Presentation
Left facial droop
Patient Data
A 38mm ring enhancing right frontal lobe cerebral mass results in marked secondary vasogenic edema with parafalcine herniation (9mm midline shift) and mild uncal herniation
Findings are in keeping with a cerebral abscess centered over the right basal ganglia. The abscess has decompressed into the temporal horn of the right lateral ventricle with subsequent ventriculitis effecting this region along with pooling of purulent material within the occipital horns of the lateral ventricles. Apparent susceptibility artefact surrounding the distended temporal horn of the right lateral ventricle, could reflect hemorrhagic encephalitis. There is severe vasogenic edema and subsequent mass effect with midline shift to the left of 9mm and right uncal herniation.
There are further smaller areas of restricted diffusion within the right centrum semiovale and deep white matter of the left frontal lobe, with enhancement and blooming artefact. Differentials include further areas of infection/cerebritis or metastases. Remainder of the some cortical sleep blooming artefact seen scattered throughout the cerebral hemispheres and cerebellum is nonspecific. Differentials include amyloid angiopathy, hypertension or small hemorrhagic metastases are difficult to exclude
Case Discussion
60-year-old male presented with 1-week history of worsening left sided facial droop and dysarthria. On presentation he had a GCS of 14 (E3V5M6) and was found to be tachycardic, hypertensive and febrile to 38.9o C. He had a history of lung adenocarcinoma and was completing chemotherapy.
Initial CT brain in ED showed a large right fronto-temporal contrast enhancing lesion with significant vasogenic edema and 7mm of midline shift. He was admitted under neurosurgeons and was started on IV Keppra, IV Dexamethasone and IV Piptaz as empirical cover.
Initial differential diagnoses included metastases from a lung primary or brain abscess.
MRI the next day confirmed a right cerebral abscess over the right basal ganglia. He underwent an urgent stereotactic needle aspiration of the abscess.
Intra-operative specimen Gram stain:
- Leukocytes: 1+
- Epithelials: Nil
- Gram negative bacilli: 1+
- Gram positive cocci: scant
Intra-operative specimen Culture:
- Strep. intermedius (S. milleri group) scant
- Aggregatibacter (Haemophilus) segnis scant
- Eikenella corrodens scant