ABSTRACT
We report an interesting case of a 19 year old female with findings on MRI suggestive of viral encephalitis. An extensive workup was negative for infectious causes and she was subsequently diagnosed with anti-NMDA encephalitis. Anti-NMDA encephalitis is a highly lethal but treatable form of autoimmune encephalitis that has recently been characterized. It is frequently found in young women and associated with an underlying teratoma. Although rare, this diagnosis should be considered in young females for whom a rapid onset of encephalitis cannot be explained by more common causes.
Subject(s)
Autoimmune Diseases of the Nervous System/diagnosis , Encephalitis/diagnosis , Encephalitis/immunology , N-Methylaspartate/immunology , Autoantibodies/cerebrospinal fluid , Autoimmune Diseases of the Nervous System/drug therapy , Autoimmune Diseases of the Nervous System/immunology , Diagnosis, Differential , Encephalitis/drug therapy , Female , Humans , Immunoglobulins, Intravenous/therapeutic use , Magnetic Resonance Imaging , Young AdultABSTRACT
BACKGROUND: Plasma D-dimer measurement is used in the assessment of the clinical probability of pulmonary embolism (PE), in order to minimize the requirement for pulmonary computed tomography angiography (CTA). PURPOSE: To evaluate whether doubling the threshold value of serum D-dimer from 500 µg/L to 1000 µg/L could safely reduce utilization of pulmonary CTA to exclude PE in our emergency department patient population. MATERIAL AND METHODS: Emergency department patients evaluated for PE with a quantitative D-dimer assay and pulmonary CTA were eligible for inclusion. D-dimer values were retrospectively collected in all included patients. Pulmonary CT angiograms were reviewed and scored as positive or negative for PE. Receiver-operating characteristic (ROC) analysis was used to determine the accuracy of quantitative D-dimer measurements in differentiating between positive and negative PE patients as per CTA. RESULTS: A total of 237 consecutive patients underwent pulmonary CTA and had a D-dimer measurement performed. Median D-dimer level was 1007 µg/L and in 11 (5%) patients the pulmonary CT CTA was positive for PE. The ROC curve showed an area under the curve (AUC) of 0.91 (P < 0.0001). Increasing the D-dimer threshold value of 500 µg/L to 1000 µg/L increased the specificity from 8% to 52% without changing the sensitivity. CONCLUSION: Adjusting the D-dimer cut-off value for the emergency department community population and patient age increases the yield and specificity of the ELISA D-dimer assay for the exclusion of PE without reducing sensitivity.
