Effectiveness of femoral nerve selective block in patients with spasticity: preliminary results

Highly selective motor nerve block and movement analysis for preoperative evaluation of complex spastic gait

BACKGROUND

Lower-extremity spasticity and impaired gait control after central nervous system injury are challenging to improve, because spasticity limits residual motor control while providing mechanical support. Highly selective partial neurectomies (HSPNs) can substantially reduce spasticity but may have greater risks in patients with complex lower-extremity spastic gait.

OBJECTIVE

To examine the potential of ultrasound- and stimulation-guided highly selective motor nerve blocks (HSMNBs) to assess the potential impact of reduced spasticity on gait.

METHODS

In this retrospective series, six patients underwent HSMNBs with movement assessment before and after the block. Range of motion, strength, position angles, surface electromyography, lower limb kinematics, and patient satisfaction were assessed.

RESULTS

Pre- and post-HSMNB movement analysis yielded dichotomous gait kinematics, which facilitated surgical decisions. Of the 59 metrics evaluated, 82% demonstrated a positive improvement post-block (62% improved more than one standard deviation (SD) of typically developing means, 49% improved > 2 SD) and 16% demonstrated a negative change (2% worsened > 1 SD).

CONCLUSION

HSMNB provided clear efficacy in changing clinical, surface electromyography, and gait parameters. Movement analysis provided clear and robust objective and patient-centered evidence for surgical guidance. This protocol may provide utility in evaluation of patients being considered for HSPNs for complex spastic gait patterns.

French clinical guidelines for peripheral motor nerve blocks in a PRM setting

INTRODUCTION

Motor nerve blocks with anesthetic drug for local anesthesia are commonly used in physical and rehabilitation medicine (PRM), especially in the field of spasticity. Guidelines in this context are currently lacking.

METHOD

Eighteen experts selected on the basis of their recognized experience by the scientific committees of the French PRM (SOFMER) and Anesthesia and Intensive care (SFAR) societies were invited to work and propose guidelines for the use of loco-regional anesthetic drug for motor nerve blocks in PRM setting. Eight issues were addressed: which neural blocks for which indications; drugs and contraindications; medical survey and attitude in case of adverse event; injection and guidance material; patient preparation and pain relief; efficacy assessment; patient information; education of PRM physiatrists. The Medline, Cochrane and Embase databases for the period 1999 to 2018 were consulted and 355 papers analyzed. The drafts were commented then approved by the whole group using electronic vote, before final approval by scientific committee of each society.

RESULTS

No scientific evidence emerged from the literature. Thus, these guidelines are mainly based on the opinion of the expert panel. Guidelines for each issue are reported with the main points of arguments. The main question deals with the recommendation about doses for each drug: for lidocaine - up to 2mg/kg - "check contraindications, emergency truck available, no need of previous anesthetic consultation nor presence of anesthetic physician"; for ropivacaine - up to 1.5mg/kg, with a maximum of 100mg - the same but after intravenous line. Beyond these doses, SFAR guidelines have to be applied with the need of anesthetic physician.

CONCLUSION

These are the first organizational guidelines devoted to increase the security of motor nerve block use in PRM settings.

Does the rectus femoris nerve block improve knee recurvatum in adult stroke patients? A kinematic and electromyographic study

Knee recurvatum (KR) during gait is common in hemiplegic patients. Quadriceps spasticity has been postulated as a cause of KR in this population. The aim of this study was to assess the role of rectus femoris spasticity in KR by using selective motor nerve blocks of the rectus femoris nerve in hemiparetic stroke patients. The data from six adult, post-stroke hemiplegic patients who underwent a rectus femoris nerve block for a stiff-knee gait were retrospectively analyzed. An extensive clinical and functional evaluation was performed and gait was assessed by motion analysis (kinematic, kinetic and electromyographic parameters) before and during the block realized using 2% lidocaine injected under a neurostimulation and ultrasonographic targeting procedure. The main outcome measures were the peak knee extension in stance and peak knee extensor moment obtained during gait analysis. No serious adverse effect of the nerve block was observed. The block allowed a reduction of rectus femoris overactivity in all patients. Peak knee extension and extensor moment in stance did not improve in any patient, but peak knee flexion during the swing phase was significantly higher after block (mean: 31.2° post, 26.4 pre, p < 0.05). Our results provide arguments against the hypothesis that the spasticity of the rectus femoris contributes to KR.

[Peripheral nerve blocks and spasticity. Why and how should we use regional blocks?]

Muscle spasticity causes pain, disability, and difficulties in the rehabilitation of patients with cerebrovascular lesions, head, brain or spine trauma, coma, or neurologic diseases such as multiple sclerosis, amyotrophic lateral sclerosis, or cerebral palsy. Regional blocks have a threefold use in patients with painful spasticity: diagnostic, prognostic, and therapeutic. Blocks are feasible on an outpatient or day-hospital basis. Blocks are applied most often to 4 peripheral sites: the pectoral nerve loop, median, obturator, and tibial nerves. The main indication is debilitating or painful spasticity. Peripheral blocks with local anesthetics are used as tests, to mimic the effects of motor blocks and determine their potential adverse effects, transiently and reversibly. Peripheral neurolytic blocks are easy to perform, effective, and inexpensive.

Plantar feedback contributes to the regulation of leg stiffness

BACKGROUND

Running and hopping involve moving in a bouncing fashion during which the limbs behave as springs. The ability to alter the stiffness of these leg springs is essential to maintaining an efficient gait. Since the plantar surface of the foot is the only part of the body to encounter the ground during bipedal locomotion, it would seem logical that some aspect of the neurological functioning of the foot is responsible for transmission of information about the surface characteristics to the central nervous system, resulting in changes in leg stiffness.

METHODS

Ten subjects (9 males, 1 female) participated in this experiment. Lidocaine was injected inferior and posterior to the lateral malleolus in order to achieve tibial nerve block at the level of the ankle. Subjects hopped at 2.2 Hz on a force plate while data were collected at 1000 Hz. Data were analyzed for peak force and leg stiffness and compared using a repeated measures ANOVA.

FINDINGS

Tactile sensation, deep pressure sensation, and abductor hallucis activity displayed significant decreases following the injection, as did postural stability. Subjects demonstrated a significantly decreased leg stiffness after the nerve block (P<.01).

INTERPRETATION

Plantar sensation has an effect on regulating leg mechanics in hopping. A loss of sensation in this region can exert a significant impact on the properties of the leg in gait, and future research should determine the specific pathways by which plantar feedback exerts this effect.

Spasticité : intérêt du testing par anesthésie locorégionale et blocs thérapeutiques

Peripheral nerve blockade is one of the therapeutic possibilities to treat spasticity of various muscles. Percutaneous nerve stimulation allows accurate location of nerves and neurolysis can be performed using intraneural injection of 65% ethanol or 5 to 12% phenol. Spastic contraction of various muscle groups is a common source of pain and disability which prevents from having efficient rehabilitation. Test-blocks as well as neurolytic blocks are possible in most of motor nerves of the upper and lower limbs and main indications are spastic sequelae of stroke and spinal trauma but also of multiple sclerosis, cerebral palsy and chronic coma. The use of percutaneous nerve stimulation allows accurate location and four nerves are more frequently treated: pectoral nerve loop, median, obturator and tibial nerves. In patients with spasticity of the adductor thigh muscles, nerve blocks are performed via a combined approach using fluoroscopy and nerve stimulation to identify the obturator nerve. No complications occurred and minor side effects are transient painful phenomena during injection. These approaches proved to be accurate, fast, simple, highly successful and reproducible. Percutaneous neurolytic procedures should be done as early as possible, as soon as spasticity becomes painful and disabling in patients with neurological sequelae of stroke, head trauma or any lesion of the motor neuron.

Tibial Nerve Block with Anesthetics Resulting in Achilles Tendon Avulsion

Diagnostic tibial nerve block with anesthetics is a common and safe procedure for the management of the spastic equinovarus foot. Side effects have been rarely reported. We present the case of a hemiplegic patient with a spastic equinovarus foot who presented with an avulsion fracture of the calcaneum at the insertion of the Achilles tendon consecutive to a diagnostic tibial nerve block with anesthetic agents. Although rare, such a complication should be considered when the Achilles tendon is shortened and when the patient is suspected of bone osteoporosis or dystrophy.

Acute Care Management of Post-TBI Spasticity

The management of persons with traumatic brain injury (TBI) who have acute spasticity remains a challenge. A correct stratification is essential to clinical care and determination of efficacy from proposed interventions. The secondary severe sequelae of spasticity after TBI can result in profound functional impairment. These concerns are often best addressed early in the patient's course. Limited research in the area of the acute care treatment of severe spasticity is available. The authors employ a review of the available data as well as recount their own clinical experience in the acute care management of severe spasticity to assist in developing an order for the plethora of potential treatments available to clinicians and researchers. We propose to use a case example to emphasize key clinic points in the management of spasticity in the acute care setting.