Brain abscess complicated by intraventricular rupture and ventriculitis
Presentation
Colon cancer patient presented septic and comatose to the emergency department. His wife brought the following MRI scan that had been performed at another institution.
Patient Data
There is a right periventricular ring-enhancing lesion with central diffusion restriction.
Upon arrival to our emergency department, a non-contrast brain CT scan performed.
There is dependent layering intraventricular material which appears relatively hyperattenuating to the CSF, mostly represents pus.
The ventricles are dilated with periventricular hypoattenuation, suggestive of active hydrocephalus.
The provisional diagnosis here is intraventricular rupture of the right periventricular cerebral abscess complicated by ventriculitis and active obstructive hydrocephalus.
Extensive ependymal and leptomeningeal enhancement including the cranial nerves, most evident at T1 post-contrast and FLAIR (performed post-contrast), due to extensive ventriculitis and leptomeningitis secondary to cerebral abscess rupture.
Pus filling the ventricular system and extra-ventricular CSF spaces including the basilar cisterns, which signal fails to suppress on FLAIR and demonstrates diffusion restriction.
The ventricular system is dilated with periventricular edema signal, in keeping with active obstructive hydrocephalus.
Left ventriculostomy catheter.
Case Discussion
A cerebral ring-enhancing lesion carries a long list of differential diagnoses, but in the presence of central diffusion restriction without blood products, the diagnosis of cerebral abscess is most likely. Cerebral abscess is a neurosurgical emergency requiring rapid intervention and drainage.
This case demonstrates the catastrophic consequences of delaying such a life threatening diagnosis. The right periventricular cerebral abscess ruptured into the ventricular system resulting in ventriculitis and leptomeningitis, and active obstructive hydrocephalus with a dismal prognosis.