Original articleThe prevalence of Neurally Mediated Syncope in older patients presenting with unexplained falls
Introduction
Falls are a common cause of morbidity and mortality in the elderly [1]. Related conditions such as syncope, dizziness, and vertigo are also common in this age group [1], [2], [3]. Approximately 30% of older people living in the community fall each year [4] and syncope in the elderly in long-term care settings has an annual incidence of 6% with a recurrence rate of 30% [5]. The causes of falls have been variably reported in the literature [1]. Determining the ascribable cause for a fall may not always be possible as multiple risk factors for falls are often present in the elderly because of multiple comorbid conditions, concurrent medications and physical impairment [4], [6]. The studies describing the causes and their frequency are not comparable because of methodological differences, including varying definition of falls, between studies [1], [7]. Although accidental falls have been found to be common in community based studies, the prevalence of unexplained falls appears high among older patients presenting to acute hospitals [6], [8].
Falls and syncope are conventionally considered to be separate clinical entities [9], [10]. However, there is a growing body of evidence suggesting an overlap between these two clinical syndromes [11], [12], [13] and the current fall prevention guidelines recognise this overlap [14]. The evidence for the overlap is particularly rich for Neurally Mediated Syncope (NMS) [13], and the proposed explanations for this overlap include 1) retrograde amnesia for syncope and 2) loss of balance due to modest haemodynamic changes that are insufficient to cause loss of consciousness but sufficient to cause falls in older patients [11], [12], [13], [15], [16]. Although there is evidence suggesting a causative role for NMS in falls, this has largely emanated from a single centre in the UK [6], [11], [12], [13]. It is therefore, desirable that the evidence for this concept is either reinforced or refuted by studies from other centres and from other parts of the world. The present study examines the prevalence and clinical significance of NMS in a cohort of older patients presenting with unexplained falls without any history of loss of consciousness.
Section snippets
Materials and methods
Patients admitted with unexplained and accidental falls were investigated for underlying vasovagal syncope (VVS) and carotid sinus syndrome (CSS), the two common types of Neurally Mediated Syncope (NMS). The study was approved by the Western Health medical administration, which was responsible for overseeing research activities at Western Health Service at this time. Accidental and unexplained fallers were identified from 200 consecutive admissions of those aged 65 years and older who were
Results
There were 200 admissions of falls consisting of 188 patients (10 had one or more admissions) (Fig. 1). 118 patients underwent assessment; 70 were excluded as they were either from a high care facility or had cognitive impairment. Assessment revealed either a readily identifiable medical cause for the fall or a history of loss of consciousness in 47 patients. Examples of identifiable medical causes included postural hypotension, autonomic dysfunction, intercurrent sepsis, acute myocardial
Discussion
The findings suggest that the cause of the fall was unexplained in 1 in 4 fallers who required admission to hospital, and NMS may be aetiologically related in nearly a quarter of these patients. Most unexplained fallers, unlike the accidental fallers, gave a history of previous falls. This may suggest that patients presenting with unexplained falls may be at an increased risk for recurrent falls, thus defining a high falls risk group. As reported in other studies, this study also confirms that
Learning points
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Unexplained falls are common in older people presenting to acute hospitals.
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Neurally Mediated Syncope, particularly Carotid Sinus Syndrome, may be aetiologically related in a small but a significant number of unexplained fallers.
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Unexplained fallers are likely to benefit from assessment for NMS, as it is a modifiable risk factor for falls.
Conflict of interest statement
We wish to state that the authors have no financial, personal or any other conflict of interests.
Acknowledgments
The authors thank Dr. Stewart Morrison and other resident medical staff, clinical coordinators and nursing staff of the Rapid Assessment Medical Unit for their help with this study.
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