Diagnostic Assessment — Idiopathic Hypersomnolence
Example 1 of 1 · fictitious patient (Veteran AN)
Diagnostic Assessment
Idiopathic Hypersomnolence
No Statement of Principles applies to this condition (non-SOP claim).
ADF History
Veteran AN, date of birth 19 November 1988, Australian Army, Communication Systems Operator (Signaller), enlisted 08 February 2007, medically discharged 27 August 2020. Operational service: Afghanistan, 05 March 2012 to 25 October 2012 (warlike); Middle East Area of Operations, 02 April 2018 to 30 October 2018 (non-warlike).
Occupational History
Communication systems operators establish and run radio, satellite and data networks for headquarters and deployed forces. Communications centres are staffed around the clock, so the trade involves prolonged rotating and night shift work, often 12-hour shifts with rapid changes between day and night rosters, and sustained concentration on consoles in windowless rooms. In the field, signallers travel in convoys and work from vehicles and command posts.
On operations, sleep is further disrupted by noise, shared accommodation, heat, indirect fire alarms and on-call duties, and personnel are exposed to blast and vehicle incidents during convoy moves. Respiratory and viral infections spread readily in crowded accommodation. Specialist sleep medicine services are not available in theatre.
History
Veteran AN, a signaller in the Australian Army, developed idiopathic hypersomnolence on 10 July 2013, after two years of rotating 12-hour shift work and chronic sleep restriction, a blast-related concussion and infectious mononucleosis on warlike service in Afghanistan in 2012, influenza A in January 2013, a general anaesthetic in April 2013, and the onset of posttraumatic stress disorder and depression. The diagnosis was confirmed on prolonged polysomnography and multiple sleep latency testing in March 2014, and the condition worsened on non-warlike service in the Middle East in 2018.
Timeline
- 14 Jun 2011 — Periodic health examination at the garrison health centre. The veteran reported normal sleep of seven to eight hours with no daytime sleepiness, and his Epworth Sleepiness Scale score was 4. Examination and mental state were normal. He had started rotating 12-hour shifts in a communications centre the previous week. "sleep normal, Epworth 4"
- 14 Aug 2012 — On warlike service in Afghanistan the protected vehicle in which the veteran was travelling was struck by an improvised explosive device. He was dazed and confused for about ten minutes, with amnesia for the minutes after the blast, and had headache and nausea afterwards. A medical officer diagnosed a mild traumatic brain injury and he was rested for 48 hours before returning to shifts. "IED blast, mTBI, PTA 10 min"
- 21 Sep 2012 — Seen at the role 2 facility in Afghanistan with fever, exudative pharyngitis, cervical lymphadenopathy and marked fatigue during an outbreak in shared accommodation. The heterophile antibody test was positive and EBV serology on return confirmed recent infection. He was off duty for two weeks. He was working 12-hour rotating shifts and averaging about five hours of sleep because of indirect fire alarms. "infectious mononucleosis, sleep 5 h"
- 22 Jan 2013 — Seen at the garrison health centre with fever, myalgia and cough during an influenza outbreak in the barracks. A nasal swab was positive for influenza A (H1N1). He was confined to quarters for five days. Fatigue lasted about a month. "influenza A H1N1 positive"
- 16 Apr 2013 — Arthroscopic partial meniscectomy of the right knee under general anaesthesia with propofol and sevoflurane, for a meniscal tear sustained in a fall from a vehicle in Afghanistan. He was slow to rouse in recovery. On 20 May 2013 a psychiatrist diagnosed posttraumatic stress disorder and major depressive disorder related to the 2012 blast and his deployment. "GA for arthroscopy; PTSD, MDD"
- 05 Aug 2013 — Presented to the medical officer with four weeks of excessive daytime sleepiness since about 10 July 2013, sleeping 11 to 12 hours a night yet waking unrefreshed, severe difficulty waking with confusion for up to an hour, and long unrefreshing naps. He had fallen asleep at his console twice. Epworth Sleepiness Scale 17. He was referred to a sleep physician and his sedating medications were reviewed. "EDS, sleep drunkenness, Epworth 17"
- 12 Mar 2014 — After two weeks of actigraphy off shifts and off sedating medication, polysomnography with extended 24-hour recording showed a total sleep time of 12 hours 40 minutes with an apnoea-hypopnoea index of 3, and a multiple sleep latency test showed a mean sleep latency of 6.5 minutes with one sleep-onset REM period. A sleep physician diagnosed idiopathic hypersomnolence and commenced modafinil. "MSLT 6.5 min, TST 12.7 h"
- 28 Feb 2019 — Sleep physician review after the veteran's deployment to the Middle East, where he had worked 12-hour night shifts, sustained a further concussion in June 2018 and run out of modafinil. He had fallen asleep while driving on base. Epworth score 21. Repeat multiple sleep latency testing showed a mean sleep latency of 3.2 minutes. Treatment was escalated and he was placed on a permanent no-driving and no-shift restriction. "worse, MSLT 3.2 min, Epworth 21"
Symptoms
At onset the veteran had excessive daytime sleepiness despite sleeping 11 to 12 hours a night, waking unrefreshed, profound difficulty waking with confusion and clumsiness for up to an hour (sleep drunkenness), and long naps of two to three hours that did not refresh him. He fell asleep at his console and in briefings and had poor concentration and memory.
After the 2018 worsening he fell asleep while driving, needed 14 hours of sleep on rest days and could not stay awake through a working day without stimulant medication. He now reports persisting daytime sleepiness despite treatment, brain fog, missed alarms and inability to drive more than short distances. He no longer works shifts and has reduced his working hours.
Imaging
- 28 Aug 2013 — MRI brain: "No structural abnormality of the hypothalamus, brainstem or thalamus. No evidence of contusion, haemosiderin deposition or white matter injury. Normal study."
Onset Date
The most likely date of onset of this condition is 10 Jul 2013.
At that date the veteran was serving full time with a signal regiment in Australia, working rotating 12-hour day and night shifts in a communications centre. He was recovering from a right knee arthroscopy under general anaesthesia on 16 April 2013, was being treated for posttraumatic stress disorder and depression diagnosed on 20 May 2013, and had had infectious mononucleosis and a blast-related concussion in Afghanistan in 2012 and influenza A in January 2013. From about 10 July 2013 he began sleeping 11 to 12 hours a night and remained excessively sleepy during the day.
This date is appropriate because his periodic health examination of 14 June 2011 recorded normal sleep and an Epworth score of 4, and his post-deployment health assessment of 06 December 2012 recorded poor sleep from shifts and nightmares but no excessive sleep need or daytime sleepiness. He first presented on 05 August 2013, reporting four weeks of symptoms, and the diagnosis was confirmed on 12 March 2014.
For the shift work cause, the 12 months before onset run from 10 Jul 2012 to 10 Jul 2013; he worked rotating 12-hour shifts throughout, in Afghanistan and then in Australia, as he had since June 2011. For the sleep restriction cause, the 6 months before onset run from 10 Jan 2013 to 10 Jul 2013, during which his sleep diary averaged about five and a half hours a night. For the infection causes, the 12 months before onset run from 10 Jul 2012 to 10 Jul 2013 and include the infectious mononucleosis of 21 Sep 2012 and the influenza A of 22 Jan 2013. The 2 years before onset for the brain injury cause run from 10 Jul 2011 to 10 Jul 2013 and include the concussion of 14 Aug 2012. The 3 months before onset for the anaesthesia cause run from 10 Apr 2013 to 10 Jul 2013 and include the general anaesthetic of 16 Apr 2013. Posttraumatic stress disorder and depression were present on 10 Jul 2013.
For the worsening, documented on 15 Sep 2018 on non-warlike service in the Middle East and confirmed on testing on 28 Feb 2019, the 3 months before the worsening run from 15 Jun 2018 to 15 Sep 2018, during which he worked 12-hour night shifts, averaged about five hours of sleep and took quetiapine nightly. The 6 months before the worsening run from 15 Mar 2018 to 15 Sep 2018 and include the concussion of 19 Jun 2018. His modafinil supply ran out in theatre on 20 Jul 2018.
1. What is the formal diagnosis of the condition claimed above?
The formal diagnosis is Idiopathic Hypersomnolence with long sleep time (ICD-10 G47.11). No Statement of Principles has been determined for this condition.
Idiopathic hypersomnolence (idiopathic hypersomnia) is a chronic central disorder of hypersomnolence characterised by daily excessive daytime sleepiness for at least three months, often with prolonged night-time sleep of more than 11 hours, great difficulty waking (sleep inertia or sleep drunkenness) and long, unrefreshing naps, without the cataplexy and sleep-onset REM periods of narcolepsy. The diagnosis requires objective evidence, either a mean sleep latency of 8 minutes or less on a multiple sleep latency test or a total sleep time of 11 hours or more on prolonged recording, and exclusion of insufficient sleep, sleep apnoea, circadian disorders and medication effects as the cause. Onset commonly follows a viral illness, head injury or general anaesthesia, and the condition is aggravated by shift work, sleep restriction, sedating medicines and coexisting mood and trauma disorders.
The condition began on 10 July 2013, was confirmed on 12 March 2014 and worsened on non-warlike service in the Middle East in 2018.
2. For each diagnosis identified, please also provide the following dates:
When did the veteran first experience symptoms attributable to this condition?
10 July 2013.
When did the veteran first present to a health / medical provider for this condition?
05 August 2013.
When was the condition confirmed / formally diagnosed?
12 March 2014.
When did the veteran first present to you (or your practice) for this condition?
25 June 2025.
3. How was this diagnosis confirmed? i.e. what were the key symptoms and signs, investigation results, specialist opinions?
The diagnosis was confirmed on 12 March 2014 by a sleep physician on the basis of polysomnography with extended 24-hour recording showing a total sleep time of 12 hours 40 minutes, and a multiple sleep latency test showing a mean sleep latency of 6.5 minutes with only one sleep-onset REM period. These results meet the International Classification of Sleep Disorders (third edition) criteria for idiopathic hypersomnia: daily excessive sleepiness for more than three months, no cataplexy, fewer than two sleep-onset REM periods, and objective evidence of hypersomnolence on both measures.
Alternative causes were excluded before the diagnosis was made. Two weeks of actigraphy off shift work confirmed that the sleepiness persisted with unrestricted sleep, the apnoea-hypopnoea index of 3 excluded sleep apnoea, sedating medications had been withdrawn before testing, MRI of the brain on 28 August 2013 showed no structural lesion, and thyroid function, iron studies and a full blood count were normal. Repeat testing on 28 February 2019 confirmed the worsening, with a mean sleep latency of 3.2 minutes.
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 July 2013, after 1 July 2004, during continuous full-time service. This is a Military Rehabilitation and Compensation Act 2004 (MRCA) claim. No Statement of Principles has been determined for idiopathic hypersomnolence, so the claim is decided on the sound medical-scientific evidence of what causes and worsens the condition, without the limits a Statement of Principles would impose. The reasonable hypothesis standard applies to the veteran's warlike service in Afghanistan in 2012 and non-warlike service in the Middle East in 2018, and the balance of probabilities standard applies to his peacetime service. The recognised causes below are set out in Statement of Principles style.
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.
Recognised causes on the medical-scientific evidence (no Statement of Principles)
Causative factors
Cause 1: having infectious mononucleosis or other laboratory-confirmed Epstein-Barr virus infection within the 12 months before the clinical onset of idiopathic hypersomnolence; — MET
- On warlike service in Afghanistan on 21 September 2012 the veteran developed infectious mononucleosis during an outbreak in shared accommodation, with a positive heterophile antibody test and EBV serology on return confirming recent infection. This was ten months before onset on 10 July 2013. Post-viral onset, particularly after Epstein-Barr virus infection, is one of the most consistently reported precipitants of idiopathic hypersomnolence.
Cause 2: having a systemic viral infection, including laboratory-confirmed influenza, within the 12 months before the clinical onset of idiopathic hypersomnolence; — MET
- On 22 January 2013 the veteran had influenza A (H1N1), confirmed on nasal swab, contracted during an outbreak in the barracks where he was required to live. This was less than six months before onset, and his fatigue after the infection lasted about a month. Influenza A H1N1 infection has been associated with the onset of central hypersomnolence disorders.
Cause 3: having a mild traumatic brain injury within the 2 years before the clinical onset of idiopathic hypersomnolence; — MET
- On 14 August 2012, on warlike service in Afghanistan, an improvised explosive device struck his vehicle and he sustained a mild traumatic brain injury with confusion for about ten minutes and brief post-traumatic amnesia, diagnosed by the medical officer. This was eleven months before onset. Head injury is a recognised precipitant of persistent hypersomnolence, and MRI excluded a structural lesion that would point to a different diagnosis.
Cause 4: undergoing general anaesthesia within the 3 months before the clinical onset of idiopathic hypersomnolence; — MET
- On 16 April 2013 the veteran had a right knee arthroscopy under general anaesthesia with propofol and sevoflurane, for a meniscal tear sustained in a fall from a vehicle on warlike service in Afghanistan. This was twelve weeks before onset on 10 July 2013, and he was slow to rouse in recovery. Onset of idiopathic hypersomnolence after general anaesthesia is reported in case series.
Cause 5: working rotating shifts that include night work for at least the 12 months before the clinical onset of idiopathic hypersomnolence; — MET
- The veteran worked rotating 12-hour day and night shifts in communications centres from June 2011, in Australia, throughout his warlike service in Afghanistan and after his return, covering the whole of the 12 months before onset from 10 July 2012 to 10 July 2013, as shown on his unit rosters. Prolonged circadian disruption alters sleep-wake regulation and is associated with the emergence of central hypersomnolence.
Cause 6: having chronic insufficient sleep, averaging less than 6 hours of sleep per night, for at least the 6 months before the clinical onset of idiopathic hypersomnolence; — MET
- His sleep diary, kept for his psychologist, and the post-deployment health assessment recorded an average of about five and a half hours of sleep a night from January 2013 to July 2013, because of shift rotations, nightmares and early recall to work. Chronic sleep restriction filled the whole of the 6 months before onset, from 10 January 2013 to 10 July 2013, and then gave way to a persistent excessive sleep need that did not resolve when he was later rested off shifts.
Cause 7: having depressive disorder at the time of the clinical onset of idiopathic hypersomnolence; — MET
- A psychiatrist diagnosed major depressive disorder on 20 May 2013, related to the 2012 blast and the stresses of deployment, and it was present at onset on 10 July 2013. Depressive disorders share neurochemical pathways with central hypersomnolence and are recognised as frequently preceding and coexisting with idiopathic hypersomnolence.
Cause 8: having posttraumatic stress disorder at the time of the clinical onset of idiopathic hypersomnolence; — MET
- Posttraumatic stress disorder, arising from the improvised explosive device blast on warlike service in Afghanistan on 14 August 2012, was diagnosed on 20 May 2013 and was present at onset on 10 July 2013. Trauma-related arousal and sleep disruption are associated with the development of persistent hypersomnolence in veterans.
Worsening factors
Worsening 1: working night shifts or rotating shifts that include night work for at least the 3 months before the clinical worsening of idiopathic hypersomnolence; — MET
- On non-warlike service in the Middle East the veteran was rostered to 12-hour night shifts in the communications centre from April 2018, throughout the 3 months before the worsening from 15 June 2018 to 15 September 2018, despite a recommendation against shift work. His Epworth score rose from 15 in 2017 to 21, and the mean sleep latency fell from 6.5 to 3.2 minutes.
Worsening 2: having chronic insufficient sleep, averaging less than 6 hours of sleep per night, for at least the 3 months before the clinical worsening of idiopathic hypersomnolence; — MET
- In the Middle East daytime sleep after night shifts was disrupted by heat, noise in shared accommodation and alarms, and his sleep log averaged about five hours a day from 15 June 2018 to 15 September 2018.
Worsening 3: having a mild traumatic brain injury within the 6 months before the clinical worsening of idiopathic hypersomnolence; — MET
- On 19 June 2018, on non-warlike service in the Middle East, the veteran struck his head on a vehicle door frame when the vehicle braked sharply, with brief confusion and headache for several days, diagnosed as concussion by the medical officer. This was within the 6 months before the worsening, from 15 March 2018 to 15 September 2018.
Worsening 4: taking a sedating medication, including an antipsychotic, opioid or sedating antihistamine, for at least the 1 month before the clinical worsening of idiopathic hypersomnolence; — MET
- The veteran took quetiapine 50 mg nightly, prescribed by his psychiatrist for posttraumatic stress disorder nightmares, throughout the month before the worsening and for the whole deployment. Quetiapine is sedating and increases daytime sleepiness in central hypersomnolence.
Worsening 5: having depressive disorder or posttraumatic stress disorder at the time of the clinical worsening of idiopathic hypersomnolence; — MET
- Posttraumatic stress disorder and major depressive disorder, both arising from his warlike service in Afghanistan, were active at the worsening, with a PCL-5 score of 52 and a PHQ-9 score of 18 recorded in the Middle East on 10 September 2018.
Worsening 6: inability to obtain appropriate clinical management for idiopathic hypersomnolence. — MET
- On non-warlike service in the Middle East the veteran's modafinil supply ran out on 20 July 2018 and could not be replaced in theatre, no sleep physician was available, and his restriction against night shifts was not applied. The condition went untreated for about two months before the worsening on 15 September 2018. 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 idiopathic hypersomnolence has contributed to the veteran's depressive disorder, through loss of his career, social withdrawal and frustration with persistent sleepiness, as recorded by his psychiatrist in 2019. A minor motor vehicle collision on base on 02 October 2018, when he fell asleep while driving, caused a neck strain that has since resolved.
Unintended Consequence
Met. Headaches, palpitations and anxiety from modafinil and later from dexamphetamine, prescribed for the idiopathic hypersomnolence, are unintended consequences of treatment provided and paid for by the Commonwealth while the veteran was serving (section 6A of the DRCA and the equivalent provisions of the MRCA). The sedating quetiapine prescribed by Defence-funded psychiatry also aggravated his daytime sleepiness.
Inability to Attain Appropriate Medical Management
MET. On non-warlike service in the Middle East in 2018 the veteran could not obtain his prescribed modafinil after his supply ran out on 20 July 2018, had no access to a sleep physician, and continued to be rostered to night shifts despite a written recommendation against shift work. His sleepiness went untreated for about two months, culminating in falling asleep while driving and a mean sleep latency of 3.2 minutes on testing in February 2019. Applying the objective and subjective tests in Brew v Repatriation Commission (Full Federal Court, 10 September 1999, Merkel J), operational constraints that prevent prescribed treatment and recommended workplace restrictions amount to an inability to obtain appropriate clinical management. The seven-month interval between his first presentation in August 2013 and confirmatory testing in March 2014 is also indicative of barriers to care.
5. Please provide a Health Summary and a medication / prescribing history.
See attached report.
References
- 14 Jun 2011, Periodic health examination, Medical Officer, Garrison health centre
- 14 Aug 2012, Incident report and outpatient health record, Medical Officer, Afghanistan
- 21 Sep 2012, Outpatient health record and heterophile antibody test, Role 2 facility, Afghanistan
- 06 Dec 2012, Post-deployment health assessment, Medical Officer
- 22 Jan 2013, Outpatient health record and influenza PCR, Medical Officer, Garrison health centre
- 16 Apr 2013, Operation and anaesthetic record, Orthopaedic surgeon and Anaesthetist
- 20 May 2013, Psychiatric assessment, Consultant psychiatrist
- 05 Aug 2013, Outpatient health record, Medical Officer, Garrison health centre
- 28 Aug 2013, MRI brain, Radiologist
- 12 Mar 2014, Polysomnography, multiple sleep latency test and sleep consultation, Sleep physician
- 10 Sep 2018, Outpatient health record, Medical Officer, Middle East
- 28 Feb 2019, Repeat multiple sleep latency test and specialist review, Sleep physician
