Stephen P. Burns

International standards for neurological classification of spinal cord injury (Revised 2011)

This article represents the content of the booklet, International Standards for Neurological Classification of Spinal Cord Injury, revised 2011, published by the American Spinal Injury Association (ASIA). For further explanation of the clarifications and changes in this revision, see the accompanying article (Kirshblum S., et al. J Spinal Cord Med. 2011:doi 10.1179/107902611X13186000420242 The spinal cord is the major conduit through which motor and sensory information travels between the brain and body. The spinal cord contains longitudinally oriented spinal tracts (white matter) surrounding central areas (gray matter) where most spinal neuronal cell bodies are located. The gray matter is organized into segments comprising sensory and motor neurons. Axons from spinal sensory neurons enter and axons from motor neurons leave the spinal cord via segmental nerves or roots. In the cervical spine, there are 8 nerve roots. Cervical roots of C1-C7 are named according to the vertebra above which they exit (i.e. C1 exits above the C1 vertebra, just below the skull and C6 nerve roots pass between the C5 and C6 vertebrae) whereas C8 exists between the C7 and T1 vertebra; as there is no C8 vertebra. The C1 nerve root does not have a sensory component that is tested on the International Standards Examination. The thoracic spine has 12 distinct nerve roots and the lumbar spine consists of 5 distinct nerve roots that are each named accordingly as they exit below the level of the respective vertebrae. The sacrum consists of 5 embryonic sections that have fused into one bony structure with 5 distinct nerve roots that exit via the sacral foramina. The spinal cord itself ends at approximately the L1-2 vertebral level. The distal most part of the spinal cord is called the conus medullaris. The cauda equina is a cluster of paired (right and left) lumbosacral nerve roots that originate in the region of the conus medullaris and travel down through the thecal sac and exit via the intervertebral foramen below their respective vertebral levels. There may be 0, 1, or 2 coccygeal nerves but they do not have a role with the International Standards examination in accordance with the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI). Each root receives sensory information from skin areas called dermatomes. Similarly each root innervates a group of muscles called a myotome. While a dermatome usually represents a discrete and contiguous skin area, most roots innervate more than one muscle, and most muscles are innervated by more than one root. Spinal cord injury (SCI) affects conduction of sensory and motor signals across the site(s) of lesion(s), as well as the autonomic nervous system. By systematically examining the dermatomes and myotomes, as described within this booklet, one can determine the cord segments affected by the SCI. From the International Standards examination several measures of neurological damage are generated, e.g., Sensory and Motor Levels (on right and left sides), NLI, Sensory Scores (Pin Prick and Light Touch), Motor Scores (upper and lower limb), and ZPP. This booklet also describes the ASIA (American Spinal Injury Association) Impairment Scale (AIS) to classify the severity (i.e. completeness) of injury. This booklet begins with basic definitions of common terms used herein. The section that follows describes the recommended International Standards examination, including both sensory and motor components. Subsequent sections cover sensory and motor scores, the AIS classification, and clinical syndromes associated with SCI. For ease of reference, a worksheet (Appendix 1) of the recommended examination is included, with a summary of steps used to classify the injury (Appendix 2). A full-size version for photocopying and use in patient records has been included as an enclosure and may also be downloaded from the ASIA website (www.asia-spinalinjury.org). Additional details regarding the examination and e-Learning training materials can also be obtained from the website15.

Upper-Limb Powered Exoskeleton Design

An exoskeleton is an external structural mechanism with joints and links corresponding to those of the human body. With applications in rehabilitation medicine and virtual reality simulation, exoskeletons offer benefits for both disabled and healthy populations. A pilot database defining the kinematics and dynamics of the upper limb during daily living activities was one among several factors guiding the development of an anthropomorphic, 7-DOF, powered arm exoskeleton. Additional design inputs include anatomical and physiological considerations, workspace analyses, and upper limb joint ranges of motion. The database was compiled from 19 arm activities of daily living. The cable-actuated dexterous exoskeleton for neurorehabilitation (CADEN)-7 offers remarkable opportunities as a versatile human-machine interface and as a new generation of assistive technology. Proximal placement of motors and distal placement of cable-pulley reductions were incorporated into the design, leading to low inertia, high-stiffness links, and backdrivable transmissions with zero backlash. The design enables full glenohumeral, elbow, and wrist joint functionality. Potential applications of the exoskeleton as a wearable robot include: 1) a therapeutic and diagnostics device for physiotherapy, 2) an assistive (orthotic) device for human power amplifications, 3) a haptic device in virtual reality simulation, and 4) a master device for teleoperation.

Reference for the 2011 revision of the international standards for neurological classification of spinal cord injury

Abstract The latest revision of the International Standards for the Neurological Classification of Spinal Cord Injury (ISNCSCI) was available in booklet format in June 2011, and is published in this issue of the Journal of Spinal Cord Medicine. The ISNCSCI were initially developed in 1982 to provide guidelines for the consistent classification of the neurological level and extent of the injury to achieve reliable data for clinical care and research studies. This revision was generated from the Standards Committee of the American Spinal Injury Association in collaboration with the International Spinal Cord Societys Education Committee. This article details and explains the updates and serves as a reference for these revisions and clarifications.

2009 Review and Revisions of the International Standards for the Neurological Classification of Spinal Cord Injury

Abstract Summary: The International Standards for the Neurological Classification of Spinal Cord Injury (ISNCSCI) were recently reviewed by the ASIAs Education and Standards Committees, in collaboration with the International Spinal Cord Societys Education Committee. Available educational materials for the ISNCSCI were also reviewed. The last citable reference for the ISNCSCIs methodology is the ISNCSCI Reference Manual, published in 2003 by ASIA. The Standards Committee recommended that the numerous items that were revised should be published and a precedent established for a routine published review of the ISNCSCI. The Standards Committee also noted that, although the 2008 reprint pocket booklet is current, the reference manual should be revised after proposals to modify/revise the ASIA Impairment Scale (AIS as modified from Frankel) are considered. In addition, the Standards Committee adopted a process for thorough and transparent review of requests to revise the ISNCSCI.

Recovery of ambulation in motor-incomplete tetraplegia.

OBJECTIVE To determine the effect of age and initial neurologic status on recovery of ambulation in patients with motor-incomplete tetraplegia. STUDY DESIGN Inception cohort study. SETTING Urban, tertiary care hospital with Regional Spinal Cord Injury Center. PATIENTS One hundred five patients with American Spinal Injury Association (ASIA) C or D tetraplegia at admission or within 72 hours of injury. MAIN OUTCOME MEASURE Ambulatory status at time of discharge from inpatient rehabilitation. RESULTS Ninety-one percent (30/33) of ASIA C patients younger than 50 years of age became ambulatory by discharge, versus 42% (13/31) ASIA C patients age 50 or older (p < .0001). All (41/41) patients initially classified as ASIA D became ambulatory by discharge. CONCLUSION For patients with ASIA D tetraplegia, prognosis for recovery of independent ambulation is excellent. For patients with ASIA C tetraplegia, recovery of ambulation is significantly less likely if age is 50 years or older.

Spinal cord infarction following cervical transforaminal epidural injection: a case report.

Study Design. Case Report. Objective. A review of the literature about spinal cord infarction with epidural steroid injections and report of one case. Summary of Background Data. A 53-year-old man with a history of chronic cervical pain and multilevel degenerative disc disease with multiple posterior disc protrusions on cervical imaging. The patient received a left C6 tranforaminal injection for therapeutic pain relief, with fluoroscopic confirmation of left C6 nerve root sheath spread of injectable contrast. Approximately 10 to 15 minutes post-procedure, he noted weakness in his left arm and bilateral lower limbs. Initial cervical magnetic resonance imaging revealed no cord signal change, but a follow-up study 24 hours later demonstrated patchy increased T2 and short &tgr; inversion recovery signal in the cervical cord from the odontoid to C4–C5 vertebral levels. This was consistent with a diffuse vascular infarct to the cervical cord, resulting in motor-incomplete tetraplegia. Results. This is one of a few reported cases of spinal cord infarction after cervical epidural injections. No direct cord trauma occurred. Previously reported risk factors of spinal infarction, such as hypotension and large injectate volumes, were noncontributory in this case. Conclusions. Cervical epidural injections, despite careful localization, carry a risk of vascular infarction to the spinal cord, even in the absence of direct cord trauma. The etiology of these infarctions and identifying those patients at risk remain uncertain.

The human arm kinematics and dynamics during daily activities - toward a 7 DOF upper limb powered exoskeleton

Integrating human and robot into a single system offers remarkable opportunities for creating a new generation of assistive technology. Having obvious applications in rehabilitation medicine and virtual reality simulation, such a device would benefit both the healthy and disabled population. The aim of the research is to study the kinematics and the dynamics of the human arm during daily activities in a free and unconstrained environment as part of an on-going research involved in the design of a 7 degree of freedom (DOF) powered exoskeleton for the upper limb. The kinematics of the upper limb was acquired with a motion capture system while performing a wide verity of daily activities. Utilizing a model of the human as a 7 DOF system, the equations of motion were used to calculate joint torques given the arm kinematics. During positioning tasks, higher angular velocities were observed in the gross manipulation joints (the shoulder and elbow) as compared to the fine manipulation joints (the wrist). An inverted phenomenon was observed during fine manipulation in which the angular velocities of the wrist joint exceeded the angular velocities of the shoulder and elbow joints. Analyzing the contribution of individual terms of the arms equations of motion indicate that the gravitational term is the most dominant term in these equations. The magnitudes of this term across the joints and the various actions is higher than the inertial, centrifugal, and Coriolis terms combined. Variation in object grasping (e.g. power grasp of a spoon) alters the overall arm kinematics in which other joints, such as the shoulder joint, compensate for lost dexterity of the wrist. The collected database along with the kinematics and dynamic analysis may provide the fundamental understanding for designing powered exoskeleton for the human arm

Extent of spontaneous motor recovery after traumatic cervical sensorimotor complete spinal cord injury.

Study design:Retrospective, longitudinal analysis of motor recovery data from individuals with cervical (C4–C7) sensorimotor complete spinal cord injury (SCI) according to the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI).Objectives:To analyze the extent and patterns of spontaneous motor recovery over the first year after traumatic cervical sensorimotor complete SCI.Methods:Datasets from the European multicenter study about SCI (EMSCI) and the Sygen randomized clinical trial were examined for conversion of American Spinal Injury Association (ASIA) Impairment Scale (AIS) grade, change in upper extremity motor score (UEMS) or motor level, as well as relationships between these measures.Results:There were no overall differences between the EMSCI and Sygen datasets in motor recovery patterns. After 1 year, up to 70% of subjects spontaneously recovered at least one motor level, but only 30% recovered two or more motor levels, with lesser values at intermediate time points. AIS grade conversion did not significantly influence motor level changes. At 1 year, the average spontaneous improvement in bilateral UEMS was 10–11 motor points. There was only moderate relationship between a change in UEMS and a change in cervical motor level (r 2=0.30, P<0.05). Regardless of initial cervical motor level, most individuals recover a similar number of motor points or motor levels.Conclusion:Careful tracking of cervical motor recovery outcomes may provide the necessary sensitivity and accuracy to reliably detect a subtle, but meaningful treatment effect after sensorimotor complete cervical SCI. The distribution of the UEMS change may be more important functionally than the total UEMS recovered.

Whiplash: Pathophysiology, diagnosis, treatment, and prognosis†

We have reviewed the literature relevant to pathophysiology, diagnosis, treatment, and prognosis of whiplash‐associated disorder (WAD) since 1995 and provided a brief summary of literature pertaining to forces action on the head and neck during a motor vehicle accident. The scope of the current review is confined to the Quebec guidelines for WAD grades 1–3 but excludes grade 4 (neck complaints and fracture or dislocation). After excluding papers without scientific data and single case reports or case series with fewer than 20 patients, articles were reviewed for methodological quality. The diagnosis remains clinical. No imaging, physiological, or psychological study provides specific diagnostic criteria. In the acute period up to 2 weeks, soft collars or rest and work‐leave do not shorten the duration of neck pain. Sick leave is reduced by high‐dose methylprednisolone given within 8 h of injury, but confirmatory studies examining the cost–benefit relationship are needed. In the first 6 months, active as opposed to passive treatment results in improved outcomes. Specific exercise strategies have not been studied. For those with symptoms lasting more than 6 months, percutaneous radio‐frequency neurotomy can provide pain relief for many months in those responding to blind local anesthetic facet blocks. Intra‐articular corticosteroids are ineffective. Uncontrolled trials suggest that multimodal rehabilitation programs result in improved overall function. The overall prognosis for recovery has varied considerably across studies. Such variability is likely due to differences in case identification methods and whether outcome is assessed in terms of symptoms or the receipt of financial compensation for injury. The impact on prognosis of both collision‐ and patient‐related factors is also reviewed. Muscle Nerve 29: 768–781, 2004

Hill-Based Model as a Myoprocessor for a Neural Controlled Powered Exoskeleton Arm - Parameters Optimization

The exoskeleton robot, serving as an assistive device worn by the human (orthotic), functions as a human-amplifier. Setting the human machine interface (HMI) at the neuro-muscular level may lead to seamless integration and an intuitive control of the exoskeleton arm as a natural extension of the human body. At the core of the exoskeleton HMI there is a myoprocessor. It is a model of the human muscle, running in real-time and in parallel to the physiological muscle, that predicts joint torque as a function of the joint kinematics and neural activation levels. The study is focused on developing a myoprocessor based on the Hill phenomenological muscle model. Genetic algorithms were used to optimize model internal parameters using an experimental database that provides inputs to the model and allows for performance assessment. The results indicate high correlation between joint moment predictions of the model and the measured data. Consequently, the myoprocessor seems an adequate model, sufficiently robust for further integration into the exoskeleton control system.