Differentials
Intracerebral haemorrhage
SIGNS / SYMPTOMS
No symptoms or signs reliably distinguish haemorrhagic stroke from ischaemic stroke.
Haemorrhagic stroke is more often associated with reduced level of consciousness and signs of increased intracranial pressure than ischaemic stroke.
INVESTIGATIONS
CT or MRI demonstrates haemorrhage (hyperattenuation).
Transient ischaemic attack (TIA)
SIGNS / SYMPTOMS
Transient neurological symptoms, with no evidence of acute infarct. A TIA has a sudden onset and may last anything from a few minutes to 24 hours. Most patients with TIA usually have complete resolution of symptoms and signs within 1 hour.[66] Suspect a stroke if sudden-onset, focal neurological deficit persists for longer than 24 hours.
INVESTIGATIONS
CT or MRI may be normal or may reveal evidence of older infarcts.
Hypertensive encephalopathy
SIGNS / SYMPTOMS
The combination of headache, cognitive abnormalities or decreased level of consciousness, and hypertension significantly above patient's baseline blood pressure indicates hypertensive encephalopathy. Other possible signs/symptoms include visual changes or loss, or signs of increased intracranial pressure.[95]
INVESTIGATIONS
Cerebral oedema on CT or MRI.
Hypoglycaemia
SIGNS / SYMPTOMS
There may be a history of diabetes with use of insulin or insulin secretagogues.
Decreased level of consciousness.
INVESTIGATIONS
Low serum glucose at time of symptoms.
Complicated migraine
SIGNS / SYMPTOMS
Repetitive history of similar events; preceding aura, headache in a marching pattern differentiates complicated migraine.[95]
Stroke often presents with negative symptoms (e.g., visual loss, numbness, or weakness).
Positive symptoms (e.g., marching paraesthesias, visual hallucinations, and abnormal motor manifestations) are more likely with complicated migraine.
INVESTIGATIONS
MRI shows no evidence of infarction.
Seizure and postictal deficits
SIGNS / SYMPTOMS
History of seizures; witnessed seizure followed by postictal deficits: for example, drowsiness and tongue-biting.[95]
Wrong-way eye deviation (i.e., gaze deviation away from the side of the brain lesion, towards the hemiparetic side) should prompt consideration of seizure but can also occur with strokes affecting the pons or thalamus.
INVESTIGATIONS
Electroencephalogram confirms evidence of seizure.
MRI shows no evidence of infarction.
Functional neurological and somatic symptom disorders
SIGNS / SYMPTOMS
Neurological signs and symptoms do not fit a vascular territory.
No cranial nerve deficits.
Additionally, functional neurological disorder displays multiple signs that are neurologically inconsistent. Some patients will have had adverse life events, but, importantly, these are neither necessary nor sufficient for the diagnosis.[96] Psychological comorbidities (especially anxiety, panic, and depression) are common, affecting over 50% of patients.[97]
INVESTIGATIONS
MRI shows no evidence of infarction.
Wernicke's encephalopathy
SIGNS / SYMPTOMS
History of alcohol abuse.
Irritability, confusion, and delirium common presenting features.
INVESTIGATIONS
Decreased blood thiamine level and successful therapeutic trial of thiamine.
Brain tumour
SIGNS / SYMPTOMS
Symptoms and signs more likely to have been on-going.
May be history of cancer if metastatic lesion causing symptoms.
INVESTIGATIONS
CT head demonstrates lesion or lesions.
Sepsis
SIGNS / SYMPTOMS
Clinical evidence or strong suspicion of infection in an acutely unwell patient.
Ingestion of toxic substances
SIGNS / SYMPTOMS
History of alcohol or drug abuse.
INVESTIGATIONS
Toxicology screen positive for alcohol or drugs.
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