Abstracts

Rationale: Herpes infection of the CNS represents an important differential diagnosis in patients presenting with first time seizures in the emergency room. The clinical syndrome is often characterized by fever, headache, seizures, focal neurological signs, and impaired consciousness. HSV PCR in CSF has become the standard diagnosis and early therapy with acyclovir has been proven to be effective. However we observed, that lumbar puncture (LP) and empiric acyclovir therapy was performed frequently and without clear indication guidelines in children presenting with new-onset afebrile seizures (AS). The objectives of the study were: 1) To evaluate the incidence of CNS herpes infection in children presenting with AS who underwent LP. 2) To compare the CSF findings and blood total white blood count of AS group with a herpes control group (HCG) of children diagnosed with CNS herpes infection. 3) To review the clinical manifestations, seizure characteristics and EEG patterns between the two group as well as antiviral therapy use. Methods: A retrospective chart review was performed on all patients with age range between three months to eighteen years who presented with AS and had undergone LP at the Children’s Hospital of Buffalo between January 2000 to August 2007. The HCG included age matched patients diagnosed with CNS herpes simplex infection, disseminated herpes simplex infection and congenital herpes simplex infection. Seizure numbers and duration in both groups were recorded along with EEG characteristics. CSF parameters as well as blood WBC were recorded. The number of patients and duration of acyclovir treatment was compared between the two groups. Results: Fifty five patients were identified in the AS group (mean age: 4.4 ± 0.6 years; 31 males and 24 females) and 6 in the HCG(mean age: 1.9 ± 1.5; 5 males and 1 female). Fever was a prominent presentation in all HCG patients. The numbers and duration of seizures was similar between the 2 groups. Generalized seizures (65.4%) were more common in AS group while focal seizure (71.4%) were prominent in the HCG. Obtundation was seen in 23.6% of AS and 57.2% in HCG group, while focal neurological findings were seen in 38.2% of AS vs. 85.7% of HCG patients. Blood total WBC was 12.7 ± 8.1 per mm3 and 14.3 ± 5.3 per mm3 in the AS and HCG respectively (p=0.6074). CSF findings revealed significant findings differences in CSF white count (3.1±0.6 vs. 148.3 ± 133.5/cells per mm3 in the AS vs. HCG groups respectively (p=0.015) and CSF protein (27.4 ± 2.5 vs. 112± 43.87 mg/dl, p=0.0002 respectively). CSF herpes PCR or viral culture was negative in all AS patients. Acyclovir treatment was given in 32.7% of afebrile patients for 1 to 5 days duration. All patients in HCG received acyclovir treatment for 3 weeks. EEG was normal in 50.9% of AS patients, but none showed PLED or seizure on EEG. Conclusions: CNS herpes infection is extremely rare in afebrile children and infants presenting with acute seizures. Normal CSF study further decreases the possibility of CNS herpes infection suggesting that empiric antiviral therapy with acyclovir may not required in this setting.