Why are elderly patients, particularly those with comorbid conditions such as dementia or previous stroke, and on anticoagulation (anti-clotting) medications like warfarin (coumarin), aspirin (acetylsalicylic acid), or clopidogrel (platelet inhibitor), at a heightened risk for delayed neurological complications after a fall?

Why Elderly Patients Are at Risk for Delayed Neurological Complications After a Fall

Elderly patients face heightened risk of delayed intracranial hemorrhage after falls primarily due to anticoagulation therapy (warfarin, NOACs, aspirin, clopidogrel), age-related brain atrophy creating space for blood accumulation, and comorbidities like dementia that increase both fall frequency and bleeding complications. 1

Primary Risk Factors

Anticoagulation and Antiplatelet Therapy

• Anticoagulated patients have a 3.9% risk of significant intracranial injury versus 1.5% in non-anticoagulated patients after head trauma. 2, 3
• Warfarin carries a 10.2% risk of intracranial hemorrhage after head trauma, while NOACs (apixaban, rivaroxaban, dabigatran) carry a 2.6% risk—both substantially higher than patients without anticoagulation. 2, 4
• Antiplatelet agents including clopidogrel and aspirin carry similar bleeding risks and should not be considered safer than anticoagulants in this context. 1
• Anticoagulated patients demonstrate a 3-fold increased risk of hemorrhage expansion (26% versus 9% in non-anticoagulated patients) on repeat imaging. 2, 3

Age-Related Physiological Changes

• Elderly patients (60 years or older) exhibit greater than expected anticoagulant effects from warfarin due to altered pharmacokinetics and pharmacodynamics, requiring lower doses to achieve therapeutic anticoagulation. 5
• The terminal half-life of warfarin is approximately one week, with an effective half-life of 20-60 hours (mean 40 hours), meaning anticoagulant effects persist well beyond the initial injury. 5
• Brain atrophy in elderly patients creates additional intracranial space, allowing subdural hematomas to develop slowly and remain asymptomatic initially before causing delayed neurological deterioration. 1

Dementia and Cognitive Impairment

• Dementia doubles to triples the risk of falls in elderly patients. 6
• Patients with dementia demonstrate disease-specific motor impairments, behavioral disturbances, and functional impairments that contribute to their high fall risk. 6
• Dementia, parkinsonism, and cerebrovascular diseases are frequently found in elderly patients with recurrent falls, and these patients tend to fall more often with worse mental and functional status. 7
• In elderly patients with atrial fibrillation on warfarin, those with falls and/or dementia had a 45-47% mortality rate at 12 months compared to 12% in those without these conditions. 8

Previous Stroke History

• Patients with previous stroke often have underlying cerebrovascular disease that increases susceptibility to hemorrhagic complications after trauma. 1
• A stroke is a particularly significant event for patients with dementia, carrying greater risk of cognitive and functional decline, loss of independence, and institutionalization compared to non-dementia patients. 1

Clinical Implications and Risk Stratification

High-Risk Features Requiring Consideration

• Age >80 years increases risk of delayed complications. 1
• History of loss of consciousness or post-traumatic amnesia. 1
• Glasgow Coma Scale score <15. 1
• Concomitant use of multiple anticoagulant/antiplatelet agents. 1
• Elderly patients (≥65 years) on aspirin with high-risk features (LOC, amnesia, or GCS <15) may have up to 4% risk of delayed intracranial hemorrhage, with one study showing one patient requiring neurosurgical decompression and another dying. 1

Frailty and Falls Context

• Community-dwelling individuals over 65 years have a 1-2% risk of falling per year, though only 5% of falls result in fracture and hospitalization. 1
• A Markov decision analytic model demonstrated that a patient on warfarin would have to fall 295 times for the risk of subdural hematoma to outweigh the benefit of anticoagulation—this number is even higher with NOACs given their lower bleeding risk. 1
• Frailty increases risk of rapid deterioration of renal function, which can potentiate anticoagulant effects and further increase bleeding risk. 1

Common Pitfalls to Avoid

• Underestimating the risk in patients on "just aspirin"—elderly patients on low-dose aspirin can develop clinically significant delayed hemorrhage requiring neurosurgical intervention. 1
• Failing to recognize that delayed intracranial hemorrhage can occur up to 8 days after injury, even in patients who initially appeared well. 1
• Assuming dementia is a contraindication to anticoagulation—dementia should not be viewed as a general contraindication, especially if well managed from a logistical standpoint. 1
• Discontinuing anticoagulation without considering the indication, as thromboembolic risk may outweigh the small risk of delayed hemorrhage. 2, 3

Management Algorithm

For elderly patients on anticoagulation/antiplatelet therapy after a fall with head trauma:

1. Obtain immediate non-contrast head CT scan regardless of symptom severity or mechanism of injury. 2
2. If initial CT is negative and patient is neurologically intact at baseline: Discharge with clear written instructions about signs of delayed hemorrhage (severe headache, confusion, vomiting, weakness, seizures) and instructions to return immediately if symptoms develop. 1, 2
3. If initial CT shows intracranial hemorrhage: Immediately discontinue anticoagulant, consult neurosurgery, and administer reversal agents (4-factor PCC plus vitamin K for warfarin; andexanet alfa for factor Xa inhibitors). 2, 3
4. Consider brief observation (4-6 hours) for patients with high-risk features (age >80, LOC, amnesia, GCS <15, multiple anticoagulants). 1
5. Arrange outpatient follow-up for fall risk assessment and reassessment of anticoagulation risk/benefit ratio. 2, 3