{"id":"F2024L01706","name":"Statement of Principles concerning arachnoid cyst (Balance of Probabilities) (No. 12 of 2025)","slug":"statement-of-principles-concerning-arachnoid-cyst-balance-of-probabilities-no-12-of-2025","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":442685,"registerId":"F2024L01706-fast-fetch-1775957633712","compilationNumber":null,"startDate":"2026-04-12","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"Statement of Principles concerning arachnoid cyst (Balance of Probabilities) (No. 12 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  (Balance of Probabilities)\n\n(No. 12 of 2025)\n\nThe Repatriation Medical Authority determines the following Statement of Principles under subsection 196B(3) 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\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 (Balance of Probabilities) (No. 12 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(3) of the Veterans' Entitlements Act 1986.\n\n1.                Repeal\n\n\nThe Statement of Principles concerning arachnoid cyst (No. 92 of 2015) Federal Register of Legislation No. F2015L00925) made under subsection 196B(3) of the VEA is repealed.\n\n1.                Application\n\n\nThis instrument applies to a claim to which section 120B of the VEA or section 339 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\nOn the sound medical‑scientific evidence available, the Repatriation Medical Authority is of the view that it is more probable than not that arachnoid cyst and death from arachnoid cyst can be related to relevant service rendered by veterans 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 exist before it can be said that, on the balance of probabilities, arachnoid cyst or death from arachnoid cyst is connected with the circumstances of a person's relevant service:\n\n1.           having a moderate to severe traumatic brain injury before clinical onset of cranial arachnoid cyst;\n2.           having concussion or a moderate to severe traumatic brain injury within the 3 months before clinical worsening of cranial arachnoid cyst;\n3.           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.           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:\n2.           having a myelogram before clinical onset or clinical worsening of spinal arachnoid cyst;\n3.           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 meningitis;\n  3.           cranial or spinal tuberculosis;\n  4.           neurosyphilis;\n4.       having a subarachnoid haemorrhage within the cranium or spinal canal before clinical onset or clinical worsening of arachnoid cyst;\n5.       having spinal adhesive arachnoiditis before clinical onset or clinical worsening of spinal arachnoid cyst;\n6.       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(3) 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)          eligible war service (other than operational service) under the VEA;\n\n(b)          defence service (other than hazardous service and British nuclear test defence service) under the VEA; or\n\n(c)          peacetime service under the MRCA.\n\nNote: MRCA and VEA are also 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":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The instrument expressly repeals the 2015 Statement and replaces it (s.4). It continues to apply to claims under VEA s.120B and MRCA s.339 (s.5) but sets a specific, updated list of medical antecedent factors and timing requirements to establish service connection (s.9, s.10). The text does not state whether overall coverage is broader or narrower than the repealed instrument."},"complexity_factors":["Medical-technical definitions and distinctions between cranial and spinal arachnoid cysts (s.7(2), notes)","Multiple temporal relationships (before clinical onset; within 3 months before clinical worsening) across factors (s.9)","Enumerated, condition-specific antecedent factors (trauma, surgery, infections, haemorrhage, intrathecal procedures, myelogram, management gaps) requiring factual proof (s.9)","Cross-reference to other Statements of Principles where factors overlap, creating layered evidentiary rules (s.11)","Statutory anchoring to two different Acts and claim provisions, affecting eligibility pathways (s.5, Schedule)","Repeal and replacement of a prior instrument, requiring comparison for practitioners and decision-makers (s.4)","Definitions that constrain scope (e.g. trauma, terminal event, relevant service) are pivotal to application (Schedule 1)"],"plain_english_summary":"This Statement of Principles sets the medical rules the Repatriation Medical Authority uses to decide whether an arachnoid cyst (or death from it) is connected to a person's military service on the balance of probabilities (s.3, s.8). It applies to claims under the Veterans’ Entitlements Act s.120B and the MRCA s.339, replaces the 2015 Statement, and requires claimants to show at least one specified antecedent factor (with timing) that is related to their relevant service (s.4, s.5, s.9, s.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"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This is a straightforward reissue/replacement of the 2015 Statement of Principles concerning the same medical condition. The scope remains tightly focused on establishing medical nexus criteria for arachnoid cysts in the veterans' compensation system. No expansion beyond the original purpose of determining service-relatedness for this specific condition."},"complexity_factors":["Moderate cross-referencing between main text and Schedule 1 Dictionary (7 defined terms)","Conditional logic requiring 'at least one' factor from a list of 13 distinct medical scenarios","Temporal restrictions on several factors (e.g., 'within 3 months before clinical worsening')","Dual application structure — factors apply to both 'clinical onset' and 'clinical worsening' with different rules for each","Nested definitions (arachnoid cyst defined by inclusion and exclusion; trauma defined with internal exclusions)","Section 11 creates dynamic incorporation of other Statements of Principles by reference ('as in force from time to time')","Specific anatomical distinctions between cranial and spinal arachnoid cysts with different factor sets"],"plain_english_summary":"This instrument sets the medical test for veteran compensation claims for arachnoid cysts — defining the condition, using the \"balance of probabilities\" standard, and specifying the kinds of service-related causes or worsening that prove entitlement. It applies to veterans and current/former Defence Force members under the Veterans' Entitlements Act 1986 and the Military Rehabilitation and Compensation Act 2004.\n\nKey connection factors include head or spinal trauma/surgery, spinal procedures, infections, bleeding or adhesive arachnoiditis, and failure of care; pre-existing cysts must be shown to have been materially worsened by service."}},"importantCases":[],"_links":{"self":"/api/acts/statement-of-principles-concerning-arachnoid-cyst-balance-of-probabilities-no-12-of-2025","history":"/api/acts/statement-of-principles-concerning-arachnoid-cyst-balance-of-probabilities-no-12-of-2025/history","analysis":"/api/acts/statement-of-principles-concerning-arachnoid-cyst-balance-of-probabilities-no-12-of-2025/analysis","conflicts":"/api/acts/statement-of-principles-concerning-arachnoid-cyst-balance-of-probabilities-no-12-of-2025/conflicts","importantCases":"/api/acts/statement-of-principles-concerning-arachnoid-cyst-balance-of-probabilities-no-12-of-2025/important-cases","documents":"/api/acts/statement-of-principles-concerning-arachnoid-cyst-balance-of-probabilities-no-12-of-2025/documents"}}