Statement of Principles concerning arachnoid cyst (Reasonable Hypothesis) (No. 11 of 2025) (Cth)

Statement of Principles concerning ARACHNOID CYST (Reasonable Hypothesis) (No. 11 of 2025) The Repatriation Medical Authority determines the following Statement of Principles under subsection 196B(2) of the Veterans' Entitlements Act 1986.

Dated 17 December 2024.

Professor Terence Campbell AM Chairperson by and on behalf of The Repatriation Medical Authority

Contents 1 Name 2 Commencement 3 Authority 4 Repeal 5 Application 6 Definitions 7 Kind of injury, disease or death to which this Statement of Principles relates 8 Basis for determining the factors 9 Factors that must exist 10 Relationship to service 11 Factors referring to an injury or disease covered by another Statement of Principles Schedule 1 - Dictionary 1 Definitions

1. Name This is the Statement of Principles concerning arachnoid cyst (Reasonable Hypothesis) (No. 11 of 2025). 1. Commencement This instrument commences on 28 January 2025. 1. Authority This instrument is made under subsection 196B(2) of the Veterans' Entitlements Act 1986. 1. Repeal The 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cyst (No. 91 of 2015) (Federal Register of Legislation No. F2015L00924) made under subsection 196B(2) of the VEA is repealed. 1. Application This instrument applies to a claim to which section 120A of the VEA or section 338 of the Military Rehabilitation and Compensation Act 2004 applies. 1. Definitions The terms defined in the Schedule 1 - Dictionary have the meaning given when used in this instrument. 1. Kind of injury, disease or death to which this Statement of Principles relates 1. This Statement of Principles is about arachnoid cyst and death from arachnoid cyst. Meaning of arachnoid cyst 1. For the purposes of this Statement of Principles, arachnoid cyst: 1. means a benign, noncancerous cerebrospinal fluid-filled sac (pseudocyst), lined with arachnoid membrane, and occurring within the cranium or spinal canal; and 2. excludes arachnoid cyst associated with autosomal dominant polycystic kidney disease. Note 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. Note 2: Clinical worsening can include arachnoid cyst enlargement, rupture, or haemorrhage. Death from arachnoid cyst 1. 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. Note: terminal event is defined in the Schedule 1 – Dictionary. 1. Basis for determining the factors The 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. Note: MRCA, relevant service and VEA are defined in the Schedule 1 – Dictionary. 1. Factors that must exist At 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: 1. having concussion within the 12 months before clinical onset of cranial arachnoid cyst; 2. having a moderate to severe traumatic brain injury before clinical onset of cranial arachnoid cyst; 3. having concussion or a moderate to severe traumatic brain injury within the 3 months before clinical worsening of cranial arachnoid cyst; 4. having trauma in the region of the affected site before clinical onset of spinal arachnoid cyst; Note: trauma is defined in the Schedule 1 - Dictionary. 1. having trauma in the region of the affected site within the 3 months before clinical worsening of spinal arachnoid cyst; Note: trauma is defined in the Schedule 1 - Dictionary. 1. undergoing spinal surgery in the region of the affected site before clinical onset of spinal arachnoid cyst; Note: Examples of spinal surgery include spinal fusion, laminectomy, discectomy and interspinous device insertion. 1. undergoing spinal surgery in the region of the affected site within the 3 months before clinical worsening of spinal arachnoid cyst; Note: Examples of spinal surgery include spinal fusion, laminectomy, discectomy and interspinous device insertion. 1. undergoing cranial surgery in the region of the affected site before clinical onset of cranial arachnoid cyst; 2. undergoing cranial surgery in the region of the affected site within the 3 months before clinical worsening of cranial arachnoid cyst; 3. 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: 4. having a myelogram before clinical onset or clinical worsening of spinal arachnoid cyst; 5. having one of the following infections before clinical onset or clinical worsening: 1. bacterial infection of the brain or spinal cord, including abscess; 2. bacterial, viral or fungal meningitis; 3. cranial or spinal tuberculosis; 4. neurosyphilis; 6. having a subarachnoid haemorrhage within the cranium or spinal canal before clinical onset or clinical worsening of arachnoid cyst; 7. having spinal adhesive arachnoiditis before clinical onset or clinical worsening of spinal arachnoid cyst; 8. having a malignant neoplasm with infiltration of the meninges within the 1 year before clinical onset or clinical worsening of arachnoid cyst; 9. inability to obtain appropriate clinical management for arachnoid cyst before clinical worsening. 1. Relationship to service 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. 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. 2. Factors referring to an injury or disease covered by another Statement of Principles In this Statement of Principles: 1. if a factor referred to in section 9 applies in relation to a person; and 2. 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; then 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.