Evaluation of Insomnia

Introduction

The evaluation of patients with sleep-related complaints involves thorough history taking and a focused physical examination.

Dimensions of the Insomnia Complaint

From the standpoint of diagnosis and treatment, it is important to first identify the various dimensions of insomnia.

• The time of onset and duration of sleep symptoms should be determined. Insomnia of long duration is thought to have greater impact on daytime functioning. However, there is considerable variability in the definition of the time course for acute and long-term insomnia, with minimum durations for chronic insomnia ranging from 30 days to as long as 6 months.
• The longitudinal pattern of insomnia is also an important component of the history, as symptoms of insomnia are likely to change over time. Complaints of initial insomnia involving problems in falling asleep, for instance, can progress into one of a difficulty in sleep maintenance.
• The temporal relationship between insomnia and comorbid illnesses can also indicate what factors may have caused insomnia and provide a basis for treatment. However, this relationship can be complex and insomnia can temporally precede, follow, or occur in concurrence with the onset of a major depressive episode. Insomnia can be a predictor of affective disease, as well as a residual symptom following treatment.
• The severity of symptoms is usually dynamic; bouts of insomnia tend to recur episodically over time and individuals with insomnia remain variably symptomatic between episodes. The frequency of nights affected per week or month during each episode can be a useful indicator of severity.

The Sleep-Wake Pattern

The typical sleep-wake pattern is an essential aspect of the history in all patients with sleep-related complaints. The components of both nighttime and daytime symptoms and behaviors are outlined in Table 7-1.

Organizing clinical history-taking of the sleep complaint around these key elements to construct a typical 24-hour pattern has proven to be of great clinical utility. For example, beginning with bedtime rituals, followed by bedtime, sleep latency, occurrences during the night, wake-time, time out of bed, daytime symptoms, patterns and activities (including naps), then concluding back at the time at which the inquiry began. Once a pattern has been established, deviations from the pattern can also be noted. Obtaining the nocturnal or diurnal pattern, onset and longitudinal course and severity of the chief complaint is paramount to patient evaluation.

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Sleep-Related Patterns and Behaviors

Sleep-related bad habits, behaviors and maladaptive psychological reactions and cognitions that may perpetuate sleep/wake disturbances should be systematically explored in patients with sleep difficulties. The behaviors in which the patient engages during the few hours prior to, during and just after sleep can significantly intensify existing insomnia. These are listed in Table 7-2. Although these factors are seldom the sole cause of an insomnia complaint, a lack of awareness of them can lead to a failure in other treatment modalities.

Patients should be evaluated for bedtime and sleep habits on initial and follow-up visits. Patients with insomnia can have large discrepancies from behavioral norms during bedtime, and characteristic patterns may emerge that suggests specific underlying causes of insomnia and/or help guide treatment. Keeping track of bedtime parameters can help to quantify the severity of insomnia, identify appropriate treatments, and determine the effectiveness of treatment measures. Additionally, determining these patterns can also suggest the utility of certain behavioral interventions to improve sleep, such as restriction of overall time spent in bed.

Physicians should note the extent of dysfunctional patient beliefs and attitudes in relation to sleep, such as sleep-related anxiety at bedtime, which provide the clinician with important insights into the role psychological processes play in perpetuating or exacerbating insomnia. Information about the dysfunctional cognitions surrounding sleep, the time of onset of sleep anxiety and the state of mind of the patient during waking hours at nighttime should all be solicited.

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Daytime Symptoms and Behaviors

The patient’s daytime activities and habits, which can adversely affect nocturnal sleep and aggravate insomnia, should be explored during evaluation. Intense exercise too close to bedtime, long periods of bed rest, inactivity, shift work, untimely light exposure and excessive napping can create circadian rhythm disturbances and aggravate insomnia. The nature and extent of consequences of the chief complaint on daytime functioning may also be elucidated.

An assessment of daytime symptoms is also useful in understanding the impact of insomnia on daily functioning. Additionally, the correction of daytime impairment is an important measure of treatment efficacy. Typically, the severity of daytime symptoms in insomnia co-varies with the degree of impairment in the quality and quantity in nocturnal sleep. For example, individuals with insomnia experience an inability to nap during the day, which may be due to hyperarousal during sleep and wakefulness, in multiple biological and psychological systems.

Patients with insomnia frequently report a variety of daytime psychological symptoms, including feeling depressed, hopeless, helpless, worried, tense, anxious, irritable, fatigued, unmotivated, lonely and lacking in self confidence, than control subjects. Cognitive difficulties such as memory impairment, difficulty with focus and attention and mental slowing also occur. These subjective complaints are evident on objective testing, as impaired psychomotor performance (reaction time) has been demonstrated in patients with insomnia. Individuals with insomnia are likely to report impairments in coping, accomplishing tasks and in family and social relationships and occupational function. It is useful to understand the patient’s preferred social and occupational activities as this information can be helpful in devising a daily structure that promotes consistent sleep scheduling.

Collateral Information

History obtained from bed partners and family members is important for reporting symptoms and behaviors that occur during sleep, which are difficult to impossible for patients with insomnia to report themselves. Daytime symptoms are also important to ask about. Examples of these symptoms include:

• Snoring
• Breathing pauses during sleep
• Unusual behaviors during sleep such as walking, talking, thrashing, as well as head, body and limb movements
• The tendency to fall asleep unintentionally during the day
• The extent and frequency of naps
• Cognitive and behavioral disturbances associated with insomnia and excessive sleepiness, such as diminished social contact, slow mannerisms, decrement in mood and lapses in memory.

Symptoms of Specific Sleep Disorders

Defining symptoms for a selected list of sleep disorders are listed in Table 7-3.

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Factors Influencing Patient History

Important factors of a patient’s medical past include medical and psychiatric history, medications, family history and social/occupational history. Understanding the temporal relationship between the chief complaint and potential precipitating and perpetuating factors can be helpful in formulating treatment modalities that are specific for the underlying cause. Common precipitants include:

• Job loss or shift-work schedules
• Travel across time zones
• Breaches in relationships or loss of relatives
• Onset of medical and/or psychiatric illness
• Introduction of new medications
• Changes in dosages and times of administration of existing medications.

Perpetuating factors of insomnia which can transform insomnia into a chronic disorder include engaging in poor sleep hygiene practices and having anticipatory anxiety with the approach of bedtime. From the standpoint of future treatment, it is additionally useful to understand what if any previous interventions have been attempted, and their successes or failures.

Medical, Psychiatric and Surgical History

Comorbid disorders should be reviewed, along with their dates of onset, types of treatment and results of treatment. Past surgeries and hospitalizations should also be evaluated. Major medical disorders can affect sleep by virtue of their psychological impact, through pain and discomfort, as well as direct effects on sleep and wakefulness. It is important to note that myriad psychiatric illnesses are associated with sleep disturbance and careful evaluation of the timing of the sleep complaint in relation to psychiatric symptoms may be of high value in patients with psychiatric illness. Additionally, the patient may have a history of a primary sleep disorder and review of prior documentation including results of polysomnographic studies and other laboratory tests may be helpful.

Medication

A history of current and prior medications is an integral part of the medical history. The list should include prescribed pharmaceutical agents, over-the-counter agents, nutraceuticals, herbal substances, dietary supplements and even foods and drinks. Their effects, side effects, dosages or quantities and timing of administration should be recorded. If the use of a medication correlates temporally with the onset of the sleep complaint, a medication-induced sleep problem should be suspected. Medications can also have secondary effects by exacerbating underlying conditions. For example, weight gain associated with medication use can lead to the development of symptoms of OSAS, such as excessive sleepiness, snoring and breathing pauses during sleep. Allergies to medications should also be recorded. Medications likely to precipitate insomnia in psychiatric practice include some antidepressants and stimulants.

Substance Abuses

Insomnia, excessive sleepiness and parasomnias can be related to substance use. Chronic and excessive use of substances may lead to substance use disorders, which are characterized by either abuse or dependence. Stimulants such as caffeine, amphetamines and cocaine classically disrupt sleep. Sedatives such as opiates and analgesics cause ES. Alcohol, at low dosages, can help with sleep initiation, but this characteristic should never prompt recommendation of its use to treat insomnia. Moreover, chronic and excessive use of alcohol can lead to disturbed sleep and the complaint of insomnia.

Family History

Certain sleep disorders, such as RLS, can have a hereditary component, in which 50% of primary cases have a positive family history. The incidence of certain parasomnias of arousal such as sleep-walking and sleep terrors is ten times greater in first degree relatives than in the general population. Additionally, racial studies and chromosomal mapping, familial studies, and twin studies have determined that many of the risk factors involved in the pathogenesis of OSAS are largely genetically influenced. In fact, 35% to 40% of its variance can be attributed to genetic factors. Factors associated with craniofacial structure, body fat distribution and neural control of the upper airway muscles are thought to interact to produce the OSAS phenotype. However, the role of specific genes that influence the development of OSAS has not yet been ascertained.

Social and Occupational History

Several social or occupational factors can contribute to sleep-related complaints, necessitating evaluation. For example, sleep disturbances are common when sleep times have to change abruptly, such as with shift workers and individuals whose occupations require frequent travel across time zones. Exposure to industrial toxins and chemicals can also produce sleep/wake symptoms. Job loss and retirement can result in the loss of regularity in daily schedule, which is important in maintaining circadian rhythm consistency in some individuals, leading to erratic sleep/wake hours and the complaints of insomnia. Disruption in interpersonal relationships, family, job and hobbies can cause anxiety and subsequent insomnia.

Physical Examination

A focused physical exam can contribute essential information to the process of understanding the etiology of the sleep complaint, and may be able to elucidate the presence of specific sleep disorders such as OSAS.

Physical evaluations should include measurements of body morphology, such as neck circumference, BMI and assess for mandibular abnormalities. A thick and/or muscular neck, as well as a neck circumference of 16 inches or greater in women and 17 inches or greater in men, are associated with an increased risk for sleep-related breathing disorders. Similarly, obesity with fat distribution around the neck or midriff suggests the presence of OSAS. Nasal obstruction, mandibular hypoplasia and retrognathia are also known characteristics of people with sleep abnormalities. Oropharyngeal abnormalities such as enlarged tonsils and tongue, an elongated uvula and soft palate, diminished pharyngeal patency and redundant pharyngeal mucosa may be present.

A chest examination is important to determine pulmonary and cardiovascular comorbidities, which in turn lead to complaints of frequent nocturnal awakenings and unrefreshing sleep. Expiratory wheezes and kyphoscoliosis may be indicative of asthma and restrictive lung disease, respectively, while heart failure may also cause abnormalities of breathing during sleep.

A basic neurological examination should be performed to rule out neurological disorders that may mimic or co-exist with certain sleep disorders. For example, increased resting muscle tone, cogwheel rigidity and tremor can indicate the presence of Parkinson’s disease, which can share some of the behavioral and sensory disturbances of REM behavior disorder. A mental status examination should also be considered and include an evaluation of affect, psychomotor agitation or slowing, cognition, the possibility of reduced alertness and slurred speech, and perceptual disturbances. When mood disorders are considered, PHQ-9 can be used to screen for depression, Zung scale for anxiety and MDQ for bipolar disorder.

Sleep Evaluation Tools

Sleep Monitoring

Sleep patterns can be assessed by using patient-completed sleep logs or diaries that track sleep–wake patterns over time, which can be more useful than subjective summaries (Figure 7-1). Patients with insomnia tend to underestimate total sleep time and overestimate sleep latency, which could be due to a preferential recall bias for particularly bad nights of sleep and may not reflect the longitudinal course of their sleep disorder. A sleep diary can be both revealing as well as therapeutic, as the patient becomes aware of poor sleep patterns and behaviors, and begins to correct them.

Actigraphy utilizes small, wristwatch-like devices to record movement and can be useful as an adjunct to other procedures for the assessment of sleep–wake patterns when such information is not reliably available by other means such as sleep logs. Actigraphy can be used for the documentation of changes in sleep patterns over prolonged diagnosis and treatment periods, for the assessment of whether a patient with insomnia follows certain sleep hygiene advice and of improvement in sleep following behavioral treatment, and for the assessment of daytime and night-time sleep and daytime somnolence. However, it is not very useful in measuring exact sleep times, is rarely used in primary care, and is not appropriate for the routine diagnosis of sleep disorders.

Some patients will utilize “smart watches” to gauge their sleep. Though crude and usually not very revealing, they should not be discouraged as they can prompt conversation about sleep between patient and provider.

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Scales and Inventories

Inventories can assist in the quantification of the severity of various indicators of insomnia. Inventories are also useful in differential diagnosis; the fatigue severity scale and the Epworth sleepiness scale (ESS) are two inventories that can be useful in the assessment of the degree of fatigue and excess daytime sleepiness, which may share common characteristics. The ESS is especially useful in confirming the presence and degree of ES when patients complain of “tiredness.” It can also be used to measure degree of improvement as ES is treated.

The insomnia severity index is one of the few that have been subjected to empirical validation, and considers subjective symptoms, consequences of insomnia and the degree of concern or distress caused by the disturbance (Figure 7-2). It is a useful clinical and research tool for measuring treatment outcome.

When OSAS is suspected, its risk can be quantified by the STOP inventory, a screening questionnaire. STOP considers patient characteristics such as snoring, daytime fatigue, observed apnea and blood pressure. An alternative scoring model incorporating BMI, age, neck circumference and gender (STOP-BANG) increases sensitivity (Figure 7-3). The risk of OSAS increases with rising positive number of the STOP-BANG (Figure 7-4) such that with five positive factors, the rate of OSAS is increased 5-fold.

The Mallampati airway classification score is also useful in assessing the risk for OSAS (Figure 7-5). On average, for every 1-point increase in the Mallampati score, the odds of having OSA increases more than 2-fold. The health care provider should be vigilant of this such that with any examination of the pharynx, whether for sleep problems or not, if a Mallampati score of 2 or more is seen, the patient should be questioned and examined further to see if he/she needs to be referred for sleep testing.

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Tests and Consultations

Following the office-based evaluation, there are several situations in which sleep medicine consultations may be useful. These include cases when the diagnosis is in doubt, the treatment does not result in the alleviation of symptoms, or when the differential diagnosis warrants sleep testing.

General serum laboratory tests are not normally needed but when specific sleep disorders are suspected, lab tests should be done. These include thyroid function studies when there are symptoms suggestive of hyperthyroidism or hypothyroidism with their associated insomnia. If RLS is the diagnosis, secondary causes can be ruled out with blood tests, including complete blood count, iron studies, kidney function tests and pregnancy testing in women. The level of serum ferritin, an important indicator of iron deficiency, should be obtained in patients presenting with insomnia, as it is inversely correlated with severity of RLS symptoms. A serum ferritin level of 50 mg/L or less is considered significant. Iron supplementation has been shown to reduce RLS symptoms in such cases.

PSG is the technique of monitoring multiple physiological measures during sleep, including brain waves, eye movements, heart rate, respirations, oxyhemoglobin saturation and muscle tone and activity. It is typically performed in a sleep laboratory and is utilized for the evaluation and diagnosis of conditions such as narcolepsy, limb movement disorders, parasomnias and sleep-related breathing disorders. Generally, most patients with insomnia will not need a PSG.

Summary

In summary, obtaining a sleep history and performing a symptom-guided examination are key cornerstones of the evaluation of patients with sleep disturbances, such as insomnia. Physicians should develop a systematic process to address sleep-related complaints and their perpetuating factors (Table 7-4). In particular, the sleep-wake patterns and daytime habits of patients are critical indicators of the nature of the sleep disturbance. Monitoring tools are useful for following sleep patterns, while inventories, tests and consultations are used to complete the diagnostic picture. These measures allow physicians to arrive at a diagnostic formulation prior to resorting to treatment.

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