Fits and faints
Transient loss of consciousness may occur in the context of fits
(seizures) or faints and falls. The major causes can be classified into
cardiovascular, neurological or metabolic. Cardiovascular causes are described
Seizures: Features that suggest a seizure include witnessed convulsions (one or
both sides of the body), postictal (postseizure) confusion, drowsiness and
headache. Loss of consciousness is not invariable. Biting the side of the
tongue and urinary incontinence (due to relaxation of the bladder sphincters)
and other injuries such as shoulder dislocation are very suggestive. If there
are warning signs prior to the seizure, e.g. a certain smell, a feeling, visual
phenomena, these are described as an ‘aura’ and are in fact a type of seizure,
which may then be followed by convulsions. Auras are unusual in other types of
fits and faints except for in migraine which does not result in loss of
consciousness or seizure.
Absence seizures (previously called petit mal) are found only in
children – the individual appears briefly unresponsive to onlookers but without
seizures and without loss of muscle tone.
Not all seizures are due to epilepsy – intracranial lesions such as
tumours, stroke and haemorrhage, or extracranial causes such as drugs and
alcohol withdrawal are important underlying causes.
Metabolic causes that must be excluded in any suspected fit or faint include
hypoglycaemia and hypocalcaemia.
Hypoglycaemia is most common in
previously diagnosed diabetic patients and is often associated with hunger,
sweating and shaking, but may be asymptomatic until loss of consciousness
Hypocalcaemia may cause a
tonicclonic seizure associated with paraesthesia, numbness, cramps and tetany.
Hysteria may lead to non-epileptic attacks (pseudo-seizures) with or without
feigned loss of consciousness. The patient will drop to the ground in front of
witnesses, without sustaining any injury and have a fluctuating level of
consciousness for some time with unusual seizure-like movements such as pelvic
thrusting and forced eye closure. There may be a history of previous
psychiatric illness or other functional symptoms. This is a diagnosis of
exclusion and should be made with caution.