Medical Guidelines Introduction & Full Document Introduction & Full Document Ataxia Medical Guidelines aim to provide recommendations for healthcare professionals on the diagnosis and management of people with progressive ataxia. The progressive ataxias are rare neurological conditions, and are often poorly understood by healthcare professionals. Diagnosis has generally been a long process because of the rarity and complexity of the different ataxias1. In addition, many healthcare professionals are unsure how best to manage the conditions and there is sometimes a feeling that little can be done for these patients1,2. Although there are no disease-modifying treatments for the majority of the progressive ataxias, there are many aspects of the conditions that are treatable and it is thus important that this is recognised by the relevant healthcare professionals. The diagnosis and management of the few treatable causes is also of paramount importance. All this highlights the importance of producing these guidelines: in order to increase awareness and understanding of these conditions, and lead to their improved diagnosis and management. With new developments in genetic technologies and the discovery of more genes, diagnosis is improving and has great scope to continue to do so. In addition, research is advancing and many human trials to test medications are taking place, making us more optimistic that disease-modifying treatments will be found for the progressive ataxias. Conditions covered in these guidelines Ataxia means ‘lack of coordination’ and it is a symptom of many conditions. These guidelines have been developed by the patient support organisation, Ataxia UK, through extensive consultation with numerous UK healthcare professionals with experience of ataxia. Certain aspects of these guidelines may however be relevant to these other conditions. Table 1a: Conditions covered in these guidelines Hereditary ataxias including Friedreich’s ataxia, spinocerebellar ataxias and episodic ataxias (but excluding ataxia-telangiectasia*). Idiopathic progressive ataxias forms of cerebellar ataxia associated with neurodegeneration of unknown aetiology. Specific neurological disorders in which progressive ataxia is the dominant symptom eg: cerebellar variant of MSA. * Information about the extra neurological features of ataxia-telangiectasia (AT) is not included in this document. For more in depth knowledge about this condition please refer to the Ataxia-Telangiectasia Society who produce guidelines on AT. Table 1b: Other causes of ataxia Vascular - Inflammatory (eg: multiple sclerosis) Traumatic - Metabolic Developmental - Toxic / drug-related (eg: alcohol) Neoplastic / paraneoplastic - Epilepsy (in children) Infectious Epidemiology of the ataxias Epidemiological studies of the progressive ataxias in the UK are sparse, data from the UK are thus summarised with information from studies in other countries (see Box 1). In the UK, the latest estimates based on the studies below suggest there are at least 10,000 adults and 500 children with progressive ataxia3,4. Although the progressive ataxias are rare conditions, when taken together they are more common than other better known neurological conditions. These studies suggest that the prevalence of the progressive ataxias is higher than conditions that are generally better known such as Huntington’s disease5 and motor neurone disease6. Box 1: Epidemiological studies European studies: The most common inherited ataxia in Europe is Friedreich’s ataxia; the estimated disease incidence based on carrier frequency of 1 in 85 is 1:29,0007. Generally in Europe prevalence is quoted as between 1 in 20,000 to 1 in 50,000, with some geographical variability8. It is the most common inherited ataxia in the Caucasian population. The minimum prevalence of childhood ataxia in Europe was estimated at 26 in 100,000 in a recent systematic review4. This included conditions not covered in these guidelines (e.g. ataxic cerebral palsy), thus the estimate for progressive inherited ataxias covered in these guidelines is 4.61 in 100,000. UK studies: Estimated minimum prevalence: 10.2 in 100,000 adults with late onset cerebellar ataxia in South Wales9. Guideline development These guidelines have been developed through extensive consultation with numerous UK healthcare professionals with experience of ataxia, in collaboration with the patient support organisation, Ataxia UK. This is the third edition of these guidelines. Contributors for each section were selected due to their clinical expertise in ataxia in the relevant discipline. They reviewed the medical literature for their section, provided scientific evidence for the efficacy of different interventions and graded the level of evidence following the procedure of the Guideline International Network (GIN)10. The information on the level of evidence was then used to give a grading to each recommendation made in these guidelines. Table 2 details the level of evidence and grading system used. A Guideline Development Group consisting of neurologists with expertise in ataxia and representatives of Ataxia UK reviewed all the sections and discussed any changes with contributors until consensus was reached. Table 2: Evidence grading scheme for these guidelines Level of evidence (categorisation of reference materials)11 I Evidence obtained from a systematic review of all relevant randomised controlled trials. II Evidence obtained from at least one randomised controlled trial. III-a Evidence obtained from one or more controlled trials, pseudo-randomised by alternate allocation, birth date or other planned method. III-b Evidence obtained from prospective or retrospective cohort studies with concurrent controls, casecontrol studies, or interrupted time-series with a control group. III-c Evidence obtained from cohort studies with historical controls, two or more single-arm studies, or interrupted time-series without a parallel control group. IV Evidence comprises opinions based on clinical experience, descriptive studies or reports by clinical bodies or committees. Grading of recommendations in the guidelines based on the level of evidence12 Body of evidence can be trusted to guide practice; includes one or more level I studies, or several at level II directly applicable to the target population, and demonstrating overall consistency of results. Body of evidence can be trusted to guide practice in most situations; includes one or two studies rated as level II or several level III studies, directly applicable to the target population, and demonstrating overall consistency of results. Body of evidence provides some support for recommendation(s) but care should be taken in its application; includes studies rated as III-c, or level I or II with a moderate risk of bias, some inconsistency and applicable to target population with caveats. Population studied is not the target population, however, it would make sense clinically to apply this evidence to target population. Body of evidence is weak and recommendation must be applied with caution; includes level IV, or level I to IV studies with high risk of bias, inconsistent evidence and that are not applicable to target population. GPP. Good practice point: Recommended best practice based on clinical experience and expert opinion. (Adapted from Reference) 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.