Fits, faints and funny turns

Fits, faints and funny turns refer to episodes of transient altered consciousness, which usually present to the doctor after the event is over and may occur recurrently. They may cause great anxiety, although the child is often completely well in between episodes. A good description of the event should allow the different causes to be distinguished from each other, and it can be helpful to ask the family to video the episode. Most of the causes are benign and resolve with age. However, some forms of epilepsy can present in this way and need to be considered in the differential diagnosis. These include absence seizures, focal seizures such as temporal lobe seizures, and myoclonic seizures, which are covered in more detail in Chapter 41.


Breath-Holding Spells


Breath-holding spells (cyanotic spells) occur primarily in babies and toddlers. They normally resolve by 18 months of age. These spells are characteristically precipitated by crying due to pain or temper. The child cries once or twice, takes a deep breath, stops breathing, becomes deeply cyanotic and the limbs extend. Transient loss of consciousness may occur and even convulsive jerks. The child then becomes limp, resumes breathing and after a few seconds is fully alert again. The whole episode may last up to a minute. The key to diagnosis is the typical onset with crying and breath-holding and the absence of a postictal phase. The spells can sometimes occur several times a week and parents are often so terrified of them that they change their behaviour to avoid upsetting the child. They need to be reassured and encouraged to treat the child normally. There is no association with behavioural disorders.


Reflex Anoxic Seizures


These are also known as pallid spells or ‘white’ breath-holding attacks. The peak age is in toddlers from 6 months to 2 years. They classically follow a bump on the head or other minor injury, which triggers an excessive vagal reflex, causing transient bradycardia and circulatory impairment. The child may or may not cry, but then turns pale and collapses. There is transient apnoea and limpness followed by rapid recovery after 30–60 seconds. There may be eye-rolling and incontinence, and sometimes clonic stiffening of the limbs, but no tongue biting. After an attack the child may be tired and emotional for a few hours. The typical history and absence of postictal drowsiness helps distinguish these spells from epilepsy. Despite their appearance the attacks are always benign and disappear before school age. Parents need to be reassured and taught to put the child in the recovery position and await recovery.


Infantile Spasms


Infantile spasms (West’s syndrome) are a form of generalized myoclonic epilepsy (see Chapter 41) which can sometimes cause diagnostic confusion with other causes of loss of consciousness in young children. The onset is usually in infancy, peaking between 4–8 months. Characteristically there is a sudden tonic flexor spasm of the head and trunk causing the child to bend forwards (‘salaam’ attack). Relaxation occurs after a few seconds and the episode may reoccur in clusters up to 10 or 20 times. Clusters are commoner on awakening or just before sleep. Extensor spasms are sometimes seen. The EEG is diagnostic, showing a chaotic hypsarrhythmia pattern. In 20–30% there is an association with tuberous sclerosis, so examination of the skin using a Wood’s light is important. Infantile spasms are usually associated with severe learning disability. Treatment with vigabatrin may be beneficial.


Syncope (Fainting)


Syncope occurs when there is hypotension and decreased cerebral perfusion. It occurs particularly in teenage girls reacting to painful or emotional stimuli, or prolonged standing. Blurring of vision, light-headedness, sweating and nausea precede loss of consciousness which is rapidly regained on lying flat. It is rarely a symptom of cardiac arrhythmias or poor cardiac output in childhood. Evaluation includes a cardiac examination, standing and lying blood pressure, and an ECG if there is doubt as to the cause of the faint. In unusually severe cases diagnosis may be helped by a tilt-table test, where the patient’s ECG and blood pressure are measured while being tilted from lying to standing.


Cardiac Arrhythmias


These are a rare cause of syncope, but should be considered if there is a clear history of preceding palpitations or if there is a family history of cardiac tachyarrhythmias or sudden death. Hypertrophic cardiomyopathy is an autosomal dominant condition that may present with syncope due to episodic ventricular tachycardia. Wolff–Parkinson–White syndrome causes supraventricular tachycardia due to re-entry rhythms and has a characteristic ECG with a short PR interval and a delta wave upstroke to the R wave. A markedly increased QT interval on the ECG may be associated with ventricular tachycardia and syncope. A 24-hour ECG recording may be useful in selected cases.


Hyperventilation


Excitement in some children, particularly teenage girls, may precipitate hyperventilation to the point of losing consciousness. The hyperventilation causes the carbon dioxide level to fall, triggering apnoea. The diagnosis is usually evident: breathing is excessive and deep, and tetany may also occur. Rebreathing into a paper bag allows the carbon dioxide level to rise and restores the child to normality. If episodes occur frequently, psychological therapy may be required.


Hypoglycaemia and Other Metabolic Conditions


Metabolic disturbance, including hypoglycaemia, may cause loss of consciousness with seizures or a less dramatic alteration in consciousness. An underlying metabolic problem should be suspected if there are features such as developmental delay, dysmorphism, hepatosplenomegaly, or micro- or macrocephaly. Hypoglycaemia may be suspected if the episodes have a temporal relationship of to eating.



KEY POINTS



  • Most fits, faints and funny turns are benign.
  • A good history from a witness is crucial as the episodes are rarely observed by the doctor.
  • The diagnosis is nearly always made on the basis of the history. Physical examination does not often contribute.
  • Only carry out investigations if merited by the nature of the episode.
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Jul 2, 2016 | Posted by in PEDIATRICS | Comments Off on Fits, faints and funny turns
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