Altered cognition and consciousness

Question 1

What is the definition of consciousness?

Answer 1

• state of awareness of one’s self, environment, response to environment
• comprises of arousal and content of thought

Question 2

What is arousal?

Answer 2

• state of wakefulness

* mediated by reticular activating system

Question 3

What is awareness?

Answer 3

• broad
• cognitive functions that embody awareness of self, environment, affective states
• includes content of thought

Question 4

What can alter levels of consciousness?

Answer 4

• Altered arousal
   -structural abnormalities
   -metabolic (hypoxia, hyperglycaemia, hypoglycaemia, electrolyte imbalance, drugs, toxins)
   -psychogenic
• Altered cognition
• Altered processing of data

Question 5

What may cause a coma?

Answer 5

• B/L hemisphere damage or suppression

* brainstem lesions or damage to reticular activating system

Question 6

What are clinical features of a coma?

Answer 6

• patient unable to be aroused, unresponsive to external or internal stimuli
• unaware of reflex response

Question 7

What are clinical features of altered level of consciousness?

Answer 7

• breathing change (post-hyperventilation apnea, Cheyenne-strokes)
• pupillary change
• oculomotor responses
• motor responses

Question 8

What causes alterations in cognition? What are the features?

Answer 8

• superior colliculi
• parietal lobe
• thalamus
• pre-frontal area
• disturbance in memory
• selective attention deficits
• pattern recognition deficits

Question 9

List the alterations in processing data?

Answer 9

• agnosia
• dysphasia and aphasia
• acute confusional states

Question 10

What is agnosia?

Answer 10

• defect in pattern recognition

* cant recognize form an nature of objects

Question 11

What is dysphasia? and aphasia?

Answer 11

• impairment in comprehension and/or production of language
• expressive = motor, Brocas
• receptive = wernickes, global, conduction, anomic

Question 12

What are acute confusional states?

Answer 12

• acquired conditions
• alterations in attention, coherency of thought and action
• altered arousal, mood, emotion, perception

Caused by:
• intoxication, withdrawal, high fever. head trauma, systemic diseases

Question 13

What is delirium?

Answer 13

• state of acute confusion which may occur at any age
• common in elderly

From:
• electrolyte disturbance
• infection (UTI, pneumonia)
• drugs, withdrawal
• post surgery
• toxins

• develops over 2-3 days

Question 14

What are the clinical features of delirium?

Answer 14

Alterations in:
• alertness, perception, sensation
• movement, speech
• sleep patterns, memory, thinking
• personality, mood, behaviour

Confusion of time and space
Incontinence

Question 15

What is dementia?

Answer 15

• structurally caused
• permanent progressive decline in several dimensions
• alteration in both cognition and processing of data
• combinations of disturbances in memory, language, perception, motor skill, problem solving, abstract thinking, judgements

Question 16

What are the aetiologies of dementia?

Answer 16

• degeneration (Alzheimers, Huntington, Picks)
• cerebrovascular disease
• alcoholism
• AIDS
• cerebral tumours
• infections (abscess, neurosyphilis, meningitis/encephalitis seuqlae)
• drugs (amphetamines, barbiturates)
• epilepsy
• head injury sequelae
• metabolic (vit. B, hypothyroid, liver or renal failure)
• chronic psychosis

Question 17

What are the criteria for Brain death?

Answer 17

• 􏰂Completion of all procedures
•􏰂 Unresponsive coma (no motor or reflex)
􏰂• 􏰂No spontaneous resps. (apnea)
􏰂• 􏰂Isoelectric EEG
• 􏰂Persistence for 1 hour and 6 hours after onset

Question 18

What is cerebral death?

Answer 18

• 􏰂irreversible coma
• 􏰂death of hemisphere, exclusive of brainstem and cerebellum
• 􏰂no behavioural or environmental responses
• 􏰂cant maintain normal resp. and cardiovascular functions, temp., GI function
• 􏰂Outcome:
-remain in coma
-emerge into vegetative state
-minimal conscious state

Question 19

List the minimal conscious state that can happen when a patient emerges from a coma?

Answer 19

• 􏰂Akinetic mutism

* 􏰂locked-in syndrome

Question 20

Why is the level of consciousness the most critical index of central nervous system dysfunction?

Answer 20

• 􏰂standardized Glasgow scale is good for setting guidelines

* 􏰂tracking progression

Question 21

What is post-coma unresponsiveness?

Answer 21

• 􏰂”vegetable”
• all cortexes not responsive
• just hypothalamus, thalamus and brainstem still working (vital centres)
• can reverse if acute

Question 22

What is locked-in syndrome?

Answer 22

• can’t move
• cortex, hypothalamus, brainstem work
• efferent pathways not working – pyramidal tracts not working

Question 23

What is brain death?

Answer 23

• brainstem not working, cortex, hypothalamus either,
• irreversible
• unresponsive coma (no motor reflex responses)
• isoelectric EEG

Question 24

How can depression be mistaken for dementia?

Answer 24

• many clinically overlapping features
• lack of initiative
• apathy (don’t care)
• insomnia
• lack of focus
• confusion
• 40% of dementia patients also have depression

Question 25

What are the characteristics of a coma?

Answer 25

• varied glascow score
• brainstem eflexes still on
• still apnoea
• transient state
• some degree of electrical activity

Question 26

What are the msk implications for a patient with altered cognition?

Answer 26

• if they can’t remember how they were injured
• hard to comply with homework
• can’t ethically get consent -need guardian ship