Neurological symptoms

The effect of A-T on cells in the brain causes a wide range of physical symptoms affecting co-ordination and movement. Traditionally these have been referred to as (cerebellar) ataxia. However, while the cerebellum is definitely affected by A-T and ataxia is a major feature, there are many other effects of the condition which are not necessarily caused by problems in the cerebellum. As with so many aspects of A-T, individuals may be affected by a variety of symptoms and these may occur at quite different ages.

In addition to the problems in balance and movements, movements of the eye, which are controlled by another part of the brain, are also affected.

Movement problems

Neurological problems are often the first sign that something is wrong for a person with A-T. They usually start to show in the toddler years. The first signs are difficulty with control of the body, posture and body movement (truncal ataxia). The child may start to walk later than usual (after 18 months), may be reluctant to let go of supporting people or objects, may continue to walk unsteadily for longer than normal, may be unable to stand still without tottering back and forth and may fall frequently.

Initially it may be hard to be sure that anything is wrong and some children seem to improve from 3 to 5 years.  Eventually it becomes obvious that balance control is abnormal. Walking becomes more strenuous and appears awkward, doors and walls are frequently used for support. Running may, for a while, seem less affected; this is because less balance is needed for quick movements than slower graceful ones. Most children with A-T start to use a wheelchair around their 10th year (some even earlier).

Towards the end of the first decade and the start of the teens, other problems come to light.  These can become as disabling as the loss of body balance control. Co-ordination of the limbs becomes abnormal (peripheral ataxia). Involuntary movements may start in some children but not all.

Many of these features have rather obscure medical names:

  • Little jerks of the hands and feet which can look like fidgeting (chorea)
  • Slower, larger twisting movements of the neck, face and shoulders (athetosis)
  • The adoption of rather stiff and twisted postures (dystonia)
  • Occasional uncontrolled jerks of limbs (myoclonus)
  • Shaking episodes of a limb which are like shivering (tremors).

Generally there is a tendency for these symptoms to plateau off and stop progressing around the beginning of the teenage years although particular movements may begin at any time.

Visual problems

Eye movements become restricted in A-T. This is formally known as saccadic apraxia.   Reading and following moving objects becomes difficult. When following something, children with A-T tend to move their heads rather than their eyes. It can also be difficult for the child to choose to look in a particular direction and they sometimes find it easier to use their peripheral vision (looking out of the sides of their eyes). So while a child may not be looking directly at you, this does not mean that they aren't paying attention.

 

Dr Kate Sinclair

In this video, experts Kate Sinclair and Tom Crawford talk about the neurological features of A-T.

 

Boy in a wheelchair with rolled eyes

It can  be difficult for the child to look in a particular direction

 

 A boy with A-T concentrates to use a touch-screen

This boy has to concentrate to use a touch screen.