The Brief Case: A 10-Year-Old Girl with Meningoencephalitis

Abstract

A previously healthy, fully immunized 10-year-old girl from Minnesota presented in July with a 1-week history of headaches, dizziness, myalgias, pharyngitis, and fever and a 1-day history of double vision, unsteady gait, and slurred speech. Her symptoms began approximately 4 days after returning from a family vacation to northern Wisconsin, where she had spent significant time outdoors and had exposure to mosquitoes. Upon evaluation in the emergency department, she was afebrile with normal vital signs. She was oriented but drowsy, demonstrated dysarthric (i.e., slurred) speech and dysmetria (i.e., lack of coordination of movement), and had trouble walking. A complete blood count showed a hemoglobin of 13.3 g/dl (normal range, 12.0 to 14.5 g/dl), white blood cell count of 9.1 ϫ 10 9 /liter (3.4 ϫ 10 9 to 10.8 ϫ 10 9 /liter), and platelet count of 124 ϫ 10 9 /liter (150 ϫ 10 9 to 450 ϫ 10 9 /liter). Reactive lymphocytes (i.e., large, antigen-stimulated cells) were observed on a peripheral blood smear. A basic metabolic panel and liver function tests were within normal limits, and a urine drug screen was negative. A cranial computed tomography (CT) scan was normal, while magnetic resonance imaging (MRI) of the brain with intravenous contrast showed subtle signs of inflammation (leptomeningeal enhancement concentrated in the brainstem, cortical, limbic, and deep gray structures), which is a pattern that can be seen with viral meningoencephalitis (Fig. 1). An electroencephalogram was performed, which showed no lateralized periodic discharges or other abnormalities. Laboratory studies included serologic testing for herpes simplex virus 1 and 2 (HSV1/2), Bartonella henselae, B. quintana, and Lyme disease, all of which were negative. A tick-borne disease real-time PCR panel targeting Anaplasma phagocytophilum, Ehrlichia species, Babesia species, and Borrelia miyamotoi, performed on whole blood, was negative. A lumbar puncture was performed, and cerebrospinal fluid (CSF) showed a total nucleated cell count of 219/l, with a differential of 44% lymphocytes, 44% neutrophils, and 12% monocytes. In addition, the CSF showed a normal glucose level of 53 mg/dl (normal range, 40 to 70 mg/dl) and an elevated protein level of 95 mg/dl (12 to 60 mg/dl). Gram stain of the CSF showed white blood cells but no organisms. Bacterial culture of the CSF grew one colony of Corynebacterium species and Lactobacillus gasseri (1ϩ growth), both of which were interpreted as contaminants. Further testing on CSF included real-time PCR for cytomegalovirus, enterovirus, Epstein-Barr virus, HSV1/2, West Nile virus (WNV), varicella-zoster virus (VZV), and free-living amoe