INSOMNIA
DEFINITION
Any diagnosis of insomnia should have a type of daytime impairment due to inadequate sleep
PREVALENCE
- Affects about 10% of adults chronically
- Affects 25-50% children and adolescents
RECOMMENDED SLEEP DURATIONS BY AGE (PEDIATRICS)
- Age <5 → 11 hours
- Age 5-10 → atleast 10 hours
- Age >10 → atleast 9 hours
TYPES OF INSOMNIA
Any diagnosis of insomnia should have a type of daytime impairment due to inadequate sleep
[1] Adjustment insomnia → <3 months, identifiable stressor and expected to resolve
15-20% of insomnia. Usually resolves with time. If >3 months, called chronic insomnia.
Rx – consider treating identifiable cause. May treat with BZRAs, Ramelteon, anxiolytics and counseling.
[2] Psychophysiological insomnia → >1 month, anxiety about sleep, conditioned sleep preventing association (bedroom is stimulus for wake not sleep); they fall asleep outside home / bedroom
1-2% in general population. Heightened arousal in bed, racing thoughts when trying to sleep. Becomes conditioned that bedroom is cue to develop tension, anxiety and inability to sleep, hence sleep better away from bed/bedroom.
PSG findings – prolonged sleep latency, increased WASO and decreased sleep efficiency
MSLT – within 10-15mins
Rx – best treated with CBTi
[3] Idiopathic insomnia → since childhood, no identifiable precipitant
<10% of insomnia patients. Also called childhood-onset insomnia.
PSG – prolonged sleep latency, WASO, reduced TST and low sleep efficiency
Rx – CBTi, pharmacotherapy or both
[4] Paradoxical insomnia → >1 month, little sleep or no sleep, minor daytime consequences
<5% of insomnia patients. May report – hearing every noise in the house while in the bedroom, actively thinking entire night.
PSG – sleep latency and WASO x 1.5 times normal
Rx – consider CBTi
[5] Inadequate sleep hygiene → >1month, poor sleep hygiene
Caffeine or alcohol near bedtime, irregular bedtimes and wake times, spend too much time in bed
Long term effects – leading to alcohol dependence
Rx – good sleep hygiene, CBTi
[6] Insomnia due to drugs → >1 month, drug use or substance abuse
Withdraw the offending drug
[7] Insomnia due to mental disorder → >1 month, waxes and wanes, depression / anxiety
Most common cause of insomnia. Mostly insomnia maintenance disorder in older, and sleep onset in younger.
PSG – short REM latency
Rx – CBT and often hypnotic is needed
[8] Behavioral insomnia of Childhood → sleep associate type (require certain conditions to sleep), limited setting type (refusal to go to sleep)
Treated differently than adult insomnia
| Unmodified extinction | Reduced undesired behaviors (crying, screaming/) by eliminating attention |
| Graduated extinction | Enable child to develop self soothing skills and be able to sleep independently. Check on child every 5-10 mins briefly |
| Scheduled awakenings | Preemptively wake the child and provide usual responses as if he awoke spontaneously |
| Positive routines | Set bedtime routines with enjoyable and quiet activities |
| Delayed bedtime | Temp delay to reduce arousal at bedtime |
| Response cost | Remove child from bed if he cries, to enforce that bedroom is for sleep not to seek attention |
| Parental education | For preventing problems before they occur |
DIAGNOSIS
A+B+C
A – difficulty initiating, maintaining or waking up too early
B – sleep difficulty when adequate opportunity exists
C – daytime impairment
CAUSES
- Psychological events, results in hyperarousal
- A recent study with MR spectroscopy found a global reduction in GABA in non medicated patients with primary insomnia vs normal controls
CLINICAL FEATURES
- Difficulty falling asleep / staying asleep
- Poor quality of sleep
- Inadequate sleep
- Decreased attention
- Behavior problems
- Mood disturbance
- Learning difficulties
- Obesity
EVALUATION
The first thing is to evaluate insomnia is through a good sleep history
- Primary complaint – sleep onset, maintenance or are there frequent awakenings
- Time of symptoms; may give idea is it since childhood or after an event
- Pre Sleep conditions – pre bedtime activities, bedroom environment, physical and mental status; noise, temperature, clock seen from bed, caffeine intake
- Nocturnal symptoms – awakenings, snoring, body movements
- Sleep wake schedule – day time naps as well
- Daytime function – remember, for diagnosis of insomnia, there has to be a daytime impairment
- Probe for medical conditions, psych conditions, drug use and medications – PHQ9, GAD-7
- Epworth sleepiness scale or other sleep questionnaires
- Sleep log / actigraphy if possible
- Sleep study if suspecting sleep breathing disorder
- Any sleep aids
Typical PSG findings in patient with insomnia
- Increased sleep latency > 30 mins
- Decreased TST and sleep efficiency
- Increased N1, decreased N3
- Increased REM latency
TREATMENT
CBTi + hypnotics — IS NOT — more effective than CBTi alone
[1] CBT – works in changing patient’s belief and attitude about insomnia. Includes behavioral techniques like – stimulus control, sleep restriction with or without relaxation therapy. Should be for period of 4-8 weeks, which has proven by RCT to be effective.
[2] Sleep hygiene – although may improve sleep quality, no conclusive evidence that alone is effective treatment
[3] Relaxation therapy – may help with both sleep onset and sleep maintenance insomnia
[4] Sleep restriction
- Sleep log for 1-2 weeks to determine mean TST
- Set bedtime and wake up time to achieve mean TST with sleep efficiency >85%
- If TST/TIB >0.85, add 15-20 mins to TIB
- If TST/TIB <0.85, decrease TIB every 7 days
PHARMACOTHERAPY
[1] BZRAs → Zolpidem and Zaleplon act on a1 subunits and hence has less anxiolytic and myorelaxant activity. Zaleplon is very short acting, and less residual sedative effects.
Sleep onset insomnia – zaleplon
Sleep maintenance insomnia – Zolpidem CR, eszopiclone and temazepam
Note – these drugs may worsen NREM disorders like sleep walking, sleep violent, sleep related disorders in addition may develop dependency and abuse
Important Considerations
- Use lowest effective dose
- Take on empty stomach
- Avoid in – nursing, pregnant, liver impaired, alcohol abuse patients
- Taper off slowly
[2] RAMELTEON
First melatonin receptor agonist for insomnia. Works on MT1/MT2 receptor agonist. Good for increased latency, as it has short half life. Mayer study – 8mg 30 mins before sleep; reduced subjective sleep latency.
SEs – headache, nausea, somnolence, nightmares, hallucinations, uncommonly suicidal ideation
Avoid in hepatic impaired patients
[3] SEDATING ANTIDEPRESSANTS
Trazodone is sedating antidepressant with minimal anticholinergic activity. Usual dose is 25-100mg. Caution in QT prolonged. New case reports suggest – parkinsonian side effects. Mirtazapine has sedating side effects due to antihistamine activity. Usual dose is 7.5-15 mg.
Doxepin is a sedating TCA, but has anticholinergic side effects, doses used are 1,3,6 mg.
Seroquel at low doses causes sedation with antihistamine SEs. AEs – QT prolongation, weight gain, EPS, headache, dec WBCs.
[4] OTHER MEDICATIONS
Gabapentin – used for chronic pain and RLS at a dose of 300-900 at bedtime. Good for insomnia and pain, and or anxiety.
References:
- Insomnia: AskMayoExpert. (Accessed Aug 22 2018)
- Berry R. Fundamentals of sleep medicine. Chapter 25: Insomnia 481-514; 2012
- Sarwar A. Trazodone and Parkinsonism: The link Strengthens. Clinical Neuropharmacology 2018/. 41(3) 106-08
