Cerebral Palsy and Childhood Osteoporosis
By: John Hartford
Although osteoporosis is often associated with aging, it is a common complication of cerebral palsy beginning in childhood.
Osteoporosis is a disorder characterized by lack of bone density or bone mass. Children with these “thin bones” can sustain bone fractures from very little trauma, seriously impacting all areas of their lives. Although some progress has been made in treating osteoporosis in the elderly, there is no cure. Thus, preventing or reducing the effects of osteoporosis and maximizing bone development during critical stages of growth can minimize the lifelong risks of fractures in children with cerebral palsy.
Diagnosing Osteoporosis in Children
A bone scan using an x-ray machine is used to determine bone health. The procedure, called a densitometry, measures Bone Mineral Density (BMD). The test is painless and is usually done in a hospital or clinic radiology department. Measurements are most commonly taken of the lower spine and the upper part of the hip. The forearm is scanned if either the hip or the lumbar spine can’t be.
The test is usually sufficient to diagnose osteoporosis in adults, but not children. In 2008, the International Society of Clinical Densitometry released a position statement defining the parameters for the diagnosis of osteoporosis in children. Unlike adult osteoporosis, a diagnosis of osteoporosis in children not only requires a low BMD score, but also a significant history of bone fracture.
Causes of Osteoporosis in Children with Cerebral Palsy
Bone development begins the third week of gestation and peaks in adolescence. As described in Bone Density in Cerebral Palsy by Christine Murray Houlihan, MD and Richard D. Stevenson, MD, it involves a complicated mechanical and metabolic process. But basic to bone growth is the relationship between weight, or stress, on the bone, and the mineralization, or strength, of the bone. Cerebral palsy compromises children’s bone growth in a variety of ways:
- A child with compromised movement will not adequately stress growing bones to prompt mineralization necessary for strong bones.
- A child who uses a wheelchair or who is bedridden may have limited exposure to the outdoors and the sunlight that helps the body create vitamin D, which is necessary to the absorption of calcium.
- A child who has difficulty eating may also have nutritional issues that prevent healthy bone growth.
- Chronic malnutrition from feeding issues may stunt growth, thus impacting the hormones that play a role in bone development.
- Certain medications, especially those known to control seizures, can impact the absorption of calcium and deter bone growth.
Prevention or Treatment of Osteoporosis
Physical therapy—Regular physical therapy starting from a very young age can help put stress on bones, encouraging bone mineralization.
Nutritional therapy—About one-third of children with cerebral palsy are estimated to suffer from chronic malnutrition as the result of eating problems such as gastroesophageal reflux (GERD), chronic respiratory infections, and pressure ulcers. A nutritionist should assess whether a child is getting enough food and a balanced diet to ensure healthy growth. Infants require immediate intervention if they have trouble sucking or swallowing.
Vitamin D Supplements—Vitamin D has been shown to increase the body’s absorption of calcium, which is central to bone health. However, a doctor should always be consulted about adding a vitamin supplement to a child’s diet. Vitamin D is NOT recommended if a child is on certain seizure medications, such as Tegretol.
Medications—A variety of medications are available to combat osteoporosis in the elderly, but have not been extensively tested in children. A 2008 study involving children reports positive outcomes in using a combination of vitamin D and Actonel.
Children with cerebral palsy should be evaluated for vitamin D deficiency prior to bone surgery, according to a study published in the April-May 2011 issue of the Journal of Pediatric Orthopedics. The study of 70 patients between the ages of 2 and 19 showed that 90% who had been admitted to the hospital for surgeries requiring bone healing were at risk of poor bone healing due to insufficient vitamin D levels.