Psychiatry · Year 3 · from Psychiatry
Case 3: Narcolepsy Type 1
Patient Demographics
- Age: 22 years old
- Sex: Female
- Occupation: College senior
Chief Complaint
"I keep falling asleep at random times, and my legs give out when I laugh."
History of Present Illness
The patient is a 22-year-old college senior presenting with a 3-year history of excessive daytime sleepiness and unusual episodes of muscle weakness. Symptoms began during her sophomore year and have progressively interfered with her academics and social life.
She describes an overwhelming urge to sleep that occurs multiple times daily, regardless of how much sleep she got the night before. She has fallen asleep during classes, while studying, during meals, and during conversations. The sleepiness is not relieved by caffeine or willpower. She describes brief naps (15-20 minutes) as refreshing, but the sleepiness returns within a few hours. She sleeps 8-9 hours at night but never feels rested.
Most notably, she experiences sudden episodes of muscle weakness triggered by strong emotions, especially laughter. When she laughs hard, her knees buckle, her jaw goes slack, and her arms feel weak. She remains fully conscious during these episodes, which last seconds to a minute. She has fallen twice during these episodes but has not been injured. Her roommate witnessed an episode and thought she was having a seizure, but she was aware of her surroundings the entire time. These episodes also occur with surprise, excitement, and anger.
She reports vivid, often frightening, hallucinations as she falls asleep (hypnagogic) or wakes up (hypnopompic) - seeing figures in her room or feeling a presence. She has experienced sleep paralysis multiple times, feeling unable to move for 1-2 minutes upon waking, which is terrifying.
Her sleep is disrupted with frequent awakenings and vivid dreams. She sometimes acts out dreams (shouting, moving), and her roommate has observed her talking in her sleep.
Past Medical History
- No significant medical history
- No history of head injury or infections
- Family history negative for sleep disorders
Mental Status Examination
Appearance: Young woman, appears tired, yawned several times during interview
Behavior: Cooperative, briefly appeared to nod off during examination; during joking moment, visible knee buckling briefly observed
Speech: Normal (when alert)
Mood: "Frustrated - I feel like I'm sleeping my life away"
Affect: Appropriate, full range
Thought Process: Linear, goal-directed
Thought Content: No suicidal ideation; significant distress about impact on function
Perceptions: Reports hypnagogic hallucinations (vivid images at sleep onset); denies persistent hallucinations while awake
Cognition: Alert but had difficulty maintaining attention (drowsy); oriented x3
Insight: Good
Judgment: Good - seeking help
Screening Measures
Epworth Sleepiness Scale: 21/24 (severe sleepiness)
Diagnostic Testing
Nocturnal Polysomnography:
- Total sleep time: 410 minutes
- Sleep latency: 3 minutes (rapid)
- REM latency: 8 minutes (SOREMP - sleep onset REM period)
- AHI: 2 (no significant sleep apnea)
- No periodic limb movements
Multiple Sleep Latency Test (MSLT - following night PSG):
- 5 nap opportunities at 2-hour intervals
- Mean sleep latency: 4.2 minutes (pathologic; <8 minutes indicates pathological sleepiness)
- Sleep onset REM periods (SOREMPs): 4 of 5 naps
- Criteria for narcolepsy: Mean latency <8 minutes AND ≥2 SOREMPs
Diagnosis
Narcolepsy Type 1 (with Cataplexy) (G47.411)
DSM-5 Criteria Met: A. Recurrent periods of irrepressible need to sleep, lapsing into sleep, or napping occurring within same day - multiple times daily for >3 months: YES
B. Presence of at least one of the following:
- Cataplexy (defined as brief episodes of sudden bilateral loss of muscle tone with maintained consciousness, precipitated by laughter or joking): YES - classic cataplexy triggered by laughter
- CSF hypocretin-1 deficiency: Not tested (cataplexy is diagnostic)
- Nocturnal PSG showing REM latency <15 min OR MSLT showing mean sleep latency <8 min and ≥2 SOREMPs: YES (sleep latency 4.2 min with 4 SOREMPs)
Type 1 vs Type 2:
- Type 1: Cataplexy present (this patient)
- Type 2: No cataplexy
Associated Features Present:
- Hypnagogic hallucinations
- Sleep paralysis
- Disrupted nocturnal sleep
Treatment Plan
Patient Education:
- Chronic neurological condition (autoimmune destruction of hypocretin neurons)
- Manageable but not curable
- Symptoms can be significantly controlled with treatment
- Lifestyle adjustments needed long-term
Pharmacotherapy for Excessive Daytime Sleepiness:
- Modafinil 200 mg every morning (first-line wake-promoting agent)
- May increase to 200 mg BID if needed
- Monitor for headache, nausea
- Drug interaction: Reduces efficacy of oral contraceptives
Pharmacotherapy for Cataplexy:
- Venlafaxine 37.5 mg daily (SNRI - suppresses REM and reduces cataplexy)
- Increase to 75 mg if needed
- Do not stop abruptly (can cause severe rebound cataplexy)
Alternative Medication (if above inadequate):
- Sodium oxybate - FDA-approved for both sleepiness and cataplexy
- Highly effective but controlled substance
- Requires REMS program enrollment
- Taken at bedtime and 2.5-4 hours later
Behavioral Strategies:
- Scheduled brief naps (15-20 minutes) 2-3 times daily
- Regular sleep schedule
- Avoid sleep deprivation (worsens all symptoms)
- Avoid alcohol (worsens sleepiness and cataplexy)
Safety Considerations:
- Driving safety: May need to restrict driving until treatment effective
- Swimming, heights - avoid during uncontrolled periods
- ID bracelet recommended
Accommodations:
- Academic accommodations (extended time, permission to nap between exams)
- Letter provided for disability services
Follow-up:
- Sleep clinic in 4 weeks to assess treatment response
- Epworth Sleepiness Scale at each visit
- Adjust medications based on residual symptoms
- Long-term management with regular follow-up
Image Attribution
Image: Hypnogram showing normal sleep architecture with cycles through N1, N2, N3, and REM sleep stages across a typical night. Source: Wikimedia Commons. Used for educational purposes under Creative Commons license.