16. Inflammatory Diseases Of Brain And Meninges

Question 1

Cerebral abscess:

Answer 1

Description: pathogens within brain parenchyma, first cerebritis then demarcation into abscess. Hematologic spreading (infective endocarditis, lung infection)

Imaging:
CT/MRI-t1: hypodense center/edema
MRI-t2: hyperintense center/edema
Contrast: ring enhancement

Differentiation from tumor:
DWI-MRI: hyperintense (limited diffusion of water molecules)
ADC: hypointense

MRS: AA/lactic acid elevated, choline no elevation

Question 2

Herpetic encephalitis:

Answer 2

Description: mainly temporal region

Imaging:
MRI t2 + FLAIR: hyperintense (edema/inflammation)

Question 3

Multiple sclerosis:

Answer 3

Description: autoimmune, demyelinating

Immune system target CNS, SC, optic nerve (initial symptoms - neuritis of optic nerve)

Symptoms: young women + flares/chronic/progressive + spastic paresis + sensory disorders + cerebellar ataxia + retrobulbar neuritis + gaze palsy

Imaging:
MRI - focal changes in medulla oblongata + close to lateral ventricles + corpus callosum (T2w-FLAIR: Dawson fingers)
T1w: hypointense = black holes

Question 4

Bacterial meningitis:

Answer 4

Description: inflammation of pia/arachnoid matter

Method of choice: CSF puncture

Imaging:
MRI T1 CONTRAST (increased vascular permeability from inflammation): leptomeningeal enhancement
CT NO-CONTRAST: usually negative