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 under Syncope.
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 occurs.
· 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.