Key Questions to Ask When Evaluating a Patient with High Suspicion for Narcolepsy
When evaluating a patient with suspected narcolepsy, you should specifically ask about the classic tetrad of symptoms: excessive daytime sleepiness, cataplexy, hypnagogic/hypnopompic hallucinations, and sleep paralysis, as these are the cardinal features that distinguish narcolepsy from other sleep disorders. 1
Core Symptom Assessment
Excessive Daytime Sleepiness (EDS)
- Ask about irresistible sleep episodes or "sleep attacks" during the day
- Determine if these occur during inappropriate situations (e.g., while eating, talking, driving)
- Assess the frequency and duration of these episodes
- Inquire if brief naps (10-20 minutes) are refreshing
- Use the Epworth Sleepiness Scale to quantify sleepiness severity 2
Cataplexy
- Ask about sudden loss of muscle tone triggered by strong emotions (especially laughter, surprise, anger)
- Determine if consciousness is preserved during these episodes (differentiates from syncope)
- Ask about specific manifestations:
- Facial drooping or jaw dropping
- Knee buckling
- Objects falling from hands
- Complete collapse to the ground
- In children, ask about facial hypotonia, active tongue movements, or complex hyperkinetic movements 1
Sleep Paralysis
- Ask about episodes of complete inability to move when falling asleep or waking up
- Determine duration (typically seconds to minutes)
- Ask if these episodes cause distress or anxiety
Hypnagogic/Hypnopompic Hallucinations
- Ask about vivid, dream-like experiences when falling asleep (hypnagogic) or waking up (hypnopompic)
- Determine if these are visual, auditory, tactile, or multisensory
- Ask if these hallucinations are distressing or frightening
Additional Important Questions
Sleep Patterns
- Ask about disrupted nighttime sleep (fragmented sleep)
- Inquire about sleep schedule regularity
- Ask about automatic behaviors (performing routine activities without awareness)
- Determine total sleep time per 24 hours
Onset and Progression
- Age of symptom onset (typically second or third decade) 3
- Sequence of symptom development (EDS usually first)
- Progression of symptoms over time
- Family history of similar symptoms
Differential Diagnosis Questions
- Ask about symptoms of obstructive sleep apnea (snoring, witnessed apneas, morning headaches)
- Screen for other causes of hypersomnia:
- Insufficient sleep syndrome (sleep deprivation)
- Medication effects
- Psychiatric disorders (depression, anxiety)
- Medical conditions (hypothyroidism, head trauma)
- Ask about periodic limb movements during sleep 3
Impact Assessment
- Determine impact on:
- Academic/occupational functioning
- Social relationships
- Driving safety (history of drowsy driving, accidents, or near-misses) 1
- Quality of life
Specific Diagnostic Considerations
When evaluating cataplexy, it's crucial to differentiate it from epileptic seizures. Unlike seizures, cataplexy:
- Occurs without loss of consciousness
- Is typically triggered by emotions
- Has no post-ictal confusion
- Involves immediate recovery of muscle tone 1
For patients with excessive daytime sleepiness, always assess for comorbid conditions that may contribute to sleepiness or require separate management, including:
- Other sleep disorders (particularly sleep apnea)
- Medication effects
- Substance use (alcohol)
- Neurological disorders 1
Documentation for Diagnostic Testing
Document findings carefully to guide subsequent testing:
- Multiple Sleep Latency Test (MSLT) criteria: sleep latency ≤8 minutes with ≥2 sleep-onset REM periods 4
- Polysomnography findings: sleep-onset REM periods, fragmented sleep
- Consider cerebrospinal fluid hypocretin-1 levels in unclear cases 1
Remember that narcolepsy is often misdiagnosed or diagnosed with significant delay. A thorough clinical history focused on these key questions is essential for appropriate diagnosis and management.