19-Year-Old Woman with Headache, Fever, Stiff Neck, and Mental-Status Changes

Posted by • June 20th, 2014

In the latest Case Record of the Massachusetts General Hospital, a 19-year-old woman was admitted to the pediatric ICU because of a headache, fever, photophobia, neck stiffness, and mental-status changes. She was drowsy and disoriented with respect to year. She had truncal ataxia and rotatory nystagmus, and her face and right arm were numb.

In a 2010 study, M. pneumoniae was detected at autopsy in brain tissue of 3 patients (2 with encephalitis and 1 with acute disseminated encephalomyelitis) and in the CSF in approximately 50 patients, with the use of either culture or PCS; these findings suggest the possibility of a direct M. pneumoniae infection of the central nervous system. In addition, anti-galactocerebroside (GalC) antibodies have been detected in the blood, the CSF, or both (with the use of ELISA) in some patients with M. pneumoniae-associated encephalitis, particularly those with evidence of demyelination on MRI.

Clinical Pearls

What were the results of the California Encephalitis Project in 2006 regarding causes of encephalitis?

In the California Encephalitis Project, of the 1570 patients who participated in the study that was published in 2006, a confirmed or probable cause of encephalitis was identified in 24% (the cause was infectious in 16% and noninfectious in 8%), a possible infectious cause was identified in 13%, and no cause was identified in the remaining 63%. The most commonly identified cause was M. pneumoniae; it was considered a possible cause and not a confirmed or probable one in nearly all cases. The following viral causes were each identified in at least 1% of patients: enterovirus, herpes simplex virus, varicella-zoster virus, West Nile virus, and Epstein-Barr virus.

What is neuromyelitis optica?

Neuromyelitis optica is an inflammatory disorder typically characterized by a bilateral optic neuropathy and cervical myelopathy. Patients with neuromyelitis optica can present with longitudinally extensive myelitis without optic neuritis, and cerebral involvement with encephalopathy can be present, particularly in younger patients. Also, patients with neuromyelitis optica are more likely than patients with other demyelinating disorders to have eosinophils in the CSF. Extensive leptomeningeal enhancement is rarely described with neuromyelitis optica.

Morning Report Questions

Q: What limitations are there when interpreting serologic testing for M. pneumoniae?

A: The interpretation of serologic tests for M. pneumoniae is complicated both by the persistence of antibodies against M. pneumoniae after infection and by the imperfect sensitivity and specificity of available assays. The IgM antibody response peaks approximately 3 weeks after infection and then begins to decline, but it may persist for several months. Since tests for IgM antibodies against M. pneumoniae can have both false negative and false positive results, the serologic diagnosis is most reliable when the IgG antibody titer in convalescent-phase serum specimens is four times as high as the IgG antibody titer in acute-phase serum specimen.

Q: How reliable is PCR testing of cerebrospinal fluid for M. pneumoniae?

A: The results of PCR testing of CSF for M. pneumoniae have been reportedly inconsistent among patients with central nervous system disease that is attributed to mycoplasma infection, even when the testing is performed early in the clinical course. CSF PCR testing for M. pneumoniae is not widely available, although assays that have not been approved by the FDA are offered at some institutions and reference laboratories. The performance characteristics of these assays vary, and the reference standard to which they should be compared is unknown. PCR assays detected M. pneumoniae in the CSF in only 2% of the 111 patients in the California Encephalitis Project who received a diagnosis of encephalitis associated with M. pneumoniae.

One Response to “19-Year-Old Woman with Headache, Fever, Stiff Neck, and Mental-Status Changes”

  1. Luciano Vitola says:

    No possibility to Be ADEM ? And about Themis treatment. Was just macrolids or IgG was done?