Vertigo in older people and age-related balance disorders

The annual prevalence of balance disorders in people over age 65 is 8.3%, even higher among women. The incidence in this segment of the population is 47.1 thousand people per year¹.

The most correct term to refer to physiological changes to the vestibule caused by age is presby-vestibulopathy (PVP). The diagnosis is based on the clinical record and the clinical and otoneurologic examination. This diagnosis pertains to a chronic vestibular disorder, present for more than 3 months in a patient over age 60 who has mild bilateral hypofunction of the vestibulo-ocular reflex. It can be diagnosed with vHIT, the rotary chair or caloric tests².

In clinical practice, one must consider this diagnosis for a patient in that age range who mentions at least two of the following issues:

1. Systematic, chronic dizziness while standing, walking and with head movements.
2. More than one fall in the previous year.
3. Postural instability under dynamic and static conditions.
4. Gait disorder: slow, unsteady, unstable.

PVP tends to occur alongside other age-related physiological changes, including visual, proprioceptive, and central alterations (changes to the cortical, extrapyramidal, or cerebellar functions). There are visual alterations (macular degeneration, cataracts), proprioceptive alterations that will produce postural instability under dynamic and static conditions, and vestibular alterations (the vestibular ganglion reduced cell count and the smaller capacity to offset that centrally)³. A suitable level of vestibular compensation is hard to reach with vestibular deficit. Moreover, the compensation may be incorrect and inappropriate for each of those sensory elements in an older person. The sum of these impairments will give way to greater disability than usual. These impairments must all be treated together in rehabilitation, as leaving one untreated may very well yield therapeutic results below the expectations.

The diagnosis requires at least one fall in the previous year. Falls due to lack of balance are a significant source of morbidity and mortality among older people. Hip fractures and other injuries related to the fall may require hospitalization, a home for the elderly, and translate into high medical care costs. In general, one may say that 3 out of 10 people have fallen at least once, and 2 out of 10 people have fallen more than once in a year. The risk of falls increases by 74% in older adults under psychotropic medication. Benzodiazepines in particular increase the risk of hip fracture by 50%. Anticholinergic drugs are the second pharmacological group most frequently associated with this adverse effect.

The onset of symptoms may very well be at age 60, but balance disorders may not become significant until age 70⁴ or 80⁵.

The parameter of vestibular deficit can be measured in many ways, as already mentioned. The natural aging process has impact on each of them. Being cognizant of this process supports the correct interpretation of what is normal and what is pathological. Measuring dynamic visual acuity is not a requirement for the diagnosis of PVP. The outcome of this test blends in the action of each of the various systems involved in visual stability during active movements (vestibular, cervical proprioceptive and visuo-oculomotor). A significant reduction (>0.2logMAR) is seen in subjects over age 60, regardless of the head movement plane ⁶.

Presbycusis and vestibular hypofunction caused by presby-vestibulopathy happen simultaneously to the same patient. This fact is ascribed to the common embryonic origin of the cochlea and the saccule. This parallelism has been determined in patients over age 65 with hearing loss, whose myogenic vestibular potentials are less wide and show greater latency, compared with normal-hearing individuals over age 65⁷. The morphology underpins the cochlear-vestibular functional alteration: the study of temporal bones with and without hearing loss has yielded a negative correlation between the vestibular ganglion cell count and age and the liminar tone audiometry thresholds⁸.

Because of all the above, it is recommended to undertake a vestibular study in older patients with hearing loss, in order to diagnose subclinical vestibular issues that could account for the falls⁹.

There are multiple studies on the genetics of presbycusis to-date, but less on the genetics of presby-vestibulopathy.

Within the group of vestibular pathologies, genetic alterations have only been found in familial ataxia, bilateral vestibulopathy (6q) and familial Meniere’s disease. In other words, more genetic studies about the cochleo-vestibular function are needed¹⁰.

Table 1. The most common causes of balance disorder in older people.

References

1. Maarsingh, O.R.; Dros, J.; Van Weert, H.C.; Schellevis, F.G.; Bindels, P.J.; Van der Horst, H.E. «Development of a diagnostic protocol for dizziness in elderly patients in general practice: a Delphi procedure». BMC Fam. Pract. 2009 Feb 7; págs. 10:12.
2. Agrawal Y.; Van de Berg R.; Wuyts F,; et al. Presbyvestibulopathy: Diagnostic Criteria Consensus Document of the Classification Committee of the Bárány Society. J Vestib Res. 2019;29(4):161-170.
3. Rogers C. Presbyastasis: a multifactorial cause of balance problems in the elderly. Journal South African Family Practice, 2010; vol 52; issue 5.
4. Matiño-Soler E, Esteller-More E, Martin-Sanchez JC, Martinez-Sanchez JM, Perez-Fernandez N. Normative data on angular vestibulo-ocular responses in the yaw axis measured using the video head impulse test. Otol Neurotol. 2015 Mar;36(3):466-71
5. Dillon CF, Gu Q, Hoffman HJ, Ko CW. Vision, hearing, balance, and sensory impairment in Americans aged 70 years and over: United States, 1999-2006. NCHS Data Brief. 2010 Apr;(31):1-8
6. Agrawal Y, Zuniga MG, Davalos-Bichara M, et al. Decline in semicircular canal and otolith function with age. Otol Neurotol. 2012; 33: 832?9.
7. Kurtaran H, Acar B, Ocak E, Mirici E. The relationship between senile hearing loss and vestibular activity. Braz J Otorhinolaryngol. 2016 Nov-Dec;82(6):650-653.
8. Gluth MB, Nelson EG. Age-Related Change in Vestibular Ganglion Cell Populations in Individuals With Presbycusis and Normal Hearing. Otol Neurotol 2017 Apr;38(4):540-546.
9. El-Salam G. The relationship between presbycusis and vestibular activity. J Med Sci Res 2018; 1; 245-9.
10. Ciorba A, Hatzopoulos S, Bianchini C, Aimoni C, Skarzynski. Genetics of presbycusis and presbystasis. Int J Immunopathol Pharmacol. 2015 Mar;28(1):29-35.