Vestibular profile of type 1 versus type 2 chronic diabetes mellitus

When, where, and why should we look for vestibular dysfunction in people with diabetes mellitus?

The biochemistry of diabetes mellitus results in multi-system tissue compromise that reduces functional mobility and interferes with disease management. Sensory system compromise, such as peripheral neuropathy and retinopathy, are specific examples of tissue compromise detrimental to functional mobility. There is lack of clarity regarding if, when, and where parallel changes in the peripheral vestibular system, an additional essential sensory system for functional mobility, occur as a result of diabetes. Given the systemic nature of diabetes and the plasticity of the vestibular system, there is even less clarity regarding if potential vestibular system changes impact functional mobility in a meaningful fashion. This commentary will provide insight as to when we should employ diagnostic vestibular function tests in people with diabetes, where in the periphery we should look, and why testing may or may not matter. The commentary concludes with recommendations for future research and clinical care.

Cervical Vestibular-Evoked Myogenic Potentials in Individuals with Diabetes Mellitus: A Systematic Review and Meta-Analysis

Vestibular evoked myogenic potentials (VEMPs) in individuals with diabetes mellitus (DM) provide evidence as how diabetes can bring about changes in the peripheral nervous system. Cervical VEMP (cVEMP) evaluates the function and integrity of the sacullo- collic pathway and ocular VEMP (oVEMP) evaluates the utriculo-collic pathway. cVEMP is an ipsilateral inhibitory response of the sternocleidomastoid muscle. cVEMP is recorded at higher intensity above 80-85 dBnHL with biphasic waveforms having initial peak positivity P13 followed by a negativity N23. We performed a systematic review following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines to evaluate cVEMP in diabetes mellitus. The search was conducted in the databases: PubMed, Cumulative Index of Nursing and Allied Health Literature, Scopus, and Cochrane library using the keywords "diabetes mellitus" and "vestibular evoked myogenic potential" or "cVEMP." A two-phase selection process was used for the final inclusion of studies, and the methodological quality of these studies was assessed using the Newcastle Ottawa scale (NCOS). Meta-analysis was performed using a random-effects model. For comparisons between DM and healthy controls, a significant difference was observed for cVEMP amplitude (P = 0.01). Our meta-analysis's results suggest peripheral vestibular dysfunction can be observed in DM. It appears that cVEMPs may be useful in the early detection of neuropathy in DM.

Vestibular Rehabilitation Therapy Outcomes in Patients With Persistent Postural-Perceptual Dizziness

Objectives:

Persistent postural-perceptual dizziness (PPPD) represents an important category of vertigo. Medical treatment and psychotherapy provide convenient control of symptoms. However, these management strategies can have inconvenient side effects and short-term relief, respectively. Vestibular rehabilitation therapy (VRT) is a self-conducted habituation program that can be personalized to the subject’s needs to give adequate symptom relief without side effects. The present study aims to test the effect of VRT on patients with PPPD.

Methods:

Participants were diagnosed as having PPPD by the exclusion of organic vestibular lesions. The study involved 2 groups with PPPD: Group I, treated with the VRT, and Group II, treated with the VRT plus placebo. The Dizziness Handicap Inventory (DHI), a self-assessment scale, was used to evaluate the VRT outcomes.

Results:

There was a significant decrease in functional, physical, and total scores on the DHI in both groups after VRT. Adding the placebo did not have supplementary outcomes. The patients who did not benefit from the VRT had a significantly longer duration of PPPD, more complex aggravating factors, more composite VRT exercises, and a higher DHI score than the patients who benefited from VRT.

Conclusions:

Customized VRT adequately reduced symptoms and improved quality of life in subjects with PPPD.