Day: November 12, 2012

What are the Initial Cerebrospinal Fluid Findings in Different Types of Meningitis?

Patient Presentation
An 8-year-old male came to the emergency room with 3 days of fever, malaise and an increasing headache. His fever had a maximum temperature of 102.4° F. He had been increasingly tired and sleeping more. He was seen on day 2 and was diagnosed with an early upper respiratory infection. Over the next 24 hours, he became more irritated when awake. He was drinking and urinating little and had developed a generalized headache. He also complained of back pain with moving. The past medical history was non-contributory. The review of systems showed no emesis, constipation, or diarrhea. He may have had a rash on his trunk at the beginning of the illness.

The pertinent physical exam showed an ill-appearing child, who was in a fetal position and did not want to be moved, but was cooperative. His vital signs were normal. His capillary refill was 3 seconds. Eye examination found photophobia which made it difficult to appropriately examine the retinas. He had mild erythema of the posterior pharynx and showed some nucal rigidity. He complained of pain in his lower back with straight leg lift, but no change with straightening his knee. He complained of generalized pain with most movement. His neurological examination showed cranial nerves were intact, DTRs were 2+/2+ with normal strength. His skin showed a faint, blanching, macular diffuse rash on his abdomen.

The radiologic evaluation included head computed tomography that was negative for a space occupying lesion. The laboratory evaluation had a complete blood count remarkable for being 19.6 x 1000/mm2 with an increased lymphocytic count and normal platelets. Electrolytes, glucose, and urinalysis were normal. Liver function tests showed a mild increase in transaminases. The work-up included a lumbar puncture as soon as the head computed tomography was completed. Opening pressure was 74 mm H20 (normal 60-200 mm). It showed 19 lymphocytes, glucose of 28 mg/dL, and protein of 33 mg/dL, with no organisms on gram stain. Cerebrospinal fluid for culture and polymerase chain reaction (PCR) were sent. Blood and urine cultures were sent. The diagnosis of meningitis was made. He was given intravenous ceftriaxone, acyclovir and fluids, and transported to a regional children’s hospital for admission and treatment. The patient’s clinical course found the PCR was positive on day 2 for Echovirus 9 and antibiotics and acyclovir were discontinued. He slowly improved with lessening headache and malaise. On day 3 he had adequate fluid intake and was discharged home.

Discussion
Meningitis is an inflammation of the meninges. While any organism or disease process can cause severe neurological sequelae or death, most feared usually are rapidly growing bacteria such as meningococcus. Aseptic meningitis is usually caused by nonbacterial organisms and other diseases including enteroviruses, measles, mumps, and mycoplasma. About 75,000 cases occur in the US each year. Organisms colonize the person usually in the nasopharyngeal mucosa, spread to the blood steam and eventually reach the meninges by the blood-brain barrier and cerebrospinal fluid after evading the person’s immunological defenses.

Meningitis classically has symptoms of headache, photophobia and nucal rigidity, but these may be subtle or absent especially in younger children. Nucal rigidity is notoriously inconsistent in children less than 2 years and therefore decisions about evaluation and treatment must be presumptively made based on overall presentation and history. Fever and rash can also be seen. Diarrhea or cough may be present.

Laboratory testing usually includes complete blood count, C-reactive protein, cultures (blood, urine, CSF and possibly stool, throat), and CSF studies including PCR for enteroviruses. Blood serology (acute and convalescent) may also be important.

Presumptive treatment depends on the age and other risk factors. A broad spectrum third generation cephalosporin is usually started along with possible additional coverage for Listeria in neonates and for herpes simplex.

Complications of meningitis include disseminated intravascular coagulation, septic shock, syndrome of inappropriate antidiuretic hormone, diabetes insipidus, increased intracranial pressure, obstructive hydrocephalus (especially with tuberculous meningitis), subdural effusion, hearing loss, and abscess formation. Each of these has its own set of potential resulting complications too.

Learning Point
Patients should be stable to undergo a lumbar puncture procedure. If not, the patient must be stablized, treated presumptively and when well enough, have the procedure. Other contraindications to lumbar puncture includes hemophilia or severe thrombocytopenia, a space occupying lesion or infection near or over the lumbar puncture site.

Although appropriate cultures and PCR are the gold-standard, laboratory testing does provide important information for initial diagnosis, management and treatment of suspected meningitis. Laboratory testing aids in distinguishing between major etiological groupings. It is not uncommon that patients with aseptic meningitis are treated for presumed bacterial meningitis and/or herpes meningitis until confirmatory testing is available. It is also common that patients are presumptively treated before CSF studies are obtained because of the acuity of their presenting symptoms. Tuberculosis and fungal meningitis are less common in the U.S., however they should still be considered in at risk populations or patients with complicated clinical courses. In these cases, extra tubes of CSF that are banked can then be tested.

Initial cerebrospinal fluid findings in different types of meningitis includes:

Bacterial Partially
Treated		 Viral Tuberculosis Fungal
WBC Count > 500 200-500 10-100 50-500 25-500
WBC Type Mostly neutrophils Lymphocytes Early neutrophils,
Late Lymphocytes		 Lymphocytes Lymphotyes
Glucose (mg/dL) < 40 < 40 > 40 < 40 < 40
Protein (mg/dL) 100 < 40 < 100 50-500 25-500
Gram Stain Positive Negative Negative Rarely acid fast
bacillus positive		 May be positive
with special stain
Culture Positive Positive Negative Negative Negative

Questions for Further Discussion
1. What are indications for admission to the intensive care setting with posible meningitis?
2. What prophylactic treatment should be offered to close contacts of meningitis patients?
3. What criteria constitutes a close contact?

Related Cases

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

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

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

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

To view images related to this topic check Google Images.

Leih-Lai, M. Asi-Bautista MC, Ling-McGeorge K. The Pediatric Acute Care Handbook. Little Brown and Co., Boston, MA 1995;88-93..

Rudolph CD, et.al. Rudolph’s Pediatrics. 21st edit. McGraw-Hill, New York, NY. 2003:900-904.

Faust, SN. Pediatric Aseptic Meningitis. eMedicine.
Available from the Internet at http://emedicine.medscape.com/article/972179-overview (rev. 8/3/12, cited 8/20/12).

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.

  • 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