# Clinical Cases: Sleep Disorders in Neurology

## Case 1: Obstructive Sleep Apnea

### Patient Demographics
- **Age:** 52 years old
- **Sex:** Male
- **Occupation:** Long-haul truck driver

### Chief Complaint
"My wife says I snore so loud she can hear it from the other room, and sometimes I stop breathing. I'm also exhausted during the day."

### History of Present Illness
Mr. Robert Thompson is a 52-year-old long-haul truck driver referred by his primary care physician for evaluation of suspected sleep apnea. His wife reports he has snored loudly for years, but over the past 2-3 years, she has witnessed episodes where he appears to stop breathing for 10-20 seconds, then gasps and resumes breathing. He wakes up multiple times at night, often to urinate (3-4 times nightly). Despite getting 7-8 hours in bed, he never feels rested and experiences significant daytime sleepiness. He has fallen asleep at red lights while driving and once nearly ran off the road. He reports morning headaches that resolve within an hour of waking. He denies chest pain or palpitations.

### Past Medical History
- Hypertension (on 3 medications, still not well controlled)
- Type 2 diabetes mellitus
- Atrial fibrillation (paroxysmal)
- Obesity

### Medications
- Lisinopril 40 mg daily
- Amlodipine 10 mg daily
- Metoprolol 50 mg twice daily
- Metformin 1000 mg twice daily
- Apixaban 5 mg twice daily

### Social History
- Former smoker (quit 5 years ago, 20 pack-year history)
- Alcohol: 2-3 beers on weekends
- Long-haul truck driver for 25 years
- Married, two adult children

### Family History
- Father: Died of MI at age 58
- Brother: Also uses CPAP for sleep apnea

### Physical Examination
- **Vital Signs:** BP 158/94 mmHg, HR 78, BMI 38
- **General:** Obese male, appears fatigued
- **HEENT:**
  - Neck circumference: 19 inches (48 cm)
  - Mallampati score: IV (only hard palate visible)
  - Retrognathia present
  - Nasal passages patent
- **Cardiovascular:** Irregular rhythm, no murmurs
- **Pulmonary:** Clear to auscultation

### Sleep Questionnaires

**Epworth Sleepiness Scale:** 16/24 (normal <10; >10 abnormal)
- Sitting and reading: 3
- Watching TV: 3
- Sitting inactive in public: 2
- Passenger in car >1 hour: 3
- Lying down in afternoon: 3
- Sitting and talking: 1
- Sitting quietly after lunch: 1
- In car, stopped in traffic: 0 (but has actually fallen asleep - denial?)

**STOP-BANG Score:** 7/8 (HIGH risk for OSA)
- Snoring: YES
- Tiredness: YES
- Observed apneas: YES
- High blood Pressure: YES
- BMI >35: YES
- Age >50: YES
- Neck circumference >17 inches: YES
- Gender male: YES

### Clinical Image
![Obstructive Sleep Apnea Mechanism](case_01_image.jpg)

*Image: Anatomical illustration showing the mechanism of obstructive sleep apnea, with airway collapse during sleep due to relaxation of pharyngeal muscles, obesity, and anatomic factors.*

**Image Source:** Wikimedia Commons
**Attribution:** National Heart, Lung, and Blood Institute, Public Domain
**URL:** https://commons.wikimedia.org/wiki/File:Sleep_apnea.jpg

### Diagnostic Study: Polysomnography

**Key Findings:**
- Total sleep time: 342 minutes
- Sleep efficiency: 78%
- **Apnea-Hypopnea Index (AHI): 48 events/hour (SEVERE)**
- Obstructive apneas: 156
- Obstructive hypopneas: 186
- Central apneas: 4
- Longest apnea: 42 seconds
- **Oxygen saturation nadir: 71%** (significant desaturation)
- Time SpO2 <90%: 28% of total sleep time
- Sleep stage distribution: Reduced REM (12%), increased N1 (25%)
- Supine AHI: 62; Non-supine AHI: 34

### Assessment and Diagnosis

1. **Severe obstructive sleep apnea** (AHI 48)
   - With significant nocturnal hypoxemia
   - Supine-predominant component
2. **Excessive daytime sleepiness** - Epworth 16
3. **Cardiovascular comorbidities** likely related to OSA:
   - Resistant hypertension
   - Atrial fibrillation
4. **Occupational safety concern** - commercial driver with untreated severe OSA

### Severity Classification (AHI)
| Severity | AHI (events/hour) |
|----------|-------------------|
| Normal | <5 |
| Mild | 5-15 |
| Moderate | 15-30 |
| **Severe** | **>30** |

### Management Plan

**Primary Treatment: CPAP Therapy**
- Prescribed auto-titrating CPAP (APAP) 4-20 cm H2O
- Nasal pillows interface selected based on patient preference
- CPAP clinic education scheduled
- Humidifier added to improve comfort

**CPAP Compliance Strategies:**
- Education on benefits and proper use
- Desensitization (wear mask while awake watching TV)
- Follow-up in 2 weeks to address any issues
- Download compliance data at follow-up

**Occupational Considerations:**
- Patient counseled that he should NOT drive commercial vehicle until OSA is treated and controlled
- Federal Motor Carrier Safety Administration guidelines reviewed
- Medical examiner will need to certify fitness to drive after demonstrating CPAP compliance and symptom resolution
- Documentation of >4 hours nightly CPAP use required

**Lifestyle Modifications:**
- Weight loss goal: 10% body weight reduction
- Avoid alcohol within 3 hours of bedtime
- Sleep on side (positional therapy as adjunct)
- Avoid sedating medications

**Cardiovascular Optimization:**
- Expect improvement in BP control with CPAP adherence
- Continue current medications
- Follow-up with cardiology for atrial fibrillation

### Follow-Up (6 weeks later)

**CPAP Compliance Data:**
- Average use: 5.2 hours/night
- Percentage nights used >4 hours: 78%
- Residual AHI on CPAP: 3.2 events/hour (well controlled)

**Clinical Improvement:**
- Epworth Sleepiness Scale: 7 (normalized, was 16)
- Blood pressure: 138/84 mmHg (improved)
- Wife reports no more snoring or witnessed apneas
- Patient reports feeling "like a new person"
- Morning headaches resolved
- Nocturia reduced to 1-2 times

**Occupational Clearance:**
- Provided documentation for medical examiner
- Cleared to return to commercial driving with annual recertification requirement

### Teaching Points

1. **STOP-BANG score ≥5 indicates high risk for moderate-severe OSA** - score of 7-8 very likely severe

2. **AHI severity classification:**
   - Mild: 5-15
   - Moderate: 15-30
   - Severe: >30

3. **OSA is associated with significant cardiovascular morbidity:**
   - Resistant hypertension (improves with CPAP)
   - Atrial fibrillation (OSA treatment reduces AF recurrence)
   - Stroke
   - Coronary artery disease

4. **CPAP is first-line treatment for moderate-severe OSA** - compliance is key to benefit

5. **Commercial drivers with untreated OSA are a safety hazard** - federal regulations require treatment documentation

6. **Weight loss is an important adjunct** - 10% weight loss can reduce AHI significantly

---

## Case 2: Narcolepsy Type 1

### Patient Demographics
- **Age:** 22 years old
- **Sex:** Female
- **Occupation:** College student

### Chief Complaint
"I keep falling asleep in class, and sometimes when I laugh really hard, my knees buckle and I collapse."

### History of Present Illness
Ms. Jennifer Martinez is a 22-year-old college student referred for evaluation of excessive daytime sleepiness and "spells." She has experienced overwhelming sleepiness since age 16, initially attributed to being a "typical teenager." Despite sleeping 8-9 hours at night, she experiences irresistible sleep attacks 2-3 times daily. She has fallen asleep during exams, while eating dinner, and during conversations. More concerning, since age 17, she has experienced episodes where her muscles suddenly go weak. These episodes are triggered by strong emotions, particularly laughter. She describes her knees buckling, her jaw going slack, and sometimes collapsing to the ground. She remains fully conscious during these episodes, which last 30 seconds to 2 minutes. She also reports vivid, sometimes frightening hallucinations as she falls asleep (seeing people in her room) and occasional episodes of being unable to move when waking up.

### Sleep History
- Nighttime sleep: 8-9 hours but fragmented, wakes 2-3 times
- Naps: Takes 1-2 naps daily, 15-30 minutes, refreshing
- Sleep paralysis: 2-3 times per month
- Hypnagogic hallucinations: Weekly

### Past Medical History
- No significant medical history
- No prior sleep studies
- No psychiatric diagnosis

### Medications
- None currently
- Tried caffeine pills with minimal benefit

### Family History
- No known sleep disorders
- No autoimmune diseases

### Social History
- College junior, struggling academically due to sleepiness
- Non-smoker
- Rare alcohol use (makes symptoms worse)
- Single, lives in dormitory

### Neurological Examination
- **General:** Alert, appropriate, yawns frequently during interview
- **Mental Status:** Normal
- **Cranial Nerves:** Intact
- **Motor:** Normal strength throughout; during discussion of funny videos on her phone, examiner observes transient jaw drop and neck flexion for ~30 seconds - patient remains conscious and can speak (slurred) during episode
- **Sensory:** Normal
- **Reflexes:** 2+ throughout
- **Coordination:** Normal

### Clinical Image
![Narcolepsy Tetrad](case_02_image.jpg)

*Image: Illustration depicting the classic tetrad of narcolepsy symptoms: excessive daytime sleepiness, cataplexy, sleep paralysis, and hypnagogic hallucinations, plus disrupted nocturnal sleep.*

**Image Source:** Wikimedia Commons
**Attribution:** Medical illustration, Educational Use
**URL:** https://commons.wikimedia.org/wiki/File:Narcolepsy_symptoms.png

### Diagnostic Studies

**Epworth Sleepiness Scale:** 19/24 (severely elevated)

**Polysomnography (overnight):**
- Total sleep time: 412 minutes
- Sleep efficiency: 82%
- Sleep latency: 3 minutes (short)
- REM latency: 8 minutes (very short; normal >90 minutes)
- AHI: 2 (no significant sleep apnea)
- PLMI: 4 (no significant periodic limb movements)

**Multiple Sleep Latency Test (MSLT) - Following Day:**
- Five nap opportunities at 2-hour intervals

| Nap | Sleep Latency | REM Present? |
|-----|---------------|--------------|
| 1 (9:00 AM) | 2 minutes | YES |
| 2 (11:00 AM) | 1 minute | YES |
| 3 (1:00 PM) | 3 minutes | YES |
| 4 (3:00 PM) | 2 minutes | YES |
| 5 (5:00 PM) | 1 minute | NO |

**MSLT Results:**
- **Mean sleep latency: 1.8 minutes** (normal >8 minutes)
- **Sleep-onset REM periods (SOREMPs): 4** (need ≥2 for diagnosis)

**HLA Typing:** DQB1*06:02 positive (associated with narcolepsy, but not diagnostic alone)

### Assessment and Diagnosis

**Narcolepsy Type 1** (with cataplexy)

*Diagnostic Criteria Met:*
1. Excessive daytime sleepiness for >3 months
2. Cataplexy (clearly witnessed during examination)
3. MSLT: Mean sleep latency <8 minutes with ≥2 SOREMPs
4. (CSF orexin/hypocretin not required when cataplexy is unequivocal, but would be low if measured)

### Classic Pentad of Narcolepsy
| Symptom | Present in Patient |
|---------|-------------------|
| Excessive daytime sleepiness | YES - daily sleep attacks |
| Cataplexy | YES - emotion-triggered weakness |
| Hypnagogic hallucinations | YES - sees figures at sleep onset |
| Sleep paralysis | YES - 2-3x/month |
| Disrupted nocturnal sleep | YES - fragmented nighttime sleep |

### Management Plan

**Pharmacologic Treatment:**

*For Excessive Daytime Sleepiness:*
- **Modafinil 100 mg every morning**, titrate to 200 mg if needed
- If inadequate: can add afternoon dose or switch to armodafinil
- Alternative: methylphenidate or amphetamine salts if modafinil insufficient

*For Cataplexy:*
- **Sodium oxybate (Xyrem)** - First-line for cataplexy
  - Start 4.5 g nightly divided into two doses (at bedtime and 2.5-4 hours later)
  - Titrate up as tolerated
  - Also improves EDS and consolidates sleep
  - Schedule III controlled substance - prescribed through REMS program
  - Counsel on side effects: sedation, respiratory depression (avoid with other CNS depressants), abuse potential

*Alternative for cataplexy if sodium oxybate not tolerated:*
- Venlafaxine (SNRI) - suppresses REM, reduces cataplexy
- Clomipramine (TCA)

**Lifestyle Modifications:**
- Scheduled short naps (15-20 minutes) 1-2 times daily
- Regular sleep-wake schedule
- Avoid alcohol (worsens symptoms and dangerous with sodium oxybate)
- Avoid driving until symptoms controlled

**Safety Counseling:**
- Do not drive or operate machinery until sleepiness controlled
- Avoid swimming alone, heights, other high-risk situations
- Medical alert bracelet recommended

**Accommodations:**
- Letter provided for university disability services requesting:
  - Extended time for exams
  - Permission to take scheduled rest breaks
  - Note-taking assistance

### Follow-Up (8 weeks later)

**Response to Treatment:**
- Modafinil 200 mg daily: Significant improvement in daytime alertness
- Sodium oxybate 6 g nightly: Cataplexy episodes reduced from daily to 1-2 per month
- Sleep paralysis and hypnagogic hallucinations improved
- Epworth: 9 (normalized from 19)

**Academic Performance:** Improved, passing all courses

### Teaching Points

1. **Narcolepsy Type 1 = with cataplexy; Type 2 = without cataplexy**

2. **Cataplexy is pathognomonic for narcolepsy Type 1:**
   - Sudden, bilateral loss of muscle tone
   - Triggered by strong emotion (especially laughter)
   - Consciousness preserved
   - Lasts seconds to minutes

3. **MSLT diagnostic criteria:**
   - Mean sleep latency <8 minutes
   - ≥2 sleep-onset REM periods (SOREMPs)

4. **Pathophysiology:** Narcolepsy Type 1 results from autoimmune destruction of orexin/hypocretin-producing neurons in the hypothalamus

5. **Treatment:**
   - Sleepiness: Modafinil (first-line), stimulants (second-line)
   - Cataplexy: Sodium oxybate (first-line), SNRIs, TCAs

6. **Sodium oxybate treats multiple symptoms** (EDS, cataplexy, disrupted sleep) but requires careful counseling about risks

---

## Case 3: REM Sleep Behavior Disorder

### Patient Demographics
- **Age:** 68 years old
- **Sex:** Male
- **Occupation:** Retired accountant

### Chief Complaint
Wife reports: "He's been acting out his dreams. Last week he punched me while he was asleep. I'm scared to sleep in the same bed."

### History of Present Illness
Mr. William Chen is a 68-year-old man brought by his wife for evaluation of abnormal behaviors during sleep. For the past 2 years, he has been increasingly active during sleep, talking, yelling, and moving his arms and legs. Initially, he would just mumble and wave his arms. Over the past 6 months, the behaviors have become more violent - he has punched his wife, fallen out of bed twice, and knocked a lamp off the nightstand. His wife reports that his movements seem to correspond to "fighting" or "running" as he often yells things like "Get away!" or "I'll get you!" When she wakes him, he clearly recalls dreaming about being attacked or chased. The episodes occur later in the night (after 3-4 hours of sleep). He has no memory of the actual movements, only the dream content.

### Additional Sleep History
- No history of sleepwalking in childhood
- No snoring or witnessed apneas
- Occasional restless legs in evening (mild)
- Normal sleep duration and quality otherwise

### Past Medical History
- Hypertension
- Mild constipation (chronic)
- Noticed decreased sense of smell over past several years

### Medications
- Lisinopril 20 mg daily
- Docusate sodium as needed

### Family History
- Father: Parkinson disease, diagnosed at age 72
- No other neurological diseases known

### Social History
- Retired accountant
- Non-smoker
- Occasional glass of wine with dinner
- Married 42 years

### Neurological Examination
- **Mental Status:** Normal cognition (MoCA 28/30)
- **Cranial Nerves:** Diminished sense of smell bilaterally (hyposmia)
- **Motor:**
  - Subtle rigidity right upper extremity (cogwheeling on distraction)
  - No resting tremor observed
  - Mildly decreased arm swing on right when walking
- **Gait:** Slightly slowed, mildly reduced stride length
- **Reflexes:** Normal

### Clinical Image
![REM Sleep Behavior Disorder](case_03_image.jpg)

*Image: Polysomnography recording demonstrating REM sleep without atonia - the characteristic finding in REM sleep behavior disorder, showing sustained muscle activity in the chin EMG during REM sleep.*

**Image Source:** Wikimedia Commons
**Attribution:** Medical education, Public Domain
**URL:** https://commons.wikimedia.org/wiki/File:REM_without_atonia.png

### Diagnostic Studies

**Polysomnography (Video-PSG):**
- Sleep architecture: Normal
- AHI: 4 (normal)
- REM sleep: 18% of total sleep time
- **REM Without Atonia (RSWA):** Present - sustained chin EMG activity during REM
- **Video:** During REM periods, patient observed thrashing arms, kicking legs, and yelling "Stop!" while appearing to be dreaming

### Assessment and Diagnosis

1. **REM Sleep Behavior Disorder (RBD)** - confirmed by PSG showing REM without atonia and video documentation of dream enactment behavior
2. **High risk for future neurodegenerative disease** - particularly alpha-synucleinopathy
3. **Early parkinsonian signs present:**
   - Hyposmia
   - Subtle right-sided rigidity
   - Decreased arm swing
   - Constipation (autonomic involvement)

### Significance of RBD

**Critical Prognostic Information:**
- RBD is strongly associated with future development of alpha-synucleinopathies:
  - Parkinson disease
  - Dementia with Lewy bodies
  - Multiple system atrophy
- **80%+ of patients with idiopathic RBD will develop a neurodegenerative disease** within 10-15 years
- Average time from RBD onset to neurodegenerative diagnosis: 10-15 years

*This patient already shows subtle parkinsonian features, suggesting he is in the prodromal phase of Parkinson disease.*

### Management Plan

**Safety Measures (Highest Priority):**
- Remove dangerous objects from bedroom (nightstands, lamps)
- Pad floor beside bed with mattress or cushions
- Lower bed or consider mattress on floor
- Consider sleeping in separate beds until behaviors controlled
- Secure windows
- Remove firearms from bedroom

**Pharmacologic Treatment:**

*First-line options:*
- **Melatonin 3-12 mg at bedtime** - Start with 3 mg, increase as needed
  - Mechanism unclear but effective in ~50%
  - Excellent safety profile
  - Try first due to safety

- **Clonazepam 0.25-1 mg at bedtime** - If melatonin insufficient
  - Very effective (~90% response)
  - Use caution in elderly (fall risk, cognitive effects)
  - Start low (0.25 mg), increase slowly
  - Monitor for daytime sedation

**Patient started on melatonin 6 mg at bedtime**

**Counseling Regarding Prognosis:**
- Discussed with patient and wife the association between RBD and neurodegenerative disease
- Explained that he already shows some subtle signs that may indicate early Parkinson disease
- Emphasized that not all patients develop overt disease, and timeline is variable
- Discussed potential future symptoms to watch for
- Offered support resources

**Referral to Movement Disorders Specialist:**
- For evaluation of subtle parkinsonian signs
- Discussion of monitoring vs. early treatment options
- Participation in research studies on neuroprotective strategies

### Follow-Up (3 months later)

**Treatment Response:**
- Melatonin 6 mg: Partial improvement
- Added clonazepam 0.5 mg: Significant improvement
- Wife reports rare residual talking but no violent behaviors
- No more injuries
- Couple sleeping in same bed again

**Movement Disorder Follow-Up:**
- Confirmed early parkinsonism
- No treatment initiated yet (symptoms minimal)
- Monitoring every 6 months
- Enrolled in longitudinal research study

### Teaching Points

1. **RBD is characterized by loss of normal REM sleep atonia** - patients physically act out dreams, often violent

2. **PSG shows REM without atonia (RSWA)** - this is the diagnostic hallmark

3. **Safety is the first priority** - bedroom modifications to prevent injury to patient and bed partner

4. **RBD is highly predictive of future alpha-synucleinopathy:**
   - >80% develop Parkinson disease, DLB, or MSA
   - This is one of the strongest known prodromal markers

5. **Treatment: melatonin (safer) and clonazepam (more effective)**

6. **Distinguish from NREM parasomnias:**
   - RBD: Later in night (REM-predominant), dream recall, eyes closed, older adults
   - NREM (sleepwalking, night terrors): First third of night, no recall, eyes open, more common in children

7. **Clinical pearls suggesting prodromal Parkinson disease:**
   - RBD
   - Hyposmia (decreased smell)
   - Constipation
   - Depression
   - Subtle motor signs

---

## Key Teaching Points Summary

### Obstructive Sleep Apnea
- STOP-BANG score ≥5 = high risk for moderate-severe OSA
- AHI: Mild 5-15, Moderate 15-30, Severe >30
- CPAP is first-line for moderate-severe OSA
- Associated with resistant hypertension, atrial fibrillation, stroke

### Narcolepsy
- Type 1 = with cataplexy (low CSF orexin); Type 2 = without cataplexy
- MSLT diagnostic: Mean sleep latency <8 min with ≥2 SOREMPs
- Cataplexy: emotion-triggered muscle weakness with preserved consciousness
- Treatment: Modafinil for EDS; sodium oxybate for cataplexy

### REM Sleep Behavior Disorder
- Dream enactment behavior with REM without atonia on PSG
- >80% will develop alpha-synucleinopathy (PD, DLB, MSA)
- Safety measures are highest priority
- Treatment: Melatonin (first-line for safety), clonazepam (highly effective)