Researchers from the Johns Hopkins Children's Center report in the November issue of Pediatric Neurosurgery that these postoperative fevers are usually harmless. As a result, most of these children can probably be spared painful spinal taps or other invasive treatments.
In one of the largest studies of its kind, Hopkins researchers reviewed the charts from 106 consecutive hemispherectomies performed at the Children's Center from January 1975 to December 2001. The review included 102 hemidecortications, a less radical form of hemispherectomy that removes the overlaying gray matter of the brain, preserving the white matter around the ventricle. Medical records were examined for information regarding immediate postoperative problems and care.
Researchers found that few postoperative fevers were caused by serious postoperative complications, such as bacterial meningitis, which is commonly diagnosed by a spinal tap.
"As hemispherectomies become increasingly used in the treatment of unilateral and severe childhood epilepsy, it's important to study and understand the incidence of complications such as meningitis, and other issues in the immediate postoperative period so that we can provide the highest quality care," said lead researcher Eric Kossoff, M.D., a pediatric neurologist at the Children's Center.
The surgery, which leaves intact the deep structures of the brain (the thalamus, brain stem and basal ganglia) is performed at Hopkins on children with Rasmussen's syndrome, a variety of developmental abnormalities on one side of the brain, and on those who have had disabling strokes. First attempted by Johns Hopkins surgeon Walter Dandy, M.D. in the late 1920s, the operation was reintroduced at Hopkins in 1968 and refined in the mid-1980s by Benjamin S. Carson, M.D., director of pediatric neurosurgery and a co-author of this study.
Researchers found that more than 80 percent of patients had postoperative fevers. Of the patients with fever, 62 percent were given lumbar punctures, or spinal taps, to diagnose suspected bacterial meningitis. Only six of these patients were diagnosed with meningitis, and these children had also complained of headache, lethargy and wound discharge, which the majority of children with low-grade fever alone did not experience.
"This study has already been helpful to the physicians and nurses providing postoperative care for these children because it helps them anticipate which patients truly require spinal taps," said Kossoff. "A child with a low-grade fever who is active and does not exhibit other symptoms is unlikely to be infected, while a child with a high fever, headache, lethargy and actually appears ill is at perhaps higher risk."
Other factors that indicated infections included elevated white blood cell counts in the cerebrospinal fluid (CSF), very high temperatures, and prolonged use of steroids, commonly used in these patients.
As a result of this study, Children's Center doctors and nurses may allow fevers without other symptoms to persist for as long as two weeks if the child is active and playful. Of the 10 patients undergoing hemispherectomy since 2001, only one has required the insertion of a shunt to drain CSF, and none have been diagnosed with bacterial meningitis.
Researchers from the Department of Neurology and Pediatrics, Department of Pediatric Neurosurgery, and the Pediatric Epilepsy Center also contributed to this report. The study was supported in part by funds from the Roxanne Fellowship.
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Journal
Pediatric Neurosurgery