Mar 10 2010
In a case believed to be a United States first, the radiology team at
Lucile Packard Children's Hospital has used prenatal magnetic resonance
imaging to detect an often-misdiagnosed genetic disease.
“Dr. Barth’s experience with difficult cases and the depth of his
familiarity with the fetal imaging scientific literature really helped
our entire team provide the best possible care for this mother and
baby”
The disorder, congenital chloride diarrhea, can cause severe dehydration
and serious metabolic disturbances in newborns if not treated quickly.
"This is a disease where early diagnosis is the key to a good outcome,"
said Richard Barth, MD, the physician who recognized the unusual case.
Congenital chloride diarrhea is so rare, with only about 250 total cases
reported worldwide, that infants with the disease are often erroneously
treated for other diarrhea-causing ailments. "If the patient's
fortunate, you could stumble onto this diagnosis," said Barth, the chief
radiologist at Packard Children's and a professor of pediatric radiology
at the Stanford University School of Medicine. The case was the first
instance of CCD Barth had ever seen.
The diagnosis is one of only four known cases of CCD diagnosis ever made
via prenatal MRI. A scientific report on the four cases, including
Barth's case and three from France, was published online Dec. 9 in the
journal Ultrasound in Obstetrics & Gynecology. The report is
a collaboration between Barth and a team of French scientists in
Marseilles.
Barth made his diagnosis in February 2009 when an expectant mom was
referred to him for follow-up of an abnormal prenatal ultrasound. The
ultrasound showed classic signs of bowel obstruction, a fairly common
fetal problem. To get more information about the fetus, Barth ordered an
MRI scan, which gave him a surprise that could not have been detected by
ultrasound: Instead of showing the fetal colon filled with solid waste,
as in a bowel obstruction, it was filled with fluid. This important
clue, found thanks to the Packard team's expertise in fetal MRI, pointed
Barth toward the obscure diagnosis of CCD. "The baby's dad said, 'You're
coming up with a real zebra here,'" Barth recalls.
But that 'zebra' saved the new baby a lot of trouble when she was born
at Packard a few weeks later. Barth collaborated with obstetrics and
neonatology teams in the hospital’s Johnson Center for Pregnancy and
Newborn Services to ensure the infant's fluid and electrolyte levels
would be monitored starting at birth. This was needed because the gene
mutation that causes CCD damages a salt-transporting protein in the
intestine. The abnormality stops the body from absorbing essential
electrolytes, causing patients to have large amounts of watery,
high-salt diarrhea.
"These babies can go into shock and die because of the tremendous
electrolyte imbalance at birth," said Maurice Druzin, MD, professor and
service chief of obstetrics and gynecology at Packard Children's.
Without the prenatal diagnosis, it could easily have taken physicians a
few days to figure out what was going on, Druzin added. "The baby could
have been in serious trouble by that time," he said. Untreated patients
who survive early life may suffer permanent kidney damage, feeding
problems, severe malnutrition, and delays in growth and motor
development.
"In this case, the neonatology team was not just monitoring the baby's
electrolytes, but also taking special precautions in terms of feeding,"
said neonatologist Susan Hintz, MD, associate professor and medical
director of the Center for Comprehensive Fetal Health & Maternal and
Family Care at Packard Children's. "We took these steps due to the
strong possibility that this was CCD."
For infants whose CCD is detected early, treatment is straightforward:
intravenous fluid and salt replacement can compensate for their ongoing
diarrhea. As they get older, patients may take extra liquids and salts
by mouth, or they can opt for newer treatments. For instance, the little
girl Barth diagnosed is now taking an oral medication that modifies her
body's salt uptake and reduces diarrhea. Though these treatments do not
cure the disease, prompt diagnosis and treatment allow patients to lead
fairly normal, healthy lives.
"Dr. Barth’s experience with difficult cases and the depth of his
familiarity with the fetal imaging scientific literature really helped
our entire team provide the best possible care for this mother and
baby," Hintz said.
The patient, whose rare diagnosis was further confirmed by genetic
testing in December 2009, is now a thriving one-year-old. Her parents
report that she's starting to walk and has three teeth.
"We are grateful to Dr. Barth," said the patient's mother. "He went out
on a limb by diagnosing our baby with an extremely rare disorder and
then stood behind his diagnosis, which provided the team with the right
direction of treatment. His mood was mixed with both excitement for the
technological finding and clear compassion for our circumstances."
Looking back at this extraordinary case, Barth saluted the comprehensive
care Packard Children’s offered the newborn and her family. “When
there’s a fetal anomaly like this, families face an emotional tsunami,"
he said. "But our imaging teams have experience taking on some of the
toughest cases in the world, and our collaboration with other hospital
subspecialties is really what multidisciplinary care is all about. This
reassures families that good outcomes are possible even in the rarest of
cases."
SOURCE Lucile Packard Children's Hospital