Dr.karimiSeptember 2014

Rasool akram Hospital

Depressed Consciousnessand Coma

DefinitionConsciousness Defined as the awareness of one’s self or

surroundings;

consciousness or awareness is defined as the combination of :

Orientation , the accurate perception of what is experienced;

Judgment , the ability to process input data to generate

; and memory, the ability to store

Definition

Depressed mental status represents an a alteration in arousal and is a common presenting complaint in the emergency department (ED).

sleepiness

decreased alertness

frank coma

Definition

Confusion

The term confusion connotes an alteration in higher cerebral functions, such as memory, attention, or awareness. In addition, the ability to sustain and focus attention is impaired.

Syncope

Syncope is the sudden transient loss of consciousness with a loss of postural tone.

ARAS

The ascending reticular activating system (ARAS) is the neuroanatomic

structure primarily responsible for arousal and cortical activation

The input of somatic and sensory stimuli to the cerebral cortex is

controlled by the ARAS and functions to initiate arousal from sleep.

The differential diagnosis for depressed level of consciousness often overlaps with that for

confusion (see Chapter 17). Frequently, diagnosis and management occur simultaneously, and a structured systematic approach is used.