Table 1.

Investigations performed to rule out differential diagnoses of rapidly progressive dementia

Investigation	Differential diagnoses ruled out
Blood sugar level	Hypoglycaemic encephalopathy
CT brain, MRI brain	Stroke, brain metastases, abscesses, normal pressure hydrocephalus
Electrolytes and renal panel	Electrolyte abnormalities
Liver panel	Hepatic encephalopathy
Thyroid function test and thyroid antibodies	Hashimoto encephalopathy
CRP, ESR, autoimmune screen	Autoimmune encephalitis
Serology and CSF for HIV, cryptococcus, syphilis, tuberculosis, viral	Meningitis or encephalitis of fungal, bacterial, viral aetiologies
B12, folate	B12, folate deficiency dementia
EEG	Status epilepticus
Heavy metal screening	Heavy metal toxic encephalopathy
Paraneoplastic panel	Paraneoplastic limbic encephalopathy
Clinical features, CT brain, MRI brain	Alzheimers/frontotemporal dementia

CRP, C reactive protein; CSF, cerebrospinal fluid; ESR, erythrocyte sedimentation rate.