Disorders of consciousness

1. Disorders of consciousness Tornóci László Semmelweis University Institute of Pathophysiology

2. Consciousness is special This is the only topic in our subject which doesn’t apply to animals. Other things thought to be unique to humans: • speech (language) • foresight • tool making • free will • helping others • empathy • sense of morality (distribution of work, living in a ‘society’ is observed in animal species) There is increasing evidence that these are biologically based, so not as much unique to humans, as we may like to believe.

3. Elements of consciousness in animals • Separation of body and environment • Ability to communicate (sign language) • Ability to count • Ability to decieve others, „to lie”

4. Wild minds What animals really think?

5. Self consciousness • subjective feeling (somewhere in the head) • no specific center has been found corresponding to this sensation (this would be the home of our soul, according to some) • sSome expert say self consciousness is an illusion (Daniel C. Dennett, Susan Blackmore) We can get information about the self consciousness of another person only indirectly, mostly by attempting to communicate with him/her.

6. Suggested book about memes, evolution and nature of consciousness

7. Consciousness has two components • level (quantity, arousal or vigility) the brain is active (‘turned on’) • content (quality) the brain functions (clear thinking)

8. Disorders of consciousness • quantitative (impaired arousal) • qualitative (impaired content) Impaired arousal causes disorder of content, but impaired content is possible with normal arousal.

9. Quantitative disorders of consciousness • obtundation (impaired perception, slowreactions) • somnolence (the patient falls asleep, butcan be waken up) • stupor (the patient can be waken up bystrong stimuli, for a few seconds only) • coma (the patient cannot be waken up byany means) brain death (flat EEG, cardiorespiratory support needed)

10. Coma like syndromes • vegetative state (seemingly awakepatient, normal wake-sleep cycles, no cardio-respiratory support needed, but no cortical function) • locked-in syndrome (selective deefferen-tation, pseudocoma: patient may movethe eyes) • catatonia (psychiatric disorder)

11. Qualitative disorders of consciousness • confusion (lack of clarity in thinking,illusions, hallucinations may occur) • delirium (agitated, hypersympathotonicstate with hallucinations) Often due to alcohol/drug withdrawal. • other psychiatric disorders

12. Sleeping Sleeping, is dangerous because we are unconscious! Why do we sleep? • Sleeping provides rest, regeneration • Sleeping saves energy, when we cannot do anything useful (hibernation) • Only the brain needs sleeping, during which it is in a special state

13. Sleeping disorders • Insomnia • stress, bad habit, drug effect, depression, mania, restless legs syndrome etc. • Hypersomnia • narcolepsy (sleepy during the day, bad sleep during the night, cataplexy, persistent sleep paralysis, hypnagogue hallucinations) • depression (light deprivation) • Parasomnias

14. Parasomnias • somnambulism • bruxism (grinding of the teeth) • pavor nocturnus (night terrors) • enuresis nocturna

15. Current interpretation of sleep paralysis: abduction by aliens • Wake up to be paralyzed, unable to defend oneself • Feeling the presence of others in the room • Sliding with the bed, buzzing sound, lights above (operation) • Sexual intercourse

16. Interpretation of sleep paralysis/night terrorsin the middle age Succubus: sexually desirable witch

17. Interpretation of sleep paralysis/night terrorsin the middle age Incubus: creature sitting on the chest Henry Fuseli (1741-1825)