Hip Displacement in Cerebral Palsy: The Role of Surveillance

IntroductionHip displacement is common in cerebral palsy (CP) and is related to the severity of neurological and functional impairment. It is a silent, but progressive disease, and can result in significant morbidity and decreased quality of life, if left untreated. The pathophysiology of hip displacement in CP is a combination of hip flexor-adductor muscle spasticity, abductor muscle weakness, and delayed weight-bearing, resulting in proximal femoral deformities and progressive acetabular dysplasia. Due to a lack of symptoms in the early stages of hip displacement, the diagnosis is easily missed. Awareness of this condition and regular surveillance by clinical examination and serial radiographs of the hips are the key to early diagnosis and treatment.Hip surveillance programmesSeveral population-based studies from around the world have demonstrated that universal hip surveillance in children with CP allows early detection of hip displacement and appropriate early intervention, with a resultant decrease in painful dislocations. Global hip surveillance models are based upon the patients’ age, functional level determined by the Gross Motor Function Classification system (GMFCS), gait classification, standardized clinical exam, and radiographic indices such as the migration percentage (MP), as critical indicators of progressive hip displacement.ConclusionDespite 25 years of evidence showing the efficacy of established hip surveillance programmes, there is poor awareness among healthcare professionals in India about the importance of regular hip surveillance in children with CP. There is a need for professional organizations to develop evidence-based guidelines for hip surveillance which are relevant to the Indian context.     

基于DTI评价急性缺血性脑卒中运动功能缺损程度与肾虚髓亏证的相关性研究＊

目的 运用核磁共振弥散张量成像技术（DTI），从皮质脊髓束损伤程度评价的角度，探讨肾虚髓亏证与急性缺血性脑卒中运动功能缺损程度相关性，丰富中风病病机及证候诊断，拓宽缺血性脑卒中的中医药防治思路，为急性缺血性脑卒中肾虚髓亏证患者运动功能损伤程度提供临床依据，强调肾虚髓亏证在急性缺血性脑卒中运动功能损伤中的重要意义。方法 纳入符合诊断标准的90例病例，根据证候分别归入肾虚髓亏组和非肾虚髓亏组，每组各45例。每组患者均给予常规西药治疗。对两组患者入院后行弥散张量成像检测，同时分别于治疗前及治疗后14天，记录两组患者NIHSS评分、改良Barthel指数量表及简化Fugl-Meyer运动功能评分量表评分，比较两组病例发病时的轻重程度及治疗前后两组病例组间的恢复差异。结果 研究显示，治疗前肾虚髓亏组在NIHSS评分方面高于非肾虚髓亏组（P<0.05）；治疗前肾虚髓亏组在改良Barthel指数量表及简化Fugl-Meyer运动功能评分方面低于非肾虚髓亏组（P<0.05）。治疗前后NIHSS评分、改良Barthel指数评分及简化Fugl-Meyer运动功能评分改善情况，非肾虚髓亏组要优于肾虚髓亏组（P<0.05）。治疗前两组患者在健侧内囊后肢及大脑脚外侧处FA值及ADC值无明显差异；肾虚髓亏组在患侧内囊后肢及大脑脚外侧处FA值及ADC值均低于非肾虚髓亏组（P<0.05）。相关性分析得出，两组患者患侧内囊后肢FA值与患者治疗前NIHSS评分呈负相关；两组患者患侧内囊后肢FA值与患者改良Barthel指数评分及简化Fugl-Meyer运动功能评分呈正相关；肾虚髓亏组患者患侧内囊后肢FA值与肾虚髓亏证中医证候评分呈负相关。结论 肾虚髓亏是急性缺血性脑卒中运动功能障碍的重要病机。研究结果显示，两组皮质脊髓束损伤程度与神经功能及运动功能损伤存在相关性，且肾虚髓亏组在皮质脊髓束的损伤程度方面与其中医证候评分呈负相关。     

Altered speech-related cortical network in frontotemporal dementia

BackgroundIn healthy subjects (HS), transcranial magnetic stimulation (TMS) demonstrated an increase in motor-evoked potential (MEP) amplitudes during specific linguistic tasks. This finding indicates functional connections between speech-related cortical areas and the dominant primary motor cortex (M1).ObjectiveTo investigate M1 function with TMS and the speech-related cortical network with neuroimaging measures in frontotemporal dementia (FTD), including the non-fluent variant of primary progressive aphasia (nfv-PPA) and the behavioral variant of FTD (bv-FTD).MethodsM1 excitability changes during specific linguistc tasks were examined using TMS in 24 patients (15 with nfv-PPA and 9 with bv-FTD) and in 18 age-matched HS. In the same patients neuroimaging was used to assess changes in specific white matter (WM) bundles and grey matter (GM) regions involved in language processing, with diffusion tensor imaging (DTI) and voxel-based morphometry (VBM).ResultsDuring the linguistic task, M1 excitability increased in HS, whereas in FTD patients it did not. M1 excitability changes were comparable in nfv-PPA and bv-FTD. DTI revealed decreased fractional anisotropy in the superior and inferior longitudinal and uncinate fasciculi. Moreover, VBM disclosed GM volume loss in the left frontal operculum though not in the parietal operculum or precentral gyrus. Furthermore, WM and GM changes were comparable in nfv-PPA and bv-FTD. There was no correlation between neurophysiological and neuroimaging changes in FTD. Atrophy in the left frontal operculum correlated with linguistic dysfunction, assessed by semantic and phonemic fluency tests.ConclusionWe provide converging neurophysiological and neuroimaging evidence of abnormal speech-related cortical network activation in FTD.     

Localization of motor and verbal fluency effects in subthalamic DBS for Parkinson's disease

IntroductionSubthalamic nucleus deep brain stimulation (STN DBS) improves cardinal motor symptoms of Parkinson's disease (PD) but can worsen verbal fluency (VF). An optimal site of stimulation for overall motor improvement has been previously identified using an atlas-independent, fully individualized, field-modeling approach. This study examines if cardinal motor components (bradykinesia, tremor, and rigidity) share this identified optimal improvement site and if there is co-localization with a site that worsens VF.MethodsAn atlas-independent, field-modeling approach was used to identify sites of maximal STN DBS effect on overall and cardinal motor symptoms and VF in 60 patients. Anatomic coordinates were referenced to the STN midpoint. Symptom severity was assessed with the MDS-UPDRS part III and established VF scales.ResultsSites for improved bradykinesia and rigidity co-localized with each other and the overall part III site (0.09 mm lateral, 0.93 mm posterior, 1.75 mm dorsal). The optimal site for tremor was posterior to this site (0.10 mm lateral, 1.40 mm posterior, 1.93 mm dorsal). Semantic and phonemic VF sites were indistinguishable and co-localized medial to the motor sites (0.32 mm medial, 1.18 mm posterior, 1.74 mm dorsal).ConclusionThis study identifies statistically distinct, maximally effective stimulation sites for tremor improvement, VF worsening, and overall and other cardinal motor improvements in STN DBS. Current electrode sizes and voltage settings stimulate all of these sites simultaneously. However, future targeted lead placement and focused directional stimulation may avoid VF worsening while maintaining motor improvements in STN DBS.     

The interaction between pain and movement

Study DesignClinical commentary.Introduction/PurposePain and movement are universally relevant phenomena that influence human experiences in readily observable ways. Improved understanding of pain-movement relationships can guide medical and rehabilitative approaches to recovery and decrease risk of dysfunctional long-term consequences of otherwise normal neuromuscular responses. Therefore, the overall intent of this article is to elucidate the relationships between pain and movement as they relate to clinical decision making.ConclusionsMotor output is highly adaptable, can be influenced by multiple mechanisms at various levels along the nervous system, and may vary between individuals despite similar diagnoses. Therefore, interventions need to be individualized and consider both the types of motor response observed (ie, whether the response is protective or maladaptive), and the patient's acute physical activity tolerance when prescribing exercise/movement.     

Simulation of transcranial magnetic stimulation in head model with morphologically-realistic cortical neurons

BackgroundTranscranial magnetic stimulation (TMS) enables non-invasive modulation of brain activity with both clinical and research applications, but fundamental questions remain about the neural types and elements TMS activates and how stimulation parameters affect the neural response.ObjectiveTo develop a multi-scale computational model to quantify the effect of TMS parameters on the direct response of individual neurons.MethodsWe integrated morphologically-realistic neuronal models with TMS-induced electric fields computed in a finite element model of a human head to quantify the cortical response to TMS with several combinations of pulse waveforms and current directions.ResultsTMS activated with lowest intensity intracortical axonal terminations in the superficial gyral crown and lip regions. Layer 5 pyramidal cells had the lowest thresholds, but layer 2/3 pyramidal cells and inhibitory basket cells were also activated at most intensities. Direct activation of layers 1 and 6 was unlikely. Neural activation was largely driven by the field magnitude, rather than the field component normal to the cortical surface. Varying the induced current direction caused a waveform-dependent shift in the activation site and provided a potential mechanism for experimentally observed differences in thresholds and latencies of muscle responses.ConclusionsThis biophysically-based simulation provides a novel method to elucidate mechanisms and inform parameter selection of TMS and other cortical stimulation modalities. It also serves as a foundation for more detailed network models of the response to TMS, which may include endogenous activity, synaptic connectivity, inputs from intrinsic and extrinsic axonal projections, and corticofugal axons in white matter.     

Coupling online control and inhibitory systems in children with Developmental Coordination Disorder: Goal-directed reaching

For children with Developmental Coordination Disorder (DCD), the real-time coupling between frontal executive function and online motor control has not been explored despite reported deficits in each domain. The aim of the present study was to investigate how children with DCD enlist online control under task constraints that compel the need for inhibitory control. A total of 129 school children were sampled from mainstream primary schools. Forty-two children who met research criteria for DCD were compared with 87 typically developing controls on a modified double-jump reaching task. Children within each skill group were divided into three age bands: younger (6–7 years), mid-aged (8–9), and older (10–12). Online control was compared between groups as a function of trial type (non-jump, jump, anti-jump). Overall, results showed that while movement times were similar between skill groups under simple task constraints (non-jump), on perturbation (or jump) trials the DCD group were significantly slower than controls and corrected trajectories later. Critically, the DCD group was further disadvantaged by anti-jump trials where inhibitory control was required; however, this effect reduced with age. While coupling online control and executive systems is not well developed in younger and mid-aged children, there is evidence of age-appropriate coupling in older children. Longitudinal data are needed to clarify this intriguing finding. The theoretical and applied implications of these results are discussed.     

Assessing the impact of blood alcohol concentration on the rate of in-hospital mortality following traumatic motor vehicle crash injury: A matched analysis of the National Trauma Data Bank

Background

The purpose of this study was to compare the outcomes of trauma patients who were injured in a motor vehicle crash and tested positive for alcohol upon hospital arrival versus those who tested negative.