Hydrocephalus involves accumulation of cerebrospinal fluid (CSF) in the ventricles of the brain, with an increase in the pressure inside the head.
If the CSF pressure rises, it eventually interferes with the blood supply to the brain. Initially this causes tiredness, irritability, and drowsiness, but if it progresses then loss of consciousness will result as the brain begins to shut down.
The immediate effects of this interference with the blood supply disappear if the CSF pressure is returned to normal, such as by ventricular tap or insertion of a shunt. However, in most cases the process has been continuing for some time before diagnosis of hydrocephalus is made.
One effect of raised CSF pressure may be seen in the eyes, and this is why your doctor sometimes looks for 'papilloedema'. This is caused by pressure on the blood supply to the back of the eye.
Another appearance, particularly in babies, is the so-called 'sunset' eye sign, where the eyes are fixed in a downward position. This is due to CSF pressure affecting important nerves running from the brain which control eye movement.
If untreated the rise in CSF pressure can cause other serious problems in the brain, unrelated to blood supply. Many of our vital functions, such as heartbeat, breathing etc., are controlled from the brain stem, a structure joining the spinal cord to the brain.
There can be learning related difficulties associated with hydrocephalus such as problems with learning in educational settings, behaviour, motivation, and visual problems.
Hydrocephalus can also result in subtle effects, giving problems with co-ordination, motivation, organisational skills, and language. Physical effects such as visual problems, or the early onset of puberty in children, may also occur.
Psychological development in children and adolescents with hydrocephalus may proceed normally, but sometimes the changes associated with puberty (breast development, body hair growth, etc.) appear much earlier than expected, and the intrusion of psychological aspects of sexual development into a mind which is emotionally still very immature can cause distressing problems.
Sensitivity to Noise
Many people with hydrocephalus are very sensitive to sudden high-pitched sounds or very loud noises, e.g. amplification.
Young children react by crying and may become very distressed, although many become less sensitive over time. Some adults report feeling sensations in the shunt and others have an echoing feeling in the head, others feel panic, nausea, and may burst into tears.
Approximately one third of people with hydrocephalus have seizures at some time in their lives. A rise in intracranial pressure due to shunt blockage may trigger an epileptic seizure. Seizures sometimes occur after shunt revision. It is often just an isolated incident, but some people go on to develop epilepsy. Epilepsy is usually treated with anti-convulsing drugs and is the same for people with or without hydrocephalus.
Some children with hydrocephalus may develop early puberty. It is seen more often in girls than in boys. Preparation of the child for the onset of periods and sexual development needs to be handled sensitively.
Eye problems may be the first sign of raised pressure in the brain or shunt blockage, so it is important to monitor the eyes. Visual assessments and ocular assessments, which monitor the eye movements and examine the back of the eye, are recommended.
In some children with hydrocephalus their ability to use language is often ahead of their ability to understand it. Their vocabulary can be good because they are able to imitate what they hear. If they do not understand fully what is said their response may be inappropriate. A child with a language problem will pick out words they understand and guess the rest or give a stock answer.
If the child has a problem with forming sounds he/she may need to be referred to a Speech Therapist.
Weak Upper Limb Control and Hand Function
Problems with upper limb control and hand skills are common in people with spina bifida and hydrocephalus.
It is important to encourage the use of both hands, especially if one hand is weaker than the other. Loss of sensation in the hands results in an inability to discriminate between differences in water temperature, or the temperature of objects such as radiators, kettles, etc. Problems with fine finger movements are shown in everyday tasks such as fastening buttons, catching balls, screwing lids on jars, and using scissors, as well as handwriting.
People with hydrocephalus often have problems with visual perception. Although they recognise objects, they find it difficult to understand their position and relationships. A squint or other eye problems can exacerbate the problem. Some experience loss of depth perception or have difficulty in judging distance or speed. There may be a difficulty with scanning visual images, with consequences for reading, writing and drawing.
Sometimes people with hydrocephalus are not aware of signals given by facial expressions in others.
Perceptual difficulties are not the only problems associated with hydrocephalus. Some people with hydrocephalus may have problems with decision-making, logical thinking, organisational problems, and an inability to follow verbal instructions, short-term memory difficulties, and passive behaviour. All of these have major implications for adult life.
Spatial awareness is the ability to understand the surrounding space and judge distance, height, width, size, and volume.
Problems with spatial and visual perception are inter-related. It can affect the way people move about, e.g. a wheelchair user may bump into tables, doorways, or people's heels. Fear of tilting a wheelchair backward to climb a kerb or fear of the drop may also be apparent.
People with hydrocephalus may have a fear of being left in a room alone, of venturing outside, or of long corridors. Manual tasks might be carried out poorly e.g. matching buttons to buttonholes, getting an arm into a sleeve, making a bed. Their handwriting might also be quite poor and illegible, due to visual perception dysfunction.
What does this mean?
Reading a catalogue of the effects of hydrocephalus can be very alarming. However, it should be realised that some people with hydrocephalus may have very few of these problems. Also, many of those which have been described are found either in untreated hydrocephalus or when the treatment fails, and when successful treatment has been promptly introduced they often improve or sometimes disappear.
On the other hand, the more subtle learning and reasoning problems are usually present in some degree and are very important where a child's development and education are concerned.
Many of these effects can be reduced through teaching strategies or with treatment where relevant.
Please see additional information on Learning and Teaching here