Which initial investigations should be performed in a patient with sud

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Initial investigations for a patient with sudden onset paralysis to exclude stroke include:

Perform immediate brain imaging with a non-enhanced CT scan to rapidly exclude intracranial haemorrhage or other causes, especially if there are indications for thrombolysis, anticoagulant use, bleeding tendency, depressed consciousness, progressive symptoms, papilloedema, neck stiffness, fever, or severe headache at onset of symptoms.
If thrombectomy is considered, follow the initial CT with CT contrast angiography and possibly CT perfusion imaging (or MR equivalent) if beyond 6 hours of symptom onset.
Exclude hypoglycaemia as a reversible cause of neurological symptoms.
Use validated clinical tools such as FAST or ROSIER to support clinical diagnosis but do not rely solely on scoring systems for risk stratification.

These steps ensure rapid exclusion of haemorrhagic stroke and identification of ischaemic stroke to guide urgent treatment decisions.

References:

Which initial investigations should be performed in a patient with sudden onset paralysis to rule out a stroke?