{"id":"F2024L01705","name":"Statement of Principles concerning arachnoid cyst (Reasonable Hypothesis) (No. 11 of 2025)","slug":"statement-of-principles-concerning-arachnoid-cyst-reasonable-hypothesis-no-11-of-2025","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":442684,"registerId":"F2024L01705-fast-fetch-1775957633710","compilationNumber":null,"startDate":"2026-04-12","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"Statement of Principles concerning arachnoid cyst (Reasonable Hypothesis) (No. 11 of 2025)","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\n![RMA Australian Government Coat of Arms](image.001.jpeg)\n\n \n\nStatement of Principles\n\nconcerning\n\nARACHNOID CYST  (Reasonable Hypothesis)\n\n(No. 11 of 2025)\n\nThe Repatriation Medical Authority determines the following Statement of Principles under subsection 196B(2) of the Veterans' Entitlements Act 1986.\n\n \n\nDated    17 December 2024.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\nProfessor Terence Campbell AM\n\nChairperson\n\nby and on behalf of\n\nThe Repatriation Medical Authority\n\n \n\n \n\n   \n\n\nContents\n\n1 Name\n\n2 Commencement\n\n3 Authority\n\n4 Repeal\n\n5 Application\n\n6 Definitions\n\n7 Kind of injury, disease or death to which this Statement of Principles relates\n\n8 Basis for determining the factors\n\n9 Factors that must exist\n\n10 Relationship to service\n\n11 Factors referring to an injury or disease covered by another Statement of Principles\n\nSchedule 1 - Dictionary\n\n1 Definitions\n\n \n\n \n\n\n\n\n1.                Name\n\n\nThis is the Statement of Principles concerning arachnoid cyst (Reasonable Hypothesis) (No. 11 of 2025).\n\n1.                Commencement\n\n\n              This instrument commences on 28 January 2025.\n\n1.                Authority\n\n\nThis instrument is made under subsection 196B(2) of the Veterans' Entitlements Act 1986.\n\n1.                Repeal\n\n\nThe Statement of Principles concerning arachnoid cyst (No. 91 of 2015) (Federal Register of Legislation No. F2015L00924) made under subsection 196B(2) of the VEA is repealed.\n\n1.                Application\n\n\nThis instrument applies to a claim to which section 120A of the VEA or section 338 of the Military Rehabilitation and Compensation Act 2004 applies.\n\n1.                Definitions\n\n\nThe terms defined in the Schedule 1 - Dictionary have the meaning given when used in this instrument.\n\n1.                Kind of injury, disease or death to which this Statement of Principles relates\n  1.           This Statement of Principles is about arachnoid cyst and death from arachnoid cyst.\n\n\nMeaning of arachnoid cyst\n\n1.           For the purposes of this Statement of Principles, arachnoid cyst:\n  1.           means a benign, noncancerous cerebrospinal fluid-filled sac (pseudocyst), lined with arachnoid membrane, and occurring within the cranium or spinal canal; and\n  2.           excludes arachnoid cyst associated with autosomal dominant polycystic kidney disease.\n\n\nNote 1: Most arachnoid cysts are asymptomatic. Neurological symptoms or obstructive hydrocephalus can be caused by mass effect or altered cerebrospinal fluid flow dynamics. Clinical manifestations of an intracranial arachnoid cyst can include headache, cranial nerve dysfunction, nausea, vomiting and seizures. Clinical manifestations of a spinal arachnoid cyst can include back pain, gait and balance problems and sphincter disturbance.\n\nNote 2: Clinical worsening can include arachnoid cyst enlargement, rupture, or haemorrhage.\n\nDeath from arachnoid cyst\n\n1.           For the purposes of this Statement of Principles, arachnoid cyst, in relation to a person, includes death from a terminal event or condition that was contributed to by the person's arachnoid cyst.\n\n\nNote: terminal event is defined in the Schedule 1 – Dictionary.\n\n1.                Basis for determining the factors\n\n\nThe Repatriation Medical Authority is of the view that there is sound medical-scientific evidence that indicates that arachnoid cyst and death from arachnoid cyst can be related to relevant service rendered by veterans, members of Peacekeeping Forces, or members of the Forces under the VEA, or members under the MRCA.\n\nNote: MRCA, relevant service and VEA are defined in the Schedule 1 – Dictionary.\n\n1.                Factors that must exist\n\n\nAt least one of the following factors must as a minimum exist before it can be said that a reasonable hypothesis has been raised connecting arachnoid cyst or death from arachnoid cyst with the circumstances of a person's relevant service:\n\n1.           having concussion within the 12 months before clinical onset of cranial arachnoid cyst;\n2.           having a moderate to severe traumatic brain injury before clinical onset of cranial arachnoid cyst;\n3.           having concussion or a moderate to severe traumatic brain injury within the 3 months before clinical worsening of cranial arachnoid cyst;\n4.           having trauma in the region of the affected site before clinical onset of spinal arachnoid cyst;\n\n\nNote: trauma is defined in the Schedule 1 - Dictionary.\n\n1.           having trauma in the region of the affected site within the 3 months before clinical worsening of spinal arachnoid cyst;\n\n\nNote: trauma is defined in the Schedule 1 - Dictionary.\n\n1.           undergoing spinal surgery in the region of the affected site before clinical onset of spinal arachnoid cyst;\n\n\n Note: Examples of spinal surgery include spinal fusion, laminectomy, discectomy and interspinous device insertion.\n\n1.           undergoing spinal surgery in the region of the affected site within the 3 months before clinical worsening of spinal arachnoid cyst;\n\n\nNote: Examples of spinal surgery include spinal fusion, laminectomy, discectomy and interspinous device insertion.\n\n1.           undergoing cranial surgery in the region of the affected site before clinical onset of cranial arachnoid cyst;\n2.           undergoing cranial surgery in the region of the affected site within the 3 months before clinical worsening of cranial arachnoid cyst;\n3.       having intrathecal catheter placement, including lumboperitoneal shunt and spinal anaesthesia, or inadvertent dural puncture during epidural injections or epidural anaesthesia, in the region of the affected site, before clinical onset or clinical worsening of spinal arachnoid cyst:\n4.       having a myelogram before clinical onset or clinical worsening of spinal arachnoid cyst;\n5.       having one of the following infections before clinical onset or clinical worsening:\n  1.           bacterial infection of the brain or spinal cord, including abscess;\n  2.           bacterial, viral or fungal meningitis;\n  3.           cranial or spinal tuberculosis;\n  4.           neurosyphilis;\n6.       having a subarachnoid haemorrhage within the cranium or spinal canal before clinical onset or clinical worsening of arachnoid cyst;\n7.       having spinal adhesive arachnoiditis before clinical onset or clinical worsening of spinal arachnoid cyst;\n8.       having a malignant neoplasm with infiltration of the meninges within the 1 year before clinical onset or clinical worsening of arachnoid cyst;\n9.       inability to obtain appropriate clinical management for arachnoid cyst before clinical worsening.\n\n\n1.            Relationship to service\n  1.           The existence in a person of any factor referred to in section 9, must be related to the relevant service rendered by the person.\n  2.           The clinical worsening aspects of factors set out in section 9 apply only to material contribution to, or aggravation of, arachnoid cyst where the person's arachnoid cyst was suffered or contracted before or during (but did not arise out of) the person's relevant service.\n2.            Factors referring to an injury or disease covered by another Statement of Principles\n\n\nIn this Statement of Principles:\n\n1.           if a factor referred to in section 9 applies in relation to a person; and\n2.           that factor refers to an injury or disease in respect of which a Statement of Principles has been determined under subsection 196B(2) of the VEA;\n\n\nthen the factors in that Statement of Principles apply in accordance with the terms of that Statement of Principles as in force from time to time.\n\n \n\n \n\nSchedule 1 - Dictionary  \n\nNote:               See Section 6\n\n1               Definitions\n\nIn this instrument:\n\n                                arachnoid cyst—see subsection 7(2).\n\n                               MRCA means the Military Rehabilitation and Compensation Act 2004.\n\n                               relevant service means:\n\n(a)          operational service under the VEA;\n\n(b)          peacekeeping service under the VEA;\n\n(c)          hazardous service under the VEA;\n\n(d)          British nuclear test defence service under the VEA;\n\n(e)          warlike service under the MRCA; or\n\n(f)           non-warlike service under the MRCA.\n\nNote: MRCA and VEA are defined in the Schedule 1 - Dictionary.\n\n                               terminal event means the proximate or ultimate cause of death and includes the following:\n\n(a)           pneumonia;\n\n(b)           respiratory failure;\n\n(c)           cardiac arrest;\n\n(d)           circulatory failure; or\n\n(e)           cessation of brain function.\n\n                               trauma means significant injury to the vertebral column, or injury to the spinal cord or spinal meninges as a result of external force, excluding surgical or therapeutic procedures. In this definition, external force includes blunt trauma, acceleration or deceleration forces, blast force or a foreign body penetrating the spinal region.\n\n                               VEA means the Veterans' Entitlements Act 1986.\n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This is a standard replacement of an existing Statement of Principles (No. 91 of 2015). It maintains the same narrow, specific scope: determining causation links for one specific medical condition (arachnoid cyst) under veterans' compensation law. The 2025 version updates medical factors based on new evidence but does not expand beyond the original purpose of establishing service connection criteria."},"complexity_factors":["Moderate cross-referencing: Links to two separate Acts (VEA and MRCA) and incorporates definitions from external legislation","Conditional logic: Distinguishes between 'clinical onset' and 'clinical worsening' with different timeframes (12 months vs 3 months vs no timeframe)","Nested definitions: 6 defined terms in Schedule 1, with some definitions containing exclusions (e.g., 'trauma' excludes surgical procedures)","Specific exclusions: Explicitly excludes genetic conditions (autosomal dominant polycystic kidney disease) from the definition","Dual pathway structure: Separate rules for cranial (brain) vs spinal arachnoid cysts throughout the factors","Incorporation by reference: Section 11 allows other Statements of Principles to be imported dynamically"],"plain_english_summary":"This instrument updates the 2015 guidance on when Australian veterans and defence members can reasonably link an arachnoid cyst (brain or spine) to service for compensation. Based on new medical evidence, it lists medical and injury factors—such as head/spinal trauma, relevant surgery or procedures, and central nervous system infections—that can create a “reasonable hypothesis” connecting the cyst to service. It affects claimants under the VEA and MRCA, notes clinical-worsening rules for pre‑existing cysts, and excludes cysts from autosomal dominant polycystic kidney disease."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"This instrument repeals the 2015 Statement (s.4) and replaces it with an updated list of causative and aggravating factors, explicit timing windows for onset and clinical worsening (s.9), and an express inclusion of death from arachnoid cyst (s.7). It also adds inability to obtain appropriate clinical management as a listed factor and clarifies exclusions and definitions in Schedule 1 (s.7(2); Schedule 1). These changes alter the documented triggers and evidentiary framework used to link the condition to relevant service (ss.5,9–11)."},"complexity_factors":["Specialised medical terminology and concepts (arachnoid cyst, clinical worsening, subarachnoid haemorrhage, adhesive arachnoiditis)","Multiple timing windows and thresholds for causation (eg. 12 months, 3 months, 1 year) (s.9)","Different tests for cranial versus spinal presentations and for onset versus worsening (s.7(2), s.9)","Interplay with other Statements of Principles where factors refer to other injuries/diseases (s.11)","Requirement that each listed factor be related to relevant service (s.10)","Defined exclusions and definitions (eg. exclusion of ADPKD-associated cysts; definitions in Schedule 1)","Evidentiary and administrative burden on claimants to establish listed factors and service-connection (ss.9–10)","Repeal and replacement of prior instrument requiring practitioners and decision-makers to adapt to changed wording (s.4)"],"plain_english_summary":"This instrument sets the medical test the Repatriation Medical Authority uses to decide whether an arachnoid cyst (or death from one) can be reasonably linked to a veteran’s or service member’s relevant service for claims under the VEA or MRCA. It replaces the earlier 2015 Statement. It requires at least one listed medical or temporal factor (for onset or clinical worsening) to be present before a reasonable hypothesis can be raised; the RMA issues the test and decision-makers apply it when assessing entitlement (ss.5, 9–10)."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/statement-of-principles-concerning-arachnoid-cyst-reasonable-hypothesis-no-11-of-2025","history":"/api/acts/statement-of-principles-concerning-arachnoid-cyst-reasonable-hypothesis-no-11-of-2025/history","analysis":"/api/acts/statement-of-principles-concerning-arachnoid-cyst-reasonable-hypothesis-no-11-of-2025/analysis","conflicts":"/api/acts/statement-of-principles-concerning-arachnoid-cyst-reasonable-hypothesis-no-11-of-2025/conflicts","importantCases":"/api/acts/statement-of-principles-concerning-arachnoid-cyst-reasonable-hypothesis-no-11-of-2025/important-cases","documents":"/api/acts/statement-of-principles-concerning-arachnoid-cyst-reasonable-hypothesis-no-11-of-2025/documents"}}