100+ Free ABPN Sleep Medicine Practice Questions

Normal Sleep Physiology & Circadian Rhythms

Sleep architecture (N1, N2 with K-complexes/spindles, N3 slow-wave, REM), ultradian ~90-min NREM-REM cycles, REM-on cholinergic LDT/PPT and REM-off aminergic locus coeruleus/dorsal raphe, ventrolateral preoptic GABA/galanin sleep switch, lateral hypothalamic orexin/hypocretin wake-promoting, two-process model (Process S homeostatic adenosine, Process C circadian SCN), melatonin DLMO ~2 h before habitual sleep, core body temperature nadir ~2 h before wake, age-related decline in N3 and REM, sleep neurochemistry (GABA, glutamate, histamine, orexin, melatonin).

Sleep-Disordered Breathing (OSA, CSA, Hypoventilation)

OSA — apnea (≥90% airflow drop ≥10 s), hypopnea (≥30% drop ≥10 s with ≥3% desat or arousal per AASM 1A; ≥4% desat per CMS 1B), AHI/RDI severity (mild 5-15, moderate 15-30, severe >30), STOP-BANG/Berlin/Epworth screening, in-lab PSG vs Type III HSAT (cannot diagnose central events reliably). CSA — Cheyne-Stokes in heart failure (crescendo-decrescendo, cycle ~60 s), high-loop gain, opioid-induced ataxic breathing, treatment-emergent CSA on CPAP. Obesity hypoventilation (BMI ≥30 + awake PaCO2 >45 without other cause). Congenital central hypoventilation (PHOX2B). Treatment — CPAP first-line OSA, BPAP for hypoventilation/intolerance, ASV (contraindicated in symptomatic HFrEF EF ≤45% per SERVE-HF), AVAPS for OHS/neuromuscular, oral appliances mild-moderate, hypoglossal nerve stimulation (Inspire — AHI 15-65, BMI <40 (current), no concentric collapse on DISE), positional therapy, weight loss, GLP-1 agonists (SURMOUNT-OSA tirzepatide 2024).

Insomnia Disorders

Chronic insomnia ≥3 nights/week ≥3 months with daytime impairment per ICSD-3-TR and DSM-5-TR. 3P model — Predisposing, Precipitating, Perpetuating. CBT-I first-line per AASM/ACP — sleep restriction, stimulus control, cognitive therapy, sleep hygiene, relaxation; digital CBT-I non-inferior. Pharmacotherapy adjuncts — DORAs (suvorexant, lemborexant, daridorexant) preferred for chronic insomnia; benzodiazepine receptor agonists (zolpidem, eszopiclone, zaleplon) short-term; ramelteon (MT1/MT2) for sleep-onset; low-dose doxepin (3-6 mg) for sleep maintenance; trazodone off-label (limited evidence). Avoid chronic benzodiazepines, especially in elderly (Beers criteria fall risk).

Hypersomnias (Narcolepsy, Idiopathic Hypersomnia, KLS)

Narcolepsy type 1 — cataplexy + low CSF hypocretin-1/orexin-A (≤110 pg/mL or ≤1/3 normal); HLA-DQB1*06:02 ~90% but not specific; pentad (EDS, cataplexy, sleep paralysis, hypnagogic hallucinations, fragmented sleep). Narcolepsy type 2 — no cataplexy, normal hypocretin. MSLT — mean sleep latency ≤8 min + ≥2 SOREMPs (or 1 SOREMP on prior PSG); preceded by ≥6 h overnight PSG and 1-2 weeks actigraphy off REM-suppressing meds. Idiopathic hypersomnia — long unrefreshing sleep, severe sleep inertia, MSL ≤8 min with <2 SOREMPs OR ≥11 h sleep on 24-h PSG/actigraphy. Kleine-Levin — recurrent hypersomnia + cognitive/behavioral changes in adolescent males. Treatment — modafinil/armodafinil first-line EDS; pitolisant (H3 inverse agonist), solriamfetol (DNRI), methylphenidate/amphetamine; sodium oxybate and low-sodium oxybate for cataplexy + EDS; pitolisant for cataplexy; SNRIs/SSRIs/venlafaxine off-label cataplexy.

Parasomnias (NREM & REM)

NREM disorders of arousal — sleepwalking, sleep terrors, confusional arousals, sleep-related eating disorder (SRED) — emerge from N3 in first third of night, no/limited dream recall, family history common, peak childhood. Triggers — sleep deprivation, alcohol, fever, sedative-hypnotics (zolpidem-induced SRED). REM parasomnias — RBD (loss of REM atonia → dream enactment violence; PSG REM without atonia required for diagnosis; strong association with alpha-synucleinopathies — PD, DLB, MSA convert at >70% by 12-15 years; clonazepam 0.25-2 mg or melatonin 3-12 mg first-line; remove SSRIs/SNRIs/TCAs which can precipitate). Nightmare disorder (PTSD link, prazosin evidence mixed per PACT). Recurrent isolated sleep paralysis. Sleep-related hallucinations, exploding head syndrome, sleep enuresis.

Restless Legs Syndrome & PLMD

RLS / Willis-Ekbom — URGE criteria (Urge to move, Rest worsens, Gets better with movement, Evening worsening). Iron deficiency central; check ferritin and transferrin saturation; oral iron if ferritin <75 ng/mL or TSAT <20% (with vitamin C; alternate days improves absorption); IV iron (ferric carboxymaltose, ferumoxytol, low molecular weight iron dextran) if oral fails or ferritin <100. First-line per 2024 AASM clinical guideline — alpha-2-delta ligands gabapentin enacarbil/gabapentin/pregabalin (less augmentation). Dopamine agonists (pramipexole, ropinirole, rotigotine) — augmentation in 7-9% per year, limit doses (pramipexole ≤0.25, ropinirole ≤1, rotigotine 1-3). Avoid SSRIs, dopamine antagonists, antihistamines. PLMD — PLMS index >15/h adults (>5 children) on PSG + clinical impairment + not better explained.

Circadian Rhythm Sleep-Wake Disorders

DSWPD — adolescents/young adults; treat with morning bright light, evening dim/blue blockers, low-dose timed melatonin 0.3-0.5 mg 5-7 h before sleep, gradual phase advance, chronotherapy. ASWPD — older adults; evening bright light. N24SWD — common in totally blind (no light entrainment); tasimelteon (MT1/MT2) FDA-approved for non-24 in blind. Irregular sleep-wake rhythm — dementia; structured light, melatonin debated. Shift-work disorder — strategic napping, modafinil/armodafinil for shift wakefulness, melatonin for daytime sleep. Jet lag — eastward harder; advance pre-trip, light + melatonin per direction.

Pediatric Sleep Medicine

Pediatric OSA — adenotonsillar hypertrophy peak 2-8 years; AHI >1 in children abnormal, severe >10; first-line treatment adenotonsillectomy (CHAT trial 2013 — improved behavior/QoL, no IQ change); intranasal steroids and montelukast for mild residual; CPAP for residual/non-surgical. Childhood behavioral insomnia — sleep onset association vs limit-setting; extinction/graduated extinction. Confusional arousals and sleepwalking peak 4-12 years, usually outgrown. Infant sleep — back to sleep, AAP safe sleep, 12-16 h newborn, consolidate by 6 mo. Adolescent delayed phase + early school start — AAP recommends middle/high school start ≥8:30 AM. Narcolepsy can present in childhood; H1N1 Pandemrix vaccine association in Europe 2009-2010.

Sleep in Psychiatric & Neurologic Disease

Depression — early morning awakening, decreased REM latency, increased REM density; treat MDD; CBT-I improves both. PTSD — nightmares, fragmented sleep; prazosin (alpha-1 blocker) historically used (PACT trial 2018 negative overall). Bipolar — sleep deprivation precipitates mania. Schizophrenia — fragmented sleep, decreased SWS. Anxiety — sleep onset insomnia. Alzheimer/dementia — sundowning, irregular sleep-wake; light therapy, melatonin. Parkinson disease — RBD prodrome, EDS (dopamine agonist sleep attacks), insomnia, RLS. Epilepsy — frontal lobe seizures often nocturnal; sleep deprivation lowers threshold; differentiate from NREM parasomnias by stereotypy and EEG. Stroke — OSA prevalence ~70% post-stroke; CPAP improves outcomes. Headache — hypnic headache (elderly, REM, lithium/caffeine); cluster (nocturnal, REM-linked).

Polysomnography & AASM Scoring Interpretation

AASM Manual scoring rules — 30-s epochs, EEG (F4-M1, C4-M1, O2-M1), EOG, chin EMG, leg EMG, ECG, airflow (thermistor for apnea, nasal pressure for hypopnea), respiratory effort (RIP belts, esophageal pressure gold standard), SpO2. Stage criteria — N1 (low-amplitude mixed, vertex sharp), N2 (K-complexes/spindles), N3 (≥20% delta 0.5-2 Hz ≥75 µV), REM (low-voltage mixed, sawtooth, REMs, atonia). Arousal — abrupt frequency shift ≥3 s after ≥10 s stable sleep; respiratory arousal needs concurrent EMG. Apnea (≥90% drop ≥10 s) classified obstructive/central/mixed by effort; hypopnea AASM 1A (≥30% airflow + ≥3% desat or arousal) vs CMS 1B (≥4% desat, no arousal). RERA (flow-limited breaths + arousal, no desat criterion). PLMS — 0.5-10 s, 5-90 s intervals, series of ≥4. HSAT Type III — limited channels; cannot reliably score sleep, arousal, or central events; use only in high-pretest OSA, not for CSA/parasomnia/comorbid CV/lung disease.

PAP Therapy & Behavioral/Surgical Interventions

CPAP — first-line OSA, fixed pressure (titrate in-lab) or APAP (auto-adjusting 4-20 cmH2O). BPAP — for CPAP intolerance, high pressures, or hypoventilation (S/T mode for central hypoventilation). ASV — contraindicated in symptomatic HFrEF with EF ≤45% (SERVE-HF 2015 increased mortality); used for CompSAS, treatment-emergent CSA, opioid-induced CSA in non-HFrEF. AVAPS — pressure-support with volume target for OHS, neuromuscular hypoventilation, COPD-OSA overlap. Adherence — Medicare 4 h/night ≥70% nights over 30 d in 90 d; mask leak, claustrophobia, dryness (heated humidifier), aerophagia. Oral appliances — mild-moderate OSA, dentist-fitted mandibular advancement. Hypoglossal nerve stimulation (Inspire) — AHI 15-65, BMI <40, no complete concentric palatal collapse on DISE, age ≥18. UPPP, MMA, tracheostomy. Behavioral — weight loss (10% → ~25% AHI reduction), positional therapy for supine-predominant OSA, alcohol/sedative avoidance, smoking cessation, GLP-1 agonists (tirzepatide SURMOUNT-OSA 2024).