Sleep Walking Flashcards
Associated features of sleep walking?
Difficulty in arousal during the episode and amnesia following an episode.
Most common stage of sleep, sleep walking is in?
Deepest stage of NREM (stage 4) person is awake enough to act out complex behaviours but asleep enough to not remember them
Age of commonality?
More common in children than adolescents and adults.
Bits are more likely to sleepwalk than girls.
Highest prevalence is at 11/12 and becomes relatively rare by adulthood.
Study found looking at sleepwalkers?
11,000 adults
9% had sleepwalking in childhood
3% had sleepwalking as adults
Possible causes?
Sleepwalkers consume above average amounts of caffeine, tobacco and alcohol, have a higher incidence o mood and anxiety disorders.
Stress and anxiety tend to exact ever sleepwalking.
GABA, faulty and incomplete arousal explanation
Argued SW is the result of an arousal mechanism glitch so body and mind fail to wake up in synchrony.
EEG recordings show a mixture of delta waves and beta waves
Likely to be genetic however the specific pathways and processes are still unknown.
Oliviero (2008)
Failure in the brain to suppress the commands issued to the muscles during sleep. This is either because of genetic factors or because of neurotransmitter systems (GABA) are physically immature.
During normal sleep GABA inhibits the brains motor pathways.
In children the neuroma involved in the suppression system are still developing and so motor activity isn’t fully under control.
Genes?
20 times more likely to occur in close relatives of known sleepwalkers than in the general public. These families also tend to e deep sleepers.
Genetic evidence is based on small, unrepresentative samples of the most severe cases.
Lecendreux et al (2003)
50% concordance in MZ twins compared to 10-15% concordance in DZ twins.
Bassetti
Identified DQB1*05 which may be critical in SW.
Studied 16 Ps and 50% had the gene however 24% of non-SW also carried the gene.
Unknown it’s exact affects in the body but known to be involved in immune functioning.
Same genes been linked to narcolepsy and the lack o paralysis during REM
Zara et al 2008
40 Ps referred to a lab for suspected SW
15 have been injured.
Things measured included things such as playing with the Bedsheets, sitting up and walking around.
SW were prevented from going to sleep for 25 hours.
Rate of SW increased from 50% to 90%.
Sleep dep does not lead to SW in normal people so it only affects the genetically predisposed.
Small sample size, unusual setting.
SW begins at age 4 when children give up nap so sleep debts are highest.
Effects of stress?
Episodes are more likely during periods of psychological or physiological stress.
Being stressed increased SW which increases stress which increases insomnia which increases SWS rebound.
Other causes for SW?
Alcohol, fever, medications, hormone changes, sleep apnoea
