Botulinum Toxin Injections and Electrical Stimulation for Spastic Paresis Improve Active Hand Function Following Stroke

Dose and injection site of botulinum toxin type A for gummy smile management: A systematic review and bibliometric analysis

INTRODUCTION

Botulinum toxin type A (BoNT/A) is an effective non-surgical method for treating gummy smile (GS). This systematic review evaluated the efficacy, duration, and safety of different BoNT/A injections.

METHODS

Four electronic databases were searched for relevant literature, generating 1106 references.

RESULTS

The review included 13 prospective, controlled clinical trials. The mean pre-injection anterior gingival exposure ranged from 3.5 mm to 6.8 mm, reaching maximum effect at 2-4 weeks post-injection. Most studies indicated complete improvement in gingival exposure post-injection, with gingival exposure reduced to ≤3 mm. The dosage of BoNT/A was determined by the severity of gingival exposure, with effects lasting up to 12-24 weeks. Levator labii superioris alaeque nasi (LLSAN), levator labii superioris (LLS), and zygomaticus minor (ZMi) were the main targeted muscles. Next, bibliometric analysis was conducted to provide an overview of the existing publications on managing gummy smiles.

CONCLUSIONS

This data demonstrates that BoNT/A can effectively treat various types of GS triggered by muscle hyperactivity. It is a non-intrusive treatment with significant improvement, high safety, minimal side effects, and high patient satisfaction. This study was preregistered in the Prospective Register of Systematic Reviews (CRD42024509183).

CLINICAL SIGNIFICANCE

This study systematically reviewed and compared previous results on efficacy, duration, patient satisfaction, and adverse effects of different botulinum toxin type A doses and injection sites, laying a solid foundation for further studies that use BoNT/A in the management of gummy smiles.

Effectiveness of mixed reality-based rehabilitation on hands and fingers by individual finger-movement tracking in patients with stroke

BACKGROUND

Mixed reality (MR) is helpful in hand training for patients with stroke, allowing them to fully submerge in a virtual space while interacting with real objects. The recognition of individual finger movements is required for MR rehabilitation. This study aimed to assess the effectiveness of updated MR-board 2, adding finger training for patients with stroke.

METHODS

Twenty-one participants with hemiplegic stroke (10 with left hemiplegia and 11 with right hemiplegia; nine female patients; 56.7 ± 14.2 years of age; and onset of stroke 32.7 ± 34.8 months) participated in this study. MR-board 2 comprised a board plate, a depth camera, plastic-shaped objects, a monitor, a palm-worn camera, and seven gamified training programs. All participants performed 20 self-training sessions involving 30-min training using MR-board 2. The outcome measurements for upper extremity function were the Fugl-Meyer assessment (FMA) upper extremity score, repeated number of finger flexion and extension (Repeat-FE), the thumb opposition test (TOT), Box and Block Test score (BBT), Wolf Motor Function Test score (WMFT), and Stroke Impact Scale (SIS). One-way repeated measures analysis of variance and the post hoc test were applied for the measurements. MR-board 2 recorded the fingers' active range of motion (AROM) and Dunnett's test was used for pairwise comparisons.

RESULTS

Except for the FMA-proximal score (p = 0.617) and TOT (p = 0.005), other FMA scores, BBT score, Repeat-FE, WMFT score, and SIS stroke recovery improved significantly (p < 0.001) during MR-board 2 training and were maintained until follow-up. All AROM values of the finger joints changed significantly during training (p < 0.001).

CONCLUSIONS

MR-board 2 self-training, which includes natural interactions between humans and computers using a tangible user interface and real-time tracking of the fingers, improved upper limb function across impairment, activity, and participation. MR-board 2 could be used as a self-training tool for patients with stroke, improving their quality of life.

TRIAL REGISTRATION NUMBER

This study was registered with the Clinical Research Information Service (CRIS: KCT0004167).

The Effect of Botulinum Neurotoxin-A (BoNT-A) on Muscle Strength in Adult-Onset Neurological Conditions with Focal Muscle Spasticity: A Systematic Review

Botulinum neurotoxin-A (BoNT-A) injections are effective for focal spasticity. However, the impact on muscle strength is not established. This study aimed to investigate the effect of BoNT-A injections on muscle strength in adult neurological conditions. Studies were included if they were Randomised Controlled Trials (RCTs), non-RCTs, or cohort studies (n ≥ 10) involving participants ≥18 years old receiving BoNT-A injection for spasticity in their upper and/or lower limbs. Eight databases (CINAHL, Cochrane, EMBASE, Google Scholar, Medline, PEDro, Pubmed, Web of Science) were searched in March 2024. The methodology followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was registered in the Prospective Register of Systematic Reviews (PROSPERO: CRD42022315241). Quality was assessed using the modified Downs and Black checklist and the PEDro scale. Pre-/post-injection agonist, antagonist, and global strength outcomes at short-, medium-, and long-term time points were extracted for analysis. Following duplicate removal, 8536 studies were identified; 54 met the inclusion criteria (3176 participants) and were rated as fair-quality. Twenty studies were analysed as they reported muscle strength specific to the muscle injected. No change in agonist strength after BoNT-A injection was reported in 74% of the results. Most studies' outcomes were within six weeks post-injection, with few long-term results (i.e., >three months). Overall, the impact of BoNT-A on muscle strength remains inconclusive.

Lumbar epidural steroid injection for spasticity in paraplegic spinal cord injury: A case report

This is the case of a 33-year-old male with traumatic paraplegic lumbar spinal cord injury after knife assault, who was unable to participate in an intensive inpatient rehabilitation course due to bilateral lower limb spasticity. For therapeutic management of spasticity at the bedside in the inpatient rehabilitation setting, we performed an epidural steroid injection to the right L4-L5 interspace. After the intervention, a significant decrease in spasticity was noted. The patient could subsequently tolerate sit-to-stand transfers with a standing frame and ambulate with the an exoskeleton device in inpatient physical therapy, significantly improving his overall functional level in therapies. This case demonstrates that bedside epidural steroid injection can dramatically improve paraplegic spasticity secondary to lumbar spinal cord injury in the inpatient rehabilitation setting.

Management of Upper-Limb Spasticity Using Modern Rehabilitation Techniques versus Botulinum Toxin Injections Following Stroke

Our purpose is to emphasize the role of botulinum toxin in spasticity therapy and functional recovery in patients following strokes. Our retrospective study compared two groups, namely ischemic and hemorrhagic stroke patients. The study group (BT group) comprised 80 patients who received focal botulinum toxin as therapy for an upper limb with spastic muscle three times every three months. The control group (ES group) comprised 80 patients who received only medical rehabilitation consisting of electrostimulation and radial shockwave therapy for the upper limb, which was applied three times every three months. Both groups received the same stretching program for spastic muscles as a home training program. We evaluated the evolution of the patients using muscle strength, Ashworth, Tardieu, Frenchay, and Barthel scales. The analysis indicated a statistically significant difference between the two groups for all scales, with better results for the BT group (p < 0.0001 for all scales). In our study, the age at disease onset was an important prediction factor for better recovery in both groups but not in all scales. Better recovery was obtained for younger patients (in the BT group, MRC scale: rho = -0.609, p-value < 0.0001; Tardieu scale: rho = -0.365, p-value = 0.001; in the ES group, MRC scale: rho = -0.445, p-value < 0.0001; Barthel scale: rho = -0.239, p-value = 0.033). Our results demonstrated the effectiveness of botulinum toxin therapy compared with the rehabilitation method, showing a reduction of the recovery time of the upper limb, as well as an improvement of functionality and a reduction of disability. Although all patients followed a specific kinetic program, important improvements were evident in the botulinum toxin group.

Stroke Recovery Is a Journey: Prediction and Potentials of Motor Recovery after a Stroke from a Practical Perspective

Stroke recovery is a journey. Stroke survivors can face many consequences that may last the rest of their lives. Assessment of initial impairments allows reasonable prediction of biological spontaneous recovery at 3 to 6 months for a majority of survivors. In real-world clinical practice, stroke survivors continue to improve their motor function beyond the spontaneous recovery period, but management plans for maximal recovery are not well understood. A model within the international classification of functioning (ICF) theoretical framework is proposed to systematically identify opportunities and potential barriers to maximize and realize the potentials of functional recovery from the acute to chronic stages and to maintain their function in the chronic stages. Health conditions of individuals, medical and neurological complications can be optimized under the care of specialized physicians. This permits stroke survivors to participate in various therapeutic interventions. Sufficient doses of appropriate interventions at the right time is critical for stroke motor rehabilitation. It is important to highlight that combining interventions is likely to yield better clinical outcomes. Caregivers, including family members, can assist and facilitate targeted therapeutic exercises for these individuals and can help stroke survivors comply with medical plans (medications, visits), and provide emotional support. With health optimization, comprehensive rehabilitation, support from family and caregivers and a commitment to a healthy lifestyle, many stroke survivors can overcome barriers and achieve potentials of maximum recovery and maintain their motor function in chronic stages. This ICF recovery model is likely to provide a guidance through the journey to best achieve stroke recovery potentials.

A comparative genomic analysis of lichen-forming fungi reveals new insights into fungal lifestyles

Lichen-forming fungi are mutualistic symbionts of green algae or cyanobacteria. We report the comparative analysis of six genomes of lichen-forming fungi in classes Eurotiomycetes and Lecanoromycetes to identify genomic information related to their symbiotic lifestyle. The lichen-forming fungi exhibited genome reduction via the loss of dispensable genes encoding plant-cell-wall-degrading enzymes, sugar transporters, and transcription factors. The loss of these genes reflects the symbiotic biology of lichens, such as the absence of pectin in the algal cell wall and obtaining specific sugars from photosynthetic partners. The lichens also gained many lineage- and species-specific genes, including those encoding small secreted proteins. These genes are primarily induced during the early stage of lichen symbiosis, indicating their significant roles in the establishment of lichen symbiosis.Our findings provide comprehensive genomic information for six lichen-forming fungi and novel insights into lichen biology and the evolution of symbiosis.

Capacity for Hand-as-a-Holder Function of the Spastic Combination Hand: A Proof-of-Concept Study

ABSTRACT

We call a hemiparetic hand with paralyzed finger extensors and volitional but spastic flexors a "spastic combination hand." Anecdotally, patients report hand-as-a-holder function with objects like pill bottles, motivating us to formally study spastic combination hand holding capacity using cylinders with different diameters. Nine participants with spastic hemiparesis and spastic combination hand more than 24 mos performed a standardized motor task with 10 cylinder diameters ranging between 1.3 and 9.5 cm and weighing 0.8 and 8.4 oz. Using the unaffected hand, participants attempted to insert a given cylinder into their spastic combination hand, holding it independently for 5 secs. Successful holds were counted during two sessions before and one session after botulinum toxin intervention of Ashworth 3 hand muscles. Findings revealed that a median capacity of six different cylinder diameters was successfully inserted into spastic combination hand at least once before block and a median capacity of 10 cylinders was inserted after block. A mixed-effect statistical model using fixed effects of cylinder diameter and session revealed that total number of successful holds was 43% higher after botulinum. We conclude that this proof-of-concept study does support the idea that spastic combination hand has holding capacity for cylindrical objects of specified diameter and weight and that botulinum neurotoxin offers potential for enlarging spastic combination hand capacity.

Comprehensive Assessment of the Time Course of Biomechanical, Electrophysiological and Neuro-Motor Effects after Botulinum Toxin Injections in Elbow Flexors of Chronic Stroke Survivors with Spastic Hemiplegia: A Cross Sectional Observation Study

Botulinum neurotoxin (BoNT) is commonly used to manage focal spasticity in stroke survivors. This study aimed to a perform comprehensive assessment of the effects of BoNT injection. Twelve stroke subjects with spastic hemiplegia (age: 52.0 ± 10.1 year; 5 females) received 100 units of BoNT to the spastic biceps brachii muscles. Clinical, biomechanical, electrophysiological, and neuro-motor assessments were performed one week (wk) before (pre-injection), 3 weeks (wks) after, and 3 months (mons) after BoNT injection. BoNT injection significantly reduced spasticity, muscle strength, reflex torque, and compound muscle action potential (CMAP) amplitude of spastic elbow flexors (all p < 0.05) during the 3-wks visit, and these values return to the pre-injection level during the 3-mons visit. Furthermore, the degree of reflex torque change was negatively correlated to the amount of non-reflex component of elbow flexor resistance torque. However, voluntary force control and non-reflex resistance torque remained unchanged throughout. Our results revealed parallel changes in clinical, neurophysiological and biomechanical assessment after BoNT injection; BoNT injection would be more effective if hypertonia was mainly mediated by underlying neural mechanisms. BoNT did not affect voluntary force control of spastic muscles.

Assessment, goal setting, and botulinum neurotoxin a therapy in the management of post-stroke spastic movement disorder: updated perspectives on best practice

INTRODUCTION

Post-stroke spastic movement disorder (PS-SMD) appears up to 20% in the first week following stroke and 40% in the chronic phase. It may create major hurdles to overcome in early stroke rehabilitation and as one relevant factor that reduces quality of life to a major degree in the chronic phase.

AREAS COVERED

In this review, we discuss predictors,early identification, clinical assessments, goal setting, and management in multiprofessional team, including Botulinum neurotoxin A (BoNT-A) injection for early and chronic management of PS-SMD.

EXPERT OPINION

The earlier PS-SMD is recognized and managed, the better the outcome will be. The comprehensive management in the subacute or chronic phase of PS-SMD with BoNT-A injections requires detailed assessment, patient-centered goal setting, technical-guided injection, effective dosing of BoNT-A per site, muscle, and session and timed adjunctive treatment, delivered in a multi-professional team approach in conjunction with physical treatment. Evidence-based data showed BoNT-A injections are safe and effective in managing focal, multifocal, segmental PS-SMD and its complications. If indicated, BoNT-A therapy should be accompanied with adjunctive treatment in adequate time slots. BoNT-A could be added to oral, intrathecal, and surgical treatment in severe multisegmental or generalized PS-SMD to reach patient/caregiver's goals, especially in chronic PS-SMD.

Passive Properties of the Wrist and Fingers Following Chronic Hemiparetic Stroke: Interlimb Comparisons in Persons With and Without a Clinical Treatment History That Includes Botulinum Neurotoxin

Background: Neural impairments that follow hemiparetic stroke may negatively affect passive muscle properties, further limiting recovery. However, factors such as hypertonia, spasticity, and botulinum neurotoxin (BoNT), a common clinical intervention, confound our understanding of muscle properties in chronic stroke. Objective: To determine if muscle passive biomechanical properties are different following prolonged, stroke-induced, altered muscle activation and disuse. Methods: Torques about the metacarpophalangeal and wrist joints were measured in different joint postures in both limbs of participants with hemiparetic stroke. First, we evaluated 27 participants with no history of BoNT; hand impairments ranged from mild to severe. Subsequently, seven participants with a history of BoNT injections were evaluated. To mitigate muscle hypertonia, torques were quantified after an extensive stretching protocol and under conditions that encouraged participants to sleep. EMGs were monitored throughout data collection. Results: Among participants who never received BoNT, no significant differences in passive torques between limbs were observed. Among participants who previously received BoNT injections, passive flexion torques about their paretic wrist and finger joints were larger than their non-paretic limb (average interlimb differences = +42.0 ± 7.6SEM Ncm, +26.9 ± 3.9SEM Ncm, respectively), and the range of motion for passive finger extension was significantly smaller (average interlimb difference = -36.3° ± 4.5°SEM; degrees). Conclusion: Our results suggest that neural impairments that follow chronic, hemiparetic stroke do not lead to passive mechanical changes within the wrist and finger muscles. Rather, consistent with animal studies, the data points to potential adverse effects of BoNT on passive muscle properties post-stroke, which warrant further consideration.

A New Definition of Poststroke Spasticity and the Interference of Spasticity With Motor Recovery From Acute to Chronic Stages

The relationship of poststroke spasticity and motor recovery can be confusing. "True" motor recovery refers to return of motor behaviors to prestroke state with the same end-effectors and temporo-spatial pattern. This requires neural recovery and repair, and presumably occurs mainly in the acute and subacute stages. However, according to the International Classification of Functioning, Disability and Health, motor recovery after stroke is also defined as "improvement in performance of functional tasks," i.e., functional recovery, which is mainly mediated by compensatory mechanisms. Therefore, stroke survivors can execute motor tasks in spite of disordered motor control and the presence of spasticity. Spasticity interferes with execution of normal motor behaviors ("true" motor recovery), throughout the evolution of stroke from acute to chronic stages. Spasticity reduction does not affect functional recovery in the acute and subacute stages; however, appropriate management of spasticity could lead to improvement of motor function, that is, functional recovery, during the chronic stage of stroke. We assert that spasticity results from upregulation of medial cortico-reticulo-spinal pathways that are disinhibited due to damage of the motor cortex or corticobulbar pathways. Spasticity emerges as a manifestation of maladaptive plasticity in the early stages of recovery and can persist into the chronic stage. It coexists and shares similar pathophysiological processes with related motor impairments, such as abnormal force control, muscle coactivation and motor synergies, and diffuse interlimb muscle activation. Accordingly, we propose a new definition of spasticity to better account for its pathophysiology and the complex nuances of different definitions of motor recovery.

Combination therapy with repetitive facilitative exercise program and botulinum toxin type A to improve motor function for the upper-limb spastic paresis in chronic stroke: A randomized controlled trial

STUDY DESIGN

An open-label, randomized, controlled, observer-blinded trial.

INTRODUCTION

Repetitive facilitative exercise (RFE) is a movement therapy to recover from hemiparesis after stroke. However, improvement is inhibited by spasticity. Recently, botulinum toxin type A (BoNT-A) injection has been shown to reduce spasticity.

PURPOSE

To examine the combined effect of an RFE program and BoNT-A treatment on upper-limb spastic paresis in chronic stroke.

METHODS

Forty chronic stroke inpatients with upper-limb spastic paresis (Brunnstrom stage ≥III and Modified Ashworth Scale [MAS] score ≥1) were enrolled. Subjects were randomized into 2 groups of 20 each and received 4 weeks of treatment. The intervention group received RFE and BoNT-A injection; the control group underwent RFE only. Assessments were performed at baseline and at study conclusion. The primary outcome was change in Fugl-Meyer Assessment score for the upper extremity (FMA). The Action Research Arm Test (ARAT), active range of motion, Box and Block Test, and MAS were also evaluated.

RESULTS

All participants completed this study. After 4 weeks, the intervention group evidenced a significantly greater increase in FMA score (median 11.0 [range 4-20]) than the control group (median 3.0 [range 0-9]) (P < .01, r = 0.79); as well as improvements in the other measures such as ARAT (median 12.5 [range 4-22] vs 7 [0-13]) (P < .01, r = 0.6), and MAS in the elbow flexors (median -1.5 [range -2 to 0] vs -1 [-2 to 0]) (P < .01, r = 0.45).

DISCUSSION

A high degree of repetitive volitional movement induced by the facilitative technique with concomitant control of spasticity by BoNT-A injection might increase efficiency of motor learning with continuous movement of the affected upper-limb.

CONCLUSIONS

The combination of RFE and BoNT-A for spastic paresis might be more effective than RFE alone to improve upper-limb motor function and to lessen impairment in chronic stroke.

The Use of Botulinum Toxin for Treatment of Spasticity

Spasticity is one component of the upper motor neuron (UMN) syndrome resulting from a multitude of neurologic conditions, such as stroke, brain injury, spinal cord injury, multiple sclerosis, and cerebral palsy. It is clinically recognized as a phenomenon of velocity-dependent increase in resistance, i.e., hypertonia. Recent advances in the pathophysiology of spasticity improve our understanding of mechanisms underlying this complex phenomenon and its relations to other components of UMN syndrome (weakness and disordered motor control), as well as the resultant clinical problems. This theoretical framework provides a foundation to set up treatment goals and to guide goal-oriented clinical assessment and treatment. Among a spectrum of treatment options, botulinum toxin (BoNT) therapy is the preferred treatment for focal spasticity. The evidence is very robust that BoNT therapy effectively reduces spasticity; however, it does not improve voluntary movement. In this chapter, we highlight a few issues on how to achieve the best clinical outcomes of BoNT therapy, such as dosing, dilution, guidance techniques, adjunctive therapies, early treatment, repeated injections, and central effects, as well as the ways to improve motor function in selected subgroups of patients with spasticity. We also discuss the reasons of poor responses to BoNT therapy and when not to use BoNT therapy.