Consciousness Flashcards
Consciousness define
Is a state of awareness of the self and the environment
What are the 3 dimensions of unconsciousness
Coma - clouding, drowsiness, sopor
Deep sleep- stages of sleep
Unconscious mind- preconscious
Normal consciousness to coma
What is clouding
Drowsiness/agitation with memory disturbance and disorientation
Impaired attention, concentration, recognition, comprehension, understanding and judgement
Normal consciousness -> coma
What is drowsiness
Tendency to drift into sleep without sensory stimulation
Slow actions, slurred speech, reduced reflexes and muscle tone
Normal consciousness-> coma
What is a coma
Reduced eye opening, verbal response and motor response
Some characteristics of normal perception
We can distinguish perceiving with our sense organs from imagining the same objects
When we perceive something we realise it’s possible relevance to our emotions and actions
Normal sensation has a quality of objectivity
The observer feels certain that the object exists even if no one else is experiencing it at the same time
Experience of object perception is involuntary
Quality of independence
Abnormal perception
Sensory distortions - intensity and quality of perception and associated feelings False perceptions - illusion - hallucinations -pseudohallucinations
Illusions.
Complete illusions - you fill in the missing gaps
Affect illusions - these are dependent upon an individuals mood state
Pareidolic illusions - these illusions arise due to excessive fantasy thinking
Hallucinations
A perception-like experience
- in the absence of an external stimulus
- which has the full force and impact of real perception
- which is unwilled, occurs spontaneously, and cannot be readily controlled by the subject
Sleep
Sleep is a complex physiological process - not simply the absence of waking it is a special activity of the brain controlled by elaborate and precise mechanisms
Sleep behavioural definition
Recurrent regular reversible state characterised by quiescence and dismissed responsiveness to external cues
- lack of mobility.
- closed eyes.
- reduced response to external stimulation
- characteristic sleeping posture
- reversible unconscious state
Sleep measurements
EEG Eye movements Muscle tone Polysomnography - eeg, eye movements and muscle tone
Sleep- neurophysiological definitions brain activity measured by EEG
Wakefulness eyes open beta rhythm Eyes closed alpha rhythm Sleep 5 phases - non R.E.M. 1 alpha waves alpha theta transition 2 sleep spindle, k complex 3 delta waves 4 delta waves R.E.M. Theta waves PGO waves R.E.M. Atonia Sympathetic tone increased 4-6 cycles a night ~90 min R.E.M. Duration increased with every cycle
Physiological determinants of sleep
Sleep drive in the homeostatic forebrain
Circadian drive - supra chiasmatic nucleus
Circadian rhythms
Clock genes - Bmal 1 only non redundant clock gene: deletion causes immediate loss of circadian rhythm in constant darkness no resting by light
Autonomous tissue specific oscillators in mammals
SCN,liver, heart demonstrates oscillations and clock gene expression allows for fine tuning
Autoregulation: maintain oscillatory mechanism using transcriptional feedback loops to up or down regulate clock settings
Coordination: SCN is master clock synchronising circadian rhythm via neural and endocrine regulators, average free running intrinsic period = 24.18 hrs in humans
Causes of excessive sleepiness
Increased sleep drive Sleep disruption - sleep wake dysregulation - circadian misalignment - sleep disruption
Sleep wake disregulation
Narcolepsy
Idiopathic hypersomnia
Recurrent hypersomnia
Post traumatic hypersomnia
Sleep disruptions
Obstructive sleep apnea hypopnoea syndrome Depression Parasomnias R.E.M. Sleep behaviour disorder PD MS Myotonic dystrophy Restless leg syndrome Periodic limb movement disorder Central sleep apnea syndrome Central alveolar hypoventilation syndrome
Parasomnia - slow-wave sleep disorders
Sleep walking and night terrors : stage 4 non rem sleep arousal disorders
Sleep walking : motor activity - walking independent complex behaviour can occur
Night terrors - scremjnnng, autonomic hyperaeousal sweating, confusion, rapid heart rate
Common in children
Usually unaware of their activity
Aetiology unknown
Risk of injury - forensic aspects
Injury prevention is the primary objective of management
Parasomnias - R.E.M. Sleep behaviour disorders
Presence of muscle tone during R.E.M. Sleep associated with active complex behaviours in absence of epileptiform activity
Act out dramatic and or violent uncharacteristic dreams during R.E.M. Sleep
Usually amnesia for voluntary muscle activity but can remember dream
Onset ~90 mins after sleep
Shouting/grunting/assaulting sleep partner
Restless leg syndrome
Clinal features
Dysaethesias unpleasant sensations in the legs creeping, crawling, tingling, pulling, pain
Relief With voluntary movement associated motor hyperactivity
Irresistible urge to move the legs
Suppression of activity leads to discomfort
Narcolepsy
Fall asleep uncontrollably throughout the day for periods between 1-30mins
Even while engaged in activity
Abnormal sleep pattern: decreased R.E.M. Latency
Classic symptoms include cataplexy, sleep paralysis, and hyponogogic hallucinations
Cataplexy
Loss of muscle tone a symptoms of narcolepsy
Treatment for narcolepsy
Stimulants
Depression common so this is treated with antidepressants
Sodium oxybate - cataplexy-date rape drug
Apnoea
Brief interruptions of breathing during sleep
Apnoeic events - breathing pauses up to 30/hr
Central neural control of breathing not initiated
Obstructive inflow/outflow obstruct airway
Frequent arousal for deep sleep as po2 Dec
OSA
Weight loss not sleeping on back
Modafinil last dose midday
Continuous positive airway pressure (CPAP) via mask into nasal passages to keep airway open at 3-18cm water pressure
Surgery to remove obstructions
Insomnia
Perception/complaint of inadequate or poor quality sleep - difficultly falling asleep Waking up frequently Waking up too early Unrefreshing sleep Causes tiredness lack of energy irritability Transient <2 weeks Intermittent 2-4 weeks Chronic >month
Insomnia risk factors
Increased age female
Psychiatric disorders - depression, anxiety disorders
Medical disorders - hypothyroidism, pain
Substances caffeine, alcohol, nicotine.
Other shift work exercise, sleep apnoea
Iatrogenic
Insomnia- non pharmacological treatments
Avoid exacerbants - caffeine, alcohol, nicotine, exercising within 5-6 hours of sleep , noise or temp extreme, daytime naps
Pleasurable, comfortable, dark, environment
Regular schedule
Reconditioning using bed for sleep only
If can’t sleep for 30+ mins get up do a relaxing activity until sleepy
Cognitive restructuring stop thinking that with on,h a few hours sleep can do nothing when you can function
Relaxation therapy - bath breathing exercises
Sleep restriction - Dec sleep time by an hour to increase sleep drive
Insomnia pharmacological interventions
Sedative lowest dose
Nice
BZD and Z drugs both act as BZD agonists but VZD cheaper
Short acting BZD have significant effects
Sleep deprivation
European working time directive 2004
Junior dr max shift 13hrs followed by a break of at least 11
