Treatable causes in children Some of the treatable conditions mentioned above are seen in children, including: • CoQ10 (ubiquinone) deficiency (the most common presentation of this is in children) • Episodic ataxia type 2 (intermittent ataxia) • Vitamin E deficiency • Cerebrotendinous xanthomatosis In addition, the following conditions are also treatable causes of childhood ataxia. In some cases the ataxia is an epiphenomenon of another condition, so brief summaries are provided and further sources of information are included. Glucose transporter 1 deficiency (Glut-1 DS) Read more Impaired glucose transport across the blood-brain barrier results in Glut-1 deficiency syndrome, characterised by infantile seizures, developmental delay, acquired microcephaly, and hypoglycorrhachia169,170. A wider phenotype is now recognized, including ataxia, spasticity and paroxysmal movement disorders which can be triggered by exertion or fasting. A ketogenic diet has been found to be effective treatment for epilepsy, but may not help gait problems169,171 (For further information see www.ncbi.nlm.nih.gov/omim; OMIM number 606777; also contact CLIMB (www.climb.org.uk) Recommendations Grade 1. If Glut-1 DS is diagnosed treat with a ketogenic diet. D Hypobetalipoproteinaemia Read more Hypobetalipoproteinaemia is a rare disorder characterized by low levels of fats, beta-lipoproteins and cholesterol172. Familial hypobetalipoproteinemia can be severe with early onset (abetalipoproteinemia/homozygous familial hypobetalipoproteinemia), or benign (benign familial hypobetalipoproteinemia). Severe early familial hypobetalipoproteinemia is often associated with growth delay, diarrhoea with steatorrhea, and fat malabsorption. Spastic ataxia, atypical retinitis pigmentosa, acanthocytosis, a low level of liposoluble vitamins (A, E, K), major cytolysis, and even cirrhosis can occur173. Recent guidelines on the diagnosis and management of this treatable disorder have been published172. (For further information see www.orpha.net ORPHA426; also contact CLIMB www.climb.org.uk.) Management of the moderate form includes reduction of the proportion of fat in the patient’s diet and vitamin E supplementation. Recommendations Grade 1. Consider management of the moderate form of hypobetalipoproteinaemia by reducing the proportion of fat in the patient’s diet and vitamin E supplementation. GPP Hartnup disease Read more Intermittent ataxia, photosensitive rash, psychotic behaviour and intellectual disability are possible features of this condition. Patients benefit from a high-protein diet, sunlight protection, and avoidance of photosensitizing drugs174. Treatment includes nicotinamide supplements; some patients may respond to a tryptophan-rich diet174. (For further information see www.ncbi.nlm.nih.gov/omim; OMIM number 34500. Also contact CLIMB www.climb.org.uk) Recommendations Grade 1. Consider treating Hartnup disease with nicotinamide or tryptophan-rich diet, and advise patients on a high protein diet, sunlight protection and avoidance of photosensitizing drugs. GPP Biotinidase deficiency Read more This is a metabolic disorder characterised primarily by cutaneous and neurologic abnormalities. This condition should be treated with biotin175,176. (For further information see www.ncbi.nlm.nih.gov/omim; OMIM number 253260. Also contact CLIMB www.climb.org.uk) Recommendations Grade 1. Treat patients diagnosed with biotinidase deficiency with biotin. GPP Pyruvate dehydrogenase deficiency Read more This is a metabolic disorder which can cause ataxia in some affected males. Treatment is generally aimed at stimulating the PDH complex or providing an alternative energy source for the brain. It can respond to treatment with thiamine, carnitine, and lipoic acid. A ketogenic diet may be indicated especially for those presenting with a dystonic disorder. Dichloroacetate has been used, but significant side effects, such as peripheral neuropathy, may limit effectiveness177. (For further information see www.orpha.net ORPHA765 or contact CLIMB www.climb.org.uk) Recommendations Grade 1. Consider treatment with thiamine, carnitine or lipoic acid and advising on a ketogenic diet. GPP Structural disorders Read more If ataxia is caused by structural disorders these are usually surgically treatable. Brain tumours can cause ataxia but usually other symptoms such as headache, vomiting and personality change are present. Hydrocephalus can have similar symptoms and can be due to a wide variety of causes. Arnold-Chiari malformation is a congenital malformation at the back of the brain. (For more information contact the Association for Spina Bifida www.spinabifidaassociation.org) Recommendations Grade 1. If ataxia is due to structural causes a referral for surgical treatment may be recommended. GPP Acute encephalopathies Read more Intoxication, either from recreational or medically prescribed drugs, can cause acute or intermittent ataxia, but is not always immediately recognised. For more information about metabolic encephalopathies, such as branched chain amino-acidurias, contact CLIMB (www.climb.org.uk). Non convulsive status epileptics/other epilepsies Read more Can rarely present as intermittent ataxia (combined with altered consciousness) but seen more commonly in the context of a known epilepsy syndrome178. For more information contact Epilepsy Action (www.epilepsy.org.uk). Sensory ataxias Read more Refsum syndrome and chronic inflammatory demyelinating neuropathy (CIDP) are conditions affecting the nerves. Refsum syndrome also involves the cerebellum and can sometimes result in ataxia. For more information see the National Institute of Neurological Disorders and Stroke (www.ninds.nih.gov) and contact CLIMB (www.climb.org.uk)179. This information is taken from Management of the ataxias - towards best clinical practice third edition, July 2016. This document aims to provide recommendations for healthcare professionals on the diagnosis and management of people with progressive ataxia. To view the full document, including references, click here.