Ataxia: what it is, symptoms, causes and treatment

Ataxia is not a single disease but a term for a group of disorders that affect co-ordination, balance and speech. The NHS says that any part of the body can be affected, but people with ataxia often have difficulties with balance and walking, speaking, swallowing, tasks that need a high degree of control such as writing and eating, and vision. The exact symptoms and their severity vary depending on the type.

The NHS explains that ataxia usually results from damage to the cerebellum, a part of the brain at the base of the brain that controls walking and sitting balance, limb co-ordination, eye movements and speech. It can also be caused by damage to the spinal cord or other nerves.

Because it describes a pattern of symptoms rather than a diagnosis, finding the cause is a large part of care.

Symptoms depend on the type. The NHS describes symptoms of the main types, summarised below. Some types affect children from an early age, while others may not develop until much later in adulthood. Depending on the type, symptoms may stay the same, get progressively worse, or slowly improve.

In the main hereditary types, the NHS lists problems with balance and co-ordination (often causing wobbliness, clumsiness and frequent falls), increasingly slurred, slow and unclear speech (dysarthria), difficulty swallowing (dysphagia), weakness in the legs, loss of sensation in the hands and feet and eye movement problems.

The NHS says damage can occur as a result of injury or illness (acquired ataxia), or because the cerebellum or spinal cord degenerates due to an inherited faulty gene (hereditary ataxia). Sometimes there is no clear reason, which is the case with idiopathic late-onset cerebellar ataxia.

The NHS lists a wide range of causes of acquired ataxia, including severe head injury, brain infections such as meningitis or encephalitis, very rarely some viral infections such as chickenpox or measles, conditions that disrupt the blood supply to the brain such as stroke, haemorrhage or TIA, cerebral palsy, multiple sclerosis, sustained long-term alcohol-use disorder, an underactive thyroid gland, vitamin B12 deficiency, brain tumours and other cancers, certain toxic chemicals such as mercury and some solvents, and medicines such as benzodiazepines, which can occasionally trigger ataxia as a side effect.

For hereditary ataxia the NHS says Friedreich's ataxia and ataxia-telangiectasia are inherited in an autosomal recessive way, while episodic ataxia and some spinocerebellar ataxias are autosomal dominant. For recessive types, if two carriers have a baby there is a 1 in 4 chance the baby will develop ataxia. For dominant types, each child has a 1 in 2 chance.

The NHS says to visit your GP if you or your child have unexplained balance and co-ordination problems or difficulty walking, talking or swallowing. The GP may ask about family history and how symptoms have progressed, and do a simple assessment of balance, walking and co-ordination. They may ask how much alcohol you drink and what medicines you take, because excessive drinking and certain medicines can cause ataxia-like symptoms.

You may be referred for tests such as blood and urine tests to rule out other causes such as infection. If symptoms suggest acquired ataxia due to a serious underlying condition, the NHS says you are likely to be admitted immediately to your nearest hospital. Otherwise you are referred to a neurologist, or in the case of children a paediatrician, for further testing.

• Genetic testing: a blood test for known gene changes. The NHS says tests can currently detect the mutations responsible for Friedreich's ataxia, ataxia-telangiectasia and most spinocerebellar ataxias.

• Brain scans: MRI or CT to check for physical abnormalities and other problems such as a brain tumour.

• Other tests: lumbar puncture, nerve conduction studies and electromyography, videofluoroscopy of swallowing, ECG and echocardiogram.

The NHS says that it is sometimes possible to treat the underlying cause so that ataxia improves or stops getting worse, but in most cases this is not possible and treatment relieves symptoms. You will usually be cared for by a multidisciplinary team (MDT) who work with you on a care plan covering physical, social and psychological needs. Some people are seen in a specialist ataxia centre.

The NHS says the outlook varies considerably and largely depends on the type. Some types may remain relatively stable or even improve with time, but most will get progressively worse over many years. For hereditary ataxia, life expectancy is generally shorter than normal, although some people live well into their 50s, 60s or beyond. For Friedreich's ataxia it says many people live until at least their 30s and some into their 60s or beyond. For acquired ataxia the outlook depends on the underlying cause.

Ataxia UK is the leading UK charity supporting people affected by any of the ataxias, with information for people newly diagnosed and a helpline.

See a GP for unexplained balance, co-ordination, walking, speech or swallowing problems. The NHS says that acquired ataxia can develop over a few days or sometimes hours, and that if symptoms suggest a serious underlying condition you are likely to be admitted to hospital immediately.

Sudden loss of balance or co-ordination with slurred speech, facial drooping or weakness should be treated as a possible stroke, and 999 should be called.

On the NHS the GP is the first step, with referral to a neurologist (or a paediatrician for children) for tests, and long-term care by an MDT, sometimes in a specialist ataxia centre. Ataxia UK works on improving patient pathways.

Some people choose to see a private neurologist for an opinion or tests such as MRI or genetic testing. In general terms the same tests apply, and what matters is who will coordinate therapy, genetic counselling where relevant and long-term review. Ask for results to be shared with your GP and MDT.