The effect of level of injury and physical activity on heart rate variability following spinal cord injury

Objective/Background: To assess frequency domain heart rate variability (HRV) parameters at rest and in response to postural autonomic provocations in individuals with spinal cord injury (SCI) and investigate the autonomic influences on the heart of different physical activities.

Design: Cross-sectional study.

Methods: Ten subjects with complete cervical SCI and fourteen subjects with complete low thoracic SCI were prospectively recruited from the community and further divided in sedentary and physically active groups, the latter defined as regular weekly 4 hour physical activity for the preceding 3 months. Sixteen healthy individuals matched for sex and age were recruited to participate in the control group. The Low Frequency (LF), High Frequency (HF) powers and the LF/HF ratio of HRV were measured from continuous electrocardiogram (ECG) recordings at rest and after sitting using a fast Fourier transformation.

Outcome measures: The LF,HF, and the LF/HF ratio at rest and after sitting.

Results: A significant decrease in all HRV parameters in patients with SCI was found compared to controls. The change in HF, LF and LF/HF following sitting maneuver was significantly greater in controls as compared with the SCI group and greater in subjects with paraplegia as compared to subjects with tetraplegia. Better HRV values and enhanced vagal activity appears to be related to the type of physical activity in active subjects with paraplegia.

Conclusion: In this cohort of subjects spectral parameters of HRV were associated with the level of the injury. Passive standing was associated with higher HRV values in subjects with paraplegia.     

Focal hole versus screw stimulation to prevent false negative results in detecting pedicle breaches during spinal instrumentation

ObjectiveWe describe a stimulus-evoked EMG approach to minimize false negative results in detecting pedicle breaches during lumbosacral spinal instrumentation.MethodsIn 36 patients receiving 176 lumbosacral pedicle screws, EMG threshold to nerve root activation was determined using a focal probe inserted into the pilot hole at a depth, customized to the individual patients, suitable to position the stimulating tip at the point closest to the tested nerve root. Threshold to screw stimulation was also determined.ResultsMean EMG thresholds in 161 correctly fashioned pedicle instrumentations were 7.5 mA ± 2.46 after focal hole stimulation and 21.8 mA ± 6.8 after screw stimulation. Direct comparison between both thresholds in individual pedicles showed that screw stimulation was always biased by an unpredictable leakage of the stimulating current ranging from 10 to 90%. False negative results were never observed with hole stimulation but this was not true with screw stimulation.ConclusionsFocal hole stimulation, unlike screw stimulation, approaches absolute EMG threshold as shown by the lower normal limit (2.6 mA; p < 0.05) that borders the upper limit of threshold to direct activation of the exposed root.SignificanceThe technique provides an early warning of a possible pedicle breakthrough before insertion of the more harmful, larger and threaded screw.     

Tracking Spinal Cord Injury Functional Outcomes Across the Lifespan: Validation of Linking Coefficients

ObjectiveValidation of linking coefficients to transform Pediatric Spinal Cord Injury Activity Measure (PEDI-SCI/AM) scores to adult Spinal Cord Injury-Functional Index (SCI-FI) scores.DesignThis cross-sectional study administered PEDI-SCI/AM and SCI-FI computerized adaptive tests (CATs) and short forms (SFs) to children with SCI and parents or caregivers.SettingHospitals, university, and rehabilitation institute.ParticipantsAbout 107 children with SCI and 96 parent or caregivers.InterventionsNot applicable.Main Outcome MeasuresLinking coefficients estimated SCI-FI (est-SCI-FI) scores from PEDI-SCI/AM scores for matched domains. Correlations between est-SCI-FI and actual SCI-FI scores were calculated. If correlations exceeded the criterion linking (0.866), the following analyses to compare est-SCI-FI and actual SCI-FI scores were conducted: paired t tests, intraclass correlation coefficients (ICCs 3, 1), percent of cases with absolute score differences at different thresholds.ResultsTwo matched domains, PEDI-SCI/AM Daily Routine/SCI-FI Self-Care and PEDI-SCI/AM General Mobility/SCI-FI Basic Mobility, met the linking criterion for both respondent-types (parent and child) and administration modes (CAT and SF). PEDI-SCI/AM Daily Routine and SCI-FI Fine Motor Function did not meet linking criterion for respondent type or mode. The linking criterion was met for wheelchair domains (child SF and CAT) and ambulation domains (child SF only). Significant differences between est-SCI-FI and actual SCI-FI scores were noted for all matched domains except Daily Routine/Self-Care (child SF only; parent SF and CAT). ICC values showed excellent agreement (range=0.75-0.89). Absolute differences between est-SCI-FI and actual SCI-FI scores were less than 1 standard deviation (except wheelchair CAT child).ConclusionsLinking coefficients applied to PEDI-SCI/AM scores can provide valid SCI-FI estimates that vary by domain, mode, and respondent type.     

Intraspinal anomalies: presentation,assessment, treatment and association with the development of scoliosis

The most common congenital intraspinal abnormalities presenting to medical attention is either a Chiari malformation with or without associated syringomyelia or caudal anomalies, such as tethered cord and fatty filum terminale. These intraspinal defects are usually diagnosed at birth or in early childhood, but they may also be identified in adult life due to newly presented neurological symptoms. Availability and use of appropriate imaging modalities, such as MRI and regular fetal screening has reduced the incidence of delayed diagnosis of spinal dysraphism and other accompanying congenital systemic anomalies. In view of the risk for neurological complications, prophylactic surgery is often recommended in spinal dysraphism; hence knowledge of various intraspinal abnormalities, their clinical presentation and natural history will allow early diagnosis and treatment in order to prevent neurological deterioration and irreversible morbidity. This review summarizes the embryological aspects and clinical manifestations of intraspinal abnormalities and provides a rational approach for evaluation and management in this group of patients.     

The effects of locomotor training in children with spinal cord injury: a systematic review

Purpose: Discuss the effectiveness of locomotor training (LT) in children following spinal cord injury (SCI). This intervention was assessed following an exhaustive search of the literature using the Preferred Reporting Items for Systematic Reviews and Meta- Analyses: The PRISMA Statement as a guideline.

Method: Six databases were searched including PubMed, PEDro, CINAHL, Cochrane, PsycINFO, and Web of Knowledge in January 2016 and November 2016, without date restrictions. Inclusion criteria were: studies in English and peer-reviewed and journal articles with a primary intervention of LT in children following SCI.

Results: Twelve articles, reporting eleven studies, were included. A systematic review assessing locomotor training in children with SCI published in April 2016 was also included. Participants were ages 15 months to 18 years old. Forms of LT included body-weight supported treadmill or over ground training, functional electrical stimulation, robotics, and virtual reality. Protocols differed in set-up and delivery mode, with improvements seen in ambulation for all 41 participants following LT.

Conclusion: Children might benefit from LT to develop or restore ambulation following SCI. Age, completeness, and level of injury remain the most important prognostic factors to consider with this intervention. Additional benefits include improved bowel/ bladder management and control, bone density, cardiovascular endurance, and overall quality of life. Looking beyond the effects LT has just on ambulation is crucial because it can offer benefits to all children sustaining a SCI, even if restoration or development of walking is not the primary goal. Further rigorous research is required to determine the overall effectiveness of LT.     

微创和传统开放后路腰椎椎间融合术治疗腰椎退行性疾病的远期预后

目的探讨微创后路腰椎椎间融合术(MIS-PLIF)和传统开放PLIF对腰椎退行性疾病(LDD)远期疗效及安全性的影响。方法 2011年1月-2014年12月收治LDD患者182例,其中96例采用传统开放PLIF治疗(PLIF组),86例采用MIS-PLIF治疗(MIS-PLIF组)。比较2组腰椎矢状位参数、多裂肌横截面积及萎缩率、融合率、疼痛视觉模拟量表(VAS)评分、日本骨科学会(JOA)评分、Oswestry功能障碍指数(ODI)及术后并发症发生情况,分析多裂肌萎缩率与顽固性腰背痛的相关性。结果 2组术后各随访时间点椎间隙高度恢复值和节段性前凸角恢复值差异均无统计学意义(P > 0.05)。2组术后1年腰椎前凸角恢复值差异无统计学意义(P > 0.05);但术后5年和末次随访时,MIS-PLIF组腰椎前凸角恢复值显著高于PLIF组,差异均有统计学意义(P < 0.05)。MIS-PLIF组术后各随访时间点多裂肌横截面积大于PLIF组,多裂肌萎缩率低于PLIF组,差异均有统计学意义(P < 0.05)。2组术后随访6个月融合率差异无统计学意义(P > 0.05)。2组术后各随访时间点下肢痛VAS评分差异无统计学意义(P > 0.05);MIS-PLIF组术后各随访时间点腰痛VAS评分、JOA评分及ODI均优于PLIF组,差异有统计学意义(P < 0.05)。MIS-PLIF组顽固性腰背痛发生率显著低于PLIF组,差异有统计学意义(P < 0.05)。合并顽固性腰背痛患者多裂肌萎缩率高于未合并顽固性腰背痛的患者,差异有统计学意义(P < 0.05)。结论术后多裂肌萎缩可能是导致顽固性腰背痛的重要原因,相较于传统开放PLIF,MIS-PLIF治疗LDD能够更有效地保持腰椎生理曲度,改善肢体活动功能,降低多裂肌萎缩程度,有助于避免顽固性腰背痛的发生。     

New advances in Amyotrophic Lateral Sclerosis genetics: Towards gene therapy opportunities for familial and young cases

Due to novel gene therapy opportunities, genetic screening is no longer restricted to familial cases of ALS (FALS) cases but also aplies to the sporadic populations (SALS). Screening of four main genes (C9orf72, SOD1, TARDBP and FUS) identified the causes in 15% of Amyotrophic Lateral Sclerosis (ALS) patients (two third of the familial cases and 8% of the sporadic ones) but their respective contribution to ALS phenotype varies according the age of disease onset. The genetic overlap between ALS and other diseases is expanding and includes frontotemporal dementia, Paget's Disease of Bone, myopathy for adult cases, HSP and CMT for young cases highlighing the importance of retrieving the exhaustive familial history for each indivdual with ALS. Incomplete disease penetrance, diversity of the possible phenotypes, as well as the lack of confidence concerning the pathogenicity of most identified variants and/or possible oligogenic inheritance are burdens of ALS genetic counseling to be delivered to patients and at risk individuals. The multitude of rare ALS genetic causes identifed seems to converge to similar cellular pathways leading to inapropriate response to stress emphacising new potential therapeutic options for the disease.