Table 1

Investigations performed to rule out differential diagnoses of rapidly progressive dementia

InvestigationDifferential diagnoses ruled out
Blood sugar levelHypoglycaemic encephalopathy
CT brain, MRI brainStroke, brain metastases, abscesses, normal pressure hydrocephalus
Electrolytes and renal panelElectrolyte abnormalities
Liver panelHepatic encephalopathy
Thyroid function test and thyroid antibodiesHashimoto encephalopathy
CRP, ESR, autoimmune screenAutoimmune encephalitis
Serology and CSF for HIV, cryptococcus, syphilis, tuberculosis, viralMeningitis or encephalitis of fungal, bacterial, viral aetiologies
B12, folateB12, folate deficiency dementia
EEGStatus epilepticus
Heavy metal screeningHeavy metal toxic encephalopathy
Paraneoplastic panelParaneoplastic limbic encephalopathy
Clinical features, CT brain, MRI brainAlzheimers/frontotemporal dementia
  • CRP, C reactive protein; CSF, cerebrospinal fluid; ESR, erythrocyte sedimentation rate.