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Chapter 7: Disorders of conciousness and memory 311

Aetiology Adetailed history including pre-morbid cognitive state,
Predisposing factors: The very young and very old, alcohol and drugs is essential, fluctuation helps sep-

hearing loss or visual difficulty, those with diffuse arate delirium from dementia, examination should
brain disease such as dementia or taking drugs with look for focal neurological signs and any evidence
anticholinergicpropertiessuchastricyclicantidepres- of other illness. Patients with dysphasia may appear
sants, unfamiliar environment (e.g. hospital, nursing confused, and require careful assessment.
home).
Precipitating factors can be divided into intracranial Investigations

and extracranial (see Table 7.9). Blood:FBC,U&E,ESR,CRP,calcium,glucose,thyroid
function, syphilis serology, LFTs and clotting screen.
Blood cultures if pyrexial.

Clinical features Urine for microscopy and culture. Consider saving
Disorientation and impaired conscious level – urine for toxicology screen.

especially worse at night. ECGforpossibleacutemyocardialinfarction,arrhyth-
Poor cognition, incoherent thought and speech. mia, signs of hyperkalaemia.

Mood and affect labile with depression, irritability, Imaging includes CXR, and where indicated CT or

paranoia and aggression. MRI.
Hallucinations – auditory and visual.

Delusions are common.

Management
Motoractivity may be increased but is often purpose- Detection of the underlying cause of the confusional

less. state and relevant treatment.
Autonomic overactivity: Sweating, tachycardia and Supportive therapy including rehydration, correc-

dilated pupils. tion of electrolyte imbalance, improved lighting at
night, facilitation of orientation, and avoidance of
conflict.
Table 7.9 Causes of acute confusional state Cautious use of short-acting sedatives may be useful
for restlessness and agitation, but can exacerbate the
Extracranial/systemic
Infection Sepsis, e.g. UTI, pneumonia problem. Severe cases may require benzodiazepines,
Toxic Alcohol intoxication, withdrawal haloperidol or one of the newer anti-psychotics such
Drugs Prescribed/illicit drugs, including as risperidone or olanzapine.
overdose or withdrawal
Endocrine Hyper- or hypothyroidism, hyper- or Prognosis
hypoglycaemia
Metabolic Uraemia, hyper- or hyponatraemia, Where recovery occurs it is usually rapid with return to a
hypercalcaemia premorbid functional level. The prognosis is dependent
Hepatic failure on the underlying cause and co-morbid features.
Hypoxia Hypoxia and/or hypotension
Vitamin deficiency Vitamin B 12
Thiamine (Wernicke–Korsakoff) Coma
Intracrania Definition
Trauma Head injury Coma is a state of unrousable unconsciousness.
Vascular Transient ischaemic attack, stroke, any
intracranial bleed or space-
occupying lesion Aetiology
Epilepsy May be post-ictal (after a seizure) or The causes are mainly those of acute confusional state
nonconvulsive status (see Table above), although there are other causes as well.
Infection AIDS, syphilis, meningitis, encephalitis, Examples include:
brain abscess
Systemic causes such as hypoglycaemia, hy-
Tumour Astrocytoma, etc
pothyroidism, hypoadrenalism, hypopituitarism,