Explore Online Education
Apply for Membership
Access CNS Guidelines on the CNS+ App
Visit the D.C. Press Room
2022 CNS Annual Meeting
download pdf Neurosurgery, 2016
Congress of Neurological Surgeons (CNS) and the AANS/CNS Joint Section on Pediatric Neurosurgery
Joint Guidelines Committee of the American Association of Neurological Surgeons (AANS) and the Congress of Neurological Surgeons (CNS) and American Academy of Pediatrics (AAP)
Mandeep S. Tamber, MD, PhD,1 Dimitrios Nikas, MD,2 Alexandra Beier, DO,3 Lissa C. Baird, MD4, David F. Bauer, MD5, Susan Durham, MD6, Paul Klimo Jr, MD7, Alexander Y. Lin, MD,8 Catherine Mazzola, MD9, Catherine McClung-Smith, MD10, Laura Mitchell, MA11, Rachana Tyagi, MD12, Ann Marie Flannery, MD13
Mandeep S. Tamber, MD, PhDDepartment of Pediatric Neurological Surgery Children’s Hospital of Pittsburgh of UPMCPittsburgh, PennsylvaniaE-mail: email@example.comNo part of this article has been published or submitted for publication elsewhere.
This clinical systematic review and evidence-based guideline was developed by a physician volunteer task force as an educational tool that reflects the current state of knowledge at the time of completion. The presentations are designed to provide an accurate review of the subject matter covered. This guideline is disseminated with the understanding that the recommendations by the authors and consultants who have collaborated in its development are not meant to replace the individualized care and treatment advice from a patient's physician(s). If medical advice or assistance is required, the services of a physician should be sought. The recommendations contained in this guideline may not be suitable for use in all circumstances. The choice to implement any particular recommendation contained in this guideline must be made by a managing physician in light of the situation in each particular patient and on the basis of existing resources.
Background: No evidence-based guidelines exist on the role of cranial molding orthosis (helmet) therapy for patients with positional plagiocephaly.Objective: To address the clinical question: “Does helmet therapy provide effective treatment for positional plagiocephaly?” and to make treatment recommendations based on the available evidence.Methods: The US National Library of Medicine Medline database and the Cochrane Library were queried by using MeSH headings and key words relevant to the objective of this systematic review. Abstracts were reviewed, after which studies meeting the inclusion criteria were selected and graded according to their quality of evidence (Classes I-III). Evidentiary tables were constructed that summarized pertinent study results, and, based on the quality of the literature, recommendations were made (Levels I-III).Results: Fifteen articles met criteria for inclusion into the evidence tables. There was 1 prospective randomized controlled trial (Class II), 5 prospective comparative studies (Class II), and 9 retrospective comparative studies (Class II).Conclusion: There is a fairly substantive body of non-randomized evidence that demonstrates more significant and faster improvement of cranial shape in infants with positional plagiocephaly treated with a helmet as compared to conservative therapy, especially if the deformity is severe, and provided that helmet therapy is applied during the appropriate period of infancy. Specific criteria regarding the measurement and quantification of deformity and the most appropriate time window in infancy for treatment of positional plagiocephaly with a helmet remain elusive. In general, infants with a more severe presenting deformity and infants who are helmeted early in infancy tend to have more significant correction (and even normalization) of head shape.Short Title: Guideline on the Role of Cranial Molding Orthosis Therapy for Patients with Positional PlagiocephalyKey Words: cranial molding orthosis, infants, plagiocephaly, positional plagiocephaly
1. Helmet therapy is recommended for infants with persistent moderate to severe plagiocephaly after a course of conservative treatment (repositioning and/or physical therapy).
Strength of Recommendation: Level II—uncertain clinical certainty
2. Helmet therapy is recommended for infants with moderate to severe plagiocephaly presenting at an advanced age.
The incidence of non-synostotic positional calvarial deformity, heretofore referred to as positional plagiocephaly, has seen a dramatic rise ever since the 1992 American Academy of Pediatrics (AAP) recommendation that infants be placed on their back to sleep in order to reduce the risk of sudden infant death syndrome.1 Pediatricians are increasingly referring patients with skull asymmetry to outpatient neurosurgical and craniofacial clinics for evaluation and management.Plagiocephaly is a general term used for patients with cranial asymmetry that may arise in infants subject to intrauterine constraint or extrauterine compression and is perpetuated by postnatal sleeping position and concurrent torticollis or other neuromuscular conditions. The most common form of plagiocephaly is referred to as posterior plagiocephaly, in which there is unilateral flattening of the parieto-occipital region resulting in a compensatory anterior shift of the ipsilateral ear and bossing or bulging of the ipsilateral forehead. Brachycephaly, in which there is symmetrical flattening of the entire occipital region, resulting in a foreshortened antero-posterior dimension of the skull with or without an elevation of the skull vertex, is the less common variant.There is no standard treatment for positional plagiocephaly. Depending on clinical factors such as age and the severity of the presenting deformity, options for management may include observation, active repositioning therapy, physical therapy, cranial molding orthosis (helmet) therapy, surgery, or various combinations thereof. Surgery is rarely considered as a viable treatment alternative; the principal management decisions revolve around the issue of whether conservative measures (observation, repositioning, physical therapy) should be tried, how long to persist with conservative treatment prior to instituting helmet therapy, and the criteria that need to be met in order to proceed to helmet therapy.Helmets are generally custom-fitted cranial orthoses that are designed to be worn 23 hours a day for several months, until the child has achieved satisfactory cosmetic correction or they have outgrown their helmet. Frequent regular assessments are required to assess for cranial growth and the presence of any adverse effects, as well as to make any necessary adjustments to the device to allow for continual growth and change in shape of the calvarium. These orthoses may be passive (allow room for growth in the flattened areas while minimal pressure is applied to the areas with bossing) or active (compression is applied to the bossed areas, possibly resulting in a more rapid deformity correction).Despite numerous attempts at synthesis of the data regarding the effectiveness of helmet therapy in the treatment of positional plagiocephaly,2-7 controversy remains. The purpose of this systematic review is to address the clinical question: Does helmet therapy provide effective treatment for positional plagiocephaly?
The Congress of Neurological Surgeons (CNS) and the Section on Pediatric Neurosurgery initiated a systematic review of the literature relevant to the management of positional plagiocephaly. Additional details of the systematic review are provided below and within the introduction and methodology chapter of the guideline.Potential Conflicts of InterestAll guideline task force members were required to disclose all potential conflicts of interest (COIs) prior to beginning work on the guideline, using the COI disclosure form of the Joint Guidelines Committee of the American Association of Neurological Surgeons (AANS) and the CNS. The CNS Guidelines Committee and guideline task force chair reviewed any disclosures and either approved or disapproved the nomination and participation on the task force. The CNS Guidelines Committee and guideline task force chair may approve nominations of task force members with possible conflicts and restrict the writing, reviewing, and/or voting privileges of that person to topics that are unrelated to the possible COIs.Literature SearchThe task force collaborated with medical librarians to search for articles published in the US National Library of Medicine (PubMed/MEDLINE) database and the Cochrane Library for the period January 1966 through October 2014, using the MeSH subject headings and PubMed search strategies provided in Appendix A. Manual searches of bibliographies were also conducted.Article Inclusion/Exclusion CriteriaThe task force reviewed the titles and abstracts to identify studies that would address the effectiveness of cranial remolding orthosis (helmet) therapy compared to other treatments for positional plagiocephaly (including no treatment). Studies in which there was no comparison group (uncontrolled) were excluded, as without a control or reference group, it is impossible to judge whether or not an intervention is effective. Studies that employed survey methodology were also excluded. Articles that met these criteria were independently reviewed by 3 of the authors, and appropriate studies were selected for inclusion into the evidence tables for this recommendation.Search ResultsThe Medline plagiocephaly search (search #1) returned 88 abstracts, while the Medline brachycephaly (search #2) and Cochrane plagiocephaly/brachycephaly (search #3) searches returned 22 and 19 abstracts, respectively (Figure 1). After removal of duplicate results, 102 abstracts were screened in total. After review of the abstracts, 41 full-text articles were reviewed (38 articles were selected after reviewing the abstracts, and an additional 3 articles were obtained after examination of the bibliographies of the 38 initially selected articles). Of the 41 full-text articles reviewed, 26 were rejected for the following reasons: no comparison group,8-28 use of a non-helmet orthosis,29,30 comparison group did not have plagiocephaly,31,32 and study used survey methodology.33 Therefore, 15 articles satisfied our criteria for inclusion into the evidence tables.34-48
Of the 15 articles selected for inclusion into the evidence tables, there was one prospective randomized controlled trial (Class II), 5 prospective comparative studies (Class II), and 9 retrospective comparative studies (Class II). In general, the methodological quality of the studies was moderate; most suffered from similar design issues that affect the quality of data, and ultimately the strength of the inferences and recommendations that can be made.Despite the size of the underlying population presenting for management of positional plagiocephaly, most studies were only able to enroll relatively small numbers of infants in each treatment arm, which results in suboptimal statistical power. Moreover, convenience (non-randomized) sampling resulted in treatment groups that often had significant covariate imbalance with respect to important variables that relate to treatment outcome (such as patient age at initiation of treatment and severity of presenting deformity) as a result of treatment assignment being performed by physician or parent preference. This selection bias was pervasive in the non-randomized studies, and often resulted in a treatment effect against helmet therapy, as infants in the helmet therapy group tended to be older and tended to have more severe deformity than the comparison group.Confounding of the principal treatment effect secondary to contamination of intervention(s) between treatment groups also led to difficulties in interpreting the data. Most often, this contamination took the form of infants entering the helmet group who previously underwent treatment with conservative therapy with less than satisfactory results. Bias as a result of contamination was present in several studies,34,36,41 and, once again, would be expected to bias study results against helmet therapy, because of the older age and likely more severe deformity present at the time of initiating helmet therapy in the group of infants who crossed over.There were also significant issues with respect to outcome ascertainment. Assessment of treatment outcome, whether it be change in 2- or 3-dimensional anthropometric measurements or subjective physician or parent evaluation, was done in a non-blinded fashion in all studies apart from the sole randomized controlled trial.37 The absence of standardized criteria for the assessment of cranial asymmetry, both pre- and post-treatment, was clearly evident when one considers the heterogeneity of outcome measures used in the various studies. Moreover, the measurements chosen for analysis in any given study were not previously evaluated for their reliability and validity, making measurement bias a tangible concern when evaluating this body of literature. One could also be justified in questioning whether an observed statistically significant improvement in cranial asymmetry on the order of several millimeters has any clinical significance. Outcomes were often measured at different time points in the treatment (helmet) and comparison groups (usually when the infants were judged to have achieved an “acceptable cosmetic result”), further adding to the difficulty in determining the comparative effectiveness of different methods of treating positional plagiocephaly.Despite these limitations, in aggregate, the body of evidence summarized in the evidence tables does allow for some general recommendations to be made. The significant heterogeneity between studies with respect to critical elements of design, such as the study population, the nature of the intervention, and the assessment of treatment outcomes precludes, for the most part, any meaningful quantitative synthesis of the data; what follows is a largely qualitative review of the evidence relevant to this recommendation.Helmet Therapy vs Conservative TherapyA recently published randomized controlled trial37 provided Class II evidence related to this recommendation (Table 1). Eighty-four infants aged 5-6 months were prospectively randomized to custom helmet therapy (n = 42) or to the “natural course of the condition” (n = 42). Importantly, all patients received physical therapy prior to randomization. The mean duration of therapy was 4 months. Outcomes were assessed at 2 years of age in a blinded fashion. Despite what appeared to have been an adequate block randomization schema, infants in the natural course group had more severe deformity, and infants in the helmet group had more brachycephaly. The overall conclusion of the trial was that helmet therapy has no added value in the treatment of moderate-severe positional plagiocephaly. This conclusion was based on the observations that no difference was seen in the primary outcome between the 2 groups, both on an intention-to-treat and per-protocol analysis; no significant differences between treatment groups were observed with respect to the secondary outcomes, including parental satisfaction; and that all parents reported one or more side effects of helmet therapy.The conclusion of this trial stands in stark contrast to the remainder of the evidence uncovered during the course of this systematic review. The authors argue that their study has merit because it is one of the few that examined longer-term outcomes, focused on clinically meaningful differences in outcome measures rather than mere statistical significance, and because it comprehensively catalogued adverse effects related to helmet therapy.The study does have some notable criticisms. The exclusion of infants with very severe deformity and those with neuromuscular issues, who are typical helmet candidates, limits the external validity of the results. Moreover, the study documented a very low participation rate, with only 21% of eligible participants being recruited into the trial. Although there was adequate power overall, the relatively small size of the treatment groups provides no insight into possible subgroup effects. There was no objective measure of compliance with helmet therapy, making it within the realm of possibility that the lack of efficacy of helmet therapy was because of suboptimal use of the device. Full normalization of head shape was observed in only 26% of helmet therapy and 23% of natural course patients, a finding that once again alludes to possible suboptimal treatment of the presenting problem.The Class II retrospective and prospective comparative studies summarized in Table 1 provide evidence in support of the notion that helmet therapy results in better outcomes than conservative therapy in infants with positional plagiocephaly. However, because of methodological deficiencies in the design of these studies and the relatively short duration of follow-up, the data are unable to prove that helmet therapy is, in fact, superior to alternative treatment modalities or the natural history of the condition with respect to improving an infant’s head shape.Several of these studies provide evidence that helmet therapy can result in equivalent or superior treatment outcomes compared to repositioning in a fraction of the overall treatment time. The study by Loveday et al34 demonstrated similar changes in cranial vault asymmetry index (CVAI) in both the helmet and repositioning groups at the end of therapy, but the change was seen with a shorter duration of treatment in the helmet group. Since both groups commenced treatment at the same mean age, this result implies that helmet therapy results in a faster rate of improvement in head asymmetry. The fact that the mean age in the helmet group was 37 weeks, coupled with the fact that asymmetry was slightly worse in the helmet group at the initiation of therapy, may explain the relatively poor helmet results.A retrospective comparison of 35 patients with positional plagiocephaly treated with active repositioning vs 35 patients treated with custom helmets published by Lipira et al40 also demonstrated a statistically significant greater reduction in measures of asymmetry in the helmet group vs the repositioning group, specifically in the posterior head region. The mean duration of therapy was 5.2 months in the repositioning group vs 3.1 months in the helmet group.In infants who were similar with respect to age at the initiation of treatment and the duration of treatment, Mulliken et al42 reported significantly improved measures of asymmetry in those who were helmeted as compared to those who were treated with repositioning exercises. A high rate of loss to follow-up, as evidenced by the fact that pre- and post-treatment measures were available for only 17/63 infants in the repositioning group and 36/51 infants in the helmet group, limits the strength of these data. They recommended helmet treatment in infants less than 1 year of age, although no relationship was observed between the age at helmet initiation and the ultimate degree of correction.Vles et al46 studied 105 patients with positional plagiocephaly, 39 of whom were treated with repositioning and 66 who received helmet therapy. No anthropometric measures were used; rather, a subjective unvalidated deformity rating scale, scored by the infant’s caregiver, was used. Although the pre-treatment severity was significantly worse in the helmet group, likely because the choice of treatment was made by the parents (selection bias), the final outcome was better in the infants who received a helmet. Moreover, treatment time with the helmet was only one-fifth as long as the repositioning treatment. The most improvement was seen in those infants with the most severe presenting deformity. No correlation was observed between the age at helmet initiation and the degree of correction.A recent study by Kim et al35 also alludes to a greater effect of helmet therapy vs repositioning therapy in infants with more severe deformity. Likewise, the study by Plank et al,39 which examined 224 infants with moderate-severe positional plagiocephaly, the overwhelming majority of whom were treated with helmet therapy, demonstrated improved treatment outcomes in the helmet (n = 207) vs repositioning (n = 17) groups. This latter study in particular is suggestive of the notion that, in the subgroup of infants presenting with moderate-severe positional plagiocephaly, helmet therapy should be preferred over repositioning therapy.Two similar retrospective studies by Graham, one in infants with brachycephaly38 and the other in infants presenting with plagiocephaly,36 also suggest that infants treated with helmet therapy had improved outcomes compared to those treated with repositioning therapy, despite the fact that in both studies, the initial deformity was more severe in the helmet group and the infants were older in the helmet group (patients in the helmet group did require a longer duration of treatment). In addition, subgroup analyses showed that early helmeting (<8 months) resulted in better outcomes compared to late helmeting (>8 months). The effect of age on helmet treatment outcomes has been validated in 2 recent prospective studies (Table 2).Two studies, one by Clarren43 and the other by Wilbrand,45 examined the effect of helmet therapy on infants with positional plagiocephaly when compared to physical therapy. Whereas the study by Clarren was able to show improved outcomes in infants treated with a helmet based on a subjective outcome measure, a more formal outcome assessment by Wilbrand, using 3D photogrammetry, demonstrated improvement in asymmetry in helmeted infants, but at the end of treatment, no significant difference in the degree of asymmetry between helmeted and unhelmeted infants was observed.A very recent prospective, non-randomized longitudinal study by Kluba44 examined treatment outcomes in 62 patients with plagiocephaly treated with a custom helmet vs 66 patients treated without a helmet. Patients in both groups were asked to continue with any previously instituted therapy (physical therapy, repositioning). However, details of previously initiated (and ongoing) non-helmet therapy were not recorded and may have differed between groups, thereby confounding the primary result of this study. In both groups, a statistically significant decrease in asymmetry was observed. Although children in the helmet group had more severe deformity at baseline, they showed significantly better improvement than the comparison group when the outcome was adjusted for the degree of initial deformity. In both groups, a weak positive correlation was observed between the extent of initial asymmetry and the extent of improvement, a finding that was also suggested by the work of Kim et al.35
RecommendationHelmet therapy is recommended for infants with persistent moderate to severe plagiocephaly after a course of conservative treatment (repositioning and/or physical therapy).Strength of Recommendation: Level II – uncertain clinical certaintyAge at Initiation of Helmet Therapy and OutcomeTwo prospective studies serve to clarify the relationship between age at initiation of helmet therapy and treatment outcomes that was suggested by some of the methodologically weaker retrospective studies.36,38 Both studies examined patients with “significant” cranial asymmetry who appear not to have undergone any prior conservative treatment. The results of both studies were similar, although the recommended age cut-off between those infants who were expected to achieve a satisfactory treatment response and those expected to have a suboptimal response was slightly different between the 2 studies (Table 2).Seruya et al prospectively assessed the results of custom helmet therapy in 346 patients in 7 pre-defined age groups ranging from <20 weeks to >40 weeks.47 The degree of calvarial asymmetry was similar in all groups at the beginning of therapy. They found that all patients achieved normal calvarial symmetry at the end of helmet therapy, except those helmeted at >36 weeks of age. Improvement was seen even in infants aged >12 months at time of helmet therapy initiation. Duration of helmet therapy was positively correlated with age.Similarly, Kluba et al48 undertook a prospective comparison of the results of helmet therapy in 24 infants with plagiocephaly helmeted at age <6 months vs 38 helmeted at age >6 months. The degree of asymmetry was similar in both groups at the commencement of therapy, and a significant reduction in asymmetry was seen in both groups. Younger patients (<6 months) showed a greater decrease in asymmetry and attained values considered “normal.” Children starting therapy later (>6 months) showed significantly less absolute improvement and did not attain values considered “normal.” Duration of therapy was statistically significantly shorter in the younger patients.Although the data were not robust enough to definitively determine the optimal time window in infancy for treatment of positional plagiocephaly with helmet therapy, it does appear that the earlier an infant is placed in a helmet, the better the treatment outcome. That being said, it must be remembered that young infants with positional plagiocephaly may see an improvement in cranial symmetry with conservative therapy or simply observation.RecommendationHelmet therapy is recommended for infants with moderate to severe plagiocephaly presenting at an advanced age.Strength of Recommendation: Level II – uncertain clinical certainty
There is a fairly substantive body of non-randomized evidence that demonstrates more significant and faster improvement of cranial asymmetry in infants with positional plagiocephaly treated with a helmet as compared to conservative therapy, especially if the asymmetry is severe, and provided that helmet therapy is applied during the appropriate period of infancy. As outlined above, specific criteria regarding the measurement and quantification of deformity and the most appropriate time window in infancy for treatment of positional plagiocephaly with a helmet remain elusive. In general, infants with a more severe presenting deformity and infants who are helmeted early in infancy tend to have better correction (and even normalization) of head shape.The only randomized study pertaining to this recommendation provided data that showed no benefit of helmet therapy in the treatment of positional plagiocephaly in infants. Issues with the design and execution of this study may explain why the randomized data conflicts with the majority of the non-randomized evidence.When judging the totality of the evidence, it appears that currently accepted management of positional plagiocephaly in infants—using conservative therapy (repositioning and physical therapy) for the treatment of mild/moderate deformity in younger infants and reserving helmet therapy for more severe deformity, especially in those older infants who have failed to see improvement with conservative measures—can be justified by the data. Evidence in favor of helmet use must be tempered by the lack of data regarding the extent of natural improvement of positional plagiocephaly, the long-term effects of helmet therapy (and of “untreated” plagiocephaly), and the costs associated with helmet therapy.AcknowledgmentsThe authors acknowledge the Congress of Neurological Surgeons Guidelines Committee for their contributions throughout the development of the guideline, the American Association of Neurological Surgeons/Congress of Neurological Surgeons Joint Guidelines Committee for their review, comments, and suggestions throughout peer review, as well as Pamela Shaw, MSLIS, MS, and Mary Bodach, MLIS, for their assistance with the literature searches. Throughout the review process, the reviewers and authors were blinded from one another. At this time, the authors would like to acknowledge the following individual peer reviewers for their contributions: Sepideh Amin-Hanjani, MD; Maya Babu, MD; Kimon Bekelis, MD; Faiz Ahmad, MD; Daniel Resnick, MD; Patricia Raksin, MD; Jeffrey Olson, MD; Krystal Tomei, MD.DisclosuresThese evidence-based clinical practice guidelines were funded exclusively by the Congress of Neurological Surgeons and the Section on Pediatric Neurosurgery of the Congress of Neurological Surgeons and the American Association of Neurological Surgeons, which received no funding from outside commercial sources to support the development of this document. The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article.
© 2016 Congress of Neurological Surgeons
4. The Role of Physical Therapy
Find answers to frequently asked questions.