Snapshot A 59-year-old man presents to the emergency department with a headache. He has never had headaches in the past and reports his headache worsens with cough. He describes his headaches as severe and located on the right-side of his head. His headaches are unresponsive to over the counter analgesics. Medical history is remarkable for recent manipulation of his ventriculoperitoneal shunt due to malfunction. Physical examination is notable for 4-/5 power in the left-sided upper extremity. An MRI brain with contrast demonstrates a ring enhancing lesion in the right primary motor cortex. Neurosurgery has been consulted for removal of the mass in order to time empiric antibiotic administration. Introduction Definition login to view 1 more bullet Epidemiology Risk factors login to view 8 more bullets Etiology Pathogens include (note that infections are often polymicrobial) login to view 3 more bullets Pathophysiology Immune-mediated response to the microbial pathogen Presentation Symptoms login to view 1 more bullet Physical exam login to view 3 more bullets Imaging MRI brain with contrast login to view 14 more bullets Studies Making the diagnosis login to view 1 more bullet Differential Neurocysticercosis login to view 3 more bullets Glioblastoma login to view 2 more bullets Treatment Medical login to view 6 more bullets Operative login to view 6 more bullets Complications Seizures Brain herniation Ventriculitis secondary to abscess rupture and seeping in ventricles Meningitis