1. Disorders of consciousness
Dr. Kifah Alubaidy

2. Consciousness Consciousness is an awareness of the
environment and ability to respond to it.
Have two fundamental elements:
Awareness
Arousal

3. Arousal
Is primitive responsiveness to the world (involuntary responses to stimuli).
maintained by the reticular activating system

4. Awareness
The receiving and processing all the information & allow the orientation to self and outside world.
Awareness is regulated by cortical areas within the cerebral hemispheres

5. Brain metabolic demands
Cerebral neurons are fully dependent on cerebral blood flow (20% of cardiac output)
CBF 55 ml/100 g brain /min
Brain glucose need 55 mg/ 100 g brain /min
Brain O2 consumption 3.5 ml/ 100 g brain /min
Brain stores
Glucose 2 min
O sec

6. Level of consciousness
Drowsiness
Easy aroused
Persistent of alertness for brief period
Light sleep

7. Level of consciousness
Stupor
Partial degree of arousability
Awaked only by vigorous stimuli
Have motor behavior to avoid vigorous stimuli

8. Level of consciousness Coma
profound state of loss of consciousness
deep sleep like state the patient cannot be awakened
fails to respond normally to pain or light
does not have sleep-wake cycles
does not take voluntary actions

9. Acute confusional state
Delirium
is an alteration of :
Level of consciousness
Concentration & attention
Orientation
Memory & thinking
is confusion with
Psychomotor changes
Autonomic hyperactivity

10. Awake with non responsive state
Vegetative state
Awake with non responsive state
Eye open
Yawning, coughing, swallowing
No meaningful responses to stimuli
Respiratory and autonomic functions are retained
Pathology; Extensive damage in both cerebral hemispheres
Main causes are cardiac arrest & head injury

11. Akinetic mutism Partially or fully awake
Able to think & make impressions
Immobile and mute
Pathology; Damage of thalamus, frontal lobe or hydrocephalus
Abulia is mild form with mental & physical slowness an inability to initiate activity

12. Locked-in state Awake Quadriplegia, anartheria & dysphagia
Normal vertical eye movements & eyelid elevation.
Normal pupillary reactions
Pathology; Damage to the ventral pons ( CVA )

13. Causes of impaired consciousness
Damage to RAS
Distraction of large portion of both cerebral hemispheres
Suppression of reticulo-cerebral function by drags, toxins and metabolic derangements

14. Metabolic disorders Altering neuronal excitability
Interrupting O2 & energy delivery
False neurotransmitter
Brain edema
coma & Acute confusional state by widespread cortical dysfunction without FND

15. Causes Metabolic and endocrine disorders
Hyponatraemia
Hypocalcemia / Hypercalcaemia
Hypoglycemia or hyperglycemia & Diabetic ketoacidosis
Hypo or Hyperthyroidism and Hyperparathyroidism
Cushing syndrome
Anemia, Dehydration and malnutrition
Vitamin deficiencies: B12, thiamine, folate, niacin

16. Causes Organ failure Azotemia hypercapnia or Hypoxia Hepatic failure
Heart failure
Hyperammonemia
Hypertensive encephalopathy

17. Causes Intoxication Sedatives, antipsychotic, antidepressants
Anticholinergic, antiepileptic
Prednisone, dexamethasone can cause paradoxical confusion
Polypharmacy
Alcohol intoxication / withdrawal

18. Causes Infection Chest infection Urinary infection Septicemia
Viral illness
Meningitis
Encephalitis
Cerebral abscess
Subdural empyema
AIDS

19. Causes Vascular Cerebral hemorrhage Cerebral infarction
Subarachnoid hemorrhage
Vasculitis
Cerebral venous sinus thrombosis

20. Causes Rise intracranial pressure Convulsion Trauma Neoplastic
Acute hydrocephalus
Convulsion
Post-ictal state
Complex partial status
Non convulsive status epilepticus
Trauma
hemorrhage
Contusion
edema

21. HISTORY Trauma, cardiac arrest, or reported drug ingestion
Antecedent symptoms (confusion, weakness, headache, seizures, dizziness, double vision)
Fever and vomiting
Medications, illicit drugs or alcohol
Chronic liver, kidney, lung, heart disease

22. Examination Vital signs
Fever
Hypothermia
Infections
Anticholinergic intoxication
Withdrawal of ethanol
Withdrawal of sedative
Ethanol or sedative itoxication
Hypothyroidism
Hepatic encephalopathy
hypoglycemia

23. Hypertention Hypertensive encephalopathy
Ethanol or sedative Withdrawal
Anticholinergic intoxication
Subarchinoid hemorrage
Sympathomimetic intoxication
rapid rise in intracranial pressure

24. Hypotension Alcohol or barbiturate intoxication Internal hemorrhage
Myocardial infarction
Sepsis
Profound hypothyroidism
Addisonian crisis.

25. Tachycardia Bradycardia Vital signs Hypothyroidism
Ethanol or sedative Withdrawal
Anticholinergic intoxication
Thyrotoxicosis
Hypothyroidism

26. Vital signs Hyperventilation Hypoventilation Hyperglycemia
Hepatic encephalopathy
Pulmonary encephalopathy
Opiod itoxication
Ethanol or sedative itoxication

27. CNS Examination Meningeal irritation signs
positive neck stiffness, Kernig's & Brudzinski's
CNS infection
Intracranial hemorrhage
Coning

28. Fundi papilledema

29. Fundi
retinopathy
hemorrhage

30. Eye Opening Glasgow Coma Scale Spontaneous 4 To loud voice 3 To pain 2
None  

31. Glasgow Coma Scale Verbal Response Oriented 5 Confused & Disoriented 4
Inappropriate words
Incomprehensible words 2
None

32. Glasgow Coma Scale Motor Response Obeys commands 6 Localizes pain 5
Withdraws from pain
Abnormal flexion posturing 3
Extensor posturing
None

33. Posture

34. brainstem function examination
Essential to localization of the lesion in coma
pupillary size and reaction to light
spontaneous and elicited eye movements
corneal responses
respiratory pattern.

35. pupillary size and reaction to light
mid-point pupils with loss of light reflex / midbrain lesion
pin-point pupils / pontine haemorrhage
fixed dilated pupils / central diencephalic herniation
metabolic coma / pupils relatively small with brisk light reflexes
most drug intoxications / small and sluggishly reactive pupils

36. pupils

37. pupils

38. spontaneous eye movements
Conjugate deviation of eyes, The eyes look toward a cortical lesion and away from a brainstem lesion.
Depression of eyes below meridian seen with damage at level of midbrain and in metabolic coma
Spontaneous nystagmus reflects interaction between the oculovestibular system and the cerebral cortex and thus is rare in coma

39. spontaneous eye movements
conjugate deviation
depression of eyes

40. Nystagmus