What Causes Idiopathic Intracranial Hypertension?

Patient Presentation
A 14-year-old female came to the emergency room with a 3 week history of tinnitus that resolved 3 days prior to admission.
She had persistent blurred vision in her left eye and 2 days ago developed it in her right eye. She also complains of some neck pain and a headache that she was taking ibuprofen for. She denied any trauma.
The past medical history showed attention deficit disorder on methylphenidate and mild acne that was controlled with benzoyl peroxide.
The family history was negative for any hematological, neurological or ophthalmological disorders.
The review of systems showed no fever, nausea, vomiting, cough, diarrhea, difficulties walking, writing or speaking.
The pertinent physical exam showed vital signs of blood pressure = 145/105, pulse = 98, respiratory rate = 20, was afebrile, with a mini-mental status evaluation showing her to be alert and oriented x 3.
Her weight was > 95% for age with a body mass index of 35 kg/m2. Eye examination showed decreased light perception bilaterally, with papilledema and her venous pulsations could not be determined. Extraocular muscles were intact.
Neurologically cranial nerves III-XII were intact, deep tendon reflexes were normal, strength and tone were normal. She had normal sensation and was able to walk but had problems because of her vision.
She had no obvious ataxia.
The work-up included an emergency consultation with ophthalmology and neurology that confirmed decreased vision, papilledema and no venous pulsations.
She was taken to the pediatric intensive care unit, given intravenous Diamox®, Lasix® and Solumedrol®.
Magnetic resonance imaging revealed the diagnosis of a non-occulsive venous sinus thrombosis in the right transverse sinus, but it was questioned whether or it this alone could be the cause of her idiopathic intracranial hypertension.
A lumbar puncture was normal.
The patient’s clinical course showed her to have a continued decrease in her vision over the next day and therefore a lumboperitoneal shunt was placed to decrease the intracranial pressure.
This stopped the visual decline but at discharge she had not regained her prior vision and had a discharge acuity of 20/150 in her right eye and 20/180 in her left eye.
The diuretics were stopped and she was to continue prednisone, tapering it over 1 month.
During her admission she was evaluated for her hypertension and her idiopathic hypertension was being controlled on propranolol at discharge.
She had a hematological evaluation for a hypercoagulable state that was negative, but would have repeated Protein C and Protein S levels drawn later as acute levels may not be accurate. She was placed on aspirin prophylaxis.
She was discharged to home with daily occupational therapy and physical therapy. She was to follow up with a local nutritionist for her obesity, with her local physician within the week and other specialists within the month.

Figure 63 – Axial (left) and sagittal (right) T1-weighted
magnetic resonance images of the brain demostrate a relatively small
bright (seen here as white) signal abnormality in the right
transverse sinus, concerning for venous sinus thrombosis.

Figure 64 – 06-30-08 – Magnetic resonance venogram obtained with
contrast demonstrates some irregularity in the contour of the right
transverse sinus, but it is still patent and there is flow within it,
demonstrating the thrombus is non-occlusive.

Discussion
Papilledema is described as congestion and elevation of the optic nerve head, blurring of the optic nerve disc margin, obliteration of the physiological optic cup, venous congestion with loss of spontaneous venous pulses, peripapillary splinter hemorrhages and edema of the peripapillary retina.

An image of papilledema from EyeRounds.org can be seen by clicking here.
Papilledema is a neurological emergency and needs prompt evaluation by specialists.

The causes of papilledema include:

  • Cataracts
  • Demyelinating diseases
  • Drugs
  • Glaucoma
  • Hypertension
  • Iridocyclitis
  • Meningo-encelphalitis
  • Optic atrophy
  • Tumor
  • Retinitis pigmenotosa

Idiopathic intracranial hypertension (IIH) is the proper term but many other terms are used such as benign intracranial hypertension or pseudotumor cerebri which is the term used by the National Library of Medicine.
IIH is defined as elevated intracranial pressure but no clinical laboratory or radiographic evidence of hydrocephalus, infection, tumor or vascular abnormality.
IIH has papilledema, normal or small cerebral ventricular system on radiographic imaging, no intracranial mass and normal cerebrospinal fluid.
The pathogenesis of IIH is not complete understood. Proposed mechanisms include increased cerebral blood volume, increased cerebrospinal fluid secretion, increased venous sinus pressure and decreased cerebrospinal fluid absorption. All or combinations of these problems can lead to intracranial hypertension.

IIH occurs from childhood (with an increasing incidence in adolescence) to adulthood. Infants and neonates usually do not have it.
In younger children there is an equal gender distribution of patients, but as age increases female predominate.

Patients often come to attention because of headache, nausea and/or vomiting, blurred vision or diplopia, dizziness, tinnitus and stiff neck.
Other presentations include anorexia, increasing head size, pain behind the orbit, photophobia, head tilt and preference for knee-chest position.
Patients can also be asymptomatic with papilledema noticed incidentally on physical examination.
The papilledema in IIH is usually bilateral but may be unilateral or asymmetric.

Treatment to decrease the intracranial pressure and to maintain vision include stopping possible causative drugs, diuretics (i.e. acetazolamide, furosemide), serial lumbar punctures, and operative procedures such as optic nerve sheath fenestration or placement of a lumboperitoneal shunt.
With prompt treatment, visual loss can be completely reversible, but some visual loss is reported in up to 17% of patients. Recurrence rate is between 6-12%

Learning Point
Causes and possible associations with IIH include:

  • Cardiovascular
    • Heart murmur
    • Mitral valve prolapse
    • Heart transplant*
  • Collagen Vascular
    • Behçet disease
    • Panuveitis
    • Polyangiitis overlap syndrome
    • Systemic lupus erythematosus
  • Drugs
    • Amiodarone
    • Antibiotics – minocycline and tetracycline
    • Chemotherapy – cytarabine
    • Contraceptives, oral and implantable
    • Danazol
    • Desmopressin
    • Human growth hormone
    • Steroids or steroid withdrawal
    • Lithium
    • Mesalamine
    • Nalidixic acid
    • Nitrofurantoin
    • Vitamin A, retinoic acid and similar drugs
  • Endocrine
    • Addison disease
    • Cushing disease
    • Hypocalcemia
    • Hypo or hyperthyroidism
    • Ovarian dysfunction
    • Vitamin D-dependent rickets
    • Vitamin A excess or deficiency
  • Gastrointestinal
    • Crohn’s disease
  • Genetic
    • Guillain-Barré
    • Galactosemia
    • Miller-Fisher variant
  • Hematologic
    • Severe anemia
    • Hypercoagulable states*
    • Polycythemia vera
    • Wiskott-Aldrich syndrome
  • Infectious Disease
    • Illness with fever
    • Lyme disease*
    • Measles
    • Otitis media
    • Roseola
    • Sinusitis
    • Streptococcal B pharyngitis
    • Tonsillitis
    • Upper respiratory tract infection
    • Viral disease
    • Varicella
  • Pulmonary
    • Asthma
    • Chronic lung disease
    • Cystic fibrosis*
  • Renal
    • Renal failure*
    • Renal transplant*
  • Surgical/Trauma
    • Appendectomy
    • Head trauma*
    • Tonsillectomy and adenoidectomy
  • Miscellaneous
    • Malnutrition
    • Obesity
    • Postvaccination
    • Refeeding

Note: one paper (Rangwala and Liu, see To Learn More below) reviewed other reports which may not meet the standard criteria for IIH. This paper cites the following as possibly not meeting criteria for IIH: cystic fibrosis, head trauma, heart transplantation, hypercoagulable states, Lyme disease, renal failure and renal transplantation.

Questions for Further Discussion
1. What radiographic imaging tests should be performed to evaluate papilledema?
2. What disease processes are considered neurological emergencies?
3What disease processes are considered opthalmological emergencies?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Information prescriptions for patients can be found at MedlinePlus for this topic: <a href="Benign Tumors .

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

Illingworth RS. Common Symptoms of Disease in Children. Blackwell Scientific Publications: Oxford. 1998:188.

Rudolph CD, et.al. Rudolph’s Pediatrics. 21st edit. McGraw-Hill, New York, NY. 2003:2398.

Mercille G, Ospina LH. Pediatric idiopathic intracranial hypertension: a review.
Pediatr Rev. 2007 Nov;28(11):e77-86.

Rangwala LM, Liu GT.
Pediatric idiopathic intracranial hypertension.
Surv Ophthalmol. 2007 Nov-Dec;52(6):597-617.

ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    7. All medical and invasive procedures considered essential for the area of practice are competently performed.
    8. Health care services aimed at preventing health problems or maintaining health are provided.
    9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Practice Based Learning and Improvement
    13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.

  • Interpersonal and Communication Skills
    19. The health professional works effectively with others as a member or leader of a health care team or other professional group.

  • Systems Based Practice
    23. Differing types of medical practice and delivery systems including methods of controlling health care costs and allocating resources are known.
    24. Cost-effective health care and resource allocation that does not compromise quality of care is practiced.
    25. Quality patient care and assisting patients in dealing with system complexities is advocated.
    26. Partnering with health care managers and health care providers to assess, coordinate, and improve health care and how these activities can affect system performance are known.

    Author
    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital

    Date
    June 30, 2008

  • How Often Does Pneumatosis Intestinalis Occur with NEC?

    Patient Presentation
    A 38-day old male, former 29-week premature infant was doing well weaning off mechanical ventilation.
    He was not on antibiotics but had a previous suspected sepsis episode.
    He was receiving intravenous fluids and 1/3 of his fluids by nasogastric enteral feedings with breastmilk plus human milk fortifier.
    He was not having any apnea or bradycardia spells.
    The nursing staff noted that he had a bloody stool, where the blood was mixed into the stool and on top of the stool.
    The review of systems was otherwise negative.
    The pertinent physical exam showed a weight of 1.465 grams, heart rate = 188 beats/minute, respiratory rate of 66 breaths/minute, and blood pressure of 77/48. His vital sign trends were unchanged.
    HEENT showed an anterior fontanelle that was soft, open and flat.
    Lungs were without adventitial breath sounds and no increased work of breathing.
    Heart was regular rate and rhythm without a murmur.
    Abdomen was soft, nontender, rounded with hypoactive bowel sounds present. No masses were palpable or abnormal skin coloring of the abdomen or flanks.
    Neurological examination showed normal tone, strength and moving all extremities appropriately.
    The work-up included a complete blood count that showed an increased white blood cell count of 16.5 x 1000/mm2 and platelet count of 625 x 1000/mm2. A C-reactive protein, and urinalysis were negative.
    The radiologic evaluation showed thickened small bowel loops with pneumatosis intestinalis predominantly in the left lower quadrant. No portal venous gas or free air was noted.
    The diagnosis of necrotizing enterocolitis with pneumatosis intestinalis was made.
    Antibiotics were begun, enteral feedings were stopped and surveillance abdominal radiographs were ordered.
    The patient’s clinical course revealed that he received 10 days of antibiotics and never had clinical evidence of sepsis or other deterioration in his condition.
    His blood, urine and stool cultures were negative for bacteria and enteroviral cultures Clostridium difficile toxin were also eventually negative. His hematochezia resolved in 2-3 days. He continued to wean off his ventilator settings and nasogastric feedings were resumed.


    Figure 62 – AP supine radiograph of the abdomen demonstrates pneumatosis intestinalis in the left lower quadrant, consistent with a diagnosis of necrotizing enterocolitis. There was no evidence of free air or portal venous gas.

    Discussion
    Necrotizing enterocolitis (NEC) is unfortunately a common acute life threatening disease for infants. The terminal ileum is the most common area affected by NEC.
    It is a clinical entity where the patient has feeding intolerance, blood in the stools and radiographic changes.
    Patients with NEC often show abdominal distension, feeding intolerance (i.e. emesis, increased residual nasogastric feedings, bilious emesis or bilious residuals), blood in the stool, erythema or other abdominal/flank skin color changes and lethargy.
    Clinically, patients may also have difficulty with ventilation, apnea, bradycardia, bruising or bleeding problems, hypotonia, and decreased stooling.
    Radiographically patients may have focal but non-specific bowel loop distension, edematous thickening of the bowel wall, fixed dilated bowel loops indicating lack of peristalsis and possible necrosis, pneumatosis intestinalis, portal venous gas, or free intraperitoneal air from perforation.
    Laboratory testing may show evidence of metabolic acidosis, coagulopathy, increased inflammatory markers such as C-reactive protein and increased stool reducing substances from carbohydrate intolerance. NEC can be relatively mild or severe with sepsis

    NECs exact cause still is not elucidated and most likely multifactorial. The most widely accepted risk factors are prematurity, enteral feeding, bacterial colonization and mucosal injury. But how each of these factors initiates, continues or contributes to NEC is not completely elucidated.

    • Prematurity is a fairly consistent factor with 5-10% of infants &lt; 1500 gram birth weight developing NEC. The incidence of NEC decreases with gestational age and full term infants can have NEC.
    • Enteral feedings have almost always begun when NEC occurs. NEC often occurs temporally around changes in feedings (i.e. advancement, re-initiation). Use of human milk appears to decrease the incidence of NEC but does not eliminate it.
    • Bacterial colonization occurs within 12-24 hours after birth; nitially with maternal vaginal flora and then that of external environment. Lactobacilli and Bifidobacterium are normal commensal bacteria that colonize weeks later. Overgrowth of a pathogen is implicated as part of the NEC pathogenesis but one single pathogen has not been identified. Gram-negative bacteria are most common but gram-positive bacteria, viruses and yeast also are involved.
    • Ischemia of the gastrointestinal tract is a factor. It may be an initial inciting event that eventually leads to NEC (i.e. ischemia causing mucosal edema, inflammation, etc.) or the end result (i.e. initial event causes mucosal edema, inflammation, etc. which then decreases the tissue perfusion and oxygenation).
    • Inflammatory response, especially activation of the cytokine cascade, also appears to be a factor. Platelet activating factor is one of the most studied mediators.

    Learning Point
    Pneumatosis intestinalis is an imaging sign and not a diagnosis itself. It is defined as abnormal gas in the gastrointestinal tract wall. In infants, it can also be caused by intestinal atresia, midgut volvulus and Hirschsprung’s disease with enterocolitis.
    It is most commonly seen in the small intestine but can be found in all areas of the gastrointestinal tract from esophagus to rectum and can be seen in all ages from infancy to adulthood.

    In premature infants who develop NEC, pneumatosis intestinal is found ~50% of the time. Therefore if it is seen, it helps to diagnose NEC; some infants may have NEC but not pneumatosis intestinalis.
    Pneumatosis intestinalis may not be seen on the initial abdominal radiograph but serial radiographs may eventually show this finding.

    Questions for Further Discussion
    1. How common is NEC in full term infants?
    2. How quickly should preterm infants have their enteral feedings increased?
    3. What is the potential role of probiotics in the treatment of NEC?
    4. What surgical techniques are used for treatment of NEC?

    Related Cases

    To Learn More
    To view pediatric review articles on this topic from the past year check PubMed.

    Information prescriptions for patients can be found at MedlinePlus for this topic: Premature Babies

    To view current news articles on this topic check Google News.

    To view images related to this topic check Google Images.

    Rudolph CD, et.al. Rudolph’s Pediatrics. 21st edit. McGraw-Hill, New York, NY. 2003:140-143.

    Kim WY, Kim WS, Kim IO, Kwon TH, Chang W, Lee EK. Sonographic evaluation of neonates with early-stage necrotizing enterocolitis.
    Pediatr Radiol. 2005 Nov;35(11):1056-61. Epub 2005 Aug 3.

    Kawase Y, Ishii T, Arai H, Uga N. Gastrointestinal perforation in very low-birthweight infants.
    Pediatr Int. 2006 Dec;48(6):599-603.

    Duran R, Vatansever U, Aksu B, Acunas B. Gastric pneumatosis intestinalis: an indicator of intestinal perforation in preterm infants with necrotizing enterocolitis?
    J Pediatr Gastroenterol Nutr. 2006 Oct;43(4):539-41.

    Gibbs K, Lin J, Holzman IR. Necrotising Enterocolitis: The State of the Science. Indian J Pediatr 2007;74:67-72.
    Available from the Internet at http://www.ijppediatricsindia.org/text.asp?2007/74/1/67/30401 (rev. 2007, cited 4/21/08).

    Duran R, Vatansever U, Aksu B, Acunas B. Gastric pneumatosis intestinalis: an indicator of intestinal perforation in preterm infants with necrotizing enterocolitis?
    J Pediatr Gastroenterol Nutr. 2006 Oct;43(4):539-41.

    ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    7. All medical and invasive procedures considered essential for the area of practice are competently performed.
    8. Health care services aimed at preventing health problems or maintaining health are provided.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Practice Based Learning and Improvement
    13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.

  • Systems Based Practice
    23. Differing types of medical practice and delivery systems including methods of controlling health care costs and allocating resources are known.
    24. Cost-effective health care and resource allocation that does not compromise quality of care is practiced.

    Author
    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital

    Date
    June 13, 2008

  • What’s Wrong With His Belly Button?

    Patient Presentation
    A 1-month-old male came to clinic because his mother was concerned about discharge from his umbilicus.
    At 2 weeks he was growing well and his umbilical cord stump was still attached and there were no concerns at that time.
    The stump fell off 6 days prior and for the last 3 days he seemed to have some yellow discharge that appears on his clothes.
    The stump is not otherwise reddened or irritated. He is not bothered by it.
    The past medical history showed a full term infant without pre- or perinatal problems.
    He has been gaining weight well.
    The family history is negative for any genitourinary system or gastrointestinal problems.
    The review of systems was negative.
    The pertinent physical exam showed an alert infant with growth parameters in the 75-90%.
    There was some yellowish, crusty discharge on his undershirt.
    His umbilicus was not reddened generally but there was a 0.3 x 0.5 cm red, pedunculated mass extending from the center of the umbilicus.
    No opening was seen in the mass and no obvious discharge was seen on the umbilicus. His abdomen was non-tender. The rest of his examination was negative.
    The radiologic evaluation included an ultrasound of the abdomen which revealed an isoechoic tract extending from the umbilicus to the bladder.
    There was no fluid or cyst in the tract and the bladder appeared normal. A voiding cystourethrogram also showed normal bladder anatomy and no vesicoureteral reflux.
    The diagnosis of urachal remnant was made. He was referred to urology who were planning surgical resection.


    Figure 60 – Midline sagittal ultrasound image demonstrates a hypoechoic tubular structure with minimal fluid within it that communicates with the umbilicus (to the left) but not with the bladder dome (to the right).


    Figure 61 – Lateral view of the voiding phase of a voiding cystourethrogram that demonstrates a normal appearing bladder and urethra. No reflux of contrast through the urachus is demonstrated.

    Discussion
    The allantois develops in the human embryo on the 16th day of embryogenesis. It develops from the posterior portion of the yolk sac forming a small diverticulum adjacent to the forming cloaca.
    The allantois is usually obliterated during embryogenesis, but a remnant may persist. This remnant connects from the umbilicus to the bladder and is called an urachal duct remnant. If the remnant is entirely open then it is called an urachal fistula and would drain urine through the umbilicus.
    It is also possible only parts of the remnant are obliterated. If the remnant is obliterated near the bladder, leaving open the umbilical end, this is called a urachal sinus. If the remnant is obliterated at the bladder and umbilical end but the central portion remains, this is called an urachal cyst.
    The fluid from an urachal sinus or cyst is caused by the secretory activity of the urachal duct lining.

    The vitelline duct is formed by the lateral folding of the foregut and hindgut. It connects the umbilicus to the distal ileum. Usually it is also obliterated but sometimes remnants persist. Its most common remnant is the Meckel’s diverticulum.
    The vitelline duct can also be patent over its entire length creating a vitelline fistula which may cause a fecal discharge at the umbilicus. A central portion of the vitelline duct may remain patent creating a vitelline cyst.
    A vitelline cyst may present as intestinal obstruction as it can become entangled in the intestines.

    Around the end of the 3rd month of embryogenesis, all that should remain externally of the original allantois and vitelline ducts after all the folding of the midgut/abdominal area of the embryo is the umbilical cord with 2 arteries, 1 vein and Wharton’s jelly to protect it.

    Learning Point
    The differential diagnosis of a mass of the umbilicus includes:

    • Umbilical granuloma – usually 0.1-1.0 cm, red, friable tissue, usually easily treated with silver nitrate cautery.
    • Urachal duct remnant – including fistula, sinus tract or cyst. May present with mucous drainage or urine.
    • Vitelline duct remnant – including polyp (usually brighter red than umbilical granuloma and does not respond to silver nitrate cautery), fistula, sinus tract or cyst. May present with fecal or mucus discharge.
    • Omphalocoele – abdominal contents pass through a periumbilical defect and the viscera are covered by a membrane. Needs surgical treatment.
    • Umbilical hernia – small defects in the periumbilical structure of the anterior abdominal wall that closes with time as the musculature develops. Usually closes by 1 year of age.

    Questions for Further Discussion
    1. How long after birth should the umbilical cord separate, and what causes the separation?
    2. How common is a single umbilical artery and what is its clinical significance?
    3. How do umbilical infections present and what organisms commonly cause these infections?

    Related Cases

    To Learn More
    To view pediatric review articles on this topic from the past year check PubMed.

    Information prescriptions for patients can be found at MedlinePlus for this topic: Infant and Newborn Care.

    To view current news articles on this topic check Google News.

    To view images related to this topic check Google Images.

    Sadler, TW. Langman’s Medical Embryology. 5th edit. 1985. pp. 51, 71, 239, 257.

    Minkes RK,
    Chen LE,
    Mazziotti MV,
    Kim ES, and
    Bloss RS.
    Disorders of the Umbilicus. eMedicine.
    Available from the Internet at http://www.emedicine.com/ped/TOPIC2948.HTM (rev. 4/27/2006, cited 4/14/2008).

    Pomeranz A. Anomalies, abnormalities, and care of the umbilicus. Pediatr Clin North Am. 2004 Jun;51(3):819-27, xii.

    ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    7. All medical and invasive procedures considered essential for the area of practice are competently performed.
    8. Health care services aimed at preventing health problems or maintaining health are provided.
    9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Practice Based Learning and Improvement
    12. Evidence from scientific studies related to the patients’ health problems is located, appraised and assimilated.
    13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.

  • Systems Based Practice
    23. Differing types of medical practice and delivery systems including methods of controlling health care costs and allocating resources are known.
    24. Cost-effective health care and resource allocation that does not compromise quality of care is practiced.

    Author
    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital

    Date
    June 2, 2008