By KRISTA CONGER
Catching a ball or walking gracefully are difficult for any young child to master. But such tasks may be permanently out of the question for a child with a motor disorder, symptoms of which vary from mild clumsiness to an inability to sit, walk, feed oneself or talk. However, medications and rehabilitation therapy can often lead to meaningful improvements even in children who depend on wheelchairs.
"People see complicated, sick-looking kids who can’t walk, and they think that nothing can be done," said Terence Sanger, MD, PhD. "But we can make a tremendous difference in their quality of life even with small improvements. The point is, you’ve got to try." A 20 percent gain in function can allow a child to use a fork for the first time or to use more buttons on a communication device, noted Sanger.
Terence Sanger assesses arm mobility in a young patient. He is one of just a handful of physicians nationwide who focuses on pediatric movement disorders. Photo: Krista Conger
As medical director of the Lucile Packard Children’s Hospital movement disorders clinic, Sanger is one of fewer than 10 physicians in the country specializing in child movement disorders. He and his colleagues treat conditions that severely limit a child’s ability to move normally. Although many of these conditions are associated with specific diseases in adults, such as Parkinson’s and Huntington’s, the same symptoms in children can present a significant diagnostic challenge.
"The largest cause of childhood motor disorders is cerebral palsy," said Sanger, assistant professor of neurology and neurological sciences at the medical school. But he cautions against a blanket diagnosis to explain symptoms. "There are many diseases that look exactly like cerebral palsy but are not, and many of these diseases are treatable. Any time the symptoms aren’t completely consistent with cerebral palsy you’ve got to look into it."
The interplay between development and an emerging motor disorder can be complicated: some birth injuries don’t become obvious until the child begins learning to walk, run or perform other highly coordinated activities, while other motor disorders wreak havoc by interfering with critical developmental steps.
For example, involuntary muscle contractions leading to fisting or back arching can prevent even the youngest infants from learning important skills like reaching for and manipulating objects. Relaxing the muscles with medications can allow the child to continue normal development and, in a few instances, even prevent the condition from returning once treatment is discontinued.
"Development in kids means that things change with time, often quite dramatically," said Sanger. "A physician needs to be in tune with normal development. A stiff walk when a child is 12 to 14 months old may not mean anything, but at age 2, you should be concerned."
Even children with mild disorders can benefit from early identification and treatment. "An important goal of our clinic is monitoring, sometimes of children as young as 3 to 5 months old," said Sanger. "We really want to pick up problems early, when evidence suggests that the available treatments are more effective."
Sanger is now working with colleagues in the Bay Area to offer baclofen therapy for children with severe dystonia or spasticity that does not respond to oral medications. Baclofen is a muscle relaxant effective in very small amounts when pumped continuously into the spinal fluid. If patients are carefully selected for intrathecal baclofen therapy, many or most of them will experience significant improvement in their symptoms, according to Sanger.
Packard Children’s Hospital neurosurgeons also perform deep brain stimulation on motor disorder patients for whom surgery is the last option. This type of surgery involves implanting a pacemaker into the areas of the brain that are thought to cause dystonia or other types of movement disorders. The surgery can offer significant improvement for more than half of appropriately selected pediatric patients, according to recent estimates.
Sanger is working on several research projects that, he hopes, will lead to new ways to evaluate and treat children with movement disorders. He is currently recruiting children with arm stiffness or dystonia to participate in two drug trials at Packard, as well as a trial of special movement measuring technology at the School of Medicine.
One clinical trial is attempting to determine whether botulinum toxin (which is often used for cosmetic procedures) injected into the arms can improve the ability to reach toward objects. The other trial is designed to determine whether Artane, a drug developed for adult Parkinson’s patients, can improve the quality and speed of arm movements in children. Sanger also heads a federally funded task force dedicated to finding current problems and solutions in childhood motor disorder treatment.
Stanford Report, June 4, 2003