Vestibular dysfunction with ageing-Vestibular function declines starting at age 40 -- ScienceDaily

The incidence and prevalence of different types of dizziness and balance disorders that affect both genders in old age are high, and even higher in the long-lived elderly. Balance depends on many factors, including the adequate function of sensory, vestibular, visual, and somatosensory structures; muscle strength; joint mobility; and cognition. The all-too-common aspects of self-medication, polypharmacy, and sedentary lifestyle are aggravating or significant causative factors. The definition of vertigo, previously an exclusive prerogative of rotary dizziness, was recently expanded to include any dizziness associated with movement of the patient or objects in the environment, even if they do not move. Dizziness-related falls are common and can result in severe consequences, such as repeated concussions and the dreaded hip fracture.

Currently, the implications of otoconia degeneration of otolith organ function are unknown, but it is suspected that these changes in otoconia are involved in the development of peripheral vestibular disorders, ageung as benign paroxysmal positional vertigo BPPV Jahn et al. Lawson et al. Table 1 shows the characteristics of the vestibular disorders in the patients. Sinusoidal rotation at 0.

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Your comment wiyh be reviewed and published at the journal's discretion. These together with our findings highlight the need to incorporate vestibular function testing within the routine falls assessment for all patients, not just those clearly reporting vertigo or dizziness. These can treat ear infections that are causing your balance disorder. Key points about vestibular balance disorders Vestibular balance disorders can affect orientation and balance. A pilot study of falls risk and vestibular dysfunction in older fallers presenting to hospital Vestibular dysfunction with ageing departments. One reason for non-detection may be that the majority dysfuncton Group F participants did not report vertigo or dysfunvtion Vestibular dysfunction with ageing the period of the falls, both commonly reported symptoms in patients with vestibular impairments. Know why a new medicine or treatment is prescribed, and how it will help you. Design: case-controlled study. These are called semicircular canals. Between-group differences were determined using Kruskal—Wallis with post hoc Bonferroni adjusted Mann—Whitney tests.

Background: vestibular disorders are common in the general population, increasing with age.

  • Background: vestibular disorders are common in the general population, increasing with age.
  • Dizziness and vertigo are symptoms of a vestibular balance disorder.
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The vestibular system sub-serves a number of reflex and perceptual functions, comprising the peripheral apparatus, the vestibular nerve, the brainstem and cerebellar processing circuits, the thalamic relays, and the vestibular cerebral cortical network. This system provides signals of self-motion, important for gaze and postural control, and signals of traveled distance, for spatial orientation, especially in the dark. Current evidence suggests that certain aspects of this multi-faceted system may deteriorate with age and sometimes with severe consequences, such as falls.

Often the deterioration in vestibular functioning relates to how the signal is processed by brain circuits rather than an impairment in the sensory transduction process.

We review current data concerning age-related changes in the vestibular system, and how this may be important for clinicians dealing with balance disorders. Age-related vestibular dysfunction and associated imbalance has a major impact on morbidity, mortality, and health-care resources. The overall prevalence of vestibular dysfunction in adults aged over 40 in the USA is Patients with vestibular dysfunction are at significantly greater risk of falls odds ratio These patients, though asymptomatic, also have an increased risk of falls odds ratio 6.

Risk factors for decline in vestibular function include smoking, hypertension, and diabetes but even when these are controlled for the effect of age is far more pronounced 3.

Progressive disequilibrium of aging is a complex, multifactorial condition leading to instability and increased risk of falls 7 , 8 , with vestibular dysfunction, albeit in combination with other factors e.

One factor in balance dysfunction may be changes in the robustness of peripheral vestibular signaling in the elderly Another factor may be changes in how sensory information is processed by central circuits, as exemplified by a study which found that compared with younger subjects, the elderly favor the use of proprioceptive rather than visual and vestibular cues for postural motor control Overall, there is an age-related decline of peripheral vestibular sensing and the central combination of different sensory signals for balance.

Herewith, we review the literature regarding these two aspects. Neuronal and hair cell loss are the two biggest effects that aging has on the peripheral vestibular system; affecting both the otolith organs and the semicircular canals. Multiple studies have shown that aging reduces the number of sensory hair cells in the vestibular end organs 13 — The vestibular nerve has two divisions, receiving conveying afferents from both the semicircular canals and the otolith organs via the superior and inferior vestibular nerves, respectively 15 , Ganglion cell counts from temporal bones from 75 individuals showed age-related reduction in ganglion cell counts with a greater decline in the superior division compared with the inferior division.

The signal from the otolith organs comprising the utricle and saccule transduces linear acceleration and detect tilt , and with respect to these organs, with age, they are not only affected by degeneration of the ganglion cells but also by hair cell loss, in addition to specific degenerative effects within the otolith organ ultrastructure.

The use of vestibular evoked myogenic potentials VEMPs has been used in multiple studies to assess the effect of aging upon otolith function. VEMPs are short-latency myogenic potentials that are elicited from specific muscles, in response to vestibular stimulation via sound. Reduction in the amplitude of VEMPs is indicative of reduced otolith organ function, while increased VEMP latency may relate to slowed brainstem signal processing 25 , Brantberg et al.

These findings have been corroborated by Agrawal et al. Further, a more recent study by Li et al. With respect to cVEMP, they found that the amplitude decreased by 0.

Aging has been associated with reduction in otoconia mass as well as fracture and fragment formation in both animals and humans 31 — While it is easy to assume that reduction in otoconia would result in the reduction of organ function, otoconia degeneration has been shown to affect the utricle more than the saccule 31 , 36 , which would not explain the findings in the Agrawal et al.

In contrast, it has been previously reported that, while hair loss occurs in all the peripheral vestibular organs with increasing age, the utricle is relatively spared Currently, the implications of otoconia degeneration of otolith organ function are unknown, but it is suspected that these changes in otoconia are involved in the development of peripheral vestibular disorders, such as benign paroxysmal positional vertigo BPPV Benign paroxysmal positional vertigo is one of the most common causes of vertigo, especially in the elderly as there is an increase in the incidence with age, peaking at 60 38 — It is a disorder characterized by vertigo upon certain positional head movements.

BPPV is caused by the presence of otoconia debris, which moves in the endolymph or cupula of the semicircular canals 41 , It is thought that the otoconia are dislodged from the utricular macula, which is precipitated by the morphological changes that can happen to the otoconia during aging While BPPV can be effectively treated with repositioning maneuvers 43 , a large observational study of 1, BPPV sufferers has recently shown that comorbidities, such as hypertension, osteoporosis, and diabetes, may be correlated with the risk of recurrence of BPPV in the elderly The semicircular canals transduce head angular acceleration via the anterior, posterior, and horizontal semicircular canals.

Decline in the semicircular canals forms a significant component of the overall age-related decline in the vestibular system. A study of 67 human temporal bones from birth to age found that Type I hair cells in the cristae are lost at a significantly greater rate than in the macula 1 , further reflected by a cross-sectional study, which found the decline in semicircular canal function to be greater than the decline in otolith function Decline in the semicircular canals can be evaluated through the angular vestibule—ocular reflex VOR , for example, using caloric testing; although this technique only tests the horizontal semicircular canals.

Up to a few years ago, the only way to assess the VOR was with rotating chairs or by caloric ear stimulation.

Recently, advances in understanding of vestibulo—ocular physiology, largely by Curthoys and Halmagyi in Sydney, have led to the development of, first, a bed-side clinical head thrust or impulse test HIT and, subsequently, video-image-based versions of the test that are now available commercially for clinical use vHIT or videoHIT , which allow not only for the assessment of the horizontal but also the anterior and posterior semicircular canals Numerous studies have investigated age-related decline in the semicircular canal function.

Baloh et al. Notably, this decline was not associated with any symptoms or signs of disequilibrium By contrast, the patients, whose VOR responses were depressed at the start of testing, did not show any significant decline Carol et al.

Agrawal et al. Decline in each semicircular canal was strongly correlated with decline in the other two; interestingly, decline in the horizontal and superior semicircular canals was well correlated with decline in utricular but not in saccular function. Decline in posterior semicircular canal function, however, showed no clear trend compared with function of the otolith organs. From reviewing the above studies, it can be observed that decline in the function of the semicircular canals plays a significant component of age-related decline in the vestibular system, with a significantly higher prevalence and severity than otolith associated age-related decline.

Given the function of the semicircular canals is to measure angular acceleration, it could be postulated that decline in these structures may be more associated with patient-reported dizziness—the presence of which represents a significant increase in the risk of falls in patients with vestibular dysfunction 3.

The main component of the brainstem vestibular system is the vestibular nuclear complex straddling the pontomedullary junction. This complex of nuclei receives primary vestibular afferents conveyed by the vestibular nerve and also connects to various structures, including the cerebellum Lopez et al. This study also found that aging had no effect on the volume or length of the vestibular nuclei However, both studies have found an increase in giant neurons in the elderly, related to lipofuscin deposits within the cells 49 , Similar studies have been done in animals, with one study showing an age-related decline in the number of neurons of the mouse vestibular nuclei Conversely, a study in male golden hamsters found conflicting results The cerebellum plays a critical role in the function of the vestibular system and is known to receive efferent inputs from the vestibular nuclei 54 , In aging, cerebellar volume and Purkinje cell density in the cerebellar vermis and white matter in the floccular nodular lobe have been shown to decrease 56 — There is also a vast network in the cerebral cortex that activates with vestibular stimulation 59 — Cyran et al.

Using galvanic vestibular stimulation GVS , which bypasses the peripheral vestibular system and directly stimulates the vestibular nerve, they found a reduction in connectivity with increasing age while controlling for vascular, atrophic, or structural connectivity changes. Jahn et al. Specifically, by measuring torsional nystagmus in response to GVS, they found a U-shaped distribution of central vestibular function by age.

They speculate that due to a reduction in neuronal hair cells and other peripheral vestibular changes, central processing becomes hypersensitive in order to compensate for such a loss. After the sixth decade, central compensation will breakdown as well and thus lead to impaired vestibular function in the elderly.

The cerebellum is also involved in vestibular adaptation. Previous work has focused on the cerebellar role in VOR adaptation However, recent work has demonstrated an additional but critical role for the cerebellum, which mediates the partitioning of vestibular signals involved in eye movement control versus those that ascend to perceptual regions mediating sensations of self-motion i.

Curiously, relatively little work has been focused on the effect of aging upon cerebellar function However, it is likely that aging in the cerebellum will impact directly upon vestibular reflex and perceptual functioning and adaptation to lesions or with training. Spatial orientation is a critically important function in everyday life.

Up to third of newly diagnosed dementia patients complain of spatial disorientation 67 , causing significant disruption of everyday life. A core brain area implicated in spatial orientation and memory is the hippocampus Indeed, previous neuroimaging study has shown hippocampal atrophy with bilateral vestibular failure Animal neuronal recordings also show cells sensitive to spatial orientation status that are disrupted by vestibular loss.

A key concept is the notion of converting vestibular motion signals to spatial signals. Given the above evidence, it has been argued that the hippocampus is important for this.

However, some authors have found normal path integration function with hippocampal lesions in humans but not rats This conundrum has recently been solved by a recent human lesion study, which shows in fact that the important region is the temporoparietal junction In addition, this study also found no impact of hippocampal lesions upon angular path integration function.

It follows that dementia, which is more frequent in the elderly, may affect spatial orientation by its effect on vestibular cortical regions such as the TPJ Another currently unsolved question is the cortical location mediating the sensation of vertigo.

Current wisdom suggests that the posterior insular cortex is the primary vestibular cortex. However, focal stroke, including in the posterior insular, did not affect vestibular sensation of self-motion kaski. Previous work 65 , 71 suggests, however, that the vestibular sensation of self-motion may be distributed and hence not localizable.

Whether such vestibular cortical networks are disrupted by aging will require further work. As with most systems in the body, aging causes a degenerative effect within the vestibular system. Aging in the vestibular system is a multifactorial process, affecting both the peripheral organ and central circuits, from the peripheral end-organ to the brainstem to the cerebellum to the cerebral cortex.

It follows that diseases that affect any one of these brain areas will disrupt one or more facets of vestibular functioning. Recent studies using VEMP and VOR testing have shown that there is a quantifiable decline in function in specific peripheral vestibular organs with age, which theoretically correlates with the histological and microscopic changes previously seen. There is also similar ongoing research using GVS to identify functional loss with age of central vestibular pathways.

While the cause of dizziness in the elderly is a multisystem processes, the data suggest that aging causes a reduction in peripheral vestibular function and also the cortical efficiency with which these signals are used for balance, which together play a significant role in the increasing the risk of falls in the elderly. LR and DA: initial drafting of manuscript. QA: initial drafting and final revision of manuscript.

BS: general organization of manuscript. Interim and final revision of manuscript.

Postural control is mediated by central processes dependent on the integration of peripheral sensory inputs, mostly arising from the visual, proprioceptive and vestibular systems. Individuals referred to a falls clinic are older, more impaired and report more falls than those referred to a neuro-otology department. Older adults referred to a falls versus a neuro-otology clinic are older, more impaired, and report more falls. Cognitive motor interference for preventing falls in older adults: a systematic review and meta-analysis of randomised controlled trials. Studies indicating greater vestibular dysfunction in fallers base this on non-clinical or low sensitivity [ 4 , 5 , 8 ] tests, which can be influenced by co-morbid conditions or secondary effects of the ageing process i. Exercise recommendations for improving postural stability do not currently include a vestibular component [ 30 ]. Non-diagnosis of vestibular impairment has important implications for falls interventions.

Vestibular dysfunction with ageing. What causes vestibular balance disorders?

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This study assessed vestibular disorders in elderly patients, describing the causes, clinical characteristics, therapies and treatment outcomes. Five-year hospital-based prospective study, conducted at the ENT clinic of a tertiary referral center. Subjects were consecutive elderly patients with dizziness, treated and followed-up for a minimum of six months.

Data was generated using structured questionnaire and case record files. Analyzed results were presented in simple descriptive forms as graphs and tables. Among the elderly patients, prevalence of vestibular disorders was The symptoms were associated with nausea or vomiting in While Positional vertigo was diagnosed in At follow-up, Prevalence of vestibular disorders in elderly patients is high, most patients present early with intermittent, relatively innocuous symptoms which may be difficult to lateralize.

Positional vertigo was the most common cause, it is frequently relieved with labyrinthine sedatives but tends to recur intermittently. Primary care clinicians, otolaryngologists, ophthalmologists and neurologists are sometimes confronted with patients who complain about inability to maintain their balance. Balancing is an interplay and integration of contributions from vision, vestibular sense working in conjunction with the cerebellum, proprioception, muscle strength and reaction time [ 1 ].

The most common causes of dizziness are peripheral vestibular disorders, but physicians must differentiate between complaint of dizziness that is non-specific ranging from disequilibrium, presyncope, lightheadedness, giddiness, fainting attacks, to central nervous system disorders [ 2 , 3 ].

Vertigo is a subtype of dizziness and refers to an erroneous perception of self or object motion or an unpleasant distortion of static gravitational orientation as a result of a mismatch between vestibular, visual, and somatosensory systems [ 4 ]. It was reported that about two-third of people with dizziness may have a vestibular etiologic diagnosis [ 5 ]. Dizziness often arises from malfunctioning of the vestibular apparatus in the ears peripheral and its connections to the central nervous system central.

Thus in the general population, it can be associated with diseases of the vestibular labyrinthine resulting from head injuries, infections, other types of assaults in the ear, as well as drug-induced cytopathic changes. With advancing age, there is a gradual but progressive loss of functioning of the vestibular sensory cells and this can manifest as dizziness.

The effects of dizziness in the elderly can be particularly disturbing, as it has been associated with depressive symptoms, perceived fatigue, excessive drowsiness, recurring falls and fall-related injuries such as fractures of long bones [ 1 , 6 ]. Thus there is a growing public health concern about dizziness and balance disorders among the elderly worldwide.

The prevalence of dizziness and vestibular disorders among elderly subjects vary from different locations. This may be due to non-uniformity in terminology, the criteria used for estimating the balance disorder, as well as disparity in the age regarded as elderly. In Massachusetts, USA approximately one in five Few studies have focused on the etiology of vertigo, specific peripheral diseases especially Meniere's disease, cervical vertigo, audiological and vestibular tests reports among adult population in sub-saharan Africa, including Nigeria.

However, little is known about the effects of vestibular disorders in the elderly population, therapies commonly prescribed for controlling these disorders, and outcome of the treatments. These may not be unconnected with difficulties in follow-up and high default rate among our patients especially when they improve clinically. This study aimed to explore the clinical characteristics, causes, consequences and the outcome of treatment among elderly patients with vestibular disorders.

It will assist in policy formulation for improved health and general well-being among elderly people, as well as appraise the efficacy or otherwise of our treatment modalities, and propose if there is a need for modification.

Study design: This was a hospital-based prospective study. The sources of these patients were referrals from the departments of family medicine general out-patient department , internal medicine, ophthalmology, and from general practitioners in and around Sagamu. Before seeking consent, patients were informed about the nature, general criteria for inclusion, benefits, and the fact that the patients may voluntarily decline to continue participation in the course of study without affecting their treatments.

Patients that consented were included in the study, and those who did not consent were excluded. Also excluded were patients with other forms of dizziness other than as described above, patients with severe hearing impairment with associated difficulties in communication, those that were too weak to undergo vestibular assessments, patients with active ear infections, and those with tympanic membrane perforations.

The information obtained included socio-demographic data such as age, sex, occupation and marital status. The main distinguishing question was whether the patient experienced a sensation of turning around relative to the environment, or vice-versa. An affirmative answer to this question led to the characterization of the dizziness, in terms of onset, and duration of symptoms, associated symptoms of nausea and vomiting, premonition in the form of an aura, the behavior of the dizziness, aggravating factors and its laterality noted on neurovestibular clinical examination.

Previous medical consultations, treatment as well as the source of referrals were also noted. Neurovestibular examination was conducted on each of the patients, and particularly clinical tests for balance, including static balance test Rhomberg's test, Unterberger test and dynamic balance test, tandem walk. Dix-Hallpike test was performed on each of the patients with suspected positional vertigo. The clinical diagnosis, investigations, and the mainstay of managing the dizziness were recorded.

All the patients were followed up for at least six months post initial presentation, and the outcome of treatment of the vestibular disorders was noted. The results were analyzed using SPSS version Discrete variables were described with proportions while continuous variables were described with measures of central tendencies such as means, and of dispersions as standard deviations.

There were sixty six elderly patients with vestibular disorders seen during the study period, constituting a prevalence of The age distribution according to the sex of the patients is shown in Figure 1. Table 1 shows the characteristics of the vestibular disorders in the patients. The median duration of symptoms before presentation was 3.

The vestibular symptoms were associated with nausea or vomiting in about a quarter Half of the patients The clinical spectrum of the causes were varied, however a third In The detail of the distribution is shown in Table 2. The clinical course of the patients also revealed variability as depicted in Table 3.

Majority of the patients The other referrals were from physicians especially neurologists, ophthalmologists, and other specialties. While some patients were followed-up to close to three years, the minimum period of follow-up for each patient was six months after the initial consultation and management.

The outcome from the follow-up revealed that The vestibular system provides information to the central nervous system CNS on the orientation of the body in space, together with somatosensorial information.

The most common manifestation of vestibular disorder displayed in general population was spinning sensation [ 12 ]. The prevalence of This is higher than the prevalence of between 2. The difference may be attributable to the hospital-based nature of our study, and the fact that some elderly patients in the community are incapacitated and find it difficult to access medical care from hospitals.

The vestibular symptoms can be disturbing and with increasing severity or recurrence, may even force subjects to premature retirement from work; almost half of the patients in this study were retired. Majority The apparent equality in frequencies of vestibular disease between the sexes with M:F of This may be a reflection of the socio-demographics of the elderly in our communities. Stevens et al, [ 14 ] however noted that dizziness problems were not associated with gender.

Many of our elderly subjects for reasons of believe, culture, ignorance and possibly economy, still patronize unorthodox medical practitioners. However the fact that In addition, there was associated nausea or vomiting in The aura can be a warning signal of an imminent vertiginous episode, and the subject can take remedial measures to prevent or possibly ameliorate its effects. However, only Half of our patients While prolonged dizziness may be one of the cardinal symptoms suggestive of CNS disorders [ 15 ], it sometimes results from continued irritation and provocation of the vestibular apparatus.

The peripheral vestibular pathology is often asymmetric and may be difficult to lateralize. Methods of lateralizing of vestibular lesions by alternate binaural bithermal caloric test ABBT with its various modifications, electronystagmography, and the more modern methods [ 16 ] are not available in our center, thus it was difficult to lateralize the symptom in It is obvious that the typical characteristics of vestibular disturbances experienced by our elderly patients were of short duration, mostly without an aura, intermittent, probably non-lateralizing and not associated with nausea and vomiting.

These characteristics may suggest more of peripheral vestibular lesions of less serious magnitude. The most common diagnosis made in our patients was positional vertigo. This was underscored by that fact that in Many authors [ 3 , 17 , 18 ] had reported benign paroxysmal positional vertigo BPPV as the most common type of vestibular disorders found in adults and elderly patients.

BPPV is a diagnosis with stringent criteria, including intermittent positional vertigo lasting less than one minute, and confirmation with Dix-hallpike test [ 5 ]. Some of our patients, despite having positional vertigo, did not completely fit into the above criteria.

Fife [ 17 ] however believes that these other forms of positional vertigo are variants of BPPV. While positional vertigo can be benign and amenable to treatment with canalith positioning technique like Epley and Semont maneuvers, the paroxysmal recurrences in BPPV can become troublesome.

In almost a fifth Post and Dickerson [ 3 ] also noted that a final diagnosis was not obtained in about 20 percent of their patients with dizziness.

Delineating a vestibular pathology can sometimes be a daunting task, as it will involve careful and meticulous clinical oto-neurological evaluation, and sometimes specific investigations. These investigations are not only expensive, but mostly uncomfortable for the patients. This is due to their provocation of vertiginous attacks that the patient is even afraid of, thus compounding the situation in elderly subjects.

Thus the physician in a developing country is hampered technically in exploring a diagnosis by unwilling and possibly incapable patients, scarce and expensive investigations, and thus confined to clinical evaluation most of the time.

A working knowledge of these disorders will help the physician make the diagnosis efficiently by gathering key elements of the history and fine-tuning diagnostic testing [ 19 ]. Vestibular disturbances secondary to assaults and injuries to the labyrinth seems to be common in our environment, being attributable to Falls are the leading cause of traumatic brain injuries TBI for older adults [ 20 — 22 ], displacing road traffic accidents, which occurs in the general adult population [ 23 ].

Conversely, vertiginous episode in the elderly also predispose them to falls and other domestic accidents including head injuries [ 1 ]. Labyrinthine assaults also occur from ingestion of medications; these include across the counter drugs like acetylsalicylate, which many elderly patients take for head and body aches, or a part of prescription for other ailments especially among hypertensives.

The pathophysiology of cervical vertigo has been attributed to disorders of the cervical spine, the vertebral artery and the cardiovascular system [ 24 ] which are common in the elderly.