Brain Abscesses Associated with Asymptomatic Pulmonary Arteriovenous Fistulas

Cerebritis, optic ischemia, and cavernous sinus thrombosis arising from sinonasal mucormycosis

Brain and ocular infections can be the worst and fatal consequences of sinonasal infections in immunomodulated or immunocompromised patients. We report a case of a 35-year-old female who received an allogenic hematopoietic stem cell transplantation for acute myeloid leukemia, suffering from maxillo-spheno-ethmoidal rhinosinusitis which was complicated by cavernous sinus thrombosis, orbital cellulitis, optic ischemia and cerebritis.

Endovascular management of pulmonary arteriovenous malformations presenting as multiple brain abscesses

Pulmonary arteriovenous malformations (PAVMs) are rare vascular lesions characterised by abnormal connections between the pulmonary artery and vein bypassing the pulmonary capillary bed and causing right-to-left shunt. Paradoxical embolism is known to occur in these cases, leading to inoculation of septic focus in the systemic circulation. We report a case of multiple PAVMs who presented clinically with seizures and altered sensorium. On radiological work-up, multiple brain abscesses and large PAVMs were evident. The patient was successfully treated by endovascular embolisation of the PAVMs using a vascular plug and multiple coils. The patient showed complete clinical recovery and resolution of brain abscesses on follow-up.

Silent persistent left superior vena cava right-to-left shunt as a unique cause of recurrent brain abscesses

We present a novel case of recurrent brain abscesses found to be the result of a silent congenital right-to-left extra-cardiac shunt, a persistent left superior vena cava (PLSVC) draining into the left atrium. The patient’s brain abscess was evacuated surgically, treated with antibiotics, and his shunt was subsequently repaired. The case suggests that attention should be paid to evaluation for shunt physiology allowing for bypass of the pulmonary circulation in those with recurrent brain abscesses.

Brain abscess associated with Mycoplasma faucium – The initial presentation of pulmonary arteriovenous malformation

Brain abscesses represent a pathology with significant morbidity and mortality. An underlying predisposing condition may not be apparent or identifiable in some instances. We present a patient with cerebral abscess who was found to have, previously undiagnosed, pulmonary arteriovenous malformations (PAVMs). PAVMs are rare pulmonary vascular anomalies resulting in intrapulmonary right to left shunt. These have been implicated in the development of brain abscesses. Conventional cultures from the lesion were non-revealing; hence, sample was sent for next-generation sequencing (NGS) which revealed multiple organisms, with predominance of Mycoplasma faucium, a bacterium initially felt to be a commensal of the oropharynx, but recently implicated as a human pathogen. This case, along with other documented associations between brain abscesses and pulmonary AVMs, highlights that brain abscess could be an initial clinical presentation in asymptomatic PAVMs. Additionally, novel testing such as NGS should be utilized in select settings where microbiological diagnosis can be elusive. This will help institute pathogen-directed specific antimicrobial therapy for favorable clinical outcomes.

Precision diagnosis and therapy of a case of brain abscesses associated with asymptomatic pulmonary arteriovenous fistulas

BACKGROUND

Brain abscesses, a severe infectious disease of the CNS, are usually caused by a variety of different pathogens, which include Streptococcus intermedius (S. intermedius). Pulmonary arteriovenous fistulas (PAVFs), characterized by abnormal direct communication between pulmonary artery and vein, are a rare underlying cause of brain abscesses.

CASE PRESENTATION

The patient was a previous healthy 55-year-old man who presented with 5 days of headache and fever. Cerebral magnetic resonance imaging (MRI) suggested a brain abscess. Thoracic CT scan and angiography demonstrated PAVFs. Aiding by metagenomic next-generation sequencing (mNGS) of the cerebrospinal fluid (CSF) sample which identified S. intermedius as the causative pathogen, the patient was switched to the single therapy of large dose of penicillin G and was cured precisely and economically.

CONCLUSIONS

It is an alternative way to perform mNGS to identify causative pathogens in patients with brain abscesses especially when the results of traditional bacterial culture were negative. Further thoracic CT or pulmonary angiography should also be undertaken to rule out PAVFs as the potential cause of brain abscess if the patient without any known premorbid history.