Statement of Principles concerning spinal adhesive arachnoiditis (Reasonable Hypothesis) (No. 74 of 2020)

The core legal concept is "reasonable hypothesis." Under sections 120 and 120A of the VEA, for operational service, the standard of proof for connecting a disease to service is the reasonable hypothesis unless a relevant SoP exists. Where an SoP applies, the hypothesis must be consistent with the factors listed. The SoP effectively codifies what the RMA considers to be sound medical-scientific evidence sufficient to raise that hypothesis. The instrument distinguishes between "clinical onset" and "clinical worsening." Onset refers to the first appearance of the condition's symptoms and signs. Worsening refers to a material increase in severity after the condition was already present but did not arise out of service. For worsening factors, section 10(2) requires that the spinal adhesive arachnoiditis was suffered or contracted before or during (but not arising out of) the person's relevant service. This means the condition must pre-exist or be contemporaneous with service but not be caused by it, and the factor must materially contribute to its aggravation. Another key concept is the definition of "severe spinal trauma." It means application of significant external force causing fracture or crush injury of the vertebral column, or other direct injury to the spinal cord or meninges resulting in neurological dysfunction, and explicitly excludes surgical and therapeutic procedures. This ensures that surgical interventions are covered by separate factors (2 and 19) rather than the trauma factor. The instrument also defines closed lists: "specified list of radiological contrast agents" includes only dimeglumine iocarmate (Dimer-X), meglumine iothalamate (Conray), metrizamide (Amipaque), and sodium iodomethanesulfonate/methiodal sodium (Abrodil). Water-soluble agents from this list have a 10-year window before onset or worsening; oil-soluble agents have no time limit. The "specified list of infections" covers fungal or bacterial spinal cord infection, fungal or bacterial meningitis, neurosyphilis, spinal toxoplasmosis, spinal tuberculosis, and vertebral osteomyelitis at the affected site. Absent are viral infections, which means a veteran with viral meningitis would need to rely on another factor. The instrument also introduces the concept of "intrathecal drug delivery system" and "inability to obtain appropriate clinical management" (worsening only). The latter factor is broad and potentially controversial, as it may involve assessing the quality of military or post-service healthcare and whether a failure to provide appropriate management materially worsened the condition. Section 11 adds a cross-reference mechanism: if a factor refers to an injury or disease that is itself covered by another SoP, the factors of that other SoP apply. For example, if severe spinal trauma is itself a disease with a SoP, a claimant must satisfy that SoP as well. This can create chains of causation requirements.

The primary affected cohort is current and former members of the Australian Defence Force and veterans who have rendered "relevant service" as defined in the Schedule 1 Dictionary. That definition covers operational service, peacekeeping service, hazardous service, and British nuclear test defence service under the VEA, as well as warlike and non-warlike service under the MRCA. It also includes members of Peacekeeping Forces and members of the Forces. The instrument directly binds decision-making officers at the Department of Veterans' Affairs and the Military Rehabilitation and Compensation Commission when assessing claims for disability pension or compensation relating to spinal adhesive arachnoiditis. It also binds the Veterans' Review Board and the Administrative Appeals Tribunal on review. Legal practitioners representing veterans must master the 34 factors, the time frames, and the cross-references to other SoPs. Medical specialists who provide medico-legal reports are indirectly affected: they must frame their opinions using the SoP's definitions and time windows, and they must be aware that a diagnosis requires both imaging or surgical demonstration of fibrosis and adhesions and neurological symptoms consistent with the observed pathology. A radiologist's finding of arachnoiditis without clinical correlation is insufficient under the SoP. The instrument also affects the Commonwealth as the compensator; the stricter the factors, the fewer successful claims, reducing the fiscal burden. However, the RMA's determination that there is sound medical-scientific evidence for each factor means that the SoP is intended to represent the current state of knowledge, so claimants whose circumstances fall outside the factors are unlikely to succeed even with expert evidence. The instrument also indirectly affects manufacturers of intrathecal drug delivery systems, methylprednisolone acetate (Depo-Medrol), myelographic contrast agents, and Thorotrast, though it does not create any liability for them. It serves as a de facto statement of causal risk for those products in a military service context. Finally, the SoP affects the RMA itself, which must monitor medical evidence and revise the instrument when necessary. The next revision will again affect all stakeholders.

This SoP does not create duties in the ordinary sense; it is an evidentiary instrument that defines when a reasonable hypothesis is deemed raised. The key right it confers on claimants is that if they can establish at least one factor from the list that is related to their relevant service, they are entitled to have the claim assessed on the basis that the reasonable hypothesis standard is satisfied. This right is conditional on the factor actually existing and being related to service under section 10. For clinical onset factors, the factor must be related to service as a cause; for clinical worsening factors, the factor must be related to service as a material contributor to aggravation, and the condition must have pre-existed or arisen during service without being caused by it. Decision-makers have a duty to consider each factor that is raised by the evidence and to determine whether it exists and is related to service. They also have a duty to apply the definitions strictly. For example, they must not accept a diagnosis of spinal adhesive arachnoiditis unless both imaging or surgical demonstration and neurological symptoms are present. They must check time limits: severe spinal trauma within 10 years before clinical onset, epidural blood patch within 3 months, intrathecal Depo-Medrol within 2 years, etc. If the evidence shows a factor outside the time window, it cannot be used. Claimants have the right to present evidence of any factor on the list, but they also bear the practical burden of proving the factor exists. The SoP also gives the RMA the power (and duty) to maintain the instrument. Section 11 imposes an additional duty: if a factor refers to an injury or disease covered by another SoP (for example, ankylosing spondylitis or sarcoidosis), the decision-maker must apply the factors of that other SoP as in force from time to time. This means the claimant may need to satisfy that other SoP as a condition precedent. The instrument also defines "terminal event" for death claims, which decision-makers must check against the proximate cause listed. In summary, the key right is the ability to use a factor as a causation shortcut; the key duty is strict adherence to the instrument's text and definitions.

This instrument contains no penal provisions. It is not a regulation that imposes fines or imprisonment. The notion of enforcement is therefore indirect and arises through the administrative review process. If a decision-maker fails to apply the SoP correctly, the veteran can seek internal review by the Veterans' Review Board and further review by the Administrative Appeals Tribunal. The Tribunal may set aside the decision and substitute a correct one. The ultimate enforcement mechanism is judicial review in the Federal Court or the Federal Circuit and Family Court of Australia on grounds of jurisdictional error, such as misinterpreting the SoP or making a decision without evidence. The SoP itself is a legislative instrument that must be registered under the Legislation Act 2003 and is subject to disallowance by either House of Parliament, but this is a legislative oversight power, not an enforcement mechanism. There are no penalties for a veteran who makes a false claim based on the SoP; general criminal law (fraud) applies separately. Medical practitioners who perform procedures that cause arachnoiditis are not penalised under this instrument; it only affects compensation claims. The concept of enforcement is best understood as ensuring that decision-makers apply the SoP correctly. The instrument imposes no positive duties on anyone outside the claims system. Therefore, the "enforcement" is through the normal avenues of administrative law: review rights and the possibility of a tribunal or court correcting an erroneous decision. Veterans' advocates should be aware that if a decision-maker incorrectly finds a factor not present or misapplies a time limit, the appropriate remedy is to appeal, not to invoke a penalty provision, as none exists.

This SoP operates within the statutory framework of the VEA and the MRCA. It is made specifically under subsection 196B(2) of the VEA and applies to claims under section 120A of the VEA and section 338 of the MRCA. It interacts directly with the standard of proof provisions. For operational service under the VEA, the standard is reasonable hypothesis. The SoP provides a safe harbour: if a factor is satisfied, the hypothesis is established. For non-operational service, the standard is balance of probabilities, but the SoP still applies as a guide to what constitutes sound medical evidence. The instrument also interacts with other SoPs through section 11. If a factor refers to an injury or disease that has its own SoP, the factors of that SoP must be applied. For example, if a veteran's factor is "having ankylosing spondylitis involving the affected site," and ankylosing spondylitis has its own SoP, then the veteran must also satisfy that SoP's factors to connect the ankylosing spondylitis to service. This can create a cascade of causation evidence. The SoP may also interact with the Safety, Rehabilitation and Compensation Act 1988 (SRCA) if a claimant has dual coverage, but the instrument explicitly references only VEA and MRCA. Privacy laws such as the Privacy Act 1988 govern the handling of medical evidence, but the SoP does not override them. The instrument interacts with criminal laws only tangentially: if a veteran fraudulently claims a factor, they may be prosecuted under the Criminal Code. The SoP also interacts with the general law of evidence in tribunals and courts, but as a legislative instrument, it takes precedence over common law causation tests for the purposes of VEA and MRCA claims. The SoP does not affect state workers' compensation laws; a veteran could have a separate claim under state law, but the SoP would not apply there. Clinicians performing intrathecal injections should be aware of the SoP's time frames for medico-legal purposes, but the instrument does not create a standard of care in tort. The definitions of "terminal event" may align with but are not identical to definitions in other jurisdictions (e.g., life insurance). The SoP also interacts with the Rehabilitation and Compensation aspects of the MRCA, but those provisions are not detailed in this instrument. Overall, the SoP is a specialised causation rule that sits within the veterans' compensation system and must be read together with the parent Acts and other SoPs.

This instrument, Statement of Principles concerning spinal adhesive arachnoiditis (Reasonable Hypothesis) (No. 74 of 2020), is a replacement for the earlier SoP No. 116 of 2011 (Federal Register of Legislation No. F2011L01748). The 2011 version was made under the same subsection 196B(2) of the VEA. The 2020 instrument repeals the 2011 version in its entirety. The 2020 version updates the list of factors based on current sound medical-scientific evidence as assessed by the RMA. Comparing the two instruments without the text of the 2011 version is not possible, but from the 2020 instrument we can infer that new factors have been added or time windows adjusted. For example, the 2020 version includes factors for epidural blood patch, intrathecal methotrexate/cytosine arabinoside, intrathecal radioactive gold, lumboperitoneal shunt, and the inability to obtain appropriate clinical management (factor 34 for worsening only). The 2011 version may have lacked some of these. Also, the definition of "specified list of radiological contrast agents" in 2020 includes four specific agents; earlier versions may have had a different list. The RMA has the power to amend SoPs at any time if new evidence emerges. The instrument was made on 30 October 2020 and commenced on 30 November 2020. There is no indication of any further amendment between 2020 and the present. The amendment history is therefore limited to the repeal of the 2011 instrument and the making of the 2020 instrument. Future amendments will occur when the RMA issues a new SoP. It is worth noting that the RMA regularly updates SoPs, so practitioners should always check whether a later version exists. The current instrument is No. 74 of 2020; the numbering suggests many other SoPs were made in 2020 as well. The RMA also determines SoPs for "Reasonable Hypothesis" and "Balance of Probabilities" separately; this one is the Reasonable Hypothesis version, meaning it applies to claims where the lower standard is used. There is likely a separate Balance of Probabilities SoP for this condition (No. 73 of 2020 or similar), which would have the same factors but apply to non-operational service.

The source text itself contains no reference to any litigation. However, Statements of Principles are frequently the subject of litigation in the Veterans' Review Board, Administrative Appeals Tribunal, and the Federal Court. The central issues that typically arise are whether the RMA had sufficient evidence to include a factor, whether the factor is too restrictive, and whether the definitions are properly applied. In the case of this particular SoP, litigation could arise over the interpretation of "severe spinal trauma" , specifically, whether a particular external force meets the definition of "significant" and whether the resulting neurological dysfunction is required. Also, the exclusion of viral infections from the specified list could be challenged if medical evidence shows viral meningitis can cause arachnoiditis. The intrathecal methylprednisolone factor (factor 8) is only for clinical onset, not worsening. This could be litigated if a veteran with pre-existing arachnoiditis receives a Depo-Medrol injection and argues it worsened the condition. There is no factor for that scenario, so the claim would fail unless another factor applies. The time limits (e.g., 10 years for trauma, 2 years for Depo-Medrol) could be challenged if new evidence suggests longer latency periods. The "inability to obtain appropriate clinical management" factor (factor 34) is vague and could lead to disputes over what constitutes "appropriate" clinical management. Decision-makers may take different views, leading to inconsistent outcomes and appeals. Section 11, which cross-references other SoPs, could lead to litigation over whether the referenced condition's SoP applies correctly. For example, if a veteran has ankylosing spondylitis and spinal adhesive arachnoiditis, the decision-maker must also consider the ankylosing spondylitis SoP. If that SoP has different definitions, it may create confusion. There is no publicly reported Federal Court case specifically on spinal adhesive arachnoiditis SoP cited in the instrument, but practitioners should be aware that the general law on SoPs (e.g., Repatriation Commission v Gosewinkel [2000] FCA 1289) applies. The instrument is designed to reduce litigation by providing a clear list, but it inevitably generates disputes over factual application.

Several traps await the unwary. First, the condition definition itself: a person can have imaging evidence of arachnoid fibrosis but no neurological symptoms, or vice versa. The SoP requires both. A veteran with MRI findings of adhesive arachnoiditis but no neurological deficit does not meet the definition, and no factor can save the claim. Second, intrathecal methylprednisolone acetate (Depo-Medrol) is only a factor for clinical onset (factor 8), not for clinical worsening. If a veteran already has arachnoiditis and then receives an intrathecal Depo-Medrol injection that makes it worse, they cannot use factor 8. They would need a worsening factor such as intrathecal drug delivery system (factor 25) or another factor, but those may not apply. This is a significant gap. Third, the time limits are strict. Severe spinal trauma must occur within 10 years before clinical onset (factor 1) or before worsening (factor 18). For water-soluble contrast agents, the window is 10 years. For epidural blood patch, 3 months. For Depo-Medrol, 2 years. If the event is outside the window, the factor does not exist, even if the veteran has clear medical evidence linking the event to the condition. Fourth, the "inability to obtain appropriate clinical management" factor (factor 34) applies only to clinical worsening. It cannot be used for initial onset. That means a veteran who developed arachnoiditis because a military doctor failed to treat an infection appropriately cannot rely on factor 34; they would need factor 12 (infection before clinical onset). But if the infection occurred during service and was inadequately treated, the factor 12 might be satisfied if the infection itself is on the specified list. Fifth, the definition of "severe spinal trauma" excludes surgical and therapeutic procedures. A veteran who had a spinal tap or epidural that caused trauma cannot use factor 1; they must use factor 2 (spinal surgery) if the procedure counts as surgery, but not all procedures are surgeries. This could leave a gap for procedures like lumbar puncture that cause arachnoiditis but are not considered surgery. Sixth, the specified list of infections is closed. Viral infections, Lyme disease, or other rare infections are not included. A veteran with viral meningitis that caused arachnoiditis has no infection factor unless it also caused another listed infection. Seventh, the cross-reference in section 11 means that if a factor refers to an injury or disease with its own SoP, that SoP must be satisfied. For example, ankylosing spondylitis (factor 15/31) has its own SoP. If the veteran cannot connect the ankylosing spondylitis to service under that SoP, the arachnoiditis claim fails. This can create a cascade where multiple SoPs need to be satisfied. Eighth, for worsening factors (18-34), the condition must have been suffered or contracted before or during service but not arise out of service. If the arachnoiditis actually arose out of service (e.g., from a service-related spinal surgery), it is not a worsening claim; it is an onset claim, and the worsening factors cannot be used. The claim must be based on onset factors. Ninth, the "terminal event" definition for death claims is limited to five specific events. If a person dies from a cause not listed (e.g., suicide, overwhelming sepsis) but the arachnoiditis contributed, the claim may fail unless the terminal event fits within circulatory failure or cessation of brain function broadly interpreted. Tenth, the SoP does not allow for cumulative factors. A veteran with two minor factors (e.g., a mild trauma and an infection that are both related to service but do not individually meet the time frames or definitions) cannot combine them to raise a hypothesis. Only one factor must exist.

"Compliance" in the context of this SoP means correctly applying its provisions in claims assessment and preparation. For advocates and lawyers, compliance involves the following steps. First, confirm that the claimed condition meets the definition in s 7(2). Obtain a radiology report (MRI, CT myelogram, or surgical findings) that states fibrosis and nerve root adhesions in the arachnoid and subarachnoid space. Also obtain a clinical report from a neurologist or neurosurgeon documenting neurological symptoms and signs consistent with that pathology (e.g., radicular pain, motor weakness, sensory loss, bladder dysfunction). Asymptomatic radiological findings will not suffice. Second, determine the date of clinical onset, both as a factual matter and as a defined legal term. Gather evidence of the first appearance of symptoms. For worsening claims, also determine the date of clinical worsening and confirm that the condition pre-existed or arose during but not out of service (see s 10(2)). Third, take the claimant through the list of 34 factors systematically. For each factor, gather documentary evidence: service medical records, hospital records, imaging reports, operative notes, and witness statements. For factor 1 (severe spinal trauma), ensure the trauma meets the definition: significant external force causing fracture, crush injury, or direct injury to spinal cord/meninges with neurological dysfunction. Exclude surgical trauma. For factor 2 (spinal surgery), obtain the operative report showing surgery at the affected site within 10 years. For factor 8 (Depo-Medrol), prove intrathecal injection within 2 years before onset. For factor 34 (inability to obtain appropriate clinical management), generate evidence of missed treatment, lack of specialist referral, or systemic failures in the Defence or VA health system that materially worsened the condition. Fourth, for each candidate factor, establish the relationship to relevant service under s 10. This may mean showing that the trauma occurred during a deployment, or that the spinal surgery was performed in a military hospital, or that the infection was contracted during peacekeeping service. For worsening factors, also show that the condition existed before the service-related factor. Fifth, check section 11: if a factor refers to a condition that has its own SoP (e.g., ankylosing spondylitis, sarcoidosis, infection, spinal trauma itself), obtain the current SoP for that condition and ensure it is satisfied. This may require a separate claim or additional evidence. Sixth, for death claims, identify the terminal event from the defined list and ensure it is contributed to by the arachnoiditis. Obtain a death certificate and medical evidence of causation. Seventh, prepare a written submission that maps the evidence to the factor and the SoP's language. Avoid arguing that the SoP should be ignored because the veteran's circumstances are unique; the SoP is binding. Eighth, if no factor appears to apply, consider whether any factor can be argued based on a reasonable interpretation of the definitions. For example, "inability to obtain appropriate clinical management" may be broader than first appears. If still no factor, advise the claimant that the claim is likely to fail and consider whether the RMA can be petitioned to amend the SoP. For decision-makers, compliance means checking each factor on the list against the evidence, applying the exact definitions, and not straying beyond the instrument. The SoP is designed to produce consistent outcomes, and deviation invites appeal.