Acute Mental Status Change - A Diagnostic Challenge

Case Presentation: A 45 year old female without significant medical or surgical history was brought to the ER via ambulance after a four day history of malaise, fatigue, fever and chills, followed by an hour of crawling on her floor speechless and confused. She had no sick contacts and no recent illnesses. Her vital signs included T=103.2^oF, HR=125, RR=16, BP=94/44. O₂sat was 95% on room air. Her skin exam was normal. Cardiovascular exam revealed normal S₁ and S₂ without murmurs, gallops, or rubs. Her level of consciousness was labile, ranging from alert to obtunded. She was unable to follow commands but did withdraw to pain, formed words which were nonsensical. There were no neurologic deficits other than those related to her mental status.

Laboratory tests were as follows: Serum WBC 5.8 with 10% bands, 77% PMNs, and 8% lymph. CSF revealed glucose of 80mg/dl, protein 98gm/dl, and 3+ PMNs with 15% bands. CSF WBC was 750k/mm³, RBC was 110m/mm³. CSF antigen panel was negative. Urine toxicology screens were negative. A CT scan of the head without contrast was normal. EKG was normal. The patient was admitted to ICU and given ceftriaxone, vancomycin, and acyclovir.

On hospital day #2 her neurologic exam progressed to include left sided weakness and neglect. EEG was normal. On hospital day #3 she developed skin changes consistent with Osler nodes and Janeway lesions. Blood culture and sensitivities revealed methicillin-sensitive Staphylococcus aureus (MSSA) in 2/2 bottles. MRI showed a deep right sided parietal lesion. Trans-thoracic echocardiogram (TTE) was normal, with a well-visualized tri-leaflet aortic valve. On hospital day #4, TTE was repeated; again the aortic valve was well visualized and without vegetation. Soon thereafter, trans-esophageal echocardiogram (TEE) revealed a 1.8 x 1.0 cm vegetation on the left coronary cusp of the aortic valve. Based on susceptibility studies, the patient was given a 28 day course of IV penicillin, and all signs and symptoms resolved. All other diagnostic tests returned without positive findings.

Discussion: TTE cannot definitively rule out aortic valve vegetation despite a quality study with adequate valve visualization. Although sensitivity has been reported as 94-100% for TEE, vs 44%-63% for TTE, current recommendations still tend to favor the TTE as the initial study. However, if the clinical suspicion is moderate to high, or in the patient with staphylococcal bacteremia, it may be more cost-effective to use TEE as the initial study than it is to use TTE. Our patient had no known risk factors for endocarditis, yet would have gained benefit from use of TEE as the initial study.

This abstract was submitted as part of an Associate's competition amongst all residents in the state of Massachusetts, and was selected to be presented as a poster at the 2001 Annual Meeting of the ACP-ASIM. The abstract was required to conform to certain size and space restrictions.

Click Here to view the poster that was presented. This file is in PDF format.

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