it is about level of consciousness in human and conditions that mimics.

1. OUTLINE
1. INTRODUCTION
2. CONSCIOUSNESS SYSTEM
3. LEVELS OF CONSCIOUSNESS
4. CONDITIONS THAT MIMIC COMA
COMA 1

2. INTRODUCTION
• Consciousness is “state of arousal and awareness of
self and surroundings”
• A conscious individual is:
• Aware of himself and environment (sensory) and
• Capable of responding correctly to verbal and
mechanical stimuli (motor)
COMA 2

3. INTRO….
 Consciousness is determined by two main Functions
1. AROUSAL (Level Of Consciousness)
The degree of ability to interact with
environments
2. AWARENESS (Content Of Consciousness)
The Depth and Content of the aroused state
Attention depends on awareness
3
COMA

4. • It maintains consciousness (arousal & awareness)
• It is one of ascending system at the posterior fossa
• extends from medulla  cerebral cortex
• It is diffused and organized, located in:
1. Brainstem
2. Diencephalon
3. Cerebral hemispheres
4
COMA

5. 5
Excitability & Responsiveness of Thalamic
and Cortical Input  Facilitates Sensory
Processing at the Cortex
Facilitate Sensory Transmission
Tonic Activity of Brainstem Cholinergic and Monoaminergic Neurons
keeps the Reticular Activating System in an Excited State
Sensory Input from Collaterals of every Major Sensory Pathway
At the level of CERBERAL CORTEX At the level of THALAMUS
HYPOTHALMUS
Histaminergic neurons
COMA

6. 6
These Cortical areas contribute to the Selection
and Processing of Behaviorally Significant Sensory
Stimuli
Project to the Primary and Associative
Sensory Areas
Cholinergic Neurons in the Nucleus Basalis of
Meynert
The Prefrontal Cortex

 Excitatory Input

COMA

7. • ARAS extends from the lower border of medulla to the ventromedial
thalamus & then project to whole of the cerebral cortex.
• It receives collaterals from the spinothalamic & trigeminal thalamic
pathways.
COMA 7

8. Altered level of
consciousness
Concussion
Seizures
Syncope
Metabolic encephalopathy
Coma
Persistent vegetative state
Minimal conscious state
Altered content of
consciousness
Dementia,
Delusions,
Confusion, and
Inattention
Both
Transient
causes
Prolonged or
irreversible states
• There fore, altered CONSCIOUSNESS could be :-
8
COMA

9. • Lesions that alter consciousness are located either at the :
1. Posterior fossa level
• lesions of the brainstem… ARAS
2. Supratentorial or
A. Posterior hypothalamus bilaterally
B. Bilateral interruption of the ascending projections at
the level of the thalamus
C. Diffuse or bilateral hemispheric cortical lesions
3. Both
9
COMA

10. 10
COMA

11. • ALTERATIONS IN AROUSAL
• Do not actually form discrete levels
• Rather are made up of a Continuum of subtly changing behavioral
states
• Range from ALERT  COMATOSE
• These States are Dynamic and thus may change with time
• Five Points on the Continuum Of Arousal are often used in
describing the clinical state of a patient :
1. Alertness
2. Lethargic
3. Obtundation
4. Stuporous
5. Comatose
11
LEVELS OF CONSCIOUSNESS
COMA

12. • The state of paying close and continuous
attention.
• An alert patient opens the eyes, looks at you, and
responds fully and appropriately to stimuli
(arousal intact).
1. Alertness
COMA 12

13. 2. Lethargy
Refers to a state of minimally reduced wakefulness
where in the patient is prominently drowsy and
attention is impaired.
COMA 13

14. 3. Obtundation
• Refers to mild to moderate reduction in alertness
accompanied by decreased interest in the
environment.
COMA 14

15. 4. Stupor
• Refers to a higher degree of arousability in which
the patient can be transiently awakened by vigorous
stimuli, accompanied by motor behavior that leads
to avoidance or withdrawal from uncomfortable or
aggravating stimuli.
COMA 15

16. 5. Coma
• Is prolonged unconsciousness
• Is a state of extended unconsciousness in which
the patient is unarousable and shows little or no
spontaneous movement and little or no alerting
response to painful or noxious stimuli.
COMA 16

17. COMA 17

18. Levels of unconsciousness
Alertness Lethargy Obtundation Stupor Comatose
COMA 18

19. 1. Locked in syndrome
• It is pseudo coma in which Ventral brain stem
destruction by sparing the RAS.
• Patient is mute and quadriplegic but not comatose
with variable preservation of consciousness.
• Patient is awake but speechless and motionless
with little response to stimuli and sustained eye
opening along with aphonia or hypophonia.
CONDITIONS THAT MIMIC COMA
COMA 19

20. 2. Vegetative state
 It signifies an awake but unaware of environment
 It describes an organic body capable of growth and
development but devoid of sensation and thought.
 Patient has massive bilateral hemisphere damage with
intact brainstem.
 In the vegetative state patient is characterized by
 Open eyelids
 Retained respiratory and autonomic functions.
 Yawning,
 Coughing,
 Swallowing,
 Limb and head movements persist
COMA 20

21. 3. Minimally conscious states
 Closely related vegetative state but less severe
Patients show limited but clear evidence of
awareness of themselves or their environment by
at least following simple commands, gestural or
verbal yes/no response.
COMA 21

22. 4. Akinetic mutism
 Partially or fully awake state in which the patient is
able to form impressions and think, but remains
virtually immobile and mute.
 They lack motor functions such as speech facial
expression, gestures but demonstrate alertness.
 They can move their eyes in response to auditory
stimulus or move after repeated commands.
COMA 22

23. 5. Abulia
• Describes a milder form of akinetic mutism
• Characterized by;
• mental and physical slowness and
• diminished ability to initiate activity.
COMA 23

24. 6. Catatonia
 is a curious hypo mobile and mute syndrome that
occurs as part of a major psychosis, usually
schizophrenia or major depression
 Catatonic patients;
 Few voluntary movements.
 may not appear distressed.
 waxy flexibility," or catalepsy.
 have some memory of events.
Catatonia is superficially similar to akinetic mutism, but
clinical evidence of cerebral damage such as
hyperreflexia and hypertonicity of the limbs is lacking
COMA 24