Sleep disorders

Insomnia is difficulty with sleep initiation, maintenance, or quality despite adequate opportunity for sleep, with daytime dysfunction; it becomes chronic insomnia disorder once symptoms occur at least 3 nights per week for at least 3 months. Treat first-line with cognitive behavioral therapy for insomnia, reserving hypnotics such as zolpidem, eszopiclone, or low-dose doxepin for refractory or short-term use.

Narcolepsy is a chronic central disorder of hypersomnolence marked by irresistible, recurrent daytime sleep attacks, most often from loss of orexin (hypocretin) producing neurons in the lateral hypothalamus; cataplexy, when present, is considered pathognomonic. Diagnosis follows a normal overnight polysomnogram and a multiple sleep latency test showing shortened sleep latency and rapid sleep-onset REM. Manage first with scheduled naps and sleep hygiene, then a wakefulness-promoting agent such as modafinil, adding pitolisant or sodium oxybate specifically for cataplexy.

Obstructive sleep apnea is repetitive upper airway collapse during sleep, diagnosed by an apnea-hypopnea index of 5 or more per hour with symptoms, or 15 or more per hour regardless of symptoms, and treated first with weight loss plus positive airway pressure.

Restless leg syndrome is a common sensorimotor disorder marked by an urge to move the legs with an uncomfortable sensation, worse at rest and in the evening, and relieved by movement. Diagnosis is clinical; management starts with correcting iron deficiency, then a dopamine agonist or an alpha-2-delta calcium channel ligand.

Major depressive disorder is a mood disorder defined by 5 or more of 9 major depressive episode symptoms, including depressed mood or anhedonia, present nearly every day for at least 2 weeks and causing significant functional impairment. Diagnosis is clinical, screened with the Patient Health Questionnaire. First-line treatment is cognitive behavioral therapy, a selective serotonin reuptake inhibitor (SSRI) such as sertraline, or both, escalating to augmentation, esketamine, or electroconvulsive therapy for refractory or acutely suicidal presentations.

Posttraumatic stress disorder follows exposure to actual or threatened death, serious injury, or sexual violence, producing intrusive re-experiencing, avoidance, negative alterations in cognition and mood, and hyperarousal that persist beyond 1 month with significant distress or impairment. First-line treatment is trauma-focused cognitive behavioral therapy combined with an SSRI or SNRI, with prazosin added for persistent nightmares.

Alcohol withdrawal syndrome is a staged, timeline-bound hyperexcitability state that follows abrupt cessation or reduction of heavy alcohol use, progressing from minor symptoms through alcoholic hallucinosis and withdrawal seizures to delirium tremens, a medical emergency with mortality as high as 5%. Diagnosis is clinical and severity is graded with the CIWA-Ar; first-line treatment is symptom-triggered benzodiazepine dosing plus thiamine given before glucose.

Hyperthyroidism is the clinical syndrome of thyroid hormone excess, produced by a range of causes from Graves disease and autonomously functioning nodules to destructive thyroiditis and exogenous hormone ingestion. Diagnosis begins with a suppressed thyroid-stimulating hormone and elevated free thyroxine, followed by radioactive iodine uptake testing or antibody measurement to identify the cause, and first-line treatment is a beta blocker for symptom control while the underlying cause directs thionamide, radioactive iodine ablation, or thyroidectomy therapy.

Parkinson disease is a slowly progressive neurodegenerative disorder from loss of substantia nigra dopaminergic neurons with alpha-synuclein Lewy body pathology, presenting with asymmetric rest tremor, bradykinesia, rigidity, and gait impairment. Diagnosis is clinical; first-line treatment is levodopa-carbidopa or a dopamine agonist.

Dementia with Lewy bodies is a synuclein-related neurodegenerative dementia defined by dementia plus parkinsonism, fluctuating attention, visual hallucinations, and REM sleep behavior disorder arising within about two years of each other. Diagnosis is clinical; acetylcholinesterase inhibitors treat cognitive symptoms and first-generation antipsychotics must be avoided because of severe neuroleptic sensitivity.