Actinomyces meyeri-induced brain abscess in pregnancy: a case report

BACKGROUND: Brain abscesses can occur when suppurative, bacterial or protozoan infections spread to the brain. Here, we report a rare case of Actinomyces meyeri-induced brain abscess in a pregnant woman. CASE PRESENTATION: We present the case of a 38-years-old primipara admitted to the emergency department at our hospital with a 4-day history of fever and vomiting. The symptoms worsened rapidly during the 8 h prior to admission, and the patient experienced a sudden loss of consciousness 4 h before arrival to the unit. Brain magnetic resonance imaging revealed abnormal signals in the right parietal–temporal lobe, suggesting the possibility of abscess rupture into the ventricle and sulcus. Right lateral ventricle compression and midline structure deviation to the left were noted. A right temporal–occipital mass with midline shift was detected. Emergency procedures were promptly performed, including craniotomy, removal of the right temporal–occipital mass, decompressive craniectomy, implantation of an intracranial pressure monitoring device, and external ventricular drainage. Cerebrospinal fluid culture indicated infection with Actinomyces meyeri. After administration of antibiotics, including linezolid and meropenem injections, along with treatments to decrease intracranial pressure, the patient’s vital signs stabilized. However, the patient developed hydrocephalus, requiring placement of a hydrocephalus shunt several months later. Throughout this period, the patient remained in a coma vigil state, and labor was induced for the fetus. CONCLUSIONS: Although the patient did not present with any apparent predisposing causes for brain abscess, a scout view of CT revealed dental caries. In addition, the occurrence of the brain abscess may have been influenced by the hormonal changes during pregnancy, including increased secretion of estrogen and progesterone, as well as decreased immune function. Early diagnosis and intervention are crucial in such cases. Therefore, it is recommended to seek early medical attention if symptoms such as fever, vomiting, and changes in mental state occur during pregnancy, as the prognosis for both the mother and infant is poor once the abscess ruptures. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12883-023-03453-7.