Also see the blog Cranial orthoses (or helmets)
THE STUDIES IN FAVOUR OF HELMETS
Many non-randomized studies are in favour of using a helmet to treat plagiocephalies(1), including a recent study which used a 3-dimension scan, instead of the usual craniometer used in studies and in clinical settings and which gives a 2-dimension measure. This study follow-up was up to 4 years of age, a longer period than other studies.(2) The Congress of Neurological Surgeons published guidelines, based on a systematic review, recommending that infants with a severe plagiocephaly be prescribed a cranial orthosis early in infancy since there was significant correction and even normalization of the head shape.(3)
THE STUDIES AGAINST HELMETS
On the other hand, the group Choosing Wisely Canada, whose mandate is to give a national voice to reduce unnecessary tests and treatments, published recommendations from the Canadian Pediatric Neurosurgery Study Group[i] and stated that they do not recommend the prescription of cranial orthoses for mild to severe plagiocephalies.(4) This group come to this conclusion based on a series of questionnaires sent to their members. Choosing Wisely Canada also refers to a randomized controlled study to make its recommendations. It was a generally well-done study including single-blind randomization but contained several biases which limited its validity.(1)
THE LIMITATIONS OF A RANDOMIZED CONTROLLED STUDY AGAINST HELMETS
In spite of the quality of the study used by Choosing Wisely Canada, based on its single-blind randomisation,(1) there were several limitations which are analysed below.
| Limitations of the study(1) | Analysis/Our practice |
| A prolonged wear of the helmet of up to 4 months, between the age of 6 and 10 months, and more if necessary. | We usually recommend a wear duration between 2 to 3 months; optimal results being usually obtained after this period (when the helmet is worn 23 hours per day). Furthermore, a limited period of 2 to 3 months maximizes the compliance to the treatment and limit potential side effects. |
| Up to 73% of helmets rotated or shifted on their heads. | The helmet must be well adjusted to the head of the child, without which the response to treatment become sub-optimal. A proper adjustment also improves compliance to treatment, including an adequate number of hours of helmet per day. |
| Participation rate being low, the study does not have enough power to generalise results. | One must be prudent before applying results from a study which lack power. We take this into account in our practice by assessing every patient in a unique fashion. |
| The number of hours of helmet wear was not measured. | While it is possible that the number of hours of helmet wear was sufficient for optimal treatment, this study does not allow to demonstrate it. In our practice (as is the case in the study), we recommend it for 23 hours per day. A lesser wear would probably reduce the effectiveness of the helmet. |
| Only term babies were included (born at gestational age of more than 36 weeks) | The risks of having a positional plagiocephalies probably increase with prematurity along with delays in the attainment of developmental motor milestones. Neurodevelopment assessment is important in the decision to prescribe a cranial orthosis in order to determine whether it is possible for the head shape to improve on its own based on the capability of the child to not be lying on his back so much. |
| Very severe plagiocephalies were excluded. | Very severe plagiocephalies was excluded from the study. It is unclear whether this sub-group was also excluded from the recommendations of the Canadian Pediatric Neurosurgery Study Group via Choosing Wisely. In our practice, very severe plagiocephalies usually warrant a cranial orthosis. |
| Babies with “muscular torticollis” were excluded | In our practice, most children have a congenital torticollis. Recommendations from the study will thus not apply to these children. There is an increased risk of persisting plagiocephaly in the presence of a torticollis given the preference for the head to turn on one side. |
| Children with congenital pathologies have been excluded. | Just as with prematurely born babies, developmental motor delays may potentially be present in children with congenital pathologies which in turn might increase the risk of persisting plagiocephaly, which thus might lead to the need for a helmet to properly treat it. |
It is interesting to note that parents, whose child wore the helmet during the study, demonstrated a satisfaction rate slightly higher and an anxiety level slightly lower at the 2-year-of-age follow-up mark.(1)
THE ANALYSIS OF THE REPORTED SIDE EFFECTS OF A RANDOMIZED CONTROLLED STUDY AGAINST HELMETS
There were frequent reported side effects in a study used by Choosing Wisely Canada to make its recommendations not to prescribe cranial orthoses. Some of the side effects might be even more often seen in practice but of little consequence while others depend on the fabrication process. Another study was done exclusively on helmets’ side effects and reported that side effects were minor and self-resolved when the helmet was stopped.(5)
| Reported side effects(1) | Analysis/our practice |
| Problems with accepting the helmet (24%) | The decision must be made jointly with the family to ensure compliance with the helmet |
| Skin irritation (96%) | In our practice, most children do not have skin irritation or reaction. Some might react to or exacerbate their eczema with the helmet foam. When there is a form of skin irritation, the foam may be covered with a fine plastic covering which usually resolve the issue. At times, treatment for the premorbid eczema might need to be adjusted. When the helmet is too small, redness might be present, which is a sign that the helmet needs adjusting or changed. Regular follow-ups are done with the orthotist to adjust the helmet. When the helmet is started before age 8 months, because of the rapid head growth, it is at times necessary to do a second helmet to complete treatment. |
| Augmented sweating (71%) and unpleasant odor in the helmet (76%). | In our practice, this problem happens quite often and is worse during summer because of the heat. It might be useful to remove the helmet for short periods and wipe it. Time in cooler air conditioned. |
| Pain associated with the helmet (33%). | There is no pain associated with the helmet except when it is too small. It must then be adjusted or replaced. Regular follow-ups with an orthotist are regularly planned to avoid this problem. In the study, helmets turned or shifted on the heads indicating a sub-optimal adjustment, which might explain the reported side effect. |
| Feeling hindered from cuddling their children (77%). | This reported side effect is usually not seen in our practice. In our recommendations to parents, we reassure them with the diagnosis given that it is only a benign positional plagiocephaly, that the helmet is generally well tolerated by children and that treatment usually lasts for only 2 to 3 months. |
REFERENCES
1. van Wijk RM, van Vlimmeren LA, Groothuis-Oudshoorn CGM, Van der Ploeg CPB, IJzerman MJ, Boere-Boonekamp MM. Helmet therapy in infants with positional skull deformation: randomised controlled trial. 2014;348:g2741.
2. Kunz F ST, Grose S, et al. Head orthosis therapy in positional plagiocephaly: longitudinal 3D-investigation of long-term outcomes, compared with untreated infants and with a control group. Eur J Orthod. 2019;41(1):29-37.
3. Tamber MS ND, Beier A, et al. Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline on the Role of Cranial Molding Orthosis (Helmet) Therapy for Patients With Positional Plagiocephaly. Neurosurgery. 2016;79(5):E632-E3
4. Group CPNS. Five Things Physicians and Patients Should Question. Choosing Wisely. 2021.
5. Gump WC MI, Moriarty TM. . Complications associated with molding helmet therapy for positional plagiocephaly: a review. . Neurosurg focus.35(4):E3.
[i] Group composed of paediatric neurosurgeons who practice medicine in Canada.