Diagnostic Assessment — Periodic Limb Movement Disorder
Example 1 of 1 · fictitious patient (Veteran AM)
Diagnostic Assessment
Periodic Limb Movement Disorder
BOP Code: 20 of 2023 (Periodic Limb Movement Disorder)
RH Code: 19 of 2023 (Periodic Limb Movement Disorder)
ADF History
Veteran AM, date of birth 03 April 1979, Australian Army, Rifleman (Infantry), later Section Commander, enlisted 20 January 1998, medically discharged 15 November 2013. Operational service: East Timor, 02 October 1999 to 15 April 2000 (warlike); Afghanistan, 10 March 2011 to 24 August 2011 (warlike, aeromedically evacuated after blast injury).
Occupational History
As an infantry soldier and section commander the veteran conducted foot and vehicle patrols carrying loads of 35 to 50 kilograms, close combat, live-fire training and prolonged field exercises with fragmented, shift-based sleep. Infantry soldiers have high rates of musculoskeletal injury, blast and penetrating trauma, head injury from vehicle incidents and falls, and noise exposure.
On operations infantry soldiers are exposed to improvised explosive devices, indirect fire and small-arms contact, and to traumatic events including the death and wounding of comrades. These exposures carry a recognised risk of traumatic brain injury, spinal injury, posttraumatic stress disorder and depression.
History
Veteran AM, an infantry section commander in the Australian Army, sustained a severe traumatic brain injury, a cervical spinal cord injury, a stroke from vertebral artery dissection and crush-related renal failure in an improvised explosive device blast in Afghanistan on 22 August 2011, and developed periodic limb movement disorder on 10 November 2011 while in a spinal rehabilitation unit. The disorder was confirmed on polysomnography and worsened in 2014 after a further head injury and stroke.
Timeline
- 22 Aug 2011 — During warlike service in Afghanistan the veteran's patrol vehicle struck an improvised explosive device. He was unconscious for about six hours, with a Glasgow Coma Scale score of 7 at the role 3 hospital. CT showed bifrontal contusions and a C5-6 fracture-dislocation with spinal cord compression, and CT angiography showed a left vertebral artery dissection with an acute left cerebellar infarct. He had crush injuries to both legs with rhabdomyolysis and lost about three litres of blood. He regained consciousness the same evening and was aeromedically evacuated on 24 August 2011. "severe TBI, C5-6 cord injury"
- 29 Aug 2011 — At a tertiary hospital in Australia a renal physician diagnosed acute kidney injury from rhabdomyolysis, which failed to recover, and commenced haemodialysis three times a week. Serum ferritin was 12 micrograms per litre after the haemorrhage and repeated surgery, and iron deficiency was recorded. The cervical spine was surgically decompressed and fused. "haemodialysis commenced, ferritin 12"
- 10 Oct 2011 — A consultant psychiatrist diagnosed posttraumatic stress disorder related to the blast and to traumatic events in East Timor in 1999, and a major depressive episode of moderate severity. Sertraline 100 mg daily and mirtazapine 30 mg at night were commenced, with weekly psychology and fortnightly psychiatry review in the rehabilitation unit. "PTSD and MDD, sertraline commenced"
- 25 Oct 2011 — A neurologist reviewed MRI of the brain and spine, which showed periventricular and juxtacortical demyelinating plaques separate from the traumatic changes, and cerebrospinal fluid oligoclonal bands. With a documented episode of right optic neuritis in June 2009, relapsing-remitting multiple sclerosis was diagnosed. An asymmetric left-sided rest tremor and bradykinesia present since early 2011 were investigated with DaT-SPECT, which was abnormal, and young-onset Parkinson's disease was diagnosed. "MS and Parkinson's disease diagnosed"
- 14 Nov 2011 — Night nursing staff in the spinal rehabilitation unit reported repetitive kicking movements of both legs during sleep from 10 November 2011, and the veteran reported waking unrefreshed, frequent awakenings and severe daytime fatigue interfering with therapy. He denied any urge to move his legs while awake. Nursing sleep charts from 15 October to 09 November 2011 had recorded settled sleep without limb movements. "kicking in sleep, unrefreshed"
- 15 Feb 2012 — Overnight polysomnography showed periodic limb movements of sleep at 48 per hour, with a periodic limb movement arousal index of 21 per hour, an apnoea-hypopnoea index of 3 and no REM sleep without atonia. A sleep physician diagnosed periodic limb movement disorder, finding the features were not explained by restless legs syndrome, sleep apnoea or another sleep disorder. "PLMS index 48, PLMD diagnosed"
- 05 Mar 2014 — After discharge the veteran fell down a flight of stairs at home when his spastic legs gave way. He was unconscious for about 40 minutes, with a Glasgow Coma Scale score of 10, and CT showed a left acute subdural haematoma and frontal contusion. He regained consciousness on the day of the fall. "fall, moderate TBI, subdural"
- 20 Mar 2014 — While still in hospital he developed right arm weakness and expressive dysphasia. MRI showed an acute left middle cerebral artery territory infarct, attributed to new atrial fibrillation associated with his dialysis. Ferritin was 18 micrograms per litre. "left MCA stroke, AF"
- 20 May 2014 — Repeat polysomnography showed periodic limb movements of sleep at 86 per hour with an arousal index of 38 per hour. He reported near-constant night-time awakenings and marked daytime sleepiness, and his wife had moved to a separate room. The sleep physician recorded a clear worsening of the periodic limb movement disorder. "PLMS index 86, worsened"
Symptoms
At onset the veteran had repetitive kicking and jerking of both legs during sleep, observed by nursing staff, with frequent awakenings, unrefreshing sleep and daytime fatigue that limited his participation in rehabilitation. After onset the movements occurred nightly and his daytime functioning deteriorated further.
He now reports broken sleep every night, waking several times with leg jerks, marked daytime sleepiness and poor concentration. His wife sleeps in a separate room because of the movements. The symptoms worsened noticeably after his fall and stroke in 2014.
Imaging
- 22 Aug 2011 — CT head, cervical spine and CT angiography: "Bifrontal haemorrhagic contusions. C5-6 fracture-dislocation with canal compromise. Left vertebral artery dissection with acute left cerebellar infarct."
- 25 Oct 2011 — MRI brain and cervical spine: "Multiple periventricular and juxtacortical T2 hyperintense demyelinating plaques. Post-traumatic bifrontal gliosis and left cerebellar infarct. Cervical cord contusion with myelomalacia at C5-6 after fusion."
- 25 Oct 2011 — DaT-SPECT: "Reduced tracer uptake in the right putamen more than the left, consistent with presynaptic dopaminergic deficit."
- 05 Mar 2014 — CT head: "Left acute subdural haematoma 7 mm with left frontal contusion. No midline shift."
- 21 Mar 2014 — MRI brain: "Acute left middle cerebral artery territory infarct. Stable demyelinating plaques and old post-traumatic changes."
Onset Date
The most likely date of onset of this condition is 10 Nov 2011.
At that date the veteran was serving full time and was an inpatient in a spinal rehabilitation unit after the blast of 22 August 2011 on warlike service in Afghanistan. He was on haemodialysis three times a week, had a residual incomplete cervical spinal cord injury and the effects of a severe traumatic brain injury and a cerebellar stroke, and was taking sertraline and mirtazapine for posttraumatic stress disorder and depression.
This date is appropriate because nursing sleep charts from 15 October to 09 November 2011 recorded settled sleep without limb movements, and night staff first observed repetitive leg kicks from 10 November 2011, reported to the medical officer on 14 November 2011. It falls within uninterrupted full-time service.
For the traumatic brain injury and cerebrovascular accident factors, the 3 months before onset run from 10 Aug 2011 to 10 Nov 2011; the blast injury and the cerebellar infarct occurred on 22 Aug 2011, 80 days before onset, and he regained consciousness that day, so onset occurred within 3 months of regaining consciousness. For the drug factors, the 30 days before onset run from 11 Oct 2011 to 10 Nov 2011, during which he took sertraline and mirtazapine daily as prescribed from 10 Oct 2011. Chronic renal failure, the spinal cord lesion, iron deficiency, Parkinson's disease, multiple sclerosis, posttraumatic stress disorder and depression were each established before 10 Nov 2011 and present on that date.
For the worsening factors, the documented worsening was on 20 May 2014. The 3 months before the worsening run from 20 Feb 2014 to 20 May 2014, which include the moderate traumatic brain injury of 05 Mar 2014, after which he regained consciousness the same day, and the stroke of 20 Mar 2014. The 30 days before the worsening run from 20 Apr 2014 to 20 May 2014, during which he continued sertraline and mirtazapine.
1. What is the formal diagnosis of the condition claimed above?
The formal diagnosis is Periodic Limb Movement Disorder (ICD-10-AM G47.61), under the Statements of Principles concerning periodic limb movement disorder, Balance of Probabilities No. 20 of 2023 and Reasonable Hypothesis No. 19 of 2023.
Periodic limb movement disorder is a sleep disorder in which repetitive, stereotyped, involuntary movements of the limbs during sleep, typically extension of the big toe and flexion of the ankle, knee and hip, occur at least 15 times an hour and cause clinical sleep disturbance and impaired daytime functioning. The movements fragment sleep through repeated arousals, producing unrefreshing sleep, fatigue, poor concentration and mood disturbance. The disorder is closely associated with injury or disease of the brain and spinal cord, renal failure, iron deficiency and certain antidepressant medications.
The diagnosis followed the severe traumatic brain injury, cervical spinal cord injury, stroke and renal failure from the 2011 blast. It began on 10 November 2011, was confirmed on polysomnography in February 2012 and worsened in 2014.
2. For each diagnosis identified, please also provide the following dates:
When did the veteran first experience symptoms attributable to this condition?
10 November 2011.
When did the veteran first present to a health / medical provider for this condition?
14 November 2011.
When was the condition confirmed / formally diagnosed?
15 February 2012.
When did the veteran first present to you (or your practice) for this condition?
07 August 2025.
3. How was this diagnosis confirmed? i.e. what were the key symptoms and signs, investigation results, specialist opinions?
The diagnosis was confirmed by overnight polysomnography on 15 February 2012, which showed periodic limb movements of sleep at 48 per hour, well above the adult threshold of 15 per hour, with an associated arousal index of 21 per hour. The veteran had a clinical sleep disturbance, with frequent awakenings and unrefreshing sleep, and impaired daytime functioning that limited his rehabilitation. This meets the Statement of Principles definition of periodic limb movement disorder.
The features were not better explained by another primary sleep disorder: the apnoea-hypopnoea index was 3, there was no REM sleep without atonia, and he denied the urge to move or evening symptoms of restless legs syndrome. A sleep physician confirmed the diagnosis. Repeat polysomnography on 20 May 2014 confirmed worsening to 86 movements per hour.
4. What do you consider to be the cause(s) of the condition in this veteran? Give consideration to constitutional and common risk factors, pre-existing injuries or diseases, and occupational or lifestyle risks, as well as direct causative mechanisms.
Legislation: the clinical onset of this condition was on 10 November 2011, after 1 July 2004, during continuous full-time service. This is a Military Rehabilitation and Compensation Act 2004 (MRCA) claim and the Statements of Principles apply. The Balance of Probabilities instrument applies to peacetime service, including his inpatient rehabilitation and treatment in Australia. The Reasonable Hypothesis instrument applies to his warlike service in Afghanistan in 2011, where the blast caused the brain injury, spinal cord injury, stroke, renal failure and iron deficiency and contributed to his posttraumatic stress disorder, and to his warlike service in East Timor in 1999 to 2000.
Each factor must be related to the person's relevant service. Under the beneficial approach required by the legislation, the absence of documentation does not mean that an event or exposure did not occur: lack of evidence is not evidence of lack.
Balance of Probabilities — Statement of Principles concerning Periodic Limb Movement Disorder, No. 20 of 2023
Causative factors
Factor 9(1): having chronic renal failure at the time of the clinical onset of periodic limb movement disorder; — MET
- Acute kidney injury from rhabdomyolysis after the crush injuries of 22 August 2011 failed to recover, and a renal physician commenced haemodialysis three times a week on 29 August 2011. He was undergoing chronic dialysis and needed renal replacement therapy on 10 November 2011, the date of onset, meeting the definition of chronic renal failure. Uraemia is a well-recognised cause of periodic limb movements.
Factor 9(2): having a spinal cord lesion at the time of the clinical onset of periodic limb movement disorder; — MET
- The C5-6 fracture-dislocation of 22 August 2011 caused a cervical spinal cord contusion, confirmed as myelomalacia on MRI on 25 October 2011, with an incomplete spinal cord injury. The lesion was present at onset on 10 November 2011, while he was an inpatient in the spinal rehabilitation unit.
Factor 9(3): taking venlafaxine or a selective serotonin reuptake inhibitor as prescribed for ongoing use within the 30 days before the clinical onset of periodic limb movement disorder; — MET
- A consultant psychiatrist prescribed sertraline 100 mg daily, a selective serotonin reuptake inhibitor, for ongoing use from 10 October 2011 for his service-related posttraumatic stress disorder and depression. He took it daily throughout the 30 days before onset, from 11 October 2011 to 10 November 2011, administered by ward staff.
Worsening factors
Factor 9(4): having chronic renal failure at the time of the clinical worsening of periodic limb movement disorder; — MET
- He remained on haemodialysis three times a week for chronic renal failure when the periodic limb movement disorder worsened, documented on polysomnography on 20 May 2014.
Factor 9(5): having a spinal cord lesion at the time of the clinical worsening of periodic limb movement disorder; — MET
- The incomplete cervical spinal cord injury persisted, with spasticity of both legs, at the worsening on 20 May 2014. The spasticity caused the fall of 05 March 2014.
Factor 9(6): taking venlafaxine or a selective serotonin reuptake inhibitor as prescribed for ongoing use within the 30 days before the clinical worsening of periodic limb movement disorder; — MET
- Sertraline 100 mg daily continued as prescribed for ongoing use throughout the 30 days before the worsening, from 20 April 2014 to 20 May 2014, for his posttraumatic stress disorder and depression.
Factor 9(7): inability to obtain appropriate clinical management for periodic limb movement disorder. — MET
- After his medical discharge on 15 November 2013 his care moved to the civilian system and his referral for sleep physician follow-up was lost. He had no specialist review of the disorder for six months, during which no attempt was made to review the sertraline or mirtazapine that aggravate it or to correct his iron deficiency, and the disorder worsened from 48 to 86 movements per hour. Under Brew v Repatriation Commission (1999) this is an inability to obtain appropriate clinical management.
Reasonable Hypothesis — Statement of Principles concerning Periodic Limb Movement Disorder, No. 19 of 2023
Causative factors
Factor 9(1): having chronic renal failure at the time of the clinical onset of periodic limb movement disorder; — MET
- Chronic renal failure requiring dialysis followed rhabdomyolysis from the crush injuries in the improvised explosive device blast on warlike service in Afghanistan on 22 August 2011. He was on chronic haemodialysis at onset on 10 November 2011.
Factor 9(2): having a spinal cord lesion at the time of the clinical onset of periodic limb movement disorder; — MET
- The cervical spinal cord contusion was sustained in the blast on warlike service in Afghanistan on 22 August 2011, shown as myelomalacia at C5-6 on MRI on 25 October 2011, and was present at onset on 10 November 2011.
Factor 9(3): taking a drug from the specified list of drugs: (a) as prescribed for ongoing use; and (b) within the 30 days before the clinical onset of periodic limb movement disorder; — MET
- Sertraline, a selective serotonin re-uptake inhibitor, and mirtazapine were prescribed for ongoing use from 10 October 2011 for posttraumatic stress disorder and depression arising from his warlike service in Afghanistan and East Timor. He took both throughout the 30 days before onset, from 11 October 2011 to 10 November 2011.
Factor 9(4): having iron deficiency at the time of the clinical onset of periodic limb movement disorder; — MET
- Serum ferritin was 12 micrograms per litre on 29 August 2011, after haemorrhage of about three litres in the blast on warlike service and repeated surgery, and remained below 30 micrograms per litre, at 21 micrograms per litre, on 08 November 2011. Iron deficiency was present at onset on 10 November 2011.
Factor 9(5): having a cerebrovascular accident within the 3 months before the clinical onset of periodic limb movement disorder; — MET
- A left cerebellar infarct from traumatic left vertebral artery dissection, caused by the blast on warlike service in Afghanistan, was shown on CT angiography on 22 August 2011. This was 80 days before onset and within the 3 months before onset, from 10 August 2011 to 10 November 2011.
Factor 9(6): having moderate to severe traumatic brain injury within the 3 months before the clinical onset of periodic limb movement disorder, and in the case of sustained unconsciousness following injury to the head, the clinical onset of periodic limb movement disorder occurred within 3 months of regaining consciousness; — MET
- The veteran sustained a severe traumatic brain injury in the blast on warlike service in Afghanistan on 22 August 2011, with about six hours of unconsciousness, a Glasgow Coma Scale score of 7 and bifrontal contusions. He regained consciousness that evening. Onset on 10 November 2011 was 80 days later, within 3 months of the injury and of regaining consciousness.
Factor 9(7): having Parkinson's disease at the time of the clinical onset of periodic limb movement disorder; — MET
- A neurologist diagnosed young-onset Parkinson's disease on 25 October 2011, with asymmetric rest tremor and bradykinesia present from early 2011 and an abnormal DaT-SPECT. The tremor was first recorded by the medical officer on warlike service in Afghanistan in May 2011. Parkinson's disease was present at onset on 10 November 2011.
Factor 9(8): having multiple sclerosis at the time of the clinical onset of periodic limb movement disorder; — MET
- Relapsing-remitting multiple sclerosis was diagnosed on 25 October 2011 on MRI showing demyelinating plaques and cerebrospinal fluid oligoclonal bands, with a prior episode of optic neuritis in June 2009. It was present at onset on 10 November 2011.
Factor 9(9): having a clinically significant depressive disorder or posttraumatic stress disorder at the time of the clinical onset of periodic limb movement disorder; — MET
- Posttraumatic stress disorder arising from the blast on warlike service in Afghanistan and from traumatic events on warlike service in East Timor, and a major depressive episode, were diagnosed on 10 October 2011. Both warranted ongoing management, with weekly psychology and fortnightly psychiatry review, and were present at onset on 10 November 2011.
Worsening factors
Factor 9(10): having chronic renal failure at the time of the clinical worsening of periodic limb movement disorder; — MET
- Chronic renal failure from the blast-related rhabdomyolysis on warlike service still required haemodialysis at the worsening on 20 May 2014.
Factor 9(11): having a spinal cord lesion at the time of the clinical worsening of periodic limb movement disorder; — MET
- The cervical spinal cord lesion from the blast on warlike service was present at the worsening on 20 May 2014, with spastic paraparesis.
Factor 9(12): taking a drug from the specified list of drugs: (a) as prescribed for ongoing use; and (b) within the 30 days before the clinical worsening of periodic limb movement disorder; — MET
- Sertraline and mirtazapine, prescribed for posttraumatic stress disorder and depression from his warlike service, continued as prescribed for ongoing use throughout the 30 days before the worsening, from 20 April 2014 to 20 May 2014.
Factor 9(13): having iron deficiency at the time of the clinical worsening of periodic limb movement disorder; — MET
- Serum ferritin was 18 micrograms per litre on 20 March 2014, from ongoing dialysis-related blood loss due to the renal failure caused by the blast on warlike service, and iron deficiency was present at the worsening on 20 May 2014.
Factor 9(14): having a cerebrovascular accident within the 3 months before the clinical worsening of periodic limb movement disorder; — MET
- An acute left middle cerebral artery infarct occurred on 20 March 2014 from atrial fibrillation associated with the dialysis required for his blast-related renal failure. This was within the 3 months before the worsening, from 20 February 2014 to 20 May 2014.
Factor 9(15): having moderate to severe traumatic brain injury within the 3 months before the clinical worsening of periodic limb movement disorder, and in the case of sustained unconsciousness following injury to the head, the clinical worsening of periodic limb movement disorder occurred within 3 months of regaining consciousness; — MET
- On 05 March 2014 the veteran fell down stairs when his legs, weakened and spastic from the spinal cord injury sustained on warlike service, gave way. He sustained a moderate traumatic brain injury, with about 40 minutes of unconsciousness, a Glasgow Coma Scale score of 10 and a subdural haematoma, and regained consciousness that day. The worsening on 20 May 2014 was within 3 months of the injury and of regaining consciousness.
Factor 9(16): having Parkinson's disease at the time of the clinical worsening of periodic limb movement disorder; — MET
- Parkinson's disease, first manifest during warlike service in Afghanistan in 2011, had progressed with gait freezing and was present at the worsening on 20 May 2014.
Factor 9(17): having multiple sclerosis at the time of the clinical worsening of periodic limb movement disorder; — MET
- Relapsing-remitting multiple sclerosis was present at the worsening on 20 May 2014, with stable plaques on MRI on 21 March 2014.
Factor 9(18): having a clinically significant depressive disorder or posttraumatic stress disorder at the time of the clinical worsening of periodic limb movement disorder; — MET
- Posttraumatic stress disorder and depression from his warlike service in Afghanistan and East Timor continued to require fortnightly psychiatric management at the worsening on 20 May 2014.
Factor 9(19): inability to obtain appropriate clinical management for periodic limb movement disorder. — MET
- After his medical discharge for the blast injuries sustained on warlike service, his sleep physician referral was lost in the transfer to civilian care. He had no specialist review from November 2013 to May 2014, and his iron deficiency and aggravating medications were not addressed while the disorder worsened. Under Brew v Repatriation Commission (1999) this is an inability to obtain appropriate clinical management.
The % contribution of the causes is 100% and significant.
Sequelae
The periodic limb movement disorder is a sequela of the veteran's accepted conditions: the cervical spinal cord injury, severe traumatic brain injury, cerebellar stroke, chronic renal failure and iron deficiency from the 2011 blast, and the sertraline and mirtazapine prescribed for his accepted posttraumatic stress disorder and depression. The resulting sleep fragmentation has in turn aggravated his daytime fatigue, depression and cognitive difficulties.
Unintended Consequence
Met. The periodic limb movement disorder is in part an unintended consequence of sertraline and mirtazapine, prescribed and paid for by the Commonwealth while the veteran was serving for his service-related posttraumatic stress disorder and depression (section 6A of the DRCA and the equivalent provisions of the MRCA).
Inability to Attain Appropriate Medical Management
MET. Following his medical discharge on 15 November 2013, the sleep physician referral was lost in the transition from Defence to civilian care and he had no specialist review for six months. During that time his iron deficiency was not corrected and his serotonergic medications were not reviewed, and the periodic limb movement index rose from 48 to 86 per hour. Applying the objective and subjective tests in Brew v Repatriation Commission (Full Federal Court, 10 September 1999, Merkel J), a breakdown in the transfer of care that leaves a diagnosed disorder without specialist management amounts to an inability to obtain appropriate clinical management. The three-month wait between his first presentation in November 2011 and the confirming polysomnogram in February 2012 is also indicative of barriers to care.
5. Please provide a Health Summary and a medication / prescribing history.
See attached report.
References
- Jun 2009, Ophthalmology consultation, Ophthalmologist
- 22 Aug 2011, Trauma admission, CT and CT angiography reports, Role 3 hospital, Afghanistan
- 29 Aug 2011, Renal medicine consultation, Renal physician
- 10 Oct 2011, Psychiatric assessment, Consultant psychiatrist
- 25 Oct 2011, MRI brain and spine, DaT-SPECT and neurology consultation, Neurologist
- 08 Nov 2011, Pathology report, iron studies
- 14 Nov 2011, Inpatient progress notes and nursing sleep charts, Spinal rehabilitation unit
- 15 Feb 2012, Diagnostic polysomnography report, Sleep physician
- 15 Nov 2013, Medical discharge documentation, Medical Officer
- 05 Mar 2014, Emergency admission and CT head report, Neurosurgical registrar
- 21 Mar 2014, MRI brain and stroke unit discharge summary, Neurologist
- 20 May 2014, Repeat polysomnography report, Sleep physician
- Statement of Principles concerning Periodic Limb Movement Disorder (Balance of Probabilities) No. 20 of 2023, Repatriation Medical Authority
- Statement of Principles concerning Periodic Limb Movement Disorder (Reasonable Hypothesis) No. 19 of 2023, Repatriation Medical Authority
