Hallucinations

Question 1

Probability diagnosis

Answer 1

Drugs: illicit or prescribed

Alcohol: acute or chronic

Schizophrenia

Febrile delirium

Affective (mood) disorders

Drug withdrawal inc. alcohol, hypnotics

Dementias esp. Lewy body disease

Question 2

Serious disorders not to be missed

Answer 2

Vascular:

• Cerebrovascular disease
• Migraine (luminous)

Infection:

• Encephalitis/meningitis
• Septicaemia
• Any serious febrile illness

Tumours:

• Cerebral tumours
• Cancer treatment

Other:

• Hypoxia
• Liver failure
• Metabolic/electrolyte imbalance
• Dehydration

Question 3

Pitfalls (often missed)

Answer 3

Major depression

Extreme fatigue

Vitamin deficiency esp. B group

Seizure disorders esp. complex partial

Rarities:

• Narcolepsy
• Post-concussion
• Bereavement
• Multiple sclerosis

Question 4

Masquerades checklist

Answer 4

Depression

Diabetes

Drugs: iatrogenic/social–illicit

Thyroid/other endocrine: hypothyroid?

Urinary tract infection esp. elderly

Question 5

Is the patient trying to tell me something?

Answer 5

Consider conversion disorder (hysteria); fabrication.

Question 6

Key history

Answer 6

General health, febrile illness, psychological issues, neurological features, nutrition and head injury.

Elicit type of hallucination:

• auditory, visual
• olfactory
• tactile
• hypnogogic or hypnopomic

PMHx, family and psychosocial

Hx of CVD, diabetes, hypertension or migraine.

Check thyroid symptoms, particularly for hypothyroidism.

Drug history: prescribed; OTC; alcohol; social esp. marijuana, opioids, amphetamines, LSD, petrol sniffing.

Question 7

Key examination

Answer 7

General features: appearance of patient, vital signs

General respiratory, neurological and cardiovascular examination

Pulse oximetry

Mental state examination

Question 8

Key investigations

Answer 8

First line:

• urinalysis
• blood glucose
• FBE
• U&E

Consider:

• LFTs (γGT)
• ECG
• KFTs
• cerebral imaging

Question 9

Diagnostic tips

Answer 9

Pay close attention to drugs use, esp. alcohol, caffeine, narcotics and illicit agents

Auditory hallucinations – incl. schizophrenia; depression; bereavement.

Visual: organic disease

Olfactory: complex partial seizures (temporal lobe)

Tactile: drugs (alcohol, opioids e.g. cocaine, amphetamines esp. ‘ice’)