Marienfeld: Expressive aphasia presentation of B. henselae encephalitis 69 Figures 3a (left) and b. Follow-up axial and coronal FLAIR sequences. Previ- ously seen abnormality in the left insula, with no interval change. Figures 3c-e (counter clockwise). Diffusion-weighted image and T1- weighted image pre- and post-con- trast. No interval change; no enhance- ment seen post-con- trast to suggest a subacute process. the patient had a witnessed generalized tonic- clonic seizure. A lumbar puncture showed 133 red blood cells (RBC)/microliter (0 cells/microliter) in tube 1 with no white blood cells (WBC). There were no RBCs in tube 4 with one WBC/microliter (normal 0- 5 cells/microliter). The CSF glucose was 60mg/dl (40-70mg/dl), and the protein was 64mg/dl (15-45mg/dl). HSV, VZV, En- terovirus PCR, West Nile and Lyme antibod- ies, as well as VDRL and CSF culture, were all negative or absent. The following morning the patient was aphasic, febrile, had an elevated WBC count to 12,000/microliter, and his level of alert- ness worsened. A repeat EEG showed non- focal findings, including a moderate generalized slowing and frontal intermittent polymorphic delta slowing with no epilepti- form activity. Considering the history of stray kittens in his home, a suspicious skin lesion, and previous axillary lymphadenopa- thy, the possibility of Bartonella henselae infection was raised. At approximately 48 hours from symptom onset, B. henselae serology studies were sent, and the patient was given one dose of Azithromycin 500mg IV. The next morning, the patient’s symp- toms and aphasia had resolved. He was switched to doxycycline and rifampin, based on CSF penetration profiles, and discharged home with a 14-day course of the above an- tibiotics. B. henselae titers were reported as IgG positive 1:1024 (nl < 64) and IgM pos- itive 1:20 (nl < 16). Follow-up imaging sev- eral weeks later showed no interval change (Figures 3 a-e). Today, the patient has resumed his oc- cupation as a musician, singer, and song- writer. He is teaching classes and currently in the recording studio working on an album. DISCUSSION Our patient is the first adult case of serologically confirmed B. henselae infec- tion presenting with a recurring expressive aphasia that we have encountered. The pa- tient had a prior stroke in a region associated with speech apraxias and expressive aphasias, and he presented with mutism at that time. Several studies suggest that the blood brain barrier is dysfunctional in re- gions of prior infarct, which provides a po- tential portal of entry to the central nervous system [8,9]. Entry of B. henselae and in- flammatory mediators at this site could ex- plain initial symptoms of recrudescence of his previous focal deficit. However, while initially presenting with an expressive apha- sia, he went on to develop several symptoms inconsistent with a purely ischemic cause or solely recrudescence of a prior stroke. While epileptiform phenomenon can develop in the setting of old cortical ischemic lesions, this is less likely given the non-focal and non- epileptiform EEG findings, the waxing and waning consciousness in the setting of a