Rebecca Sposato MS, RN

Normal Sleep Adults need 6-8 hours of sleep to maintain healthy physiology and optimal mental abilities Children and infants need more The brain uses sleep to: Reduce physiological demands on the body Process emotions and memories Learning: long term potentiation of neurons Neuro “housekeeping and repair” Zeitgebers – cues and sensory input from the environment that influence circadian rhythm Human circadian rhythm is actually 25hr long

Neurology of Sleep Neuro-chemicals contributing to sleep: serotonin, melatonin, anandamine Suprachiasmatic Nerve: regulates circadian rhythm Basal forebrain: active during deep slow wave sleep Brain temp decreases by 1-2 degrees Atonia: the acetylcholine neurons in the medulla inhibit activity in the spinal cord during REM, so people do not act out their dreams

Encephalograms Dozens of electrodes placed over scalp Chin/eyes for sleep Synchrony: many neurons fire together Voices in chorus Desynchrony: Neurons firing without a pattern Voices in chit-chat The bigger the wave the greater number neurons acting in unison

Encephalograms Beta: alert, active thinking Alpha: alert, relaxed Theta: Drowsy, K complex and sleep spindles felt as sleepiness Stage 3: deeper sleep Stage 4: deepest sleep, large broad waves, person feels refreshed afterwards

Hypnogram Sleep continuity: cycles in 90 minutes intervals Sleep latency: delay in the onset of theta /delta waves Sleep fragmentation: interrupted or shortened cycles

Dyssomnias >35% of the population report impaired sleeping Primary Hypersomnia: prolonged sleep, accompanied by feelings of sleepiness during day Primary Insomnia: difficulty in initiating, maintaining sleep or sleep experienced as non-restorative sustained over 1 month EEG shows more alpha/beta and less theta/delta Restless Leg Syndrome: Sensation of irritation precedes spastic movement of legs in early sleep Worst when stressed or pregnant Medicate with dopamine agonists

Dyssomnias Narcolepsy: irresistible brief episodes of sleep during waking routine Occur during periods of low stimulation, low activity 2-6 episodes per day, last about 20 minutes, refreshing Must occur daily >3months Cataplexy: loss of voluntary muscle tone, often triggered by emotional outburst (cry, laugh) Last seconds to minutes, retains consciousness 70% of narcoleptics develop this feature Hypnagogic hallucinations: dreamlike visions while awake

Parasomnia Abnormal sleep behaviors or physiological events in association with specific stages of sleep Nightmare (REM): vivid dreams with threatening themes, often abruptly awaken person Night Terrors (deep stage): anxiety and physiological arousal, results in abrupt awakening, person often lacks recall of dream or awakening Sleepwalking (deep stage): complex motor behavior occurring out of bed, no recall of the event

Breathing related sleep disorders Obstructive Sleep Apnea: brief episodes (20-30 sec) of apnea or hypopnea related to obstructed airway Snore-silence-gasp breathing pattern Occurs when flesh of the throat sags into the airway Continuous positive airway pressure (CPAP) mask Central Sleep Apnea: brief episodes of apnea or hypopnea not associated with chest or airway abnormalities Most often in elderly with cardio and neuro conditions that affect ventilatory regulation Alveolar Hypoventilation Syndrome: low o2 levels from impaired ventilatory control, no apnea

Circadian Rhythm Sleep Disorder Persistent or recurrent disruption in sleep pattern from altered circadian rhythm or mismatch in sleep-wake cycle and external demands on timing and duration of sleep Delayed onset Jet-lag Shift Work

Sleep and Health Insomnia is physiologically taxing on the mind/body Metabolic syndrome Suboptimal physical performance Impaired memory and concentration irritability

Sleep and Mental Health Lack of sleep can accentuate any mental illness Psychosis, delirium, anxiety Many mental illnesses contribute to insomnia Mania, depression, anxiety, schizophrenia etc. Depression can also contribute to hypersomnolence Substance use cause temporary insomnia, followed by rebound hypersomnolence

Interventions Sleep log Polysomnography – diagnostic sleep lab study, includes: Video recording Heart rate/oxygen monitor/resp. rate/depth EEG Sleep hygiene –modify routine to promote sleep Pharmacological – sedatives or hypnotic medications Benzodiazepines, Ambien, Lunesta etc.