What is the diagnosis and workup for a patient with easy onset of sleep, frequent nocturnal awakenings, and difficulty getting back to sleep?

Diagnosis and Workup for Sleep Maintenance Insomnia

This patient has chronic insomnia disorder characterized by sleep maintenance difficulties—specifically frequent nocturnal awakenings and early morning awakening with inability to return to sleep. 1

Primary Differential Diagnoses

The clinical presentation suggests several possible diagnoses that must be systematically evaluated:

1. Chronic Insomnia Disorder (Most Likely)

• Defined by difficulty maintaining sleep or early-morning waking with inability to return to sleep, occurring ≥3 nights per week for ≥3 months, causing clinically significant distress or daytime impairment. 1
• The easy sleep onset argues against pure sleep initiation insomnia, making this a sleep maintenance subtype. 1
• More common in older adults and women, who typically report problems with waking after sleep onset rather than sleep onset latency. 1

2. Advanced Sleep-Wake Phase Disorder (ASWPD)

• Characterized by falling asleep very easily in early evening hours and waking undesirably early (atypical compared to peers). 1
• Patients report extreme difficulty staying awake during evening hours and frequently fall asleep before completing work or social obligations. 1
• Key distinguishing feature: The patient's desired sleep timing versus their actual sleep timing—if they want to sleep later but cannot, consider ASWPD. 1

3. Comorbid Medical or Psychiatric Conditions

• Depression is 2.5 times more likely in patients with insomnia and represents the most consistent association with chronic insomnia. 1, 2
• Medical disorders (chronic pain, cardiopulmonary disorders, neurologic conditions) commonly cause sleep maintenance problems. 1
• Medications and substance use must be evaluated. 1

4. Other Sleep Disorders to Exclude

• Obstructive sleep apnea (OSA): Can present with frequent awakenings; screen with STOP questionnaire if snoring or witnessed apneas present. 1
• Restless legs syndrome (RLS): Uncomfortable leg sensations worse at night, improved with movement. 1
• Irregular Sleep-Wake Rhythm Disorder (ISWRD): Multiple non-circadian sleep-wake bouts, more common in neurodegenerative disorders. 1

Systematic Workup Approach

Step 1: Detailed Sleep History (Essential First Step)

Obtain specific information using these validated screening questions 1:

Sleep Pattern Questions:

• Usual bedtime and wake time (to establish sleep-wake schedule)
• Frequency of nocturnal awakenings (how many times per night)
• Ability to return to sleep after awakening
• Total sleep time needed to feel alert
• Duration of symptoms (acute vs. chronic: <3 months vs. ≥3 months) 1

Daytime Consequences:

• Excessive daytime sleepiness, fatigue, or unintentional napping 1
• Cognitive impairment, mood disturbance, or functional impairment 1

Circadian Rhythm Assessment:

• Does the patient fall asleep before desired or before completing evening activities? (suggests ASWPD) 1
• Is there a progressive shift in sleep-wake times? (suggests N24SWD) 1

Red Flags for Other Sleep Disorders:

• Snoring, gasping, or witnessed apneas (OSA) 1
• Urge to move legs or uncomfortable leg sensations at rest (RLS) 1
• Acting out dreams or complex sleep behaviors (REM behavior disorder) 1
• Nocturia frequency 1

Step 2: Document Sleep-Wake Patterns

Require sleep diaries and/or wrist actigraphy for ≥7 days (14 days if suspecting N24SWD). 1

• This objective documentation is mandatory for diagnosing circadian rhythm disorders. 1
• Sleep diaries capture subjective sleep quality, timing, and daytime symptoms. 1

Step 3: Screen for Comorbid Conditions

Psychiatric Assessment:

• Screen for depression and anxiety—depression increases insomnia risk 2.5-fold. 1
• Assess for recent personal losses or stressors. 1

Medical History:

• Chronic pain, cardiopulmonary disease, neurologic disorders, neurodegenerative conditions 1
• Complete medication review (many medications disrupt sleep) 1
• Substance use history (alcohol, caffeine, nicotine timing) 1

Physical Activity Level:

• Amount and timing of daily exercise 1

Step 4: Physical Examination

Focus on findings suggesting specific sleep disorders:

• Body mass index and neck circumference (OSA risk) 3
• Signs of neurodegenerative disease (ISWRD association) 1
• Cardiovascular and pulmonary examination 1

Step 5: Laboratory Testing (Selective)

Only when clinically indicated:

• Ferritin level if RLS suspected (treat if <45-50 ng/mL) 1
• Thyroid function if clinically indicated 1
• Polysomnography is NOT indicated for routine insomnia diagnosis 1

Step 6: Consider Polysomnography Only If:

• High suspicion for OSA (STOP questionnaire positive, witnessed apneas, snoring) 1, 3
• Suspected narcolepsy (requires polysomnography plus multiple sleep latency test) 1, 3
• REM behavior disorder suspected (requires polysomnography for diagnosis) 1, 3
• Treatment-refractory insomnia despite appropriate therapy 1

Critical Diagnostic Pitfalls to Avoid

Common Mistake #1: Assuming all sleep complaints are "just insomnia" without screening for OSA, RLS, or circadian disorders. 1, 3

Common Mistake #2: Ordering polysomnography for uncomplicated insomnia—this is not indicated and wastes resources. 1

Common Mistake #3: Missing ASWPD in patients who fall asleep easily but wake early—the easy sleep onset is the key distinguishing feature from typical insomnia. 1

Common Mistake #4: Failing to document sleep patterns objectively with sleep diaries/actigraphy before diagnosing circadian disorders. 1

Common Mistake #5: Not checking ferritin in patients with leg discomfort—this is a treatable cause of RLS. 1

Diagnostic Algorithm Summary

1. Obtain detailed sleep history using structured questions (duration ≥3 months, frequency ≥3 nights/week for chronic insomnia) 1
2. Document with sleep diary/actigraphy for ≥7 days 1
3. Screen for depression, anxiety, medical conditions, and medications 1
4. Use STOP questionnaire if OSA suspected 1
5. Check ferritin if RLS symptoms present 1
6. Reserve polysomnography for suspected OSA, narcolepsy, REM behavior disorder, or treatment-refractory cases only 1, 3

If criteria met for chronic insomnia disorder (≥3 months, ≥3 nights/week, daytime impairment, no other sleep disorder identified), proceed directly to treatment with cognitive behavioral therapy for insomnia (CBT-I) as first-line therapy. 1