Insomnia Insomnia

Primary Sleep Disorders 147
bedpartners should be interviewed whenever possible. A thorough physical examination
should be performed; symptoms elicited during the history may suggest particular
systems that require particular emphasis. RLS is a clinical diagnosis based
on the four essential clinical features just noted. Polysomnography is not necessary
in straightforward cases unless further evaluation for PLMs during sleep is desired.
Medical causes should be excluded through careful physical examination and
appropriate laboratory evaluation. Nightmares do not require polysomnography unless
the history or physical examination leads one to suspect the patient has another
contributing sleep disorder. Sleep starts rarely require evaluation beyond a careful
history and examination; if features of the history suggest possible seizures,
polysomnography with full montage electroencephalogram (EEG) monitoring may
be necessary. If OSA or PLMD is suspected, all-night polysomnography is recommended
for documentation and determination of severity. If narcolepsy is suspected,
then polysomnography followed by MSLT is required for definitive diagnosis. The
PSG is a polygraph of EEG findings, eye movements, electromyography readings,
oxygen saturation, limb movements, airflow, and chest and abdominal movements
taken during sleep, usually for the entire night. An MSLT is a series of four or five
opportunities, each separated by a 2-hour interval, to take a 15- to 20-minute nap.
The time to the onset of sleep (sleep latency [SL]) is calculated for each nap. The
presence or absence of REM sleep is also noted. The mean SL provides a measure
of the severity of sleepiness, and the occurrence of REM sleep during the naps is
helpful in the diagnosis of narcolepsy. Mean SLs of 5 minutes or less are indicative
of pathological sleepiness and SLs of 10 or more are normal. The presence of REM
sleep on two or more naps is abnormal and is found in many narcoleptic patients.
Nocturnal polysomnography should be performed on the night immediately preceding
the MSLT to factor out the impact of sleep deprivation on the mean SL and
the patient should be free of any medication effects that may influence sleep.
Case 2: OSA Syndrome Presenting with Insomnia
A 42-year-old man presented with the complaint of approximately a 5year
history of insomnia and severe nighttime snoring. Previously, he was a
relatively light, but good sleeper. About 5 years ago he started having problems
with sleep maintenance insomnia. He also had snoring at night severe
enough for his wife to move out of the bedroom in order to be able to sleep.
She also had witnessed some pauses in his breathing. He denied falling asleep
in sedentary and unusual situations. He denied falling asleep while at work or
driving, but he stated that he feels very fatigued and tired. He denied taking
daytime naps. He denied uncomfortable sensations in his legs, morning heartburn,
or waking up with a bitter taste in his mouth. He denied morning headaches,
morning dry mouth, loss of muscle tone in response to emotions, sleep
paralysis, or hypnagogic hallucinations.
His bedtime was between 10 and 11 PM and it took him about 10–15 minutes
to fall asleep, however, after 2 or 3 hours he was awake and could not