[The concept and practical management of frailty in neurology].

Frailty is a clinical situation of decreased homeostatic reserve that, after a minor trigger (acute illness, fall, taking a drug...) increases the risk of an adverse event such as hospital admission, institutionalization, functional and/or cognitive decline, death, etc. Frailty can be understood as physical frailty, Fried's phenotype, a true geriatric syndrome that can be reversible by avoiding its progression to more advanced stages of irreversibility and dependence, and Rockwood's frailty due to accumulation of deficits, as a continuum of health or classification typology of the elderly along the frailty spectrum (healthy, robust, vulnerable, mild-moderate-severe and extreme frailty or end of life). The diagnosis of physical frailty is part of the comprehensive geriatric assessment, recommending the use of a performance test such as gait speed (<0,8m/s), Timed Up and Go (>12 s) or Short Physical Performance Battery (<10). Physical frailty is reversible by a multidisciplinary management based on three fundamental pillars: multicomponent physical exercise and resistance training, adequate protein and micronutrient intake (leucine, vitamin D, etc.) and appropriate pharmacological prescription, management of comorbidity and geriatric syndromes. Frailty is a risk factor for neurological disease progression and increased risk of adverse events in neurodegenerative diseases such as mild cognitive impairment, dementia, Parkinson's disease and cerebrovascular disease. Frailty based on the Clinical Frailty Scale or VIG-Frail shows patient typologies in relation to a greater or lesser state of fragility, being a basic prognostic tool of great utility in making diagnostic and therapeutic management decisions. It opens up a new opportunity for improvement in the management of neurological disease in the diagnosis and treatment of frailty.