Sleep Pearls 2

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a) What are the EEG frequencies? b) When is alpha seen? c) Which type is seen during brief awakenings?: a) delta (<4Hz), theta (4-7Hz), alpha (8-13Hz), beta (>13Hz)

b) relaxed wakefulness with closed eyes

b) bursts of alpha are commonly seen in arousals
What high amplitude negative wave is seen in transition between stages 1 & 2?: vertex sharp waves, more prominent in central tracings
Describe defining features of spindles, K complexes, and delta waves.: spindles: 12-14Hz oscillations

K complex: upward initial negative deflection, minium 0.5 sec, no amplitude criterion

delta waves: >75microvolt amplitude, <2Hz
Describe REM EEG: low voltage, mixed frequency
saw-tooth waves
may be in theta range
Describe drug spindles: usu. 15 HZ (slightly higher than typical 12-14)
may be seen at sleep onset, REM
Describe alpha activity: --more prominent in occipital leads (good to detect sleep-wake transitions)
--common in eyes-closed wakefulness
--suppressed in wake when eyes are open
--can be determined from biocalibrations when pt asked to close eyes
What are essential pieces of the 10-20 system>: --even #: right side
--central leads used for staging
--electrode pair=derivation
referential recording=signle reference electrode in midline
--standard EEG amplifier gain=50microvolts=1cm pen deflection
What is effect of setting low frequency filter too high in slow wave sleep?: the amplitude will be significantly reduced
Why does eye movement toward an electrode cause a downward deflection?: PSG's are set so that negative voltage causes an upward deflection. When eyes move toward an electrode, positive voltage is recorded.
Distinguish high amplitude EEG activity in eye leads from REMs.: EEG activity (K complexes) produce in phase deflections, whereas REMS produce conjugate out-of-phase deflections.
Define sleep latency: lights out to any epoch of scored sleep (usu. < 30min)

latency to sustained sleep--after 3 consecutive stages of sleep
What is somnambulism?: --Sleepwalking
--Seen as body movments occurring out of slow wave sleep in early part of night
What are the physiological changes in REM?: irregular breathing with reduction in tidal volume because the diaphragm is the only active inspiratory muscle, and blunted response to hypoxia

--nocturnal tumescence, complex dreaming & nightmares occur
Define criteria for scoring arousals.: --in NREM: minimum 3 second duration of abrupt shift in EEG frequency
--in REM: EEG shift must have concurrent increase in EMG amplitude

--increases in EMG itself without EEG change is not evidence of an arousal
Which class of medications may cause both slow and rapid eye movements in NREM sleep?: SSRI's, and less commonly, TCA's
Define the REM rule: Sleep is scored as REM if it is contiguous wit unequivocal REM sleep and meets criteria for REM, except no REMs are present
What is a brief arousal separates NREM from REM sleep?: Epochs with REM-like EEG and EMG prior to arousal are scored stage 2 if arousal occurred less than 3 minutes after last sleep spindle or K complex. Otherwise the segment is considered REM.
What factors reduce REM latency?: REM latency=70-120min
sleep apnea
depression
narcolepsy
withdrawal of REM suppressant meds
later than normal sleep time
prior REM deprivation
buproprion in depressed pts
What defines sleep efficiency?: (TST/TIB) * 100%
What is the effect of fluoxetine or paroxetine on REM?: REM density (#REMs per minute) and latency to REM onset increase, but amount of REM sleep decreases
Benzos increase SWS. T or F?: False. Benzos decrease SWS.
What affects 60Hz artifact?: --adequate electrode application is key
--use of a "notch" filter if high filter setting is above 60 (i.e. in EMG channels, high filter is set at 90-100)
--high-freq filters attenuate signals above the desired range
--low electrode impedance (<5000 ohms)
What is sweat artifact?: --characterized by slowly undulating baseline moveement
--mimics delta waves and causes overscoring of SWS
--rx is to cool pt/room and changing electrodes to side opposite pt is lying on
How does changing the low frequency setting affect slow wave sleep scoring?: --Low filter settings can reduce the amplitude of slow waves (usu. < 2Hz)
--typical setting for EEG, EOG=0.3Hz; EKG,EMG=10Hz
How might nasal pressure transducers be misleading?: 1) 10% are mouth breathers
2) NPT underestimates low flow rates, classifying hypopneas as apneas
Thermistors and thermocouples produces changes in...: voltage and resistance, respectively
How should nasal pressure transducers be amplified?: DC signal, or
AC signal with long time constant or very low filter (<0.01)
Effect of OSA on SWS & REM: decrease
Define UARS: RAI>10 + EDS
no discrete apnea or hypopnea
high Pes deflections preceding arousal
Effect of EtOH: suppresses REM
increases REM latency and shifts REM to AM
Criteria for split study: AHI > 40
AHI 20-40 with severe desat
UPPP problems: nasopharyngeal inlet stenosis
velopharyngeal incompetence
Why can severe hypoxemia and hypercapnia occur during REM after nCPAP initiation?: REM rebound and high REM density may occur after CPAP initiation. Obese and/or baseline hypercapnic pts are predisposed. Supplemental O2 may be required for several weeks before improvement as REM rebound decreases.
In what stage is snoring loudest?: a) slow wave
What is OSA's effect on BP and HR?: OSA attenuates normal sleep-associated dip in BP. CPAP reduces the HR variability seen in OSA probably by decreasing sympathetic activity
Does medroxyprogesterone improve the AHI in pts with OHS? What are the side effects?: No, but daytime PaCO2 is lowered.
Alopecia, decreased libido, and hyperglycemia may occur.
What is the usual cause of SDB in children? How does pediatric OSA manifest?: Tonsillar hypertrophy
Long periods of hypoventilation (with increased ETCO2) and desaturation
What is the active respiratory muscle in REM?: diaphragm, but neural input may decrease during REM bursts
How does idiopathic CSA manifest?: frequent awakenings (insomnia), EDS, and snoring
In what stages do central apneas mostly occur?: NREM 1 and 2
What does a delay in the nadir of desaturation represent?: Long circulation time from severe cardiac dysfunction
What can cause central apneas after CPAP initiation?: Uncovering of Cheyne-Stokes after obstruction is eliminated, or
high pressures may lead to arousals and hyperventilation
What defines PLMD?: PLMS, and insomnia or EDS
What defines a PLM?: occurs in a sequence of 4 leg movements separated by 5-90 sec
PLMS following arousals or associated with apneas are not counted
What percentage of patients with RLS have PLMS, and vice versa?: 70-90% of pts with RLS have PLMS, but only 30% with PLMS have RLS
What is a PLMA?: arousal must occur simultaneously or within 3 sec of the PLM
What are the cardinal sx of RLS?: Dysesthesia or paresthesia, worse at night, and temporarily relieved by movement or worsened by rest
What is the mechanism of carbidopa, and does it enter the CNS?: Carbidopa is a decarboxylase inhibitor that does not enter CNS. It prevents the peripheral conversion of of L-dopa to dopamine.
What are the disadvantages of carbidopa/LDOPA?: Short half-life causes rebound sx during night and morning.

Augmentation happens more when L-dopa is >300mg and when RLS is present. Sx occur in day and in arms.
What are pergolide's side effects?: nausea, orthostasis, nasal congestion
What are the advantages of the dopamine agonists, pramipexole and ropinirole?: Longer half-life than CD/LD, lees likely to cause augmentation, nausea, and orthostasis
How is pramipexole metabolized? ropinirole?: pramipexole is renally cleared
ropinriole is hepatically cleared
What % of narcoleptics have a positive MSLT?: 60-80%
Criteria for narcolepsy: Mean sleep latency < 5min
EDS
SOREMS in 2+ napsy
Which of the amphetamines has the shortest half life?: methylphenidate (must be dosed several times a day)
What are treatment options for cataplexy?: REM suppressants:
Tricyclics (protriptyline, imipramine)
SSRIs (fluoxetine)
Venlafaxine
GHB
What drug can cause status cataplecticus?: prazosin
Which condition can result in a moderately reduced nocturnal REM latency (<60min)?: Depression
What are features of idiopathic hypersomnia?: nl-long TST
nl sleep architecture
no SOREMS
reduced sleep latency
unrefreshing naps unlike narcolepsy
In which stage(s) do somniloquy and enuresis usually occur?: any
In which stage does bruxism usually occur?: 2
Are nightmares more likely to occur in NREM or REM?: NREM
Are seizures more likely to occur in REM or NREM?: NREM
What are differences between sleep terrors and nightmares?: Sleep terrors: early in night, NREM3/4, screams, autonomic activation, confusion and amnesia after
Nightmares: REM, rarely confused after, rare screams
Compare sleepwalking and RBD: Sleepwalking: out of NREM3/4 usually, hx childhood sleepwalking, confused, no recall of dream content

RBD: most common in early morning (2nd half of night), may scream
Which seizures occur more frequently or only at night?: frontal (seen in eye leads) and temporal (seen in mastoid leads) epilepsies
How does temporal lobe epilepsy present?: lip smacking, confused awakenings, automatic behavior like wandering,
What is paradoxical intention treatment for insomnia?: Patient is told to lie in bed and stay awake
Describe stimulus control.: Bed is for sleep and sex. Pt is to get out of bed if unable to sleep.
Which disorder is common in blind persons?: Non-24 hour sleep wake disorder. Progressive delays in sleep and wake time.
How does chronotherapy for DSPS work?: Bedtime is progressively delayed several hours on successive days and the sleep period moves around the clock to desired bedtime.
Explain why bright light therapy may not promote earlier sleep time in DSPS.: The exposure might be on the wrong side of the phase response curve. Start at habitual wake time and move back in 30-60 minute increments until phase advancement occurs.
What is the ideal timing for bright light?: soon after nadir body temp, which is 1-2 hours after mid-sleep time
What are options for eastward traveling persons?: Phase advance with early AM bright light
Arrive several days earlier
Go to bed and arise progressively earlier for 1 week prior to arrival
What are common PSG findings in depression?: Reduced sleep efficiency
reduced REM latency
reduced NREM sleep
1st REM episode is longer and has higher REM density
What are s/s of sleep panic attacks?: occur from NREM at 2/3 transition 1-2 hours after sleep onset, awake and alert after, intact recollection
What adjustments are generally made to sensitivity in older and pediatric patients?: Sensitivity is increased (set around 30uv/cm) for older adults.
Sensitivity is decreased (set around 100uv/cm) for younger pts because of high amplitude activity.
Which type of amplifier can be used for airflow and effort channels?: either AC or DC
What is the major difference between DC and AC amplifiers?: DC has no low filtering ability. It is for slowly changing variables such as SpO2 and CPAP.

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