Myths and Facts about Sleep and Chronic Pain Jonathan Fleming MD Consultant, Sleep Disorders Program, UBC  Hospital, and Associate Head for Education,  Department of Psychiatry, UBC For Webinar Series:

Chronic Pain: Improving Life While Living It

We acknowledge the financial assistance  of the Province of British Columbia

CIRBD2012

Objectives • Describe how normal sleep is generated and maintained • Describe how pain interferes with sleep and how disturbed sleep exacerbates pain • Describe strategies that have been proven to improve sleep quality, reduce pain and improve quality of life in patients with chronic pain

Sleep physiology • sleep is part of a homeostatic process – the need for and duration of sleep is mostly determined by the amount and quality of the sleep in the preceding sleep period – the timing of sleep is regulated by a circadian process mediated by light’s effects on the brain (suprachiasmatic nucleus)

Sleep and light • cave

Sleep is NOT an homogeneous state

• Five sleep stages based on brain waves (EEG) – Stage Awake – Stage I - a transitional state – Stage II – a quiet brain in a moveable body – Stage III/IV – deepest but shortest period of sleep – Stage REM – dream sleep; an active brain in a paralyzed body

Sleep is NOT an homogeneous state

• Five sleep stages based on brain waves (EEG) – Stage Awake – Stage I - a transitional state – Stage II – a quiet brain in a moveable body – Stage III/IV – deepest but shortest period of sleep – Stage REM – dream sleep; an active brain in a paralyzed body

Hypnogram

Sleep versus arousal • sleep occurs when the sleep drive overcomes the arousal drive; insomnia occurs when the arousal system overcomes the sleep system – sleep facilitators • sleep disruption from any cause • sedative drugs

– arousal facilitators • sleep! • physical/psychic discomfort from any cause • stimulant drugs

SPIELMAN 3 Factor Model Spielman A: Clin Psychol Rev 1986; 6:11-25

Predisposing Precipitating Perpetuating Insomnia threshold

Premorbid

Acute

Early

Chronic 9

Sleep and pain • pain is one of many stimuli that can impede the sleep drive – exprimentally disrupted sleep can cause somatic pain in susceptible individuals – disrupted sleep affects pain perception – disrupted sleep affects mood, resilience and adaptation

• several studies demonstrate a correlation between pain intensity and sleep disturbance severity • chronic pain patients with insomnia experience greater disability levels than those with insomnia alone

Sleep Disorders Causing Disrupted Sleep • Primary Insomnia • Secondary (Co-morbid Insomnia) – Psychiatric disorders – Medical disorders – Substance Use (including therapeutic agents)

• • • •

Respiratory Sleep Disorders Restless Legs Syndrome Periodic Limb Movements Circadian Rhythm Disorders

NRS and sleep architecture • alpha-EEG activity during non-REM sleep has been shown to be significantly more pronounced in people with NRS compared with healthy controls – suggesting that NRS is a sleep disturbance characterized by some form of vigilance during sleep – from 1975–2001 studies found alpha activity in stages 2–4 non-REM sleep in adults and children with Fibromyalgia and in individuals with Chronic Fatigue Syndrome

Alpha-Delta Sleep Anomaly Rains JC & Penzien DB J Psychosom Res 54: 77‐83, 2003

Alpha-Delta Sleep Anomaly • led to speculation that abnormal alpha activity in FM patients may interfere with the restorative function of NREM sleep, leading to increased daytime symptoms • BUT – the alpha EEG sleep anomaly is neither sensitive nor specific to chronic pain conditions – occurs in patients who have non-painful medical or psychiatric illness

NRS and sleep architecture • Cycling Alternating Pattern (CAP) – a 20–40 second period of EEG activity in nonREM sleep that consists of fluctuating arousals – characterized by bi-phasic sequences • the first phase characterized by transient electrocortical events such as arousals, k-complexes, and delta burst • the second phase consists of recurring EEG background activity

– correlates with NRS – 55% of patients with FM and CFS have CAP or CAP-like activity

Cycling Alternating Pattern (CAP) Parrino L et al, Sleep Medicine 10: 1139–1145 2009

• A3 Subtype (K-complexes then desynchrony)

CAP rate and insomnia • Paradoxical insomnia (sleep state misperception) – sleep is experienced as an almost continual state of wakefulness – mismatch between objective and subjective findings • Longer sleep latency • Very short sleep times (2000 lux) • rest in a comfortable chair; avoid horizontal rests • napping reduces nocturnal sleep efficiency; if required keep short (