Paul Reading
Consultant Neurologist
The James Cook University Hospital
Faculty of General Adult Psychiatry (RCPsych)
Annual Conference, October 2015, London
Defining parasomnias :
“undesirable phenomena arising from sleep
or the sleep / wake transition”
 some movement during sleep is normal …
... a parasomnia (or nocturnal seizure) may be suspected if :
(i) confused or agitated behaviour arising from sleep
(ii) excess of rhythmical / jerky limb or body movements
I. non-REM sleep parasomnias
II. REM sleep behaviour disorder (RBD)
} (i)
III. periodic limb movements (PLM’s)
IV. sleep-wake transition disorders
V. other sleep-related “movement disorders”
}
(ii)
VI. nocturnal (partial) seizures, often frontal lobe origin
VII. “psychiatric” (dissociative, malingering, others…)
} (i),(ii)
WAKING
REM
REM
Sleep
REM
REM
REM
I
II
typical hypnogram
of young adult
III
IV
slow-wave sleep (SWS) ≈ sleep quality (>90mins per night)
1
2
3
4
5
time (hours through night)
6
7
I. Non-REM Sleep Parasomnias
 “arousal disorders”
sudden but incomplete arousal
from deep slow wave sleep
 recall absent / minimal
even if (partially) responsive
during event
}
 common in children (>8%)
“night terrors”
age 3-5, intense fear
• confusional arousals
“Schlaftrunkenheit”
• sleep walking and
other behaviours
•
overlap
Reading P Pract Neurol 2007; 7: 6–15
no warning of event / arousal,
directly from slow wave sleep
1. Hublin C et al Neurology 1997;48:177-181
2. Klackenberg G Acta Paediatr Scand. 1982;71:495-499
Night terrors
common in (younger) children
Typical features of adult non-REM
sleep parasomnias
 sleep walking may occur in 1- 4% of adults
usually a positive childhood history of arousal disorder (>85%)
a positive family history also in > 75%
 more complex behaviours frequently emerge
often instinctive, goal-directed or involving “basic drive states”
e.g. food, sex, protection
but also:
driving, phoning, texting, internet use,
housework, DIY, changing nappies
 agitated / aggressive behaviours not rare
note: 2% of UK population (n > 2000) report having experienced
violent or injurious behaviour from bed partners during sleep
(Ohayon 1997 J Clin Psychiatry)
Mildly agitated adult non-REM
sleep parasomnia (female)
Moderately aggressive adult nonREM sleep parasomnia (male)
Typical features of adult non-REM
sleep parasomnias
 low frequency, usually one event per night
clustering common (several nights per week then none for a month)
discreet triggers may be identified (e.g. hotels)
 usually within 30-90 minutes of sleep onset
 can last up to several minutes
 events may be similar but no true stereotypy
 offset of events can be hard to distinguish
note: frontal lobe seizures tend to end abruptly
 if dream recalled, no narrative thread (“sleep mentation”)
usually ill-perceived threat or sense of impending doom / spiders
The neurobiology of sleep walking
beyond the surface EEG
 very few studies
no convincing lesion data
or animal models
 no structural correlates
a “wiring problem”?
hereditary?
 one SPECT study
Bassetti et al 2000
In sleep walking:
- vermis (A) and post
cingulate activated (B)
- fronto-parietal cortex
underactive (C & D)
(compared to awake controls)
Bassetti C et al, The Lancet 2000; 356: Pg 484-485
Full EEG trace during non-REM sleep parasomnia
supports concept of “localised sleep” in frontal areas
Courtesy of Prof Matthew Walker, UCL
Potential triggers for non-REM
sleep parasomnias
 In clinical populations:
- increased sleep “depth”
sleep deprivation (quality / quantity)
including shift work
drugs (Zolpidem, sodium oxybate
alcohol?)
- internal arousing factors
fever, anxiety, snoring,
nocturia, leg jerks (PLM’s)
- external arousing factors
uncomfortable / noisy environment or partner
Example of adult sleep-walking in which
overnight tests provided useful information

27 year-old recently “retired” marine
significant parasomnia several nights each week
sleepy during the day
(ESS 15)
even on “normal” night
no clues from history but overnight sleep unrefreshing
noted to be generally restless overnight
bed clothes disrupted in morning
denied evening symptoms of restless legs syndrome
←
 overabundance of light (stage 2 non-REM) sleep
 sudden arousals from deep (stage 4 non-REM) sleep
←
Treating PLMD with dopamine agonist improved parasomnia and EDS
II. REM sleep behaviour disorder
differentiation from non-REM sleep parasomnias
In (violent) RBD, typically:
 subjects male & middle-aged / elderly
 very strong link with parkinsonism
 no clear awareness of environment
i.e. not able to navigate / use objects;
eyes generally closed
 subjects do not “wander”
rare to leave the bed
 attacks brief / explosive / recurrent
upper limbs typically involved
vocalisation common (aggressive)
 any violence unplanned / unintentional
victims are bystanders
 fairly easy to arouse subjects with
subsequent vivid dream recall
64 year-old retired headmaster
developed upper limb tremor and signs of PD 2 years after sleep disturbance
“Secondary” RBD
 inflammatory plaque
Mathis JNNP 2007
 inflammatory plaque
Tippmann-Peikart et al
Neurology 2006
 post operative changes
Provini Mov Dis 2004
 small nucleus near locus
coeruleus controls muscle
atonia in REM sleep
sublaterodorsal (SLD)
nucleus in rats
 descending pathway direct
to alpha-motor neurons
glycinergic
 produces areflexia
 failure of this mechanism
leads to RBD
 same pathways active
silent EMG
in voluntary
muscles
during cataplexy attacks in
narcolepsy
III.
Nocturnal (partial) seizures commencing
with “confusional arousal”
frontal lobe origin (e.g. focal cortical dysplasia)
The “semiology” of non-REM sleep parasomnias
compared to nocturnal (frontal lobe) partial seizures
Derry et al Arch Neurol
2006
Derry et al Sleep 2009
(useful algorithm)
Seizure or parasomnia?
the value of video observation
42 year-old woman with “night terrors” from early 30’s
became sleep “phobic”
IV. Differentiating non-REM sleep
parasomnias from malingering
IV. Differentiating non-REM sleep parasomnia
from “pseudo-parasomnia”
 Mr NR, age 59, 1 year history of “mischievous” acts at night




up to several times a week, no subsequent recollection
no prior history of sleep disorder, not a snorer or generally restless
several nights of observation on ward unhelpful
polysomnography unremarkable
no response to empirical clonazepam or topiramate
other relevant information: wife depressed (high dose venlafaxine)
he never “misbehaved” if son at home

sleep diary filled by wife over 4 weeks with contemporaneous
actigraphic monitoring of subject
several typical events reported in diary
∆:
“parasomnia by proxy”; “pseudo-parasomnia”
events resolved spontaneously, patient cancelled follow-up