A 70-year-old man presented to our hospital with a two-week history of fever associated with lower back pain. He had a past history of recurrent infective endocarditis, for which he was admitted to our hospital in 2005 and in 2009. Streptococcus bovis was isolated during the first visit in 2005 as the causative organism of infective endocarditis. In addition, vegetation was found on the posterior leaflet of the mitral valve. During the second admission, blood culture showed the growth of a Streptococcus species. However, specific culture results were not reported. Similar to the first admission, vegetation growth was again found on the posterior leaflet of the mitral valve. On both admissions, the patient successfully recovered following the appropriate antibiotic treatment with reduction of vegetation.
On admission, the patient's core body temperature was 39.0
, blood pressure 130/80 mmHg, and pulse rate was 88 beats/minute. Auscultation revealed a regular heart beat with an early systolic murmur was found at the left lower sternal border (grade III/VI). Neurological examination was unremarkable. No peripheral stigmata of infective endocarditis were noted.
Laboratory tests showed absence of leukocytosis (white blood cell 7,400/mm3), but mild anemia (hemoglobin 8.5 mg/dL), and thrombocytopenia (platelets 120,000/mm3) was noted. Except for a C-reactive protein (CRP) value of 4.17 mg/dL (0.1-0.8 mg/dL), no other laboratory tests showed significant abnormalities (blood urea nitrogen 15 mg/dL, creatinine 0.8 mg/dL, total protein 6.9 g/dL, albumin 3.4 g/dL, aspartate aminotransferase 27 IU/L, alanine aminotransferase 14 IU/L).
Chest radiography showed no pulmonary edema or active lesions in the lungs. In transthoracic echocardiography, a 2.7×1.4 cm sized vegetation on the posterior leaflet of the mitral valve () was noted. Furthermore, moderately severe mitral regurgitation, trivial aortic regurgitation, and moderate tricuspid regurgitation was also noted. Other findings included left ventricular (LV) hypertrophy (LV mass 270.5 gm), LV enlargement (LV end diastolic dimension 61 mm, LV end systolic dimension 41 mm), left atrial (LA) enlargement (LA dimension size 40.1 mm), and mild pulmonary hypertension (pulmonary arterial pressure 37 mmHg).
A 2.7×1.4 cm sized vegetation on the posterior leaflet of mitral valve.
After diagnosis of infective endocarditis was confirmed, treatment was immediately started with intravenous ceftriaxone and gentamycin, on suspicion of recurrent infective endocarditis.
On the second day of antibiotic therapy, fever and other signs of infection resolved. We continued antibiotic treatment for four weeks. However, blood culture demonstrated no growth of bacteria and fungi. Although his clinical signs and symptoms related to infective endocarditis improved, and CRP level decreased, his back pain did not completely resolve. Consequently, we decided to order a plain lumbar spine radiograph to evaluate the lower back pain, which showed disc space narrowing and endplate erosion of the L3 and L4 vertebral bodies (). Magnetic resonance imaging of the lumbar spine was performed to further evaluate the erosive lesions, which confirmed acute spondylodiskitis of L3, L4 vertebrae and L3-4 disc space (). Pyogenic spondylodiskitis was highly suspicious to be associated with infective endocarditis according to the clinical course and patient's history. The patient was discharged after four weeks of intravenous antibiotic treatment without complication. We decided to conduct follow-up evaluation of the patient's spinal lesions at the orthopedic outpatient clinic.
Plain radiograph shows narrowing of the disc space at L3-L4 level. Destruction of the superior endplate of the L4 vertebra, and the inferior endplate of L3 vertebra is seen (arrow).
Spine MRI shows abnormal high signal density in the disc within the adjacent vertebral bodies at L3-L4 level (arrow). Bony destruction of vertebral bodies is seen in L3 and L4.
During follow-up at the outpatient clinic, the size of mitral valve vegetation was shown to be reduced on echocardiography (1.35×0.67 cm). There were no symptoms of infective endocarditis or pyogenic spondylodiskitis.