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Posterior Fossa Syndrome

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What is Posterior Fossa Syndrome?

Posterior Fossa Syndrome (PFS) is identified by a collection of symptoms including reduced or absent speech, irritability, low muscle tone (hypotonia), unsteadiness and reduced coordination (ataxia) and the inability to coordinate voluntary movements. The condition can also be referred to as Cerebellar Mutism because of the significant impacts on speech. The mutism is considered a severe loss of coordination of the voluntary movements involved in speech.

PFS can occur following surgery to remove tumours from the Posterior Fossa region of the brain. This is the area at the back of the brain including the cerebellum and brainstem.

Diagram of the brain with posterior fossa structures labelled: cerebellum, pons, medulla

When does it occur?

The symptoms may be immediate or delayed following surgery. Virtually all cases will occur within the first week of surgery, 50% within the first two days. It is not uncommon for a child to speak a few words after surgery and then have difficulty in the days following.

What is the chance of PFS occurring?

Research suggests that PFS is rare (only eight out of 100 children undergoing posterior fossa surgery will develop a degree of cerebellar mutism). It can vary in the way it presents, from only mild to very severe in some cases.

Are there factors that can increase the risk of developing PFS?

The exact cause is not known.

Research indicates that it can be due to the location and type of tumour. Medulloblastoma appears to increase the risk although it can occur with other types of tumours located in the posterior fossa region of the brain. It is more likely to occur when the tumour is larger.

Will my child recover?

It does get better but the pattern of recovery is different for each child. Children who have more severe symptoms of PFS early on are more likely to have symptoms that last longer. Each child will need ongoing rehabilitation by a team of therapists to help their recovery in a range of different areas depending on their individual difficulties. The rehabilitation team will include the following specialists:

Speech and language therapist: they help support any speech, language and communication difficulties. In addition they help with swallowing difficulties, supporting the process of eating and drinking and ensuring it is safe and pleasurable.

Physiotherapist: they help in maximising strength, balance and coordination of movements, helping children regain their physical skills.

Occupational therapist: they help support children participate in everyday life activities, enabling them to regain their independence.

Clinical psychologist: they can help identify and support any difficulties with ongoing learning as well as supporting children with emotional or behavioural issues as they adjust to what has happened to them.

How long does the mutism last?

The period of mutism can be very variable. In all cases so far there has been a return of speech. However the speech may not sound as it did before the surgery; it may have altered pitch and intonation and be slower than normal with a change in the rhythm. Children may have difficulty initiating answers and speak less than before.

Is there a pattern to the way speech returns?

In most cases, the communication comes back very gradually with more spontaneous sounds first (laughing and crying) followed by individual sounds, slowly developing into single words and extending into short phrases. For some children, they may be able to communicate non-verbally using head nods/shakes, gestures or communication boards.

Your child’s speech and language therapist will be able to help in maximising all means of communication and supporting the gradual return of their speech.

Does PFS affect my child’s eating and drinking?

The condition can also affect the coordination of the movements involved in chewing and swallowing. In severe cases, children may have difficulty swallowing their saliva, therefore making it unsafe for them to have anything to eat and drink. Usually children regain the voluntary movements of the lips and tongue first before being able to eat and drink, For example being able to stick out their tongue and move it from side to side. Children who have been severely affected often need tube feeding, especially when radiation therapy and chemotherapy is given at the same time as the child is trying to regain their ability to eat.

Does PFS affect my child’s ability to move around?

Most children will have some difficulty in the early stages. For a few children it will take many months to regain their physical abilities. Most but not all will be able to walk independently. However ongoing difficulties with balance, coordination, fine and gross motor control are common.

Does PFS impact on my child’s mood?

Moods swings and irritability are very common in children with PFS. Their agitation can be very distressing for families to see. This can be particularly evident after the initial stages of recovery following the brain surgery. This can be made worse by the fact a child may be scared or unable to communicate, especially if they are suffering from cerebellar mutism. A child may also appear uncooperative and be reluctant or unwilling to undertake therapy during their rehabilitation. This is to be expected but your therapy team will know what to do to support your child and family.

What are the impacts of PFS on parents?

Seeing your child suffer from the symptoms of PFS can be very distressing for parents. It is very normal to feel overwhelmed at times, especially as you already have to deal with your child’s diagnosis and treatment. Being there for your child, providing reassurance and familiarity will help them begin their gradual process of recovery.

Is there specialist rehabilitation support available at Addenbrooke’s Hospital?

The Brainbow service, based at Addenbrooke’s Hospital, is a specialist rehabilitation service supporting children following the treatment for brain tumours. The Service consists of a physiotherapist, occupational therapist, speech and language therapist and clinical psychologist. You and your child will be able to receive support from each member of the team, depending on their individual needs. Whilst your child is in hospital therapy can be provided on the ward. The Brainbow service also offers an outpatient service to ensure that any on-going rehabilitation needs are being fully supported even once your child goes home. If clinically appropriate, your child may be offered support by the Brainbow service or they will liaise directly with local teams to ensure that any necessary support is delivered closer to home.

If you have any further questions about PFS or you would like to discuss your child’s needs in more detail, please speak to a member of the Brainbow service.

The Brainbow service is based on the paediatric day unit and can be contacted on telephone number 01223 596163.

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Cambridge University Hospitals
NHS Foundation Trust
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Telephone +44 (0)1223 245151