Comparing Electrical Stimulation With and Without Ultrasound Guidance for Phenol Neurolysis to the Musculocutaneous Nerve

AAPM&R consensus guidance on spasticity assessment and management

BACKGROUND

The American Academy of Physical Medicine and Rehabilitation (AAPM&R) conducted a comprehensive review in 2021 to identify opportunities for enhancing the care of adult and pediatric patients with spasticity. A technical expert panel (TEP) was convened to develop consensus-based practice recommendations aimed at addressing gaps in spasticity care.

OBJECTIVE

To develop consensus-based practice recommendations to identify and address gaps in spasticity care.

METHODS

The Spasticity TEP engaged in a 16-month virtual meeting process, focusing on formulating search terms, refining research questions, and conducting a structured evidence review. Evidence quality was assessed by the AAPM&R Evidence, Quality and Performance Committee (EQPC), and a modified Delphi process was employed to achieve consensus on recommendation statements and evidence grading. The Strength of Recommendation Taxonomy (SORT) guided the rating of individual studies and the strength of recommendations.

RESULTS

The TEP approved five recommendations for spasticity management and five best practices for assessment and management, with one recommendation unable to be graded due to evidence limitations. Best practices were defined as widely accepted components of care, while recommendations required structured evidence reviews and grading. The consensus guidance statement represents current best practices and evidence-based treatment options, intended for use by PM&R physicians caring for patients with spasticity.

CONCLUSION

This consensus guidance provides clinicians with practical recommendations for spasticity assessment and management based on the best available evidence and expert opinion. Clinical judgment should be exercised, and recommendations tailored to individual patient needs, preferences, and risk profiles. The accompanying table summarizes the best practice recommendations for spasticity assessment and management, reflecting principles with little controversy in care delivery.

Spasticity Treatment Beyond Botulinum Toxins

Botulinum toxin (BonT) is the mainstream treatment option for post-stroke spasticity. BoNT therapy may not be adequate in those with severe spasticity. There are a number of emerging treatment options for spasticity management. In this paper, we focus on innovative and revived treatment options that can be alternative or complementary to BoNT therapy, including phenol neurolysis, cryoneurolysis, and extracorporeal shock wave therapy.

Recommendations for Ultrasound Guidance for Diagnostic Nerve Blocks for Spasticity. What Are the Benefits?

The diagnostic nerve block (DNB) for spasticity is the percutaneous application of an anesthetic to an individual peripheral nerve trunk (mixed motor sensory nerve), nerve branch to a muscle or an intramuscular branch. The DNB causes a temporary paralysis to assess the contribution of muscle(s) on the spastic pattern and may unmask a fully or partially increased joint range of motion. The anesthetic literature supports the use of ultrasound (US) guidance to improve nerve blocks for sensory targets. This communication summarizes the potential advantages that support the use of US to improve DNB technique. Nerves are much smaller than muscle targets and have various known innervation patterns. US allows for rapid localization of the target before injection, particularly in complex anatomy patterns. The nerve trunks are typically found adjacent to or encapsulating blood vessels, which can be quickly identified with or without color Doppler, allowing the clinician to scan from the vessels to the target and avoid intravascular injection. Lower stimulation levels can be used as the targeted muscle(s) can be seen stimulating rather than only on the surface. A shorter needle insertion time and lower stimulation levels should cause less discomfort to the patient. Smaller volumes of anesthetic may be used as the fluid is seen reaching its target and cessation of stimulation is observed. Further study is needed to identify evidence supporting US utilization with electrical stimulation in DNBs for spasticity management, as US use during nerve blocks for perineurial anesthesia has demonstrated improved patient safety and procedural efficiency.

Sonographic peripheral nerve cross-sectional area in adults, excluding median and ulnar nerves: A systematic review and meta-analysis

INTRODUCTION/AIMS

Although electromyography remains the "gold standard" for assessing and diagnosing peripheral nerve disorders, ultrasound has emerged as a useful adjunct, providing valuable anatomic information. The objective of this study was to conduct a systematic review and meta-analysis evaluating the normative sonographic values for adult peripheral nerve cross-sectional area (CSA).

METHODS

Medline and Cochrane Library databases were systematically searched for healthy adult peripheral nerve CSA, excluding the median and ulnar nerves. Data were meta-analyzed, using a random-effects model, to calculate the mean nerve CSA and its 95% confidence interval (CI) for each nerve at a specific anatomical location (= group).

RESULTS

Thirty groups were identified and meta-analyzed, which comprised 16 from the upper extremity and 15 from the lower extremity. The tibial nerve (n = 2916 nerves) was reported most commonly, followed by the common fibular nerve (n = 2580 nerves) and the radial nerve (n = 2326 nerves). Means and 95% confidence interval (CIs) of nerve CSA for the largest number of combined nerves were: radial nerve assessed at the spiral groove (n = 1810; mean, 5.14 mm2 ; 95% CI, 4.33 to 5.96); common fibular nerve assessed at the fibular head (n = 1460; mean, 10.18 mm2 ; 95% CI, 8.91 to 11.45); and common fibular nerve assessed at the popliteal fossa (n = 1120; mean, 12.90 mm2 ; 95% CI, 9.12 to 16.68). Publication bias was suspected, but its influence on the results was minimal.

DISCUSSION

Two hundred thirty mean CSAs from 15 857 adult nerves are included in the meta-analysis. These are further categorized into 30 groups, based on anatomical location, providing a comprehensive reference for the clinician and researcher investigating adult peripheral nerve anatomy.

Phenol neurolysis in people with spinal cord injury: a descriptive study

STUDY DESIGN

Descriptive study.

OBJECTIVES

The study's main objective was to describe the common targets of phenol neurolysis and review the safety and efficacy of the dose used for this spasticity management procedure in people with spinal cord injury (SCI).

SETTING

An acute rehabilitation hospital.

METHODS

Data from people with SCI who underwent phenol neurolysis procedures for spasticity management between April 2017 and August 2018 were included in this study. We collected demographics and phenol neurolysis procedure-related information.

RESULTS

A total of 66 people with SCI and spasticity underwent phenol neurolysis of 303 nerves over 102 encounters. During these encounters, 97% of procedures were performed using both electrical stimulation and ultrasound guidance. The median (IQR) total volume of 6% aqueous phenol used per encounter was 4.0 (2.0-6.0) ml with a median (IQR) of 1.5 (1.0-2.3) ml per nerve. The most frequent target was the obturator nerve (33%), followed by the pectoral nerves (23%). Immediate post-phenol neurolysis improvement or reduction in spasticity was reported for 92% of all documented encounters. There was no documentation of any post-procedure-related adverse events in this cohort during this specified time frame.

CONCLUSIONS

Our findings suggest that phenol neurolysis can be safely used to manage spasticity in people with SCI under combined electrical stimulation and ultrasound guidance. Further research is required to assess the procedure's safety, efficacy, and cost-effectiveness on patient-reported outcomes compared to other spasticity interventions.

Comparison of Ultrasound and Electrical Stimulation Guidance for Onabotulinum Toxin-A Injections: A Randomized Crossover Study

Background

Botulinum neurotoxin (BoNT) injection is an established therapy for limb spasticity and focal limb dystonia. Comparative benefits of injection guidance procedures have not been rigorously studied.

Objectives

We compared 2 targeting techniques for onabotulinumtoxin-A (onabotA) injection for the treatment of focal hand dystonia and upper limb spasticity: electrophysiologic guidance using electrical stimulation (E-stim) and ultrasound (US).

Methods

This was a 2-center, randomized, crossover, assessor-blinded trial. Participants with focal hand dystonia or upper limb spasticity, on stable onabotA therapy for at least 2 previous injection cycles, were randomly assigned to either E-stim or US with crossover at 3 months. The primary outcome was improvement in dystonia or spasticity severity on a visual analog scale (VAS; 0-100) measured 1 month after each injection. The secondary outcome was participant discomfort assessed on a VAS. Repeated-measures analysis of covariance was used with linear mixed-model covariate selection.

Results

A total of 19 participants (13 men) completed the study, 10 with upper limb spasticity and 9 with dystonia. Benefit was equivalent between the 2 techniques (VAS least-square mean [LSmean] 51.5 mm with US and 53.1 with E-stim). E-stim was perceived as more uncomfortable by participants (VAS LSmean 34.5 vs. 19.9 for E-stim and US, respectively). Procedure duration was similar with the 2 procedures. There were no serious adverse events related to either approach.

Conclusions

US and E-Stim localization guidance techniques provide equivalent efficacy in onabotA injections for spasticity and dystonia. US guidance injections are more comfortable for participants. Both techniques are effective guidance methods, with US potentially preferable based on participant comfort.

Impact of Predefined Angles and a Revised APPLES Mnemonic on Accuracy and Performance Time for Simulated Ultrasound-Guided Injections

OBJECTIVES

Our objective was to determine whether predefined angles would improve performance time and accuracy of ultrasound-guided procedures by novice operators and whether a revised APPLES (approach, position, perpendicular, lift, entry, sweep) mnemonic was a helpful guide for performing the procedure.

METHODS

Participants attempted to hit targets in-plane and out-of-plane at different depths with a needle under ultrasound guidance with and without predefined angles. Participants were then asked if they thought that the mnemonic would be helpful when learning both methods for ultrasound-guided procedures.

RESULTS

There were 120 participants all of whom had performed fewer than six ultrasound guided procedures. Accuracy increased in all groups when angles were provided; however, only the 3-cm in-plane approach achieved statistical significance. Performance time also achieved statistical significance in two of the four groups. Ninety-five percent of participants thought that the revised APPLES mnemonic would be helpful for learning and performing ultrasound-guided procedures in the future.

CONCLUSIONS

Predefined angles seem to positively impact procedure time and accuracy for some target depths, and the APPLES mnemonic could be a helpful mental checklist for many novice operators. These may be useful tools to facilitate safe and efficient ultrasound-guided procedures in the clinical space.

A Novel Approach to New-Onset Hemiplegic Shoulder Pain With Decreased Range of Motion Using Targeted Diagnostic Nerve Blocks: The ViVe Algorithm

Introduction: Hemiplegic shoulder pain (HSP) is the most common pain disorder after stroke with incidence estimates of 30–70% and associated with reductions in function, interference with rehabilitation, and a reduced quality of life. Onset may occur as soon as a week after stroke in 17% of patients. Management of HSP represents a complex treatment pathway with a lack of evidence to support one treatment. The pain has heterogeneous causes. In the acute setting, decreased range of motion in the shoulder can be due to early-onset spasticity, capsular pattern stiffness, glenohumeral pathology, or complex regional pain syndrome (CRPS). As contracture can form in up to 50% of patients after stroke, effective management of the painful shoulder and upper limb with decreased range of motion requires assessment of each possible contributor for effective treatment. The anesthetic diagnostic nerve block (DNB) is known to differentiate spasticity from contracture and other disorders of immobility and can be useful in determining an appropriate treatment pathway.

Objective: To create a diagnostic algorithm to differentiate between the causes of HSP in the stiff, painful shoulder in the subacute setting using diagnostic techniques including the Budapest Criteria for CRPS and DNB for spasticity and pain generators.

Results: Examination of each joint in the upper extremity with HSP may differentiate each diagnosis with the use of an algorithm. Pain and stiffness isolated to the shoulder may be differentiated as primary shoulder pathology; sensory suprascapular DNB or intra-articular/subacromial injection can assist in differentiating adhesive capsulitis, arthritis, or rotator cuff injury. CRPS may affect the shoulder, elbow, wrist, and hand and can be evaluated with the Budapest Criteria. Spasticity can be differentiated with the use of motor DNB. A combination of these disorders may cause HSP, and the proposed treatment algorithm may offer assistance in selecting a systematic treatment pathway.

Medical Updates in Management of Hypertonia

Identifying the subtypes of hypertonia is becoming increasingly important. Treatment strategies, including tone-modulating surgical interventions, medication type and dosing, and chemodenervation, may differ depending on the type of hypertonia present. It is important to delineate how hypertonia interferes with function and quality of life so that the appropriate intervention can be selected at the right time. Outcomes of treatment depend heavily on clear communication of goals. Botulinum toxin should not be used in isolation but as an adjunct to rehabilitation modalities.

Novel Conservative Approach to High Surgical Risk Frail Proximal Femur Fractures

One of the major impacts following a neck of femur fracture is pain. Most patients (nearly all) undergo an operation. This usually includes the frailest terminal patients and deemed a palliative procedure to reduce ongoing pain. The operation comes with risks and can reduce life expectancy in these patients and result in prolonged hospital admission, delirium, and postoperative complications. This case highlights a novel approach to managing the frailest end-of-life patients that does not require them to undergo a conventional operation. The case resulted in a quick discharge from hospital and for the patient and family to maximise the time out of hospital, with a reduced analgesic burden and a peaceful passing away. We feel that this could be an alternative, more humane option for such patients.

Cryoneurotomy as a Percutaneous Mini-invasive Therapy for the Treatment of the Spastic Limb: Case Presentation, Review of the Literature, and Proposed Approach for Use

Objective

To provide a proof-of-concept study demonstrating that the decades old procedure of cryoneurotomy, used traditionally for analgesia, is a safe adjunctive and effective treatment for limb spasticity.

Design

Case series.

Setting

Publicly funded outpatient hospital spasticity clinic and community interventional anesthesia clinic.

Participants

Patients (N=3) who had plateaued with standard of care spasticity treatments including botulinum toxin. Two hemiplegic stroke patients with elbow spasticity and 1 pregnant patient with multiple sclerosis and a spastic equinovarus foot for whom botulinum toxin was now contraindicated.

Interventions

Selective anesthetic diagnostic motor nerve blocks with ultrasound and e-stimulation with 1cc of 1% lidocaine to the motor nerve to the targeted spastic muscle were performed to either the musculocutaneous nerve to brachialis, radial nerve to the brachioradialis or the tibial nerve. If the benefits included improved active and passive range motion and or decreased clonus, a percutaneous cryoneurotomy was performed.

Main Outcome Measures

Active and passive range of motion were measured using the Modified Tardieu Scale. The change in resistance to passive stretch was measured using the Modified Ashworth Scale (MAS). Videos of the before and after treatment were collected.

Results

Both elbows’ treatments resulted in MAS improving from a 3 to a 1+. Greatly improved active range of motion was noted at 94 and 64 degrees, respectively, as well as improvements in passive range on the Modified Tardieu Scale. The tibial nerve cryoneurotomy resulted in improvements in all parameters with a much improved gait. Results were maintained up to 17 months of follow-up.

Conclusion

Cryoneurotomy as a treatment for spasticity is a novel safe adjuvant treatment. Our initial results suggest patients can achieve significantly increased active and passive range of motion in the upper extremity and decreased clonus, and improved gait after tibial nerve cryoneurotomy.

Phenol Neurolysis for Management of Focal Spasticity in the Distal Upper Extremity

BACKGROUND

When managing patients with focal spasticity, phenol neurolysis is often avoided largely because of its presumed poor adverse effect profile. It is suggested that dysesthesias may be more common with phenol neurolysis of the mixed sensorimotor nerves (eg, radial, median, and ulnar nerves) compared to neurolysis of pure motor nerves. However, these risks may be mitigated with precise localization of pure motor branches by ultrasound and electrical stimulation (EStim).

OBJECTIVE

To explore practice patterns of phenol neurolysis to distal upper extremity mixed sensorimotor nerves with ultrasound and EStim guidance.

DESIGN

A retrospective analysis of all neurolysis procedure records at a single institution from January 2013 to February 2018. Demographic and clinical variables including primary neurological diagnosis, concurrent spasticity treatments, nerves injected, phenol dosage and adverse events were abstracted from the electronic medical records.

PARTICIPANTS

57 patients who received phenol neurolysis with ultrasound and EStim guidance for spasticity management to radial, median, or ulnar nerves.

MAIN OUTCOME MEASURES

Reported adverse effects.

RESULTS

A total of 57 patients who collectively received neurolysis to 139 nerves across 102 encounters, met inclusion criteria. Most prevalent diagnoses included traumatic brain injury (N = 27, 47.4%) and stroke (N = 18, 31.6%), with a smaller subset having spinal cord injury (N = 10, 17.5%). Most patients received concomitant chemodenervation with botulinum toxin (N = 44, 77.2%). The average phenol dosage per nerve was 1.8 mL, with a range of 0.5-9.0 mL. Reported adverse effects included three cases of prolonged pain, but no dysesthesias were reported during the follow-up period (>40 days).

CONCLUSIONS

Phenol neurolysis with ultrasound and EStim guidance was successfully and safely used to manage focal spasticity in the distal upper extremity.

LEVEL OF EVIDENCE

III.