Between-days intra-rater reliability with a hand held myotonometer to quantify muscle tone in the acute stroke population

A myotonometer can objectively quantify changes in muscle tone. The between-days intra-rater reliability in a ward setting for the acute stroke population remains unknown. This study aimed to investigate the device’s between-days intra-rater reliability when used in a ward setting for acute stroke participants. Muscle tone of biceps brachii, brachioradialis, rectus femoris, and tibialis anterior was recorded in the ward at bedside by one physiotherapist on two consecutive days. This study included participants who were within 1 month of their first stroke occurrence. Participants who were medically unstable or who suffered from brain stem injury were excluded. Reliability was assessed by the intraclass correlation coefficient (ICC), standard error of measurement (SEM), smallest real difference (SRD), and the Bland-Altman limits of agreement. The results indicated excellent between-days intra-rater reliability (ICC > 0.75). SEM and SRD show small differences between measurements. The Bland-Altman analysis indicated a tendency of overestimation of the rectus femoris. MyotonPRO demonstrated acceptable reliability when used in a ward setting in those patients with acute stroke. However, results should be interpreted with caution, due to the limitations of the study and the varying level of consistency observed between different muscles

Manually controlled instrumented spasticity assessments: a systematic review of psychometric properties

status: publishe

Relationship of intraoperative electrophysiological criteria to outcome after selective functional posterior rhizotomy

Journal ArticleAt British Columbia's Children's Hospital, the criteria used in selective functional posterior rhizotomy (SFPR) evolved in three distinct phases. In Phase 1 the electrophysiological criteria for abnormality included a low threshold to a single stimulation, a sustained response to 50-Hz stimulation, and spread outside the segmental level being stimulated. In Phase 2 the electrophysiological criteria were unchanged, but fewer L3-4 nerve roots were cut. In Phase 3, fewer L3-4 nerve roots were cut, as in Phase 2, but based on the results of posterior nerve root stimulation in nonspastic controls, the only electrophysiological criterion used was contralateral and suprasegmental spread. The present study examined the relationship between the criteria used in each phase and patient outcome. The records of 77 consecutive children who underwent SFPR and had a minium follow-up period of 1 year were reviewed, comprising 25, 19, and 33 patients in Phases 1, 2, and 3, respectively. Outcome parameters included quantitative assessments of lower-limb spasticity and range of motion, and qualitative assessments of lower-limb function. In Phase 3, 52% of the nerve roots were cut, compared to 66% in Phases 1 and 2. In all three phases there was a significant decrease in lower-limb spasticity and an increase in range of movement, with the smallest decrease in spasticity in Phase 3. Over 90% of children in each phase improved with respect to lower-limb function, and excluding independent walkers and quadriplegics confined to a wheelchair, improvement in the level of ambulation occurred in 87.5%, 71.4%, and 73.7% of patients, in Phases 1, 2, and 3, respectively

Undirected compensatory plasticity contributes to neuronal dysfunction after severe spinal cord injury

Severe spinal cord injury in humans leads to a progressive neuronal dysfunction in the chronic stage of the injury. This dysfunction is characterized by premature exhaustion of muscle activity during assisted locomotion, which is associated with the emergence of abnormal reflex responses. Here, we hypothesize that undirected compensatory plasticity within neural systems caudal to a severe spinal cord injury contributes to the development of neuronal dysfunction in the chronic stage of the injury. We evaluated alterations in functional, electrophysiological and neuromorphological properties of lumbosacral circuitries in adult rats with a staggered thoracic hemisection injury. In the chronic stage of the injury, rats exhibited significant neuronal dysfunction, which was characterized by co-activation of antagonistic muscles, exhaustion of locomotor muscle activity, and deterioration of electrochemically-enabled gait patterns. As observed in humans, neuronal dysfunction was associated with the emergence of abnormal, long-latency reflex responses in leg muscles. Analyses of circuit, fibre and synapse density in segments caudal to the spinal cord injury revealed an extensive, lamina-specific remodelling of neuronal networks in response to the interruption of supraspinal input. These plastic changes restored a near-normal level of synaptic input within denervated spinal segments in the chronic stage of injury. Syndromic analysis uncovered significant correlations between the development of neuronal dysfunction, emergence of abnormal reflexes, and anatomical remodelling of lumbosacral circuitries. Together, these results suggest that spinal neurons deprived of supraspinal input strive to re-establish their synaptic environment. However, this undirected compensatory plasticity forms aberrant neuronal circuits, which may engage inappropriate combinations of sensorimotor networks during gait executio

A novel therapy to regain control of spinal motoneurons in stroke survivors

Thesis (Ph.D.) - Indiana University, School of Public Health, 2014The purpose of this research was to demonstrate that hemiplegic stroke survivors possess the ability to modulate their H-reflex amplitude through exercise induced operant conditioning. To better understand the changes in the spinal cord associated with hemiplegic stroke, two important inhibitory spinal cord mechanisms, namely post activation depression (PAD) and Group I reciprocal inhibition (RI) were also examined. Examining PAD with conditioning-test intervals between 80 to 300 ms showed a substantial depression in the amplitude of the H-reflex in healthy individuals. In stroke patients there was significantly less inhibition at all intervals, with full recover of the H-reflex at the 300 ms interval. In healthy individuals conditioning the soleus H-reflex with common peroneal nerve stimulation caused an initial inhibitory phase at about 10 ms interval (D1 inhibition) and a second phase of inhibition at longer intervals (> 100 ms; D2 inhibition). In stroke patients, no statistically significant inhibition was observed, although partial interaction analysis suggested that D1 inhibition followed a pattern similar to that of healthy individuals. Finally, a three-week exercise induced operant conditioning program was examined in three stroke patients. All patients demonstrated success for down-regulating the amplitude of the soleus H-reflex. More importantly, after training all subjects demonstrated improvements in gait parameters. It is concluded that spinal cord inhibitory mechanisms are different between healthy controls and stroke patients, and that exercise induced operant conditioning is a promising method for regaining functional control of motoneurons

Chapter Emerging Techniques for Assessment of Sensorimotor Impairments after Spinal Cord Injury

Mechanical properties of the plantar soft tissue, which acts as the interface between the skeleton and the ground, play an important role in distributing the force underneath the foot and in influencing the load transfer to the entire body during weight-bearing activities. Hence, understanding the mechanical behaviour of the plantar soft tissue and the mathematical equations that govern such behaviour can have important applications in investigating the effect of disease and injuries on soft tissue function. The plantar soft tissue of the foot shows a viscoelastic behaviour, where the reaction force is not only dependent on the amount of deformation but also influenced by the deformation rate. This chapter provides an insight into the mechanical behaviour of plantar soft tissue during loading with specific emphasis on heel pad, which is the first point of contact during normal gait. Furthermore, the methods of assessing the mechanical behaviour including the in vitro/in situ and in vivo are discussed, and examples of creep, stress relaxation, rate dependency and hysteresis behaviour of the heel pad are shown. In addition, the viscoelastic models that represent the mechanical behaviour of the plantar soft tissue under load along with the equations that govern this behaviour are elaborated and discussed

Neurophysiological methods for the assessment of spasticity: the Hoffmann reflex, the tendon reflex, and the stretch reflex

Purpose: To review the literature concerning neurophysiological methods to assess spasticity with respect to mechanisms and methodology, and to describe the three most commonly used methods: the Hoffmann reflex (H-reflex), the Tendon reflex (T-reflex), and the Stretch Reflex (SR).\ud Method: A systematic internet database search was performed to identify neurophysiological measurement methods of spasticity. A systematic exclusion procedure resulted in 185 included references, completed by additional informal search. For this paper, information about the H-, T- and stretch reflexes was extracted from these references. \ud Results: Although the reflexes are basically monosynaptic, there are many supraspinal pathways which modulate the responses in terms of their amplitude and latency. As a consequence the methods are sensitive to a considerable number of experimental conditions and are characterized by a moderate reliability and sensitivity. Correlations with other (i.e. biomechanical, neurophysiological or clinical) spasticity assessment parameters are moderate to poor. Standardised and broadly accepted protocols are still largely lacking preventing an effective exchange of knowledge. \ud Conclusions: The clinical and experimental use of the three methods is restricted due to moderate reliability and sensitivity. It is recommended to perform combined neurophysiological – biomechanical assessment of spasticity during active, functional movement

Treatment of Rat Spinal Cord Injury with the Neurotrophic Factor Albumin-Oleic Acid: Translational Application for Paralysis, Spasticity and Pain

Sensorimotor dysfunction following incomplete spinal cord injury (iSCI) is often characterized by the debilitating symptoms of paralysis, spasticity and pain, which require treatment with novel pleiotropic pharmacological agents. Previous in vitro studies suggest that Albumin (Alb) and Oleic Acid (OA) may play a role together as an endogenous neurotrophic factor. Although Alb can promote basic recovery of motor function after iSCI, the therapeutic effect of OA or Alb-OA on a known translational measure of SCI associated with symptoms of spasticity and change in nociception has not been studied. Following T9 spinal contusion injury in Wistar rats, intrathecal treatment with: i) Saline, ii) Alb (0.4 nanomoles), iii) OA (80 nanomoles), iv) Alb-Elaidic acid (0.4/80 nanomoles), or v) Alb-OA (0.4/80 nanomoles) were evaluated on basic motor function, temporal summation of noxious reflex activity, and with a new test of descending modulation of spinal activity below the SCI up to one month after injury. Albumin, OA and Alb-OA treatment inhibited nociceptive Tibialis Anterior (TA) reflex activity. Moreover Alb-OA synergistically promoted early recovery of locomotor activity to 50±10% of control and promoted de novo phasic descending inhibition of TA noxious reflex activity to 47±5% following non-invasive electrical conditioning stimulation applied above the iSCI. Spinal L4–L5 immunohistochemistry demonstrated a unique increase in serotonin fibre innervation up to 4.2±1.1 and 2.3±0.3 fold within the dorsal and ventral horn respectively with Alb-OA treatment when compared to uninjured tissue, in addition to a reduction in NR1 NMDA receptor phosphorylation and microglia reactivity. Early recovery of voluntary motor function accompanied with tonic and de novo phasic descending inhibition of nociceptive TA flexor reflex activity following Alb-OA treatment, mediated via known endogenous spinal mechanisms of action, suggests a clinical application of this novel neurotrophic factor for the treatment of paralysis, spasticity and pain

Emerging Techniques for Assessment of Sensorimotor Impairments after Spinal Cord Injury

Gait function can be altered after incomplete spinal cord (iSCI) lesions. Muscular weakness, co‐activation of antagonist muscles, and altered muscle mechanics are likely to provoke abnormal gait and postural movements. Functional scales are available for assessment of functional walking in SCI patients, such as walking index for spinal cord injury (WISCI II), timed up and go (TUG) test, 10‐meter walk test (10MWT), and 6‐minute walk test (6MWT). Novel metrics for a more detailed comprehension of neuromuscular control in terms of degree of voluntary motor control have been recently proposed. This section describes novel techniques based on muscle synergy and frequency domain analysis of electromyographic signals. Such techniques are illustrated as potential tools for assessment of motor function after SCI with experimental data and a case study describing a diagnostic scenario. This chapter presents a discussion of the current status of the emerging metrics for assessment of sensorimotor impairments. Conclusions are given with respect to the availability of enriched information about neuromuscular behavior between functional tasks (walking and pedalling) and the potential relevance of these new techniques to improve the efficacy of treatment to improve locomotion after iSCI