Differentials

Epidural haematoma

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

'Lucid interval', younger patients, usually an associated skull fracture.

Rarer in older patients (>60 years).

INVESTIGATIONS

CT of the brain shows lenticular shape that does not normally cross suture lines.

Intracerebral haematoma

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

There may be no differences in symptoms and signs.

INVESTIGATIONS

CT of the brain shows haematoma within brain parenchyma.

Diffuse axonal injury (DAI)

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

History of trauma involving shear or acceleration/deceleration force; high-grade diffuse axonal injury typically results in coma.

INVESTIGATIONS

Absence of subdural collection on CT of the brain; small hyperdense lesions may be seen. MRI of the brain with gradient-recalled echo or susceptibility-weighted imaging shows small regions of susceptibility artefact in the cortex, corpus callosum, or brainstem.

Stroke

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

No history of preceding trauma (though a fall may have resulted from the stroke). May have a history of atrial fibrillation, cardiac arrhythmia, or prothrombotic disorder. May have had a previous transient ischaemic attack.

INVESTIGATIONS

Ischaemic stroke: Non-contrast CT can shows hypoattenuation (darkness) of the brain parenchyma and loss of grey matter/ white matter differentiation; hyperattenuation (brightness) in an artery indicates a clot within the vessel lumen.

Haemorrhagic stroke: Non-contrast CT shows hyperattenuation suggestive of acute blood, often with surrounding hypoattenuation due to oedema.

Seizure

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

After postictal state, patient typically returns to baseline. There may be a lingering Todd's paralysis for up to 48 hours after a focal motor seizure.

INVESTIGATIONS

Electroencephalogram may show seizure activity.

Substance abuse

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Usually no history of trauma.

Known history of substance misuse.

INVESTIGATIONS

Toxicology screen may be useful in differentiating causes of altered mental status.

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