Effects of Hydrocephalus

The Effects of Hydrocephalus:

The accumulation of cerebrospinal fluid (CSF) in the ventricles of the brain, with an increase in the pressure inside the head are the defining characteristics of hydrocephalus and thus isn't an effect.
There are two sources of this pressure in the cranium, the first is the pressure caused by the production of the CSF itself, but a much higher pressure is produced by the heart in order to pump blood to the brain.
Eventually the pressure of the CSF will interferes with the blood supply to the brain, depriving it of oxygen and glucose which it needs in constant amounts to continue to function. 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. In most cases the process will have been continuing for some time before diagnosis of hydrocephalus is made. During this time the interference with the blood supply leads first to a 'dying back' of the very fine blood vessels in the brain. Even this process is largely reversible if prompt action is taken, but at this time there is often insufficient clinical evidence to suspect hydrocephalus.
The next stages involve progressive damage to the actual nerve cells in the brain and to their eventual destruction, and this cannot be reversed. The areas of the brain which are most affected, the functions associated with thought and learning as well as with co-ordinated skilled movement, begin to deteriorate.
A physical problem may be seen in the eyes (papilloedema), but is not pressent in all cases. This is caused by pressure on the blood supply to the back of the eye. If CSF pressure remains high for too long, damage to the optic nerves can become permanent resulting in blindness, though fortunately nowadays this is uncommon. 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.
Many of our vital functions such as heart beat, breathing etc are controlled from the brain stem, a structure joining the spinal- cord to the brain. Very high CSF pressure can compress this sufficiently to cause the heart and breathing to stop. Once again this is uncommon as signs of raised pressure are usually recognised before this. A similar problem might sometimes arise, particularly in those with spina bifida, due to compression of the cerebellum, a part of the brain lying at the back of the head. This can also give rise to breathing, speaking and swallowing difficulties.

In cases where damage to the brain has occured there can be a number effects. The precise effects are different form person to person, a persons abnormalities as well as by the pre-existing degrees of ability and personality will affect the effects. Learning disorders are common amongst those with hydrocephalus, but their exact effects vary considerably. Much is said and written about intelligence, and particularly about IQ (intelligence quotient) in people with hydrocephalus.
The may be subtle problems of co-ordination of hand movements with what the person sees, as well as a degree of clumsiness, which make it difficult to perform certain tasks or do certain jobs.
Other effects of hydrocephalus may also be seen, and some of these are difficult to explain. For instance, some people are very seriously distressed by every day noises such as vacuum cleaners or washing machines.

The Psychological effects

There may be real problems with concentration and reasoning which require a sympathetic but skilled approach. For instance, it will often be necessary to teach simple every day tasks like getting out of bed, washing one's face, dressing and going downstairs as separate short items rather than all at once, and to keep them consistent and repetitive.
Damage to the nerves in the brain which normally allow us to learn very quickly how to do a complex series of things may result in a difficult in learning which is unrelated to intelligence. Much can be done to help, and professional advice should be sought where needed.
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. Again, specialist advice should be sought if necessary.
People with hydrocephalus generally score better on verbal tests than on performance tests, this is thought to reflect the distribution of nerve damage in the brain. Certainly during periods of rising CSF pressure, such as in untreated cases or when a shunt is blocked, the effect on performance IQ is more marked. Generally speaking, people who have had hydrocephalus since birth or childhood have, as a group, a lower average IQ than a comparable group without hydrocephalus, but it is important to realise that there is a wide range in each group, and some people with hydrocephalus have very high scores.