Botulinum toxin assessment, intervention and after-care for lower limb spasticity in children with cerebral palsy: international consensus statement

The effects of botulinum toxin injection frequency on calf muscle growth in young children with spastic cerebral palsy: a 12-month prospective study

PURPOSE

This study was a 12-month prospective investigation of changes in the medial gastrocnemius (MG) muscle morphology in children aged 2-5 years with spastic cerebral palsy (CP) who had received no previous intramuscular injections of botulinum neurotoxin type-A (BoNT-A) and were randomised to receive either single or multiple (three) BoNT-A injections to the gastrocsoleus. MG morphological changes were compared to age-matched typically developing (TD) peers.

METHODS

Thirteen children with spastic CP with a mean age of 45 (15) months and 18 TD children with a mean age of 48 (14) months participated in the study. The principal outcome measures were MG muscle volume, fascicle length, pennation angle and physiological cross-sectional area (PCSA), which were obtained using 2D and 3D ultrasound.

RESULTS

The single and multiple injection frequency groups significantly increased MG muscle volume at 12 months relative to the baseline by 13 and 15 %, respectively. There were no significant differences in the MG muscle volume 28.5 (12.3) versus 30.3 (3.8) ml, fascicle length 48.0 (10.4) versus 44.8 (1.2) mm or PCSA 7.0 (1.2) versus 6.6 (1.7) cm(2) between the single and multiple injection groups, respectively, at 12 months follow-up. The change in MG muscle volume in the single and multiple injection groups was significantly lower than the TD peers by 66 and 60 %, respectively.

INTERPRETATION

In young children with spastic CP, naive to BoNT-A treatment, MG muscle growth over 12 months does not appear to be influenced by intramuscular BoNT-A injection frequency. However, MG muscle growth in the spastic CP groups was significantly lower than the age-matched TD peers. It is unclear whether this is an effect of intramuscular BoNT-A injections or reduced growth rates in children with spastic CP in general. Controlled investigations and longitudinal studies with multiple measurement time points are required in order to determine the influence of BoNT-A treatment on muscle physiological and mechanical growth factors in young children with spastic CP.

A systematic review of interventions for children with cerebral palsy: state of the evidence

AIM

The aim of this study was to describe systematically the best available intervention evidence for children with cerebral palsy (CP).

METHOD

This study was a systematic review of systematic reviews. The following databases were searched: CINAHL, Cochrane Library, DARE, EMBASE, Google Scholar MEDLINE, OTSeeker, PEDro, PsycBITE, PsycINFO, and speechBITE. Two independent reviewers determined whether studies met the inclusion criteria. These were that (1) the study was a systematic review or the next best available; (2) it was a medical/allied health intervention; and (3) that more than 25% of participants were children with CP. Interventions were coded using the Oxford Levels of Evidence; GRADE; Evidence Alert Traffic Light; and the International Classification of Function, Disability and Health.

RESULTS

Overall, 166 articles met the inclusion criteria (74% systematic reviews) across 64 discrete interventions seeking 131 outcomes. Of the outcomes assessed, 16% (21 out of 131) were graded 'do it' (green go); 58% (76 out of 131) 'probably do it' (yellow measure); 20% (26 out of 131) 'probably do not do it' (yellow measure); and 6% (8 out of 131) 'do not do it' (red stop). Green interventions included anticonvulsants, bimanual training, botulinum toxin, bisphosphonates, casting, constraint-induced movement therapy, context-focused therapy, diazepam, fitness training, goal-directed training, hip surveillance, home programmes, occupational therapy after botulinum toxin, pressure care, and selective dorsal rhizotomy. Most (70%) evidence for intervention was lower level (yellow) while 6% was ineffective (red).

INTERPRETATION

Evidence supports 15 green light interventions. All yellow light interventions should be accompanied by a sensitive outcome measure to monitor progress and red light interventions should be discontinued since alternatives exist.

Qualitative development of the 'Questionnaire on Pain caused by Spasticity (QPS),' a pediatric patient-reported outcome for spasticity-related pain in cerebral palsy

PURPOSE

To develop a patient-reported outcome measure for spasticity-related pain in children/adolescents (age 2-17 years) with cerebral palsy (CP), the 'Questionnaire on Pain caused by Spasticity (QPS).'

METHODS

Using a semi-structured interview guide, concept elicitation interviews on spasticity-related pain in upper and lower limbs were conducted in 21 children and caregiver pairs. Data were used to modify initial QPS modules and develop six draft modules, which were subsequently refined and finalized in four consecutive cognitive interview waves (12 children and caregiver pairs).

RESULTS

To accommodate the broad range in the children's communication skills, QPS child/adolescent modules were developed in both interviewer-administered and self-administered formats. With the additional parent modules, three QPS modules were developed for each of the upper and lower limb applications. Information gained from the parent/caregiver modules complements the child/adolescent assessment. Parents report observed signs and frequency of pain in the same situations used to capture the child/adolescent reports of pain severity (e.g., rest, usual daily activities, active mobilization, and physically difficult activities). Participating children/adolescents and parents/caregivers reported that the final QPS instruments were comprehensive, relevant to the child's spasticity-related experience, and easy to understand and complete.

CONCLUSIONS

The QPS is a novel instrument for the assessment of spasticity-related pain in children/adolescents with CP that was developed with direct patient input. Its modules allow the use of this instrument in children/adolescents with varied levels of impairment and communication skills.

Muscle volume alterations in spastic muscles immediately following botulinum toxin type-A treatment in children with cerebral palsy

AIM

With evidence for an atrophic effect of botulinum toxin type A (BoNT-A) documented in typically developing muscles, this study investigated the immediate morphological alterations of muscles in children with cerebral palsy (CP) after BoNT-A treatment.

METHOD

Fifteen children (10 males, five females; age range 5-11y, mean age 8y 5mo, SD 1y 10mo) with spastic diplegic CP [Gross Motor Function Classification System Levels I (n=9) and II (n=6)] receiving BoNT-A injections for spasticity management were included. None of the children was a first-time receiver of BoNT-A. Magnetic resonance imaging and Mimics software assessed muscle volume, timed 2 weeks before and 5 weeks after injection. All participants received BoNT-A bilaterally to the gastrocnemius muscle, and five participants also received BoNT-A bilaterally to the medial hamstring muscles. Functional assessment measures used were the 6-Minute Walk Test (6-MWT), the Timed Up and Go (TUG) test, and hand-held dynamometry.

RESULTS

Whilst total muscle group volume of the injected muscle group remained unchanged, a 4.47% decrease in the injected gastrocnemius muscle volume (p=0.01) and a 3.96% increase in soleus muscle volume (p=0.02) was evident following BoNT-A. There were no statistically significant changes in function after BoNT-A as assessed by the TUG. There was also no statistically significant change in distance covered in the 6-MWT. Muscle strength, as assessed using hand-held dynamometry was also not statistically different after BoNT-A treatment.

INTERPRETATION

Muscle volume decreases were observed in the injected muscle (gastrocnemius), with synergistic muscle hypertrophy that appeared to compensate for this decrement. The 4% to 5% decrease in the volume of BoNT-A injected muscles are not dramatic in comparison to reports in recent animal studies, and are a positive indication for BoNT-A, particularly as it also did not negatively alter function.

Study protocol: precision of a protocol for manual intramuscular needle placement checked by passive stretching and relaxing of the target muscle in the lower extremity during BTX-A treatment in children with spastic cerebral palsy, as verified by means of electrical stimulation

BACKGROUND

Intramuscular injection of botulinum toxin type-A given by manual intramuscular needle placement in the lower extremity under general anaesthesia is an established treatment and standard of care in managing spasticity in children with spastic cerebral palsy. Optimal needle placement is essential. However, reports of injection and verification techniques used in previous studies have been partly incomplete and there are methodological shortcomings. This paper describes a detailed protocol for manual intramuscular needle placement checked by passive stretching and relaxing of the target muscle for each individual muscle injection location in the lower extremity during botulinum toxin type-A treatment under general anaesthesia in children with spastic cerebral palsy. It explains the design of a study to verify this protocol, which consists of an injection technique combined with a needle localizing technique, as by means of electrical stimulation to determine its precision.

METHODS

SETTING

University Medical Centre, Department of Paediatric Rehabilitation Medicine, the Netherlands.

DESIGN

prospective observational study.

PARTICIPANTS

children with spastic cerebral palsy, aged 4 to 18 years, receiving regular botulinum toxin type-A treatment under general anaesthesia to improve their mobility, are recruited from the Department of Paediatric Rehabilitation Medicine at VU University Medical Centre, Amsterdam, the Netherlands.

METHOD

a detailed protocol for manual intramuscular needle placement checked by passive stretching and relaxing of the target muscle has been developed for each individual muscle injection location of the adductor brevis muscle, adductor longus muscle, gracilis muscle, semimembranosus muscle, semitendinosus muscle, biceps femoris muscle, rectus femoris muscle, gastrocnemius lateralis muscle, gastrocnemius medialis muscle and soleus muscle. This protocol will be verified as by means of electrical stimulation.Technical details: 25 mm or 50 mm Stimuplex-needle and a Stimuplex-HNS-12 electrical stimulator will be used.

DISCUSSION

Botulinum toxin type-A injected in the intended muscle is expected to yield the greatest effect in terms of activities. Protocols for manual intramuscular needle placement should be described in detail and verified to determine its precision. Detailed and verified protocols are essential to be able to interpret the results of botulinum toxin type-A treatment studies.

Efficacy of botulinum toxin A in children with cerebral palsy in Gross Motor Function Classification System levels IV and V: a systematic review

AIM

Previous studies have shown the efficacy of botulinum toxin type A (BoNT-A) in the management of ambulant individuals with cerebral palsy (CP). There is little evidence on its use in non-ambulant children with CP. This review aimed to investigate indications and efficacy for BoNT-A use in managing pain, care, and comfort, and improving function in children with CP in Gross Motor Function Classification System (GMFCS) levels IV and V.

METHOD

Electronic databases were searched from the earliest available date to June 2012 using a combination of subject headings and free text. Inclusion criteria consisted of studies with (1) participants aged 18 or under, (2) participants with CP in GMFCS levels IV and V, (3) participants receiving BoNT-A treatment, and (4) studies published in English-language peer-reviewed journals.

RESULTS

The search resulted in a total of 814 studies, of which 19 met the inclusion criteria. Eighteen studies provided level IV or V evidence and one level I evidence according to the American Academy for Cerebral Palsy and Developmental Medicine guidelines for the development of systematic reviews. Most of the studies were of weak to moderate methodological quality.

INTERPRETATION

The evidence that BoNT-A is effective in reducing postoperative pain in children with CP in GMCFS levels IV and V is limited, with only one level I study identified. Remaining indications were general pain reduction, maintaining hip integrity, achieving functional changes, and goal attainment. A high percentage of participants in the studies showed positive changes in these areas. With the poor level of evidence of the included studies, no definite conclusion could be drawn on the indications for BoNT-A use in children with CP in GMCFS levels IV and V. Further investigation by rigorous studies is required.

Longitudinal development of gross motor function among Dutch children and young adults with cerebral palsy: an investigation of motor growth curves

AIM

The aim of this study was to describe patterns for gross motor development by level of severity in a Dutch population of individuals with cerebral palsy (CP).

METHOD

This longitudinal study included 423 individuals (260 males, 163 females) with CP. The mean age at baseline was 9 years 6 months (SD 6y 2mo, range 1-22y). The level of severity of CP among participants, according to the Gross Motor Function Classification System (GMFCS), was 50% level I, 13% level II, 14% level III, 13% level IV, and 10% level V. Participants had been assessed up to four times with the Gross Motor Function Measure (GMFM-66) at 1- or 2-year intervals between 2002 and 2009. Data were analysed using non-linear mixed effects modelling. For each GMFCS level, patterns were created by contrasting a stable limit model (SLM) with a peak and decline model (PDM), followed by estimating limits and rates of gross motor development.

RESULTS

The SLM showed a better fit for all GMFCS levels than the PDM. Within the SLM, significant differences between GMFCS levels were found for both the limits (higher values for lower GMFCS levels) and the rates (higher values for GMFCS levels I-II vs level IV and for GMFCS levels I-IV vs level V) of gross motor development.

INTERPRETATION

The results validate the existence of five distinct patterns for gross motor development by level of severity of CP.

Safety of botulinum toxin A in children and adolescents with cerebral palsy in a pragmatic setting

This retrospective study aimed to examine the safety of botulinum toxin A (BoNT-A) treatment in a paediatric multidisciplinary cerebral palsy clinic. In a sample of 454 patients who had 1515 BoNT-A sessions, data on adverse events were available in 356 patients and 1382 sessions; 51 non-fatal adverse events were reported (3.3% of the total injections number, 8.7% of the patients). On five occasions, the adverse reactions observed in GMFCS V children were attributed to the sedation used (rectal midazolam plus pethidine; buccal midazolam) and resulted in prolongation of hospitalization. Of the reactions attributed to the toxin, 23 involved an excessive reduction of the muscle tone either of the injected limb(s) or generalized; others included local pain, restlessness, lethargy with pallor, disturbance in swallowing and speech production, seizures, strabismus, excessive sweating, constipation, vomiting, a flu-like syndrome and emerging hypertonus in adjacent muscles. Their incidence was associated with GMFCS level and with the presence of epilepsy (Odds ratio (OR) = 2.74 - p = 0.016 and OR = 2.35 - p = 0.046, respectively) but not with BoNT-A dose (either total or per kilogram). In conclusion, treatment with BoNT-A was safe; adverse reactions were mostly mild even for severely affected patients. Their appearance did not necessitate major changes in our practice.

Are results after single-event multilevel surgery in cerebral palsy durable?

BACKGROUND

Gait and function may deteriorate with time in patients with spastic diplegia. Single-event multilevel surgery often is performed to either improve gait or prevent deterioration. However it is unclear whether the presumed gait improvements are durable.

QUESTIONS/PURPOSES

We therefore determined whether (1) single-event multilevel surgery improves gait in patients with spastic diplegia and (2) whether the improved function is durable.

METHODS

We retrospectively reviewed the data of 14 patients with spastic diplegia. At the time of surgery, one patient had gross motor Level I function, 10 patients had Level II function, and three patients had Level III function. There were four females and 10 males with a mean age of 13 years (range, 7-18 years). The mean number of orthopaedic procedures per single-event multilevel surgery session was 7.4 ± 2.8 (median, 6.5; range, 4-15). We used instrumented gait analysis to determine joint ROM, movement analysis profiles, and the gait profile score. The minimum followup was 1 year (mean, 2 years; range, 1-3 years).

RESULTS

At last followup, movement analysis profiles for knee flexion, for ankle dorsiflexion, and for foot progression improved as did the gait profile score. Additional surgery after the index procedure was performed in nine of the 14 patients because of relapse of the original or new gait problems. Major surgical adverse events occurred in one of the 14 patients.

CONCLUSIONS

Severe gait dysfunction in patients with spastic diplegia can be improved short-term in one operative session by single-event multilevel surgery, but to preserve the early improvements many patients require additional surgery. It is unknown whether the improvements will last for decades.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Abo-, inco-, ona-, and rima-botulinum toxins in clinical therapy: a primer

Botulinum neurotoxin (BoNT) is an acetylcholine release inhibitor and a neuromuscular-blocking agent used for the treatment of a variety of medical and cosmetic indications. Currently, in the United States, there are four BoNT formulations licensed for use: abobotulinumtoxinA, incobotulinumtoxinA, onabotulinumtoxinA, and rimabotulinumtoxinB. These revised name designations were established to reinforce the understanding that each BoNT product has an individual potency and is not interchangeable with any other BoNT product. The therapeutic use of BoNTs is expanding and new formulations are on the horizon. This article is a primer that describes distinctions among currently available, licensed BoNT formulations. Toxin pharmacology, product characteristics, storage, handling, preparation, and dosages will be reviewed. In addition, issues related to dose equivalency ratios, immunogenicity, potency, and toxin spread will be discussed. Therapeutic indications and safety are discussed briefly. Knowledge of the available and licensed BoNT formulations and the ability to make distinctions in toxin pharmacology, product characteristics, and indications are vital for product selection, preparation, drug information, avoidance of drug errors, quality assurance, and patient safety.

Botulinum toxin-A use in paediatric hypertonia: Canadian practice patterns

BACKGROUND

This study aims to assess current practices of Canadian physicians providing botulinum toxin-A (BoNT-A) treatments for children with hypertonia and to contrast these with international "best practice" recommendations, in order to identify practice variability and opportunities for knowledge translation.

METHODS

Thirteen Canadian physicians assembled to develop and analyze results of a cross-sectional electronic survey, sent to 50 physicians across Canada.

RESULTS

Seventy-eight percent (39/50) of physicians completed the survey. The most frequently identified assessment tools were Gross Motor Function Classification System, Modified Tardieu Scale and neurological examination. Goal-setting tools were infrequently utilized. Common indications for BoNT-A injections and the muscles injected were identified. Significant variability was identified in using BoNT-A for hip displacement associated with hypertonia. The most frequent adverse event reported was localized weakness; 54% reporting this "occasionally" and 15% "frequently". Generalized weakness, fatigue, ptosis, diplopia, dysphagia, aspiration, respiratory distress, dysphonia and urinary incontinence were reported rarely or never. For dosage, 52% identified 16 Units/kg body weight of Botox® as maximum. A majority (64%) reported a maximum 400 Units for injection at one time. For localization, electrical stimulation and ultrasound were used infrequently (38% and 19% respectively). Distraction was the most frequently used pain-management technique (64%).

CONCLUSIONS

Canadian physicians generally adhere to international best practices when using BoNT-A to treat paediatric hypertonia. Two knowledge-translation opportunities were identified: use of individualized goal setting prior to BoNT-A and enhancing localization techniques. Physicians reported a good safety profile of BoNT-A in children.

Botulinum neurotoxin treatment in children with cerebral palsy: a population-based study in Norway

BACKGROUND/AIM

To study proportions and characteristics of children treated and un-treated with Botulinum neurotoxin (BoNT) in a population-based cohort of children with cerebral palsy (CP).

METHODS

All children with CP born during 1999-2003, recorded in the Norwegian CP Register were included (N=411). Gross motor function was assessed using the gross motor classification system (GMFCS).

RESULTS

Sixty-eight percent of children with bilateral spastic, 63% with unilateral spastic and 41% with dyskinetic CP had received BoNT. The percentage of children treated increased from 62% at GMFCS level I to 88% at level IV, but was only 38% among children at level V. A similar trend was seen for fine motor function. Ninety-four percent of the children received BoNT in their lower limbs. Children without significant cognitive impairment were more often treated than children with such impairment (OR: 2.61; 95% CI: 1.49-4.58).

INTERPRETATION

In this first population-based study, approximately 2/3 of all children with spastic CP were treated with BoNT. The results suggest preference for treatment of children with potential for functional improvement, while treatment to relieve pain and facilitate care, and of children with cognitive impairment appeared to be less common. Whether the latter groups are treated appropriately requires further studies.

Combining strength training and botulinum neurotoxin intervention in children with cerebral palsy: the impact on muscle morphology and strength

PURPOSE

Investigate the combination effects of strength training and Botulinum Toxin Type-A (BoNT-A) on muscle strength and morphology in children with Cerebral Palsy (CP).

METHODS

Fifteen children receiving BoNT-A, classified as Spastic Diplegic CP, GMFCS I-II, and aged 5-12 years were recruited for this study. Randomly allocated to 10 weeks of strength training either before or after BoNT-A, children were assessed over 6 months. Eight of the 15 children also completed a control period. The Modified Ashworth Scale measured spasticity. The Goal Attainment Scale (GAS) assessed achievement of functional goals. Magnetic Resonance Imaging assessed muscle volume (MV). Instrumented dynamometry assessed strength.

RESULTS

Spasticity was significantly reduced following BoNT-A injection (p = 0.033). Children made significant isokinetic strength gains (mean p = 0.022, ES = 0.57) in the intervention period compared to the control period (mean p = 0.15, ES = 0.56). Irrespective of timing, significant strength improvements were seen immediately (10 weeks) and over 6 months for all children. This was also the case for improvements in the GAS (immediately: mean p = 0.007, ES = 4.17, 6 months: mean p = 0.029, ES = 0.99), and improvements in MV in all assessed muscles.

CONCLUSION

The simultaneous use of BoNT-A and strength training was successful in spasticity reduction, improving strength and achieving functional goals, over and above treatment with BoNT-A alone. Muscles targeted for BoNT-A injection should be included in strength training.

IMPLICATIONS FOR REHABILITATION

Cerebral Palsy• Botulinum toxin type-A (BoNT-A) and strength training are available interventions that, on their own have found success in managing spasticity and muscle weakness (both significant motor impairments), respectively in children with Cerebral Palsy (CP). • This study has demonstrated that the concurrent treatment of BoNT-A and strength training can achieve positive outcomes in terms of strength, spasticity and for the achievement of set functional goals. • The results of this study show that the improved muscle strength can be associated with hypertrophy, which could indicate the potential role of strength training in altering the rate of muscle growth, in an aim to improve the failure of muscle growth associated with CP. • Home based strength training, based on a child's individual goals is shown to be successful in improving strength and goal attainment for children with CP.

Evaluation of the effects of botulinum toxin A injections when used to improve ease of care and comfort in children with cerebral palsy whom are non-ambulant: a double blind randomized controlled trial

Background

Children with cerebral palsy (CP) whom are non-ambulant are at risk of reduced quality of life and poor health status. Severe spasticity leads to discomfort and pain. Carer burden for families is significant. This study aims to determine whether intramuscular injections of botulinum toxin A (BoNT-A) combined with a regime of standard therapy has a positive effect on care and comfort for children with CP whom are non-ambulant (GMFCS IV/V), compared with standard therapy alone (cycle I), and whether repeated injections with the same regime of adjunctive therapy results in greater benefits compared with a single injecting episode (cycle II). The regime of therapy will include serial casting, splinting and/or provision of orthoses, as indicated, combined with four sessions of goal directed occupational therapy or physiotherapy.

Method/design

This study is a double blind randomized controlled trial. Forty participants will be recruited. In cycle I, participants will be randomized to either a treatment group who will receive BoNT-A injections into selected upper and/or lower limb muscles, or a control group who will undergo sham injections. Both groups will receive occupational therapy and /or physiotherapy following injections. Groups will be assessed at baseline then compared at 4 and 16 weeks following injections or sham control. Parents, treating clinicians and assessors will be masked to group allocation. In cycle II, all participants will undergo intramuscular BoNT-A injections to selected upper and/or lower limb muscles, followed by therapy.

The primary outcome measure will be change in parent ratings in identified areas of concern for their child’s care and comfort, using the Canadian Occupational Performance Measure (COPM). Secondary measures will include the Care and Comfort Hypertonicity Scale (ease of care), the Cerebral Palsy Quality of Life Questionnaire (CP QoL–Child) (quality of life), the Caregiver Priorities and Child Health Index of Life with Disabilities Questionnaire (CPCHILD©) (health status) and the Paediatric Pain Profile (PPP) (pain). Adverse events will be carefully monitored by a clinician masked to group allocation.

Discussion

This paper outlines the theoretical basis, study hypotheses and outcome measures for a trial of BoNT-A injections and therapy for children with non-ambulant CP.

Trial registration

Australia New Zealand Clinical Trials Registry:N12609000360213

Single-event multilevel surgery for children with cerebral palsy: a systematic review

AIM

To conduct a systematic review of single-event multilevel surgery (SEMLS) for children with cerebral palsy, with the aim of evaluating the quality of the evidence and developing recommendations for future research.

METHOD

The systematic review was conducted using standard search and extraction methods in Medline, EMBASE, CINAHL, and Cochrane electronic databases. For the purposes of this review, SEMLS was defined as two or more soft-tissue or bony surgical procedures at two or more anatomical levels during one operative procedure, requiring only one hospital admission and one period of rehabilitation. Studies were included if: (1) the primary focus was to examine the effect of SEMLS in children with cerebral palsy; (2) the results focused on multiple anatomic levels and reported findings of one or more World Health Organization International Classification of Functioning, Disability and Health (ICF) domains. Studies that focused on a single intervention or level, or on the utility of a specific outcome measure were excluded. Study quality was appraised with the Methodological Index for Non-Randomized Studies (MINORS) and the Oxford Centre for Evidence-Based Medicine scale. The review also examined the reporting of surgery, adverse events, and rehabilitation.

RESULTS

Thirty-one studies fulfilled the criteria for inclusion, over the period 1985 to October 2010. The MINORS score for these studies varied from 4 to 19, with marked variation in the quality of reporting. Study quality has improved over recent years. Valid measures of gait and function have been introduced and several of the most recent studies have addressed multiple dimensions of the ICF. A statistical synthesis of the outcome data was not conducted, although a trend towards favourable outcomes in gait was evident. Caution is advised with interpretation owing to the variable study quality. Uncontrolled studies may have resulted in an overestimation of treatment efficacy.

INTERPRETATION

The design and reporting of studies of SEMLS are improving with the development of multidisciplinary teamwork and frameworks such as the ICF. However, the evidence base is limited by the lack of randomized clinical trials, especially when compared with other surgical interventions such as selective dorsal rhizotomy.