Table 1

Imaging and other key findings distinguishing between differential diagnoses

Differential diagnosisImaging and laboratory findings
RhomboencephalitisLimited to the brainstem and cerebellum, ring-enhancing abscesses associated with Listeria; inflammatory CSF
Reversible cerebral vasoconstriction syndromeVasoconstriction on cerebral angiography
DemyelinationPostgadolinium enhancement with acute lesions; microhaemorrhages do not occur with demyelination; CSF evaluation especially for oligoclonal bands.
Paraneoplastic encephalitisInflammatory CSF, positive antineuronal antibodies.
CNS vasculitisCircumferential arterial wall thickening and enhancement on vessel wall MRI, inflammatory CSF; serum vasculitis screen may be positive.
SMART syndromeProminent gyral enhancement with mild mass effect and cortical thickening (hyperintense on T2 and FLAIR) with or without diffusion restriction; typically, it is unilateral.
Acute hepatic encephalopathyFLAIR hyperintensity and reduced diffusion in thalami, posterior limb of the internal capsules and periventricular white matter. Serum ammonia may be elevated.
LeucoencephalopathySymmetrical confluent T2 and FLAIR hyperintensities limited to the white matter; follow-up scans show persistent abnormalities.
Central pontine myelinolysisRaised ADC and postgadolinium enhancement
MalignancyPersistent abnormalities on follow-up scans commonly enlarging over time, asymmetrical and often focal
Gliomatosis cerebriIsointense on T1 and hyperintense on T2, elevated choline/NAA peak
Acute strokeDecreased ADC suggesting cytotoxic oedema
Cerebral venous sinus thrombosisAbnormal signal in cerebral venous sinuses
  • ADC, apparent diffusion coefficient; CNS, central nervous system; CSF, cerebrospinal fluid; FLAIR, fluid-attenuated inversion recovery; NAA, n-acetyl aspartate; SMART, stroke-like migraine attacks after radiation therapy.