Effectiveness and safety of treatments for degenerative ataxias: a systematic review

The aim of this study was to determine the effectiveness and safety of available treatment alternatives for degenerative ataxias (DA). We systematically reviewed studies that assess pharmacological, rehabilitative, or psychological treatments in patients with DA. Studies were included if they fulfilled prespecified criteria. All included clinical trials were scored for methodological quality. Main outcome measures were clinical status of neurological disorder, adverse events, and patient-based factors. Twenty-five studies were included. Most studies were of small sample sizes, wide age variations, and low scientific validity. Only one study gave information on physical rehabilitation and none on psychological therapy. The remaining 24 studies reported on the effects of different pharmacological treatments. Outcomes such as functional capacity and psychological functioning of patients were evaluated by few studies. Some evidence supports that 5-hydroxytryptophan is more effective than placebo improving neurological symptoms in patients with Friedreich ataxia (FA), olivopontocerebellar atrophy, or cerebellar atrophy. Idebenone is more effective than placebo for halting and reversing the hypertrophic cardiomyopathy associated with FA, but it seems unable to improve neurological semiology. Limited evidence for other therapies was found. No relevant side effects for drugs that shown some degree of effectiveness were reported. Availability of quality studies to evaluate the safety and efficacy of treatments for most DA is scarce. No valid information on the actual value of physical rehabilitation and psychological support as treatments for DA is available. Further investigations with improved trial designs are necessary.