Evidence of self-neglect | Longer prodrome of deterioration, not specific for aetiology |
Change in sleep | A potential red flag for affective or mixed psychiatric disorders, may also occur with autoimmune encephalitides such as Morvan’s syndrome |
Recent travel history or immunosuppression including HIV | Broadens the differential diagnosis for infective encephalitides 36 37
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Checkpoint inhibitor use (programmed cell death protein-1, cytotoxic T lymphocyte antigen-4 or their corresponding ligands | Encephalitis has been described as part of the spectrum of autoimmune diseases these drugs can cause |
Aphasia | Commonly mistaken for confusion, and commonly occurs with herpes encephalitis, cortical strokes and acute demyelinating encephalomyelopathy |
Brainstem/cerebellar signs | Thalamic damage can cause peduncular hallucinosis and fluctuating wakefulness |
Parkinsonism | Dementia with Lewy bodies in particular causes fluctuations and visual hallucinations (silent people, animals) |
Meningism | Self-explanatory |
Automatisms, focal myoclonus | Focal seizures (unlike generalised myoclonus which is in keeping with encephalopathy) |
Facio-brachial seizures, catatonia | Strongly suggests particular autoimmune encephalitides |
Petechial haemorrhages | Along with acute derangements of blood tests indicative of other organ function, may indicate fat embolus from long bone or pelvic fractures (characteristic DWI MR brain changes) |
Asterixis | Type 2 respiratory, renal or liver failure |
Systemic signs of portal hypertension | Liver failure |
Unusual affect, behaviour change suggesting auditory hallucinations, paranoia | Uncontrolled psychotic symptoms in keeping with primary psychiatric disorder |
Systemic signs of infective endocarditis | Raises suspicion for an embolic cause |