Sleep, consciousness Coma

• Still considered a conscious state
• readily reversible state of reduced responsiveness to an interaction with the environment

By reducing the sensory input, fatigue, and sleep deprivation

Thalamocortical and reticular formation activity decreased

• Metabolic energy conservation
• thermoregulation
• improved cognition
• maturation

• Stage 1 - (wakefullness to onset of sleep) typical sinusoidal aplha waves -> mixed-frequency pattern ( same as wake state)
• Stage 2 - bursts of sinusoidal waves called sleep spindles
• Stage 3 - low delta waves (slow wave sleep_
• Stage 4 - slow wave sleep

• Paradoxical sleep - low voltage, mixed frequency pattern (similar to wakefulness).
• Atonia, basal T increases, miosis, erection (5-10 min)

• Light sleep.
• muscle activity slows down
• occasional muscle twitching
• 4-5% of cycle

• Breathing pattern and heart rate slows.
• slight decreases in body temperature
• 45-55% of cycle

• Deep sleep begins
• Brain begins to generate slow delta waves
• 4-6%

• Very deep sleep
• rhythmic breathing
• limited muscle activity
• brain produces delta waves

• Rapid eye movement
• brain waves speed up
• dreaming occurs
• muscles relax and heart rate increases
• breathing is rapid and shallow

4-6 cycles

• EEG - Low voltage, fast
• Sensation - vivid, externally generated
• thought - logical progressive
• movement - continuous, voluntary
• rapid eye movement - often

• eeg - high voltage, slow
• S - dull / absent
• T - logical repetitive
• M - occasional, involuntary
• REM - rare

• eeg - Low voltage, fast
• S - vivid internally generated
• T - Vivid illogical, bizarre
• M - muscle paralysis
• REM - often

Venrolateral preoptic area (VLPO)

• Locus coeruleus (LC)
• Raphe - dorsal and median raphe nuclei
• Tuberomamillary nucleus (TBN)

Lateral hypothalamic area (LHA)

reticular formation and nucleus solitarius

GABA-ergic neurons from the ANT hypothalamus (preoptic area)-> Histaminergic nerons of POST hypothalamus -> Forebrain

Inhibit histaminergic input to the brainstem activiting system reduces arousal

Facilitates declarative and explicit memory which are memories that can be consciously recalled related to facts.

Rem on cells activate glycin in the Ventral horn of the spinal cords and inhibit the motor neurons to skeletal muscle

• decrease activity, leading to non-inhibition of cholinergic input to thalamus during REM sleep
• explains similartiies seen in EEG between REM/wake state

in pontinue reticular formation

• NE release from locus ceruleus and pontine reticular formation
• Serotonin release from raphe nucleus

lower motor nerons (via Gly) that decreases motor tone

• Phasic movements are caused by the activation of another group of nerons call REM-waking-on cell
• These motions also happen while awake.

In the reticular formation

facilitates procedural and non-declarative learning.  Unconscious memories such as skills.

foundation for synaptic reorganization, plasticity and the consolidation of information acquired in waking

hippocampus consolidates unstable memories and transfer them to the cortex for long term storage

New associative links are formed between memory traces already stored in neocortex.  Very active during development

boom

• Deficiency in Orexins (from hypothalamus)
• entering REM directly from the waking state.
• It is excessive daytime sleepiness

sudden loss of muscle tone during the awake state, often in response to emotional stimulu-excitement

• Excessive daytime sleepiness
• cataplexy
• hypnagogic (while falling asleep) or hypnopompic (while awaking) dreamlike hallucinations
• sleep paralysis

Frontal areas lag behind more posterior ones in reactivation when wakening and are first to fall asleep.

Property of being aware of oneself and one's place in the environment.  Difficulty to measure

ability of individual to respond appropriately to environmental stimuli

Low V, fast electrical activity (desynchronized

• Alertness - dependent on normal pontomesencephalic reticular formation
• Attention - same as above + frontoparietal association cortex
• Awareness - highly subjective to experience, based on integration

The state of consiousness is dependent on the continuous projection of sensory information to the cortex

The activity of RAS is direct effect in the state of wakefulness

reticular formation + thalamus + Dorsal hypothalamus + pontmesencephalic + pons/midbrain + cholinergic and adrenergic system.

arousal and awareness

reticular system + projections to the thalamus

thalamus, cerebral cortex and their white matter connections + functioning reticular system

state where patients eyes are closed is unresponsive and has no awareness of self or surroundings.

<50% of waking status

• Abnormal, monotonous for the most part
• it can even show alpha activity at times

• bilateral cerebral hemispheres
• bilateral lesion of the thalamus
• dysfunction of rostral brainstem reticular formation

• Absence of eye opening even with intense stimulation
• no evidence of awareness of self and their environment
• Duration: 1 hour

• Comatose patients who survive begin to awaken and recover gradually within 2-4 weeks
• recovery may no progress further than a vegetative state or minimally conscious state

• eye opening
• verbal responses
• motor responses (movement)

Rancho los Amigos does NOT require cooperation from the patient.  Based on observation.

• No meaninful response to stimulus
• diffuse cortical dysfunction
• absence of conscious perception

Cause by damage to the thalamus, cerebral cortex or its connection while sparing the brainstem

• Persistent - BS mediated pathways can elicit some response to auditory, tactile stimuli and open their eyes
• Permanent.

• Extreme form of coma
• no evidence of forebrain or brainstem fuction
• no brainstem relexive activity
• EEG - shows electrocerebral inactivity, flat pattern

Defined as an individual unable to communicate thoughts and feelings but demonstrate inconsistent although reproducible behavior

Better than veggy bc of metabolic activity in the precuneus and POST cingulate cortex.

• patient who is awake and conscious but cannot produce speech or movement of extremities or facial expression
• Lesion in the brainstem in the pons

• classical = communicate by eye movement
• Incomplete - no eye movement
• total - worst prognosis

Better prognosis vs veggy or minimal conscious because of higher cerebral functioning.

• Acts on all levels of the CNS
• Primary cortical response is diminished while sensory corticla activation occurs

confusion, disorientation, numbness or reduced sensation, pain, nausea, decreased muscle controla and coordination.

• Continuous monitoring of CN function, reflexive and voluntary motor behavior
• POC: 
• positioning
• ROM exercises
• Relaxation techniques.

• Pt are fast to fatigue and feel overstimulated
• visual stimulation may be disorienting
• Put weiht on shoulder or pressing down on top of head can increase somatosensory input
• Consider complex movement disorders related to force productionm timing, reaction time, sensory disturbances, lack of motivation and lack of understanding when treating these patients.