A 7-year-old girl was presented with nocturnal back and leg pain for the past 6 weeks. A tick bite in the popliteal fossa was observed 8 weeks before onset of the symptoms, but no erythema migrans. The physical examination revealed a diastolic heart murmur (3/6), suspected to be an opening sound of the mitral valve. The examination of the locomotor organs showed a lumbar rigidity with a pathological finger floor-distance of 50
cm together with a positive Lasègue sign without any other neurological symptoms.
The laboratory examinations (blood cell count, creatinine, urea, protein, aspartate and alanine aminotransferase, bilirubine, prothrombin, thromboplastin, and c-reactive protein) were normal. There was no proof of bacteria in blood cultures or throat swabs. Serological examinations for Cytomegalovirus, Epstein-Barr virus, and Coxsackievirus and for antistreptolysin, Mycoplasma pneumonia, and Chlamydia pneumoniae
were negative. The serum was positive for Borrelia burgdorferi
immunoglobulin M (IgM) und IgG antibodies (ELISA and immunoblot). In the cerebrospinal fluid (84/ul leucocytes, protein 113
mg/dL), an intrathecal borrelia IgM (33.7, normal: <1.5) and IgG (15.4, normal: <1.5) antibody synthesis was found. Immunoglobulins (IgG, IgA, IgM, IgE) and complement factors (C3, C4, CH50) were in normal range. The patient is HLA-B27 negative. Anti-nuclear antibodies (ANA) were elevated (1
640). Extractable nuclear antibodies and antibodies for double-stranded DNA were negative. The abdominal ultrasound and the magnetic resonance imaging of the pelvis revealed no pathological signs. The echocardiography (ECG) showed thickening of both mitral valve cups with a mild mitral insufficiency (I°) () and the electrocardiogram regular sinus rhythm with a physiologically incomplete right bundle branch block.
Picture showing a long axis view of the heart during diastolic opening of the mitral valve: notice the terminal clubbed thickness of both mitral valves.
Due to these findings, the diagnosis Lyme neuroborreliosis could be verified and the thickening of the mitral valve cups was assumed to be a cardiac manifestation of Lyme disease. An intravenous therapy with Cefotaxime (200
mg/kd/d) was given over a period of 14 days.
After 4 days of treatment, an improvement of the nocturnal symptoms was achieved and lumbar rigidity had significantly improved as well. After four weeks, there was still some thickening on the mitral valve. After 6 months, the patient was free of symptoms. The echocardiography showed terminal thickening of both cups of the mitral valve and only discrete mitral insufficiency. Twelve months later, the echocardiography showed an almost normal mitral valve with only trivial mitral insufficiency (). The patient was free of symptoms.
Four chamber view. 1 year later: mitral valve without thickness.