the index patient and his family members, the platelet levels were significantly lower than that observed for the healthy Kazak controls (p = 0.001). There was no significant difference in AT antigen levels between the groups; however, participants with the g.1267G > A mutation had a 44.25% reduction in heparin binding compared to the control group (p < 0.001).

Conclusion

We identified a novel hereditary mutation, g.1267G > A (p.A391T), in the AT gene, which reduces its heparin binding capacity and might be associated with resistance to heparin.     

抑郁症的早醒与睡眠脑电图的关系

目的探索伴和不伴早醒的抑郁症病人睡眠脑电图特征。方法对10例伴早醒的抑郁症(早醒组)、8例不伴早醒的抑郁症(非早醒组)和10例对照组进行睡眠脑电图检查。结果(1)早醒组的醒起时间比对照组显著为长(11.8±8.5:3.1±2.8,P<0.05);(2)非早醒组的运动觉醒时间比对照组显著为短(3.1±1.4:6.8±3.1,P<0.05);(3)早醒和非早醒组的睡眠总时间比对照组显著为短(331.7±25.6和333.9±52.7比386.7±41.3,P均<0.05);REM强度比对照组显著为强(28.7±8.8和32.8±19.5比19.4±3.7,P均<0.05)。结论(1)抑郁症的早醒可能与精神运动性阻滞相关联;(2)不伴早醒的抑郁症可能由慢波睡眠向快波睡眠的转相增快;(3)抑郁症病人的总睡眠时间减少和REM睡眠强度增加。     

Usefulness of movement time in the assessment of Parkinson's disease

Reaction time (RT) and movement time (MT) are reported to be delayed in Parkinson's disease (PD), but their clinical utility and relationship with clinical findings is still uncertain. We investigated RT and MT in 22 PD patients at baseline conditions and following acute oral trials of levodopa and biperiden, an anticholinergic drug. At baseline conditions, RT and MT of PD patients were abnormally delayed compared with those of 16 normal control subjects. Both RT and MT were longer in more severely affected patients compared with the mild PD patients; in the mild PD patients with asymmetrical signs both responses were longer on the more affected side. Bradykinesia was the clinical symptom that best correlated with the objective measurements, with a stronger correlation for MT than for RT. The oral administration of levodopa significantly improved both the responses, whereas biperiden was ineffective. The magnitude of RT and MT improvement after levodopa differed; MT improvement was related to PD severity, whereas RT improvement was not. These results suggest that MT, rather than RT, is an objective, simple, and reliable tool to evaluate bradykinesia and its levodopa-induced modifications in PD.     

A comparative study of performance in simple and choice reaction time tasks between obese and healthy-weight children

This study investigated weight status related differences in executive functions and movement execution to determine whether or not childhood obesity is associated with impaired perceptual-motor function. Nineteen obese (OB) children (10 ♂ and 9 ♀, aged 6–12 years) and nineteen gender and age matched healthy-weight (HW) peers performed two computer-based reaction time tasks. For both the simple and four choice reaction time (SRT/CRT) task condition, absolute mean reaction time (RT) and movement time (MT) were determined and expressed as a percentage of total response time (RsT). During the SRT task, OB children were intrinsically slower than their HW peers as reflected by a significantly higher absolute RT, MT and RsT. In the CRT task, however, between-group differences were only present for RT and RsT, whereas absolute MT was comparable among OB and HW participants. As a result, the relative temporal structure of RsT significantly differed between BMI groups, with a greater RT percentage among the OB children. During the CRT condition, OB children probably await final decision-making with regard to the execution of their response movement, which then no longer needs to be adjusted. Our results therefore indicate the use of a more conservative strategy within the OB group, suggesting that childhood obesity is associated with impaired perceptual-motor function. Besides the widely accepted mechanical explanation, a better understanding of the mechanisms underlying OB children's motor incompetence is needed to set up appropriate interventions to tackle this deficit and indirectly address associated health-related problems.     

Neural processing of amplitude and formant rise time in dyslexia

This study aimed to investigate how children with dyslexia weight amplitude rise time (ART) and formant rise time (FRT) cues in phonetic discrimination. Passive mismatch responses (MMR) were recorded for a/ba/-/wa/contrast in a multiple deviant odd-ball paradigm to identify the neural response to cue weighting in 17 children with dyslexia and 17 age-matched control children. The deviant stimuli had either partial or full ART or FRT cues. The results showed that ART did not generate an MMR in either group, whereas both partial and full FRT cues generated MMR in control children while only full FRT cues generated MMR in children with dyslexia. These findings suggest that children, both controls and those with dyslexia, discriminate speech based on FRT cues and not ART cues. However, control children have greater sensitivity to FRT cues in speech compared to children with dyslexia.     

Cerebral accompaniments to simple and choice reaction tasks in Parkinson's disease

In order to clarify the nature and basis of the delayed reaction time that occurs in Parkinson's disease, we measured reaction times and cerebral responses in six parkinsonian patients and six normal age-matched control subjects. Each participated in one simple reaction task and three choice reaction tasks of different complexity. The reaction times were delayed in the parkinsonian patients in all conditions but especially in the more difficult choice tasks. In addition, the cerebral responses showed delayed latencies of the N1, N2, and P3 components of the event-related cerebral potential. These findings are similar to the changes that we observed previously in patients with both Parkinson's disease and dementia, and suggest that bradyphrenia may account, in part, for the slowing of response time in Parkinson's disease.     

Cigarette smoking shortens the bleeding time

The cutaneous bleeding time was shortened after smoking high nicotine cigarettes while not after smoking nicotine free cigarettes. The ADP induced primary platelet aggregation was not enhanced. The number of circulating platelet aggregates did not change due to smoking.     

Reaction Time Responding in Rats

BLOKLAND, A. Reaction time responding in rats. NEUROSCI BIOBEHAV REV 22(6) 847–864, 1998.—The use of reaction time has a great tradition in the field of human information processing research. In animal research the use of reaction time test paradigms is mainly limited to two research fields: the role of the striatum in movement initiation; and aging. It was discussed that reaction time responding can be regarded as “single behavior”, this term was used to indicate that only one behavioral category is measured, allowing a better analysis of brain–behavior relationships. Reaction time studies investigating the role of the striatum in motor functions revealed that the initiation of a behavioral response is dependent on the interaction of different neurotransmitters (viz. dopamine, glutamate, GABA). Studies in which lesions were made in different brain structures suggested that motor initiation is dependent on defined brain structures (e.g. medialldorsal striatum, prefrontal cortex). It was concluded that the use of reaction time measures can indeed be a powerful tool in studying brain–behavior relationships. However, there are some methodological constraints with respect to the assessment of reaction time in rats, as was tried to exemplify by the experiments described in the present paper. On the one hand one should try to control for behavioral characteristics of rats that may affect the validity of the parameter reaction time. On the other hand, the mean value of reaction time should be in the range of what has been reported in man. Although these criteria were not always met in several studies, it was concluded that reaction time can be validly assessed in rats. Finally, it was discussed that the use of reaction time may go beyond studies that investigate the role of the basal ganglia in motor output. Since response latency is a direct measure of information processing this parameter may provide insight into basic elements of cognition. Based on the significance of reaction times in human studies the use of this dependent variable in rats may provide a fruitful approach in studying brain–behavior relationships in cognitive functions.     

Time estimation and time production in depressive patients

Twenty-three depressive inpatients and matched controls were studied three times at 2-week intervals. Both patients and controls initially overestimated, and subsequently approximated to, the "short" time spans (5-240 sec) whilst both correctly estimated the "long" ones (15 and 30 min) over the three occasions (Time Estimation Test, TET). There were no differences in the TET scores among the patients themselves, or between the patients and controls with the exception of one time span which the patients overestimated more than the controls. Among the depressive symptoms, only retardation was correlated with the TET scores. Similarly in the production of 30 sec (Time Production Test, TPT) there were no differences among the patients or between patients and controls. Again, only retardation was negatively correlated with the TPT score. Since the TET scores of the "short" time spans were negatively correlated with the TPT scores, it was speculated that both results derived from a single faculty, which was clinically manifested as retardation.     

Time passes slowly for patients with depressive state

Twenty-three depressive inpatients and the same number of matched non-psychiatric controls were examined on three occasions - following admission, 14 days after, and 28 days after the admission - by administering a self-rating questionnaire of time awareness and Hamilton's Rating Scale for Depression (HRS). The patients were found to feel time passing slowly. This was correlated with the severity of depression expressed as the total HRS score. No significant differences emerged between diagnostic groups, namely endogenous depression, neurotic depression, and schizophrenia or paranoid state with depressive symptoms. Correlations of the time awareness with symptoms listed in the HRS also denied a specific relationship of time awareness to specific diagnoses. The subjective feeling of slow time flow reflects, therefore, the depth of depressive state in general, which is nevertheless not specific to any diagnostic subcategory.     

Relationship between motor and cognitive disorders in Huntington's disease

Summary Akinesia and mental decline appear to be more appropriate criteria than hyperkinesia for the evaluation of the stage and progression of Huntington's disease (HD). In order to establish the relationship between motor and cognitive impairment in the disease, 20 non-demented HD patients were compared with 44 control subjects with respect to motor and cognitive performance. HD patients were significantly impaired in almost all cognitive functions in comparison with controls. Reaction time (RT) and movement time (MT) were considerably slower in HD patients when compared with controls and with patients with parkinsonism. Hyperkinesias did not correlate with cognitive impairment, but there was a good correlation between RT, MT and cognitive functions. Therefore, it seems that akinesia evaluated by RT and MT is an important sign in HD and proceeds at the same rate as mental decay.