Confusion

Question 1

Define confusion

Answer 1

Inability to think clearly and/or rapidly. Characterised by:

• Difficulty understanding a situation
• Disordered or unclear thoughts
• Associated with memory loss and/or disorientation

Can be acute, chronic progressive, often treatable.

Can be aggravated by environmental or diurnal changes

Question 2

Define delirium

Question 3

Confusion is more common in which groups of patients?

Answer 3

• Elderly
• Those with terminal illness
• Post surgery
• People with memory problems
• People with poor hearing or eyesight
• People with a brain disorder

Question 4

List some common causes of confusion

Answer 4

• Infections
• Head injury
• Stroke
• Delirium
• Dementia
• Alcohol or drug intoxication
• Sleep disorders
• Chemical or electrolyte imbalances
• Hypothermia
• Seizures

Question 5

Which neural pathways are implicated in confusion?

Answer 5

Cholinergic; 2 main nuclei that produce Ach in the brain:

• Nucleus basilis of Meynert (to cortical regions and striatum)
• Brainstem pontine nuclei (involved in control of arousal- projects to the thalamus and spinal cord ):
  
  • Lateral tegmentum
  • Pedunculopontine nucleus

Question 6

What role does Ach play in arousal?

Answer 6

Peripherally controls ANS and muscle function

Centrally involved in:

• Alertness
• Arousal
• Attention
• Sleep
• Memory
• Learning

Modulates transmitter pathways including dopamine

Question 7

Which neurotransmitters are mainly involved in arousal?

Answer 7

• Histamine
• Acetylcholine

Question 8

Describe what happens during waking in the sleep-wake cycle

Answer 8

During waking:

• Histamine levels are high and activate cholinergic pathways
• Cholinergic pathways activate the thalamic reticular nuclei
• Information able to flow freely through this area
• Information flow = arousal and alertness = consciousness

(high histamine, high Ach)

Question 9

Describe what happens during slow-wave sleep in the sleep-wake cycle

Answer 9

Slow-wave sleep:

• Low light and warmth detected by the suprachiasmatic and ventrolateral preoptic nuclei (hypothalamus)
• Inhibition of histamine cells in the tuberomamillary bodies and brainstem
• Inhibits cholinergic pathways
• Reduced activity passing through thalamus
• Prevents information flow: low arousal

(low histamine, low Ach)

Question 10

Describe what happens during REM sleep in the sleep-wake cycle

Answer 10

REM sleep:

• Inhibition increases and begins to affect other pathways
• 5HT and NA (which normally decrease cholinergi activity) decrease
• Increased cholinergic activity to the thalamus
• Increased cortical activity

(low histamine, high Ach)

Question 11

What is ‘Sundowning’?

Answer 11

Confusion late in the day caused by link between diurnal rhythm and arousal levels.

Patients with dementia may become agitated towards the late afternoon which may previously have been a busy time of day for them.

Question 12

What can cause sundowning?

Answer 12