Treatment options for tauopathies

Abstract

To date, there are no approved and established pharmacologic treatment options for tauopathies, a very heterogenous group of neuropsychiatric diseases often leading to dementia and clinically diagnosed as atypical Parkinson syndromes. Among these so-called Parkinson plus syndromes are progressive supranuclear palsy (PSP), also referred to as Steele-Richardson-Olszewski syndrome; frontotemporal dementia (FTD); and corticobasal degeneration (CBD). Available treatment strategies are based mainly on small clinical trials, miscellaneous case reports, or small case-controlled studies. The results of these studies and conclusions about the efficacy of the medication used are often contradictory. Approved therapeutic agents for Alzheimer´s dementia, such as acetylcholinesterase inhibitors and memantine, have been used off-label to treat cognitive and behavioral symptoms in tauopathies, but the outcome has not been consistent. Therapeutic agents for the symptomatic treatment of Parkinson's disease (levodopa or dopamine agonists) are used for motor symptoms in tauopathies. For behavioral or psychopathological symptoms, treatment with antidepressants-especially selective serotonin reuptake inhibitors-could be helpful. Antipsychotics are often not well tolerated because of their adverse effects, which are pronounced in tauopathies; these drugs should be given very carefully because of an increased risk of cerebrovascular events. In addition to pharmacologic options, physical, occupational, or speech therapy can be applied to improve functional abilities. Each pharmacologic or nonpharmacologic intervention should be fitted to the specific symptoms of the individual patient, and decisions about the type and duration of treatment should be based on its efficacy for the individual and the patient's tolerance. Currently, no effective treatment is available that targets the cause of these diseases. Current research focuses on targeting tau protein pathology, including pathologic aggregation or phosphorylation; these approaches seem to be very promising.