Bone scans find pain source in cerebral palsy patients

Whole-body technetium-99m bone scans are helping orthopedic surgeons locate the source of unexplained pain for children with cerebral palsy who cannot describe where their discomfort resides.

A retrospective study published in the Journal of Pediatric Orthopaedics (2008;28[1]:112-117) determined that three-phase whole-body bone scans helped positively identify the source of pain for 53% of 45 patients whose ages ranged from three to 20 years.

The rate may appear low, but it is satisfying considering the circumstances, said senior investigator Dr. Freeman Miller. The protocol is almost exclusively applied for children who lack the ability to verbalize or otherwise describe the location of their pain. Miller is director of the cerebral palsy program at Alfred I. DuPont Hospital for Children in Wilmington, DE.

"It is just for children who are crying and parents who know something is wrong but don't know where the problem lies," he said.

The nuclear medicine protocol adds a global survey to the regionally focused strategy that attending physicians typically use for such cases. Miller's diagnostic protocol is organized as follows:

• A physical exam to localize the pain based on a consultation with parents or caregivers;

• A pelvic radiograph for constipation or subluxation of the hip;

• After a negative radiograph, lab tests measuring the white blood cell count and sedimentation rate for evidence of infection (a high white cell count may lead to abdominal ultrasound for various conditions or a maxillary sinus radiograph for possible sinusitis);

• After negative lab tests, a whole-body Tc-99m bone scan including planar and 3D imaging.

Based on studies conducted in Miller's department between 1998 and 2005, first author Dr. Gela Bejelidze found the source of pain was identified in all 24 patients with a positive bone scan. It was deemed instrumental in establishing a diagnosis or localization for 22 patients.

Fractures were the source of pain for 10 patients. Other diagnoses included four cases of painful internal hardware, two spondylolysis cases, two sinusitis cases, and one each of osteomyelitis, degenerative bone changes, bursitis, cellulitis, obstructed kidney, and slipped capital femoral epiphysis.

An orthopedic diagnosis was not possible for the 21 patients with a negative bone scan.

"I was pretty happy with the results," Miller said. "Without bone scanning, we would be at a loss about where to go next."

-By James Brice