Helmets for toddlers with hydrocephalus
Summary: Finding a helmet for a child with hydrocephalus is not just a simple matter of finding one large enough. You probably know that already.
A number of disorders, primarily hydrocephalus, can cause children to have larger than average heads at a very young age. Hydrocephalus is sometimes known as "water on the brain" and is a buildup of cerebrospinal fluid in the brain. There often are other complications, including motor disabilities and other disorders. If you are not familiar with the disorder, here is a Google search on it.
Parents of children with hydrocephalus contact us looking for a helmet for their child, having found that normal toddler helmets are much too small, and in some cases even adult helmets are not large enough to fit. But fit is only one question.
First, you should be aware that wearing a bike helmet will not necessarily protect any rider from an injury. Bike helmets are designed to protect the average brain against catastrophic injury. In a hard knock they do not attempt to soak up all of the energy, since no helmet with reasonable thickness can do that. It is not unusual for a person with a normal brain to experience a concussion and be knocked out during a bike crash with a helmet on. A person with a brain affected by hydrocephalus and perhaps associated disorders may have a much worse outcome. Only your medical support team can tell you about that for your child, and you will of course want to ask them if you have not already done so.
We are not aware of any extra-extra-large toddler helmets on the market, and no helmet specifically designed for riders with hydrocephalus. Manufacturers are always concerned about lawsuits if the helmet made it appear safe for a child with hydrocephalus to ride, and then the child were injured or killed.
The best advice we can offer is to always to ask your pediatrician for advice before putting a helmet on your child. If you get the green light from your physician, you may have to use an adult helmet to find one that fits. The only difference defined by US standards between the protection of an adult helmet and a toddler helmet is that the CPSC standard requires more head coverage for toddlers under five, so toddler helmets come further down on the head. If a normal adult helmet is still too small, see our page on helmets for big heads for more ideas.
If the physician confirms that biking is ok for your child, the best helmet for a child with hydrocephalus would probably be one with a round, smooth exterior and a thicker, moderately dense foam liner. You generally find helmets like that in discount stores at low prices (under $30), not in bike stores at prices above $100. Do not spend more on a super-vented, fashionable helmet, since it will have harder foam to make up for those vents.
Fitting a child with hydrocephalus is not necessarily just a question of getting a helmet with the right head circumference, since the child's head shape may differ from an adult head. If a helmet with a sizing ring ("one size fits all") does not give a good fit, you may have to find another model that uses fit pads instead of the ring. Those usually permit using a thinner pad on the sides and thicker pads at the front and back to accommodate a rounder head, or the other way around for a longer head.
Helmets are not magic, and they may or may not work for your child. Only your physician can say for sure.