Understanding and Managing Hypersomnolence Disorder
Sleep Medicine • Neurology • Psychiatry
Understanding and Managing Hypersomnolence Disorder
Hypersomnolence disorders are characterised by excessive daytime sleepiness (EDS) despite adequate or prolonged nocturnal sleep. They include idiopathic hypersomnia, narcolepsy (discussed separately), and recurrent hypersomnia. This guide outlines assessment, differential diagnosis and practical management strategies.
Definitions & common syndromes
- Idiopathic hypersomnia (IH): chronic, disabling EDS with prolonged sleep time or sleep inertia and no clear cause after evaluation.
- Recurrent hypersomnia (e.g., Kleine‑Levin syndrome): episodic periods of excessive sleepiness with cognitive/behavioural changes that remit between episodes.
- Hypersomnolence disorder (ICD/DSM category): clinically significant EDS not better explained by another sleep disorder, medical condition, substance or psychiatric disorder.
Key symptoms
- Persistent daytime sleepiness with prolonged naps that are often unrefreshing, difficulty waking (sleep inertia), long nocturnal sleep durations and impaired daytime functioning.
- In IH, patients may sleep long total sleep times (>10 hours) or have long, unrefreshing naps; mood and attention are commonly affected.
- Rule out narcolepsy features (cataplexy, SOREMPs) which alter management.
Assessment checklist
- Detailed sleep history: sleep timing, total sleep time, nap frequency/duration/refreshing quality, sleep inertia, night awakenings, and circadian pattern.
- Medication/substance review: sedatives, opioids, antihistamines, antipsychotics, alcohol.
- Screen for other sleep disorders: OSA (snoring, witnessed apneas), RLS/PLMS, circadian disorders—use STOP‑BANG, Epworth Sleepiness Scale and sleep diary/actigraphy for 1–2 weeks.
- Medical and psychiatric review: hypothyroidism, anaemia, chronic inflammation, depression, and substance use can cause or worsen EDS.
Investigations
- Nocturnal polysomnography (PSG): to exclude sleep‑disordered breathing and ensure adequate sleep opportunity prior to MSLT.
- Multiple Sleep Latency Test (MSLT): documents pathological sleep propensity but is less discriminatory for IH — mean sleep latency ≤8 minutes supports hypersomnolence; absence of SOREMPs favours IH over narcolepsy.
- 24‑hour/extended sleep recording or actigraphy: helpful when prolonged total sleep time is suspected or to document sleep duration.
- Targeted labs: TSH, full blood count, metabolic panel, and toxicology as indicated.
Differential diagnosis
- Narcolepsy type 1/2, obstructive sleep apnea, untreated depressive disorder, medication‑induced somnolence, idiopathic hypersomnia, circadian rhythm disorders, and medical causes (e.g., hypothyroidism).
- Careful history and appropriate testing are essential to avoid misdiagnosis and ineffective treatment.
Management principles
- Treat reversible causes: optimise treatment of OSA, review and stop sedating medications where possible, treat medical and psychiatric comorbidities.
- Non‑pharmacologic strategies: structured sleep schedule, planned (short) naps when helpful, sleep hygiene, and occupational adjustments (driving restrictions until controlled).
- Pharmacologic therapy: consider wake‑promoting agents and stimulants for persistent, functionally impairing EDS — choice guided by comorbidities, local licensing and side‑effect profiles.
- Multidisciplinary care: coordinate sleep medicine, neurology, psychiatry and occupational/rehabilitation services for complex cases.
Medication options & considerations
| Agent | Use | Notes/Cautions |
|---|---|---|
| Modafinil / Armodafinil | First‑line wake‑promoting for EDS | Generally well tolerated; monitor for headache, GI upset, rare severe rash; interacts with some CYP substrates. |
| Solriamfetol | Effective for EDS | Monitor BP and heart rate; avoid in uncontrolled hypertension; emerging evidence in IH. |
| Pitolisant | Licensed for EDS (where available) | May improve wakefulness and some REM symptoms; check local availability and side‑effect profile. |
| Traditional stimulants (methylphenidate, amphetamines) | Refractory cases | Effective but higher abuse potential and cardiovascular monitoring required. |
| Sodium oxybate | Severe IH with long sleep time or narcolepsy | Can improve sleep consolidation and daytime sleepiness; controlled substance with strict prescribing; contraindicated with certain sedatives and in unstable cardiovascular disease. |
Functional support & safety
- Advise patients not to drive until sleepiness is controlled; document occupational risks and liaise with employers when safety critical roles are involved.
- Provide education on recognising sleepiness, scheduling high‑demand tasks at optimal times and using environmental measures (bright light) to boost alertness acutely.
- Consider referral to occupational therapy for workplace adjustments and to psychology for coping strategies and mood comorbidity.
When to refer / red flags
- Marked functional impairment, suspected narcolepsy features (cataplexy), failure to respond to first‑line measures, concern for medication misuse, or diagnostic uncertainty—refer to sleep medicine.
- Severe mood disorder, suicidal ideation, or signs of systemic disease—urgent psychiatric or medical review.
Case vignette
Patient: L., 29, reports overwhelming sleepiness despite 9–10 hours’ nocturnal sleep and unrefreshing 1–2 hour naps. No cataplexy. PSG normal; MSLT mean sleep latency 6 minutes without SOREMPs. Diagnosis: idiopathic hypersomnia. Management: stop sedating antihistamine, trial modafinil with gradual dose titration, occupational counselling (no driving until improved), and follow‑up for symptom control and mood. Consider sodium oxybate if refractory with long sleep time.
தமிழில் — சுருக்கம்
Hypersomnolence என்பது அதிகமான நாள் பொழுது தூக்கமடைதல் ஆகும்; அதற்கான காரணங்களை பிரிசோதித்த பிறகு (OSA, மருந்துகள், மனநோய்வு) நிர்ணயிக்கப்படவில்லை என்றால் idiopathic hypersomnia என்று அழைக்கப்படுகிறது. முதலில் காரணங்களை நீக்கவும்; பின்னர் தூக்கத்தை தூண்டுகிற மருந்துகளைப் பயன்படுத்தலாம்.
Key takeaways
- Investigate reversible causes (OSA, medications, medical/psychiatric conditions) before diagnosing idiopathic hypersomnia.
- Use PSG and MSLT appropriately; extended sleep monitoring is helpful when prolonged sleep is suspected.
- Treat with wake‑promoting agents when functionally impairing—combine with non‑pharmacologic strategies and multidisciplinary support; refer to sleep medicine for complex or refractory cases.