Entamoeba histolytica brain abscess.

Brain abscess due to Entamoeba histolytica is most commonly seen in a small percentage of patients who also have an amebic liver abscess. The typical patient is a young man who after treatment for liver abscess with apparent improvement develops symptoms and signs of central nervous system involvement. The average age of the patient is 30 years, and common presentations include headache, vomiting, and altered mental status. Signs of amebic brain abscess include most commonly meningeal signs, facial nerve (VII) palsy, motor paralysis, and seizure. Most patients have abnormal cerebrospinal fluid although there is no special or characteristic abnormality. Diagnosis is by serology and PCR of brain abscess aspirate or CSF and treatment is with metronidazole.