Motor imagery in mental rotation: an fMRI study

Twelve right-handed men performed two mental rotation tasks and two control tasks while whole-head functional magnetic resonance imaging was applied. Mental rotation tasks implied the comparison of different sorts of stimulus pairs, viz. pictures of hands and pictures of tools, which were either identical or mirror images and which were rotated in the plane of the picture. Control tasks were equal except that stimuli pairs were not rotated. Reaction time profiles were consistent with those found in previous research. Imaging data replicate classic areas of activation in mental rotation for hands and tools (bilateral superior parietal lobule and visual extrastriate cortex) but show an important difference in premotor area activation: pairs of hands engender bilateral premotor activation while pairs of tools elicit only left premotor brain activation. The results suggest that participants imagined moving both their hands in the hand condition, while imagining manipulating objects with their hand of preference (right hand) in the tool condition. The covert actions of motor imagery appear to mimic the "natural way" in which a person would manipulate the object in reality, and the activation of cortical regions during mental rotation seems at least in part determined by an intrinsic process that depends on the afforded actions elicited by the kind of stimuli presented.     

Rapid response systems: a prospective study of response times

Purpose

The purpose of the study was to evaluate the time taken for delivery of each component of care following patient deterioration and to assess the effect on response times of strategies implemented to improve the system.

Methods

A model identifying the sequence of organizational responses following a patient's unexpected clinical deterioration was developed. The time to key events and interventions from initial deterioration was measured for 3 months in 2005 and again in 2006 at a tertiary care hospital with a rapid response team (RRT) in place. Strategies to improve compliance with the RRT system were introduced between the 2 periods.

Results

The number of acute deterioration episodes identified increased (61 episodes in 2005; 154 episodes in 2006), but there was no improvement in response times. The 2 components contributing most frequently to delays were the time for nursing staff to call for assistance and, where needed, for physicians to call for higher-level care. Overall, 26% of episodes in 2006 and 30% in 2005 did not receive medical attention within 30 minutes of acute deterioration.

Conclusions

Significant delays in responding to acute deterioration persist despite strategies to facilitate the functioning of the RRT system. Simple strategies such as policy directives are not sufficient to effect change in complex health care systems.     

Motor imagery of complex everyday movements. An fMRI study

The present study aimed to investigate the functional neuroanatomical correlates of motor imagery (MI) of complex everyday movements (also called everyday tasks or functional tasks). 15 participants imagined two different types of everyday movements, movements confined to the upper extremities (UE; e.g., eating a meal) and movements involving the whole body (WB; e.g., swimming), during fMRI scanning. Results showed that both movement types activated the lateral and medial premotor cortices bilaterally, the left parietal cortex, and the right basal ganglia. Direct comparison of WB and UE movements further revealed a homuncular organization in the primary sensorimotor cortices (SMC), with UE movements represented in inferior parts of the SMC and WB movements in superior and medial parts. These results demonstrate that MI of everyday movements drives a cortical network comparable to the one described for more simple movements such as finger opposition. The findings further are in accordance with the suggestion that motor imagery-based mental practice is effective because it activates a comparable cortical network as overt training. Since most people are familiar with everyday movements and therefore a practice of the movement prior to scanning is not necessarily required, the current paradigm seems particularly appealing for clinical research and application focusing on patients with low or no residual motor abilities.     

运动区皮质刺激治疗顽固性丘脑痛的初步研究

目的探讨运动区皮质刺激治疗顽固性丘脑痛的手术方法及效果。方法以条形电极对3例顽固性丘脑痛患者行对侧运动区皮质刺激并植入电子刺激器进行慢性电刺激。结果3例患者术后症状明显缓解,疼痛视觉模拟评分(VAS评分)较术前显著下降,无偏瘫、癫痫等并发症发生。结论运动区皮质刺激是控制顽固性丘脑痛的有效方法,中央沟精确定位及调节合适的刺激参数尤为重要。     

Motor innervation of the flexor pollicis brevis: an electromyographic study.

Percutaneous stimulation of the ulnar and median nerves at the wrist, with simultaneous recording of action potentials on a standard electromyograph oscilloscope, was performed to observe the motor innervation of the flexor pollicis brevis muscle. Both the deep and the superficial heads of the muscle were studied in twenty-three subjects. Results showed that the most common pattern of innervation was exclusive ulnar nerve supply in both heads, with 52.4 percent of the subjects showing this pattern. Dual supply by both median and ulnar nerves occurred next in frequency with 19.0 percent showing this pattern in both heads of the muscle. Exclusive median nerve supply was observed in only 9.5 percent of the total cases studied. The remaining 19 percent showed varying patterns, with each head of the muscle supplied differently. If no differentiation between deep and superficial heads is made, this 19 percent may be considered as dual innervation of the muscle. In this case, it may be concluded that 38 percent of the muscles studied showed some type of dual innervation.     

Motor performance in five-year-old extracorporeal membrane oxygenation survivors: a population-based study

Introduction  

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is a cardio-pulmonary bypass technique to provide life support in acute reversible cardio-respiratory failure when conventional management is not successful. Most neonates receiving ECMO suffer from meconium aspiration syndrome (MAS), congenital diaphragmatic hernia (CDH), sepsis or persistent pulmonary hypertension (PPH). In five-year-old children who underwent VA-ECMO therapy as neonates, we assessed motor performance related to growth, intelligence and behaviour, and the association with the primary diagnosis.     

The Peabody Developmental Fine Motor Scale: an interrater reliability study.

This study examined the interrater reliability of two raters on the Fine Motor scale of the Peabody Developmental Motor Scales (Folio & Fewell, 1983). The sample comprised 32 children who were 4 or 5 years of age. Half of the children were considered to have normal development and half had an identified developmental delay. The Pearson product-moment correlation coefficients between the two sets of ratings were r = .97 for the delayed group and r = .77 for the normal group. Intraclass correlations were .97 and .76 for the delayed and normal groups, respectively. These figures appear to reflect the increased variance of the performance of the children with developmental delays. The percentage agreement between the two raters was greater for the group of normal subjects. The results suggest that the Fine Motor scale of the Peabody scales includes enough items to minimize the total score difference between two raters. Individual test items with poor agreement between the two raters were identified.     

Motor impairment after severe traumatic brain injury: A longitudinal multicenter study

Neuromotor impairment is a common sequela of severe traumatic brain injury (TBI) but has been understudied relative to neurocognitive outcomes. This multicenter cohort study describes the longitudinal course of neurological examination-based motor abnormalities after severe TBI. Subjects were enrolled from the four lead Department of Veterans Affairs and Defense and Veterans Brain Injury Center sites. The study cohort consisted of 102 consecutive patients (active duty, veteran, or military dependent) with severe TBI who consented during acute rehabilitation for data collection and completed all follow-up evaluations. Paresis, ataxia, and postural instability measures showed a pattern of improvement over time, with the greatest improvement occurring between the inpatient (baseline) and 6-month follow-up assessments. Involuntary movement disorders were rare at all time points. Two years following acute rehabilitation, more than one-third of subjects continued to display a neuromotor abnormality on basic neurological examination. Persistence of tandem gait abnormality was particularly common.     

Review of Motor Control and Motor Learning

Parkinson's disease is a neurological disorder that primarily affects older individuals and their ability to engage in daily occupations. Occupational therapists are actively involved in the training and retraining of functional motor skills with this population. Motor control theories may assist clinicians in understanding the movement difficulties that these individuals experience. Motor learning principles may be implemented to facilitate the learning of adaptive skills and/or previous motor tasks. Both motor control and motor learning research findings may influence occupational therapy treatment approaches for the rehabilitation of this population. The purpose of this paper is to review the current knowledge in the areas of motor control and motor learning, discuss this knowledge as it applies to Parkinson's disease, and integrate this information into occupational therapy treatment.     

复合感知传感器频率适应性起搏的临床研究

目的研究日常活动和外界干扰时,体动和每分通气量复合感知传感器频率适应性起搏的频率应答反应。方法15例植入起搏器的心脏变时功能不全患者在复合感知、每分通气量感知和体动感知下,分别作上/下楼和拍击试验,并与15例正常窦房结变时功能者作比较。结果体动传感器组下楼和拍击试验时心率增加显著快于正常对照组,每分通气量传感器组上/下楼启动时心率增加显著慢于对照组,而复合感知传感器组的频率变时反应与对照组相似。结论体动和每分通气量复合感知起搏器的频率应答反应与正常窦房结最接近。     

情感反应中杏仁核激活的磁共振功能成像

杏仁核是脑深部的灰质核团，在脑的情感加工过程中发挥重要作用，杏仁核在情感反应中的作用机制及与其它脑区之间的相互作用和联系是当前研究的热点，其研究价值在于指导情感障碍患者的治疗。当前杏仁核与情感关系的fMRI研究多采用面孔识别等视觉刺激方法，本研究拟以轻音乐和恐怖音乐作为刺激内容，通过声音刺激途径引起脑的正负情感反应，观察杏仁核的激活情况，分析其在情感加工中的作用机制。     

Motor recovery of the upper extremities in traumatic quadriplegia: a multicenter study.

Clinicians need to know recovery of neurologic function in the upper extremities after traumatic quadriplegia to prognosticate function in self-care, to determine the effectiveness of various interventions, and to develop a comprehensive rehabilitation plan. This study was undertaken to determine the extent of recovery of key muscles of the arms in motor complete quadriplegic subjects. The hypothesis stated that patients with some motor power (grades 1.0 to 2.5/5) in muscles in the zone of partial preservation would recover at an earlier time and to a greater extent than those with no motor power (grade 0/5). One hundred fifty subjects, C4, C5, and C6 motor complete, were entered in the study within one week of injury from four centers. Serial muscle examinations of the biceps, wrist extensors, and triceps on the right and left sides were performed up to 24 months after spinal cord injury. The pattern of recovery in the key muscles of the 67 subjects with some motor power in the zone of partial preservation to grade 3/5 was significantly greater than the 83 subjects with no motor power (68% to 82% vs 14% to 36%, p less than .001) at three to six months postinjury. The plateau of the median manual muscle test score determined the extent of recovery and reached grade 4/5 in subjects with some motor power at three to six months. The pattern of recovery revealed more subjects with some motor power improved to grade 3/5 at all intervals earlier than those with no motor power (p less than .005).(ABSTRACT TRUNCATED AT 250 WORDS)     

Motor cortical representation in patients with complex regional pain syndrome: a TMS study

In a group of patients with short- and long-term (chronic) duration of complex regional pain syndrome type I (CRPS I) motor cortical representation was determined, using a transcranial magnetic stimulation (TMS) mapping method. This was done, starting with suprathreshold intensities at the location of the largest MEP amplitude, mapping systematically in all directions. Patients were compared to a group of healthy subjects. In both patient groups we found significantly larger motor cortical representation for the unaffected hand muscles compared to the affected side. This asymmetry was absent in healthy subjects. Such motor cortical representation asymmetry can be considered an effect of altered sensomotor cortical representation. On the other hand, one must also consider the increased use of the unaffected hand and the presence of pain as cortical influencing variables. The real cause must remain speculative at this time.     

脑卒中后偏瘫手运动功能的恢复：纵向fMRI对照

目的:观察脑卒中后偏瘫手运动功能恢复后纵向fMRI表现。方法:于2003-12/2006-02选择中山大学第二附属医院神经内科收治的脑卒中患者11例,为脑卒中组。经CT或MRI证实脑梗死、出血,病灶可以累及运动皮质、内囊、基底节或脑干。发病时患侧手握力至少减低到4-级或以下。康复期(到行fMRI时)握力恢复到4 级以上,所用康复方法不限。行fMRI检查时间分别在发病后2个月和6个月。患者均知情同意。同期选择健康体检者15例为正常对照组,均为右利手,其中7例完成双侧手运动fMRI,另8例仅完成右侧手运动fMRI。观察指标:①非量化指标:观察双侧主要感觉运动区(Primary sensorimotor cortex,SM1)的激活位置、形态、范围和分布,观察运动前区(Premotor cortex,PM)、补充运动区(Supplementary motor area,SMA)、角回运动区(Cingulate motor areas,CMA)和非运动区的激活出现率。②量化指标:测量SM1的激活体积:用感兴趣区技术测量每一层SM1区激活的面积,相加后乘以层厚。侧方指数按公式计算:侧方指数=(对侧SM1激活体积-同侧SM1激活体积)/(对侧SM1激活体积 同侧SM1激活体积)。结果:①正常对照组受试者手运动SM1区fMRI表现:激活区在中央前后回区,可在侧脑室顶以上2￣6个层面观察到。激活区的形态呈斑片或不规则状,不同个体或左右手之间不完全相同。右、左手运动的对侧SM1激活体积、同侧SM1激活体积和侧方指数相近,差异无显著性意义(P>0.05)。②正常对照组受试者手运动非主要运动区和非运动区fMRI表现:非主要感觉运动区及非运动区的激活体积明显比SM1区小,以PM激活的出现率最高,CMA激活出现率最低,其他非运动区,除颞叶、枕叶外,出现率都比较低或无出现激活。③脑卒中后偏瘫手运动SM1区fMRI表现:在脑卒中后的2个月和6个月,无论哪侧患肢运动,在双侧SM1区均表现为斑片或不规则的激活影像,与正常对照组的激活区相似。脑卒中患者梗死后2个月与6个月右、左侧患手运动对侧SM1激活体积相近;梗死后2个月右、左侧患手运动同侧SM1激活体积大于梗死后6个月;梗死后2个月右、左侧患手运动侧方指数小于梗死后6个月;差异均无显著性意义(P>0.05)。④脑卒中患者梗死后2个月:右、左侧患手运动时,对侧SM1激活体积与正常对照组接近,差异无显著性意义(P>0.05);同侧SM1激活体积明显大于正常对照组[分别为(997±704),(195±152)mm3;(1661±962),(352±399)mm3],差异有显著性意义(t=4.312,3.240,P<0.05)。右、左手侧方指数明显小于正常对照组(分别为0.258±0.679,0.853±0.104;0.042±0.553,0.726±0.299),差异有显著性意义(t=-3.405,-3.285,P<0.05)。⑤脑卒中患者梗死后6个月:右、左侧患手运动时,对侧SM1激活体积与正常对照组接近,差异无显著性意义(P>0.05);右侧患手同侧SM1激活体积明显大于正常对照组[分别为(717±915),(195±152)mm3],差异有显著性意义(t=2.201,P<0.05);左侧患手同侧SM1激活体积大于正常对照组,差异无显著性意义(P>0.05);右、左手侧方指数小于正常对照组,差异无显著性意义(P>0.05)。⑥脑卒中后偏瘫手运动非主要运动区和非运动区fMRI表现:非主要运动各区和非运动区的激活体积比SM1区小,非主要运动区梗死后2个月时双侧PM、CMA激活区出现率均高于梗死后6个月;梗死后2个月时右侧SMA激活区出现率高于梗死后6个月,左侧SMA激活区出现率低于梗死后6个月。非运动区左颞叶区、左额前区、左顶后区激活出现率稍高,丘脑、基底节出现率稍低,梗死后2个月与6个月比较总体差别不大。结论:脑卒中后康复者,其对侧SM1激活体积在早期(梗死后2个月)已趋向稳定,同侧SM1区早期仍有明显代偿现象,晚期(梗死后6个月)趋向正常。