Neurology Patient Frailty: A Clinician’s Guide

Frailty — a clinical syndrome characterized by decreased physiological reserve and increased vulnerability to stressors — has traditionally been associated with geriatric medicine but has profound implications for neurology.

Increasing evidence indicates that frailty affects the risk, clinical presentation, and course of common neurologic disorders, including dementia, Parkinson’s disease (PD), stroke, and multiple sclerosis (MS) — which will affect clinical management and treatment decisions.

Neurologists should become familiar with assessing and measuring frailty, which can provide “crucial information for diagnosis, prognostication, and care planning,” wrote Kenneth Rockwood, MD, professor of medicine, Division of Geriatric Medicine and Neurology, Dalhousie University, Halifax, Nova Scotia, Canada, and colleagues in a recent Lancet Neurology perspective on the topic.

Frailty is “complex,” often coinciding with other conditions, and there is a need for “frailty-informed care” that integrates multiple aspects of aging. Frailty should not be seen as a binary — frail vs not frail. Instead, there are grades of frailty, from mild to severe, which require different levels of intervention,” Rockwood told Medscape Medical News.

How Common Is Frailty?

Aging is a global phenomenon, with the proportion of people aged 65 years or older rapidly increasing. The World Health Organization (WHO) projects that the global population aged 60 years or older will likely double by 2050.

Frailty increases with age, with one study showing that 10% of adults aged 50-64 years were frail, rising to 44% of those aged 65 years or older.

However, frailty is not limited to older adults. It can also affect relatively younger individuals who have multiple comorbidities or significant disabilities resulting from chronic conditions, including neurologic disorders.

“Frailty isn’t just about aging — it’s about vulnerability,” Shaheen Lakhan, MD, neurologist, and researcher based in Miami, Florida, told Medscape Medical News.

“In neurology, we see this every day: a patient recovering from a stroke who can’t regain independence, someone with Parkinson’s who keeps falling, or a migraine sufferer whose body is too drained to fight back. Yet, we don’t routinely assess frailty, even though it’s a major predictor of who thrives and who declines,” Lakhan added.

Why Does Frailty Matter and How Should It Guide Treatment?

In the context of neurology, frailty is often under-recognized, yet can exacerbate motor and cognitive impairments, complicating the clinical trajectory of diseases like PD, MS, and stroke.

Frailty can also mask or mimic symptoms of neurologic disorders, potentially causing diagnostic uncertainty. For example, research has shown that fatigue, weakness, and cognitive slowing — all common in frailty — can mirror the early stages of dementia or PD.

Conversely, a frail patient might underreport or under-manifest classic neurologic symptoms because of their limited ability to communicate changes or to perform certain tasks that would reveal deficits on clinical assessment.

Frailty can significantly affect the risk-benefit calculus for many neurologic treatments. For example, frail patients may be less tolerant of certain medications for conditions like PD or MS.

In stroke management, surgical or endovascular procedures may carry higher risk for frail patients due to reduced cardiovascular reserve.

Rehabilitation might also be more difficult, as frailty affects a patient’s ability to engage in intensive physical or occupational therapy. Frail individuals might require a more gradual, carefully monitored approach to rehabilitation.

By recognizing the potential for increased complications, clinicians can tailor treatment regimens to the patient’s functional status, potentially improving outcomes and quality of life.

What Is Frailty’s Impact on Neurologic Disorders?

Research shows that the impact of frailty on presentation, symptoms, and outcomes may differ according to neurologic disease.

In dementia, frailty can be both a contributing factor and a consequence. Older adults with higher frailty index (FI) scores have been shown to face an increased risk for cognitive impairment and Alzheimer’s disease.

In those with established dementia, frailty can further diminish a patient’s capacity for self-care, possibly accelerating functional decline. Frail patients with dementia often require more comprehensive care, integrating cognitive and functional support tailored to their frailty status.

In PD, motor symptoms, such as bradykinesia, rigidity, and instability, overlap with key components of physical frailty. Frail patients with PD may exhibit more pronounced postural instability and a higher tendency for falls. Frailty also complicates PD treatment selection, as frail patients may be more sensitive to dopaminergic medication side effects, including orthostatic hypotension and confusion.

In patients post-stroke, frailty has been associated with poorer functional recovery, higher rates of hospital readmission, and higher mortality. Frailty can limit the intensity and duration of rehabilitation interventions, slow neurologic recovery, and enhance the risk of complications such as infections or pressure ulcers.

In MS, frailty can severely restrict mobility, disrupt self-care, and heighten the risk for secondary complications like urinary tract infections. Studies have suggested that frailty might be an overlooked factor contributing to the variability in disease progression and recovery from relapses in MS.

How Is Frailty Shaping Clinical Training and Research?

The close relationship between frailty and neurologic disease highlights the importance of geriatric medicine training as part of the neurology curriculum, Jon Stoessl, MD, with the Center for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada, wrote in The Lancet Neurology.

“Trainees in geriatric medicine usually have a rotation in neurology, whereas neurologists in training might not always have a rotation in geriatrics,” Stoessl pointed out.

He also noted that frailty has implications for clinical trials.

“Given the profound effect of frailty on the trajectory of neurological disease, the fact that some measure of frailty is not incorporated into stratification for entry into trials of disease-modifying therapies seems quite remarkable,” Stoessl wrote.

“Findings derived from a purely non-frail population, who are probably easier to recruit, are unlikely to be generalizable to all those with the disease,” he added.

Frailty Assessment Tools

Given its prognostic value, frailty assessment can help clinicians identify neurologic patients at highest risk for rapid deterioration, enabling families to better plan for the future.

Several assessment tools are widely available. They include:

• The Fried frailty phenotype, which assesses five components: Unintended weight loss, exhaustion, low grip strength, slow walking speed, and low physical activity. Patients meeting three or more criteria are classified as frail.
• The Clinical Frailty Scale (CFS) — a 9-point scale ranging from “very fit” to “terminally ill,” based on subjective clinical judgment of the patient’s mobility, energy, function, and comorbidities.
• The FI, a comprehensive tool that tallies 30 or more health deficits across various physiological and functional domains.

There are also some newer and emerging assessment tools. They include the electronic FI, which uses routinely collected electronic health record data to calculate a frailty score. This approach may save time and increase scalability, but its accuracy depends on data completeness and quality.

Wearable gait and balance sensors that attach to the patient’s wrist or ankles and measure mobility metrics such as stride length and gait variability can provide objective insights into physical frailty.

There is also the Short Physical Performance Battery — a performance-based measure that includes tests of balance, gait speed, and chair stand time. While not specific to frailty, it offers a useful snapshot of lower extremity function.

Lakhan said a frailty assessment “should be standard” in routine neurology care. But traditional frailty assessments are “clunky, time-consuming, and often subjective.”

“That’s where artificial intelligence (AI) and digital tools can be game changers. Imagine smart sensors that detect subtle gait changes before a fall happens or AI models that flag early signs of cognitive and physical decline — long before we’d catch them in clinic. These innovations could shift frailty screening from a reactive chore to a proactive, life-changing intervention,” Lakhan said.

What Guidance Is Available?

The American Academy of Neurology (AAN) does not have any guidelines specific to frailty assessment. The three current AAN guidelines most specific to older adults are:

Other guidelines that address frailty include:

Rockwood has copyright over the CFS and (with a colleague) the Pictorial Fit-Frail Scale, which are made freely available for noncommercial education and research. Lakhan and Stoessl had no relevant disclosures.