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Neurological Red Flags

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Stroke and Transient Ischaemic Attack (TIA)

Overview

Rapidly emerging focal (or sometimes global) neurological deficits suggest the likelihood of a stroke or TIA. These may include:

  • Weakness
  • Paraesthesia
  • Dysphagia
  • Dysphagia
  • Visual field defects
  • Ataxia
  • Symptoms resolving within 24 hours suggests a TIA

Initial steps

  • Stroke:
    • Investigations include:
      • Oxygen saturations – hypoxia can mimic stroke
      • Blood glucose – hypoglycaemia can mimic stroke
      • Immediate non-contrast CT head – screens for haemorrhagic stroke
    • Management involves:
      • 1st-line: aspirin 300 mg orally/rectally once haemorrhagic stroke ruled out
      • Further management steps include thrombectomy or thrombolysis depending on timeframes and where the occlusion is
  • TIA:
    • 300 mg aspirin immediately unless:
      • Person has a bleeding disorder/takes anticoagulation – immediate CT head to screen for haemorrhage
      • They already take aspirin or it is contraindicated – urgently discuss with TIA specialist

Cerebral Venous Sinus Thrombosis (CVST)

Overview

A sudden, severe ‘thunderclap’ headache or focal neurological deficits in a person with hypercoagulable states suggests cerebral venous sinus thrombosis. Although rare, the risk of CVST is higher in pregnancy or immediately post-partum. Features include:

Initial steps

  • Immediately refer to neurology
  • Initial investigations may include:
    • Blood culture – identifies underlying cause in septic CVST
    • MR venography – gold standard
  • Initial management involves:

Guillain-Barré syndrome (GBS)

Overview

Vague symptoms including low back/leg pain or paraesthesia that is ascending over days should raise suspicion of GBS. Although there classically is a history of preceding infection, people may not be able to recall if they have had one.

Initial steps

  • Immediately refer to neurology
  • Initial investigations may include:
  • Management involves:
    • IV immunoglobulin (IVIG) or plasma exchange

Subarachnoid Haemorrhage (SAH)

Overview

A sudden onset severe ‘thunderclap’ headache that reaches maximal intensity within minutes and is different to anything the patient has ever experienced suggests SAH.

Initial steps

  • Immediate non-contrast CT head:
    • Shows blood in the subarachnoid space – confirms SAH
    • If done within 6 hours and normal – do not do lumbar puncture, consider alternate diagnosis, and seek specialist help
    • If done >6 hours after symptom onset and normal – perform lumbar puncture within 12 hours – shows xanthochromia and confirms SAH
  • SAH confirmed using the above: immediately refer to neurosurgery

Extradural Haematoma (EDH)

Overview

Trauma to the head followed by a loss of consciousness, regaining consciousness (the lucid interval), then losing it again (as the haematoma expands) suggests EDH. This occurs due to the rupture of the middle meningeal artery.

Initial steps

  • Intubate and ventilate if necessary (usually a Glasgow coma scale of 8 or less)
  • Immediate CT scan:
    • May show biconvex (lentiform) hyperdense (bright) collection limited by the suture lines of the skull
  • Refer immediately to neurosurgery

Chronic Subdural Haematoma (SDH)

Overview

SDH is more common in neonates (shaken baby syndrome), the elderly, and people with chronic alcohol excess due to fragile bridging veins. Features suggesting chronic SDH include the following features developing over weeks:

  • Increasing confusion
  • Fluctuating consciousness
  • Neurological deficits
  • Headaches
  • Seizures

Initial steps

  • Immediate CT scan:
    • May show crescent-shaped collection that is not limited by the suture lines of the skull
    • In chronic SDH, it is hypodense (dark), in acute SDH it is hyperdense (bright)
  • Refer immediately to neurosurgery

Meningitis

Overview

Progressive headaches with neck stiffness, fever, and vomiting, with or without a rash is bacterial meningitis until proven otherwise. Neck stiffness may not be apparent.

Initial steps

  • In the community:
    • IM benzylpenicillin (if non-penicillin allergic) and call 999
  • In the hospital:
    • Blood cultures within 1 hour of arrival:
      • Ideally before antibiotics but do not delay treatment
    • Lumbar puncture (if not contraindicated) within 1 hour and cerebrospinal fluid analysis
      • Ideally before antibiotics but do not delay treatment
    • IV broad-spectrum antibiotics:
      • If <3 months: IV cefotaxime + amoxicillin/ampicillin
      • If 3 months – 50 years: IV cefotaxime/ceftriaxone
      • If >50 years: IV cefotaxime/ceftriaxone + amoxicillin/ampicillin

Encephalitis

Overview

Patients with fever and altered levels of consciousness suggest viral encephalitis. Additional features include:

  • Headaches
  • Seizures
  • Focal neurological deficits
  • Children and young adults

Initial steps

  • Immediately refer to hospital
  • Initial investigations may include:
    • Blood cultures
    • Lumbar puncture and cerebrospinal fluid analysis
  • Initial management includes:
    • IV aciclovir if encephalitis is suspected

Seizures

Overview

New onset seizures suggest a space-occupying lesion until proven otherwise.

Initial steps

  • Initial investigations include:
    • Tests to screen for other causes (blood glucose, FBC, U&Es, ECG, toxicology screen)
    • Neuroimaging (ideally MRI brain) to identify structural abnormalities
    • Electroencephalogram (EEG) 

Syncope and Epilepsy

Overview

Episodic loss of consciousness can suggest syncope or epilepsy, however, there are some ways to distinguish between the two:

  • Provoking factors (e.g. triggered by stress, emotion, or pain (vasovagal), passing urine, or exercise):
    • Present in syncope
    • Absent in epilepsy
  • Premonitory symptoms:
    • Nausea, light-headedness, and pallor suggest syncope
    • May be absent in epilepsy, or there may be signs of aura (such as epigastric rising)
  • Post-ictal period:
    • A prolonged post-ictal period (>20 minutes) suggests epilepsy
  • Incontinence:
    • May occur in both syncope and epilepsy

Initial steps

  • Urgently refer to neurology
  • Initial investigations include:
    • Tests to screen for other causes (blood glucose, FBC, U&Es, ECG, toxicology screen)
    • Neuroimaging (ideally MRI brain) to identify structural abnormalities or tumours
  • Immediately refer to neurosurgery if a structural abnormality or tumour is present

Elevated intracranial pressure (ICP)

Overview

Concerning causes of elevated ICP include intracranial bleeds and tumours. Red flag features suggesting an elevated ICP include:

  • Transient bilateral vision loss associated with movements such as coughing, straining, or bending down
  • Red-flag headache features:
    • Nocturnal headaches
    • Headaches that are worse with movements such as coughing, straining or bending down
    • Headaches that are worse or start in the morning
  • Associated vomiting with or without nausea

Initial steps

  • Immediately refer to neurology
  • Investigations may include:
    • CT head
    • MRI head
    • Intracranial pressure monitoring

CN III (oculomotor) nerve palsies

Overview

CN III palsies can occur due to ‘medical’ causes such as diabetes mellitus and hypertension, or ‘surgical’ causes such as tumours or aneurysms. All CN III palsies are urgent, regardless of pupil involvement, as it is difficult to rely on a clinical examination alone to rule out ‘surgical’ causes.

Features include:

Initial steps

  • Immediately refer to neurology
  • Investigations may include:
    • CT brain – to screen for a mass lesion
    • MRI brain – to screen for a mass lesion

Myasthenia gravis (MG)

Overview

Myasthenic crisis is a complication of MG that is characterised by impaired respiratory muscle function leading to respiratory failure. It requires intubation and ventilation.

Features suggesting MG:

  • Weakness that is worse towards the end of the day and improves with rest
  • Fatiguability is seen on examination – repeated muscle contraction leads to weakness
  • Diplopia, dysphagia, dysphonia, or dysarthria 

Initial steps

  • If respiratory involvement present – immediate referral to neurology
  • If no respiratory involvement – urgently refer to neurology
  • Initial investigations include:
    • Serum acetylcholine receptor antibodies (anti-AChR):
      • Usually positive
    • Pulmonary function tests – measure FVC in acute myasthenic crisis:
      • FVC is low

Cauda Equina Syndrome (CES)

Overview

CES can lead to potentially irreversible leg weakness and/or urinary/bowel incontinence. Red flag features are:

  • New or worsening lower back pain
    • This may radiate to both legs (bilateral sciatica)
  • Perianal paraesthesia or anaesthesia
  • Urinary/bowel incontinence or retention

Initial steps

  • Urgent MRI spine

Pituitary Apoplexy

Overview

This describes the sudden enlargement of a pituitary tumour due to haemorrhage or infarction and can lead to life-threatening hypopituitarism. Features include:

  • A sudden, severe headache (similar to subarachnoid haemorrhage) and neurological/ophthalmic signs such as:
    • Visual field defects – bitemporal hemianopia
    • Ophthalmoplegia
    • Fluctuating consciousness
    • Vomiting
  • Features of hypopituitarism (e.g. hyponatraemia secondary to adrenal insufficiency) 

Initial steps

  • Urgent MRI head or CT if MRI contraindicated
  • Refer immediately to neurosurgery

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