Disorders of consciousness Tornóci László Semmelweis University Institute of Pathophysiology

Consciousness is special speech (language) foresight tool making free will helping others empathy sense of morality This is the only topic in our subject which doesn’t apply to animals. Other things thought to be unique to humans: (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.

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

Wild minds What animals really think?

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) Self consciousness We can get information about the self consciousness of another person only indirectly, mostly by attempting to communicate with him/her.

Suggested book about memes, evolution and nature of consciousness

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

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

Quantitative disorders of consciousness obtundation (impaired perception, slow reactions) somnolence (the patient falls asleep, but can be waken up) stupor (the patient can be waken up by strong stimuli, for a few seconds only) coma (the patient cannot be waken up by any means) brain death (flat EEG, cardiorespiratory support needed)

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

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

Sleeping 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 Sleeping, is dangerous because we are unconscious! Why do we sleep?

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

somnambulism bruxism (grinding of the teeth) pavor nocturnus (night terrors) enuresis nocturna

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

Interpretation of sleep paralysis/night terrors in the middle age Succubus: sexually desirable witch

Incubus: creature sitting on the chest Henry Fuseli ( ) Interpretation of sleep paralysis/night terrors in the middle age