Your child may have made a good physical recovery but children who have been ill with encephalitis are likely to have some damage to nerve cells (neurons) in their brain, this is termed “acquired brain injury”. This injury can have immediate effects or can be responsible for problems that only become apparent later in your child’s development. These acquired difficulties may be physical, cognitive, behavioural, emotional and/or psycho-social.

The Effects of Encephalitis on the Brain

In order to understand the effects of encephalitis on the brain, it can be helpful to understand how the brain works. The brain is an amazing organ, it controls everything your child does. All the various parts that make up the brain work together to help children learn, play, communicate, move and behave. As children develop and get older, their brain systems work together more effectively.

The brain is made up of 1 billion neurons and each neuron makes between 1,000 and 10,000 connections. The connections form networks (neural networks). At birth all the nerve cells your child will ever have are present but there are very few connections. As your child’s brain develops more and more connections are made and these are gradually covered by a protective coating, the myelin sheath.

Copyright: National Multiple Sclerosis Society

Encephalitis may result in damage to the neurons themselves or to their myelin sheath. The neural network that these neurons are part of can become disrupted; as a result, the brain may become slower and less efficient at relaying information. (An analogy is if a road is damaged and under repair traffic will have to use minor routes, which causes delay).

The Encephalitis Society fact sheet "Caring for your brain" (which can be accessed on this website has further details, 'Caring for your brain'

Age At Diagnosis

Children's brains are rapidly enlarging in terms of size in early infant and toddler years and in terms of complexity right through childhood and adolescence. The process of neural development is also not uniform throughout the brain some areas fully developed and functional at an early age (e.g. the occipital lobes, responsible for seeing, whereas other areas (e.g. frontal lobes, responsible for planning and other 'executive' functions) only finally develop well into adolescence and early adulthood.

Damage to areas of the brain which are already fully developed and functional will become immediately obvious through temporary, or perhaps long-term, loss of skills.

Damage to areas in the process of development, may result in temporary loss of emerging skills, further development of the skills may take longer or not occur as expected.

Damage to areas of the brain which have yet to develop fully may appear to have little functional effect soon after injury. However over the years behavioural problems and subtle cognitive difficulties may begin to emerge which may not appear to have a direct relationship to the earlier encephalitis. A good analogy for damage affecting skills, which have not yet developed, or 'come on line' is a faulty light bulb. You do not know that it is not working until you turn on the switch.

Possible Difficulties that can result from encephalitis

The pattern of difficulties that may occur will be determined by:

• Location and the type of damage as well as disruption that has occurred to neurons and/or neural networks. 
• Your child’s age at the time of the illness – previously learnt skills and information are often preserved. The younger the child, the fewer skills have developed.
• Your child’s previous personality and abilities.  Their personality traits may become exaggerated.  Abilities that prior to the illness were in the higher range may dip to average.  This will present as a problem to you (and possibly to your child) but may be disregarded by their teachers.  Abilities that were in the lower range may now become a significant difficulty.

To get help with the difficulties listed below, see Children/Pathways through services.

Physical changes

Physical disabilities such as hemiplegia (weakness on one side of the body) or ataxia (unsteadiness or tremor) are easily apparent so that you can adjust your demands and expectations. However, other physical changes may be less apparent. Your child may have a general problem with co-ordination and balance or know what they want to do but be unable to put together a sequence of movements. Your child may, therefore, appear to be more clumsy or careless. Sometimes all physical actions are slowed compared with previous ability.

Your child should be referred to a physiotherapist or occupational therapist.

Fatigue

Physical and mental fatigue may be more apparent, with your child tiring more easily in such activities as physical education and games as well as in other lessons when concentration is required. Although this is more readily recognized in the early stages of recovery, it can frequently present as a long-term difficulty.

Whereas children normally may tire gradually, your child may suddenly reach a threshold where they are over-tired or ‘overloaded’ with information and unable to continue. This sudden onset cannot be controlled and the only remedy is rest or a break from that activity, although it may be the case that this break need only be brief, or may be achieved by changing activity.

Visual and Hearing Problems

Your child may have specific impairments of vision or hearing. There may be problems with visual acuity, or your child’s ability to see may be unimpaired but there may be a difficulty interpreting visual information. It may also be the case that your child is not able to interpret or to process information that they see or hear if there are other noises or things within their field of vision to distract them. If these difficulties are not identified, the resultant failure to respond to the information your child would be expected to see or hear may be misinterpreted as learning or behavioural problems.

Your child should initially be referred to an optometrist or audio specialist. If their vision and hearing is normal then your child will need a neuropsychological assessment to identify a problem with processing information, or an assessment by a specialist occupational therapist if the problem is with interpreting visual information or integrating sensory input.

Sleep problems

Sleep disorders are also common. This is partly due to the disruption of your child's normal routine while in hospital and partly due to the effect of the inflammation on the brain. It is now universally accepted that as babies grow older they develop a type of chemical clock in their brain which encephalitis can disrupt and lead to sleeplessness, sleeping at odd times or sometimes sleeping too much. Of these, sleeplessness causes most problems for parents, especially if your child is also over active in the daytime; this overactivity may also mean that your child is unable to settle to sleep at night time. Drugs that are sometimes prescribed for anxiety or sleep problems following encephalitis may have the opposite effect in some susceptible children. This is not to say that they must never be used, merely that it may take time to find something that suits your child.

Your child should be referred to a paediatric neurologist.

Epilepsy

Your child may develop epilepsy following encephalitis. This may be apparent immediately after their initial illness, or develop some time later. Seizures can take many different forms and are not confined to the type of tonic-clonic fits (these used to be called grand mal fits) that people often associate with this problem. Some types of seizure cause brief spells of apparent inattention or strange behaviours.

Epilepsy following encephalitis can be particularly difficult to treat, becoming in some children 'intractable'. If your child has epilepsy they should be referred to a paediatric neurologist and their treatment regime reviewed annually. There are 2 excellent organisations Epilepsy Action and the National Society for Epilepsy which provide information and support. If your child has epilepsy you would benefit from joining one of these organisations.

Attention and concentration

Your child's ability to concentrate may be reduced or they may be very distractible, compared with other children of the same age. They may not be able to divide their attention in order to do more than one thing at once (e.g. can’t write and listen or can’t walk and talk at the same time). They may not be able to shift their attention easily from one thing to another (e.g. from watching a demonstration to writing some notes or from playing with Lego to listening to an instruction ). They may take a long time to be able to focus their attention properly on a new activity (e.g. for a change of lesson).

Your child may, therefore, have difficulty staying on task within the classroom and may need some additional help or adaptations to the classroom environment in order to help them to do this. They may need cues to help them to keep track of a task. Children with attention problems as a result of encephalitis cannot improve their attention at will, when asked to do so. They need extra help to ensure that their learning is not impaired as a result of this difficulty.

Your child should be referred to an education or clinical psychologist.

Memory

Your child’s ability to remember may be reduced. However, there are different processes involved with memory and different aspects of this, which may not all be affected or not affected to the same degree. For instance, they may be able to remember things that they see more easily than those which they hear, or the other way round. They may be able to remember things that happened some time ago, but not activities during the day. They may have difficulty remembering instructions for a task whilst they are actually doing it.

Generally, children with such memory difficulties need a higher level of repetition and reinforcement of information than their peers. They may need cues to aid their recall and are frequently able to demonstrate their knowledge more easily through multiple choice testing, rather than tests involving free recall.

Your child should be referred to a clinical psychologist for assessment and strategies to help.

Information Processing

Your child may not be able to process information (think) as quickly as they could previously or as quickly as their peers. This means that they may get “lost” within lessons as these have moved on before your child has understood each piece of information. Your child may, therefore, often need longer to complete tasks and sometimes need information to be provided at a slower pace or to be provided with back-up information to fill in the gaps that they may have missed.

Your child should be referred to a clinical psychologist for assessment and strategies to help.

Speech and Language

Your child may lose the ability to communicate through speech and may need a system of alternative or augmented communication. They may have problems with their speech and not be able to articulate words clearly or to string these together into sentences. Or they may recover the ability to speak well, which may mask more subtle language difficulties. Some language difficulties may not be apparent until your child is older when more sophisticated use of language would normally be developed.

Although your child may be able to speak normally, they may have difficulty formulating and expressing what they want to say or they may have difficulty finding the right words. This can affect their written work as well as their speech. Conversely, they may have difficulty understanding or making sense of that which they hear or read (although their ability to read words may be good). Some of these difficulties may not be apparent in general conversation, but may have significant effects on your child’s ability in school.

Your child may not develop the ability to understand, for instance, humour, sarcasm or figures of speech. They may interpret everything very literally. They may not be able to detect inference or to identify main points of a story.

If your child’s speed of information processing is reduced this may affect their language skills. If they have problems with attention, this may affect their ability to understand language and will affect their social skills (e.g. not being able to keep track of a conversation). Your child’s social skills can also be affected by the fact that they sometimes have difficulty “reading” non-verbal communication (e.g. understanding from the expression on someone’s face that they are bored, irritated or joking)

Your child should be referred to a Speech and Language Therapist.

Executive skills

This term refers to skills that may be likened to the sort of supervisory 'jobs' that an executive may do for a company to ensure that it works efficiently. These include the ability to plan and to reason; to set goals (e.g. to know why we are doing things); to organise an activity or a task, to complete it in the right sequence and to monitor the way that we do this (e.g. realise if we are not doing it in the best way and revise our plans); to initiate an activity and to know when to stop doing it; to monitor our behaviour and to know what behaviour is appropriate in different situations.

Difficulties in this area may present as subtle or extreme so that your child may appear unable to tackle even the simplest of tasks, seem more impulsive or appear totally disorganised. These difficulties may become increasingly obvious or only begin to be apparent as your child gets older. They may then be confused with ‘normal’ teenage behaviours.

Your child may become aware of their difficulties, which could lead to a reduction in motivation and possibly other emotional and behavioural consequences.

Your child should be referred to a clinical psychologist for assessment and strategies to help.