Date amended:
Statements of Principles

Current RMA Instruments

Reasonable Hypothesis SOP

45 of 2024 as amended

Balance of Probabilities SOP

46 of 2024 as amended

Changes from previous Instruments


ICD Coding

  • Transient ischaemia attack: ICD-10 G45, G45.1, G45.2, G45.8, G45.9 or G46
  • Intra-cerebral haemorrhage: ICD-10 I61
  • Cerebral infarction: ICD-10 I63
  • Stroke (unspecified): ICD-10 I64


Brief description

A cerebrovascular accident (CVA), commonly known as a stroke, occurs when blood flow to the brain becomes interrupted and the brain tissue ends up becoming deprived of oxygen and nutrients. The effects of a stroke can be temporary or permanent. Depending on the length of time and severity of the stroke, brain cells can end up dying and individuals can be at risk of death or have ongoing impairment.

Cerebrovascular accidents are due to either cerebral ischaemia (the most common type) or haemorrhage (bleeding) into the brain. Ischaemic strokes occur when a blood vessel supplying blood to the brain is obstructed, usually by a blood clot. Haemorrhagic strokes occur when a blood vessel in the brain bursts. With cerebral ischaemia, the effects may be temporary and the impairment may be reversible, in cases referred to as TIAs (transient ischaemic attacks). 

Confirming the diagnosis

The diagnosis of a cerebrovascular accident requires both acute neurological symptoms and signs as well as confirmation by a brain CT (computerised tomography) scan or MRI (Magnetic Resonance Imaging) scan.

A transient ischaemic attack (TIA) is a clinical diagnosis and needs to be differentiated from other causes of acute transient neurological symptoms.

The relevant medical specialist is a neurologist or general physician.

Additional diagnoses covered by these SOPs

  • Brain stem stroke
  • Cerebral artery syndrome
  • Cerebral caused amaurosis fugax
  • Cerebral haemorrhage
  • Cerebral infarction
  • CVA (cerebrovascular accident)
  • Lacunar syndrome
  • TIA (transient ischaemic attack)
  • Vertebrobasilar artery syndrome or insufficiency

Conditions not covered by these SOPs   

  • Cerebral atherosclerosis #
  • Cerebral aneurysm #
  • Complicated migraine* - migraine SOP
  • Extradural haemorrhage #
  • Hypoxia not due to impairment of the blood supply #
  • Moderate to severe traumatic brain injury *
  • Subarachnoid haemorrhage *
  • Subclinical or asymptomatic cerebrovascular disease identified by neuroimaging (silent stroke) #
  • Subdural haematoma*                            
  • Vascular dementia*                                  

* another SOP applies 

# non-SOP condition

Clinical onset

Once the diagnosis of CVA is established by imaging, the clinical date of onset can be taken from when the neurological symptoms and signs consistent with the stroke first developed. 

Clinical worsening

In order to assess for possible clinical worsening, it needs to be understood that a CVA may naturally progress over 48-72 hours in the acute phase but should then subsequently peak in impairment before slowly improving over a period of 18 months. Generally, the speed of improvement is most dramatic at the beginning (first 3-6 months). 

Further comments on diagnosis

In most cases the term 'stroke' will refer to a cerebrovascular accident that can be covered under this SoP.  However, the term may also be used to describe cases involving subarachnoid or intracranial haemorrhage (not covered by the cerebrovascular accident SOP). It is important to carefully assess for the specific diagnosis and determine the correct application of the SoPs.